Maharashtra HSC Food Science and Technology cheat sheet

Food science applies chemistry, microbiology, engineering and nutrition to the conversion of raw agricultural material into safe, stable, palatable food; food technology is the industrial application of those principles.

The six constituent classes are water, carbohydrates, proteins, lipids, vitamins and minerals; water plus the macronutrients (carbohydrate, protein, lipid) typically make up more than 95% of fresh food mass.

Proximate analysis partitions a food into moisture, crude protein (Kjeldahl N × 6.25), crude fat (Soxhlet ether extract), crude fibre, ash and nitrogen-free extract (carbohydrate by difference).

Water is the largest single component of most fresh foods: fruits and vegetables 80–95%, milk about 87%, meat 60–75%, cereals 10–14%, and edible oils below 1%.

Energy yield factors (Atwater): carbohydrate 4 kcal/g, protein 4 kcal/g, fat 9 kcal/g, alcohol 7 kcal/g; total energy = sum of (g of each × its factor).

Constituents are classed as macro (present in gram quantities: water, carbohydrate, protein, lipid) or micro (milligram or microgram quantities: vitamins, minerals, trace elements).

Food is classified by function as energy-giving (cereals, fats), body-building (pulses, milk, meat, eggs) and protective (fruits, vegetables, milk) foods.

Constituents interact during processing: Maillard browning needs a reducing sugar plus an amino group; gelatinisation needs starch plus heat and water; emulsion stability needs protein or emulsifier at the oil–water interface.

Water activity aw = p/p0 (vapour pressure of the food divided by that of pure water at the same temperature); most spoilage bacteria need aw above 0.90, most yeasts above 0.88, xerophilic moulds can grow down to about 0.60.

Bound water is hydrogen-bonded to solutes and is unavailable as solvent; free water supports microbial growth and chemical reactions, so aw predicts stability better than total moisture content does.

The sorption isotherm plots moisture content against aw at constant temperature; the BET and GAB models describe the monolayer, and the monolayer value marks the moisture level of maximum stability.

Starch gelatinises when heated with water (irreversible swelling and loss of birefringence, roughly 60–75 °C for common starches); on cooling, amylose retrogrades and causes staling and syneresis.

Sugars undergo caramelisation on dry heating and Maillard browning with amino groups; both lower nutritional value and produce colour and flavour, while Maillard is fastest at aw 0.6–0.8 and pH 6–8.

Proteins are polymers of amino acids joined by peptide bonds; primary, secondary (alpha-helix, beta-sheet), tertiary and quaternary structure determine function, and denaturation unfolds structure without breaking peptide bonds.

Protein functional properties include solubility, water- and fat-binding, emulsification, foaming, gelation and texturisation; isoelectric point is the pH of minimum solubility and of maximum precipitation (casein about pH 4.6).

Fats are triacylglycerols of glycerol and fatty acids; saturated fatty acids raise melting point and oxidative stability, while each double bond in an unsaturated acid lowers melting point and increases susceptibility to oxidation.

Lipid oxidation is a free-radical chain reaction (initiation, propagation, termination) accelerated by light, heat, metals and lipoxygenase; peroxide value measures hydroperoxides, free fatty acid value measures hydrolysis, and anisidine value measures secondary aldehydes.

Fat-soluble vitamins are A, D, E and K (absorbed with lipid, stored in liver or adipose, heat-stable but oxygen- and light-sensitive); water-soluble vitamins are B-complex and C, which leach into cooking water and are destroyed by heat and alkali.

Vitamin C (ascorbic acid) is the most heat- and oxygen-labile vitamin; losses are minimised by blanching to inactivate ascorbic acid oxidase, by excluding oxygen and by avoiding copper and iron contact.

Minerals are not destroyed by heat, light or oxidation but are lost by leaching into processing and cooking water; phytate and oxalate reduce bioavailability of calcium, iron and zinc, whereas ascorbic acid and animal protein enhance non-haem iron absorption.

Intrinsic factors governing microbial growth: pH, aw, redox potential, nutrient content, antimicrobial constituents and biological structure; extrinsic factors: temperature, relative humidity, atmosphere and competing microorganisms.

Bacterial growth curve phases are lag, log (exponential), stationary and death; generation time is the time for the population to double, and spoilage becomes detectable at about 10^7–10^8 cells/g.

Cardinal temperatures: psychrotrophs grow at 0–7 °C, mesophiles 20–45 °C (optimum about 30–37 °C), thermophiles 45–65 °C; most foodborne pathogens are mesophiles, so refrigeration slows but does not stop growth.

Clostridium botulinum is an obligate anaerobe forming heat-resistant spores that produce a neurotoxin; its destruction requires 121 °C for at least 3 minutes (F0 = 12D at 121 °C), and growth is prevented below pH 4.6 or aw 0.93.

Staphylococcus aureus produces a heat-stable enterotoxin; the toxin survives boiling, so prevention means keeping food out of the 5–60 °C danger zone rather than reheating.

Salmonella, Escherichia coli O157:H7 and Listeria monocytogenes are vegetative pathogens destroyed by pasteurisation; Listeria is unusual in growing at refrigeration temperature and tolerating high salt.

Moulds grow at lower aw and pH than bacteria and are aerobic; mycotoxins such as aflatoxin (Aspergillus flavus in groundnuts and cereals) and ochratoxin are heat-stable and not removed by normal cooking.

Spoilage types: putrefaction (anaerobic protein breakdown with amines and ammonia), rancidity (lipid oxidation or lipolysis), souring (lactic fermentation), flat sour (Bacillus thermoacidurans in canned low-acid foods) and swelling of cans (gas from Clostridium or Bacillus).

Thermal death parameters: D-value is the time at a given temperature to reduce survivors tenfold; z-value is the temperature change giving a tenfold change in D; F-value is the equivalent time at a reference temperature.

Preservation works by one or more hurdles: heat, cold, reduced aw, acidification, redox control, added preservatives and competitive flora; the hurdle concept combines mild stresses so no single one damages quality.

Blanching (70–100 °C, 1–5 min) inactivates enzymes such as peroxidase, polyphenol oxidase and lipoxygenase, fixes colour, removes tissue gases and shrinks product before freezing or drying.

Pasteurisation uses temperatures below 100 °C (milk: 63 °C/30 min LTLT or 72 °C/15 s HTLC) and kills vegetative pathogens; sterilisation and commercial sterility (UHT 135–150 °C for 2–5 s) also inactivate spores.

Canning sequence: selection and washing, blanching, filling, exhausting, seaming, thermal processing (retort) and cooling; low-acid foods (pH above 4.6) need a botulinum cook, acid foods (pH 4.6 or below) need only a boiling-water process.

Freezing preserves by lowering aw and temperature; quick freezing gives many small ice crystals and less drip loss, and freezer storage is limited by ice recrystallisation, lipid oxidation and enzymatic browning unless blanched.

Drying and dehydration remove water to aw below 0.60; the drying curve shows constant-rate (surface evaporation) and falling-rate (internal diffusion) periods, and case-hardening retards drying when surface dries too fast.

Concentration by evaporation (open pan, vacuum, multiple-effect) and by membrane processes (reverse osmosis, ultrafiltration) removes water without a phase change for heat-sensitive liquids.

Irradiation doses: up to 1 kGy for sprout inhibition and insect disinfestation, 1–10 kGy for pasteurisation of pathogens, above 10 kGy for sterilisation; the process is cold and leaves no radioactivity.

Non-thermal and emerging methods include high-pressure processing (400–600 MPa), pulsed electric field, ohmic heating, microwave, ultrasound and cold plasma; they reduce thermal damage to nutrients and flavour.

HACCP has seven principles: hazard analysis, determination of critical control points, establishment of critical limits, monitoring procedures, corrective actions, verification procedures and record-keeping.

A critical control point is a step where control is essential to prevent, eliminate or reduce a significant hazard to an acceptable level; a critical limit is a measurable value such as 72 °C for 15 s or pH 4.6.

Pre-requisite programmes supporting HACCP include GMP, good hygiene practice, pest control, personnel hygiene, water quality, calibration, supplier approval, traceability and recall procedures.

Biological, chemical, physical and allergenic hazards are distinguished; allergens such as milk, egg, peanut, soy, wheat, tree nuts, fish, shellfish and sesame require segregation and cleaning validation to prevent cross-contact.

FSSAI is the statutory authority in India under the Food Safety and Standards Act, 2006; the Act consolidated earlier laws such as the PFA Act and the Fruit Products Order and covers licensing, standards, labelling and enforcement.

India's FSSAI licences are Central (manufacturers, importers, large turnover) and State (smaller units, distributors, retailers); petty food businesses register, and licences are renewed periodically.

Codex Alimentarius (FAO/WHO) sets international standards, codes of practice and guidelines; ISO 22000 specifies food safety management systems, ISO 9001 quality management, and ISO 17025 laboratory competence.

Labelling requirements include name of food, list of ingredients in descending order of weight, net quantity, date of manufacture and best-before, nutritional information, veg/non-veg mark, FSSAI licence number and allergen declaration.

Quality assurance is process-oriented and preventive (systems, audits, documentation), while quality control is product-oriented and detective (sampling and testing of finished product against specification).

Product development stages: idea generation, screening, concept testing, prototype formulation, bench-scale and pilot-scale trials, sensory and shelf-life testing, scale-up, test marketing and commercial launch.

Sensory tests are grouped as difference tests (triangle, duo-trio, paired comparison), descriptive tests (flavour profile, quantitative descriptive analysis) and affective tests (hedonic, preference, consumer acceptance).

The triangle test presents three coded samples, two identical and one different, and asks which is different; it is used to detect a detectable difference, not to measure preference.

A 9-point hedonic scale runs from 1 (dislike extremely) through 5 (neither like nor dislike) to 9 (like extremely); panelists must be given coded, randomised, temperature-controlled samples in individual booths with red light where colour bias is a risk.

Trained panels of 8–12 assessors are used for descriptive profiling, whereas consumer panels need at least 60–100 untrained respondents for reliable acceptance data.

Packaging functions are containment, protection, preservation, communication, convenience and tamper evidence; barrier properties against oxygen, moisture, light and aroma determine the choice.

Common materials: glass (inert, impermeable, heavy), metal cans and tinplate (hermetic, retortable), paper and paperboard (low barrier, printable), plastics (PET, PP, PE, PS, PVC, EVOH) and laminates combining layers for barrier and strength.

Modified atmosphere packaging replaces air with a gas mix (typically 2–5% O2, 5–10% CO2, balance N2 for fresh produce; higher CO2 for meat and fish) and works only with low temperature and a suitable film permeability.

Active and intelligent packaging includes oxygen scavengers, ethylene absorbers, moisture regulators, antimicrobial films and time–temperature indicators that signal breaks in the cold chain.

FSSAI/Codex additive classes include preservatives, antioxidants, colours, emulsifiers, stabilisers and thickeners, sweeteners, flavour enhancers, anticaking agents, humectants, acidity regulators, leavening agents and sequestrants.

Additives are identified by INS (International Numbering System) and E numbers; each has a permitted food category and maximum level, and use is justified only where there is a technological need.

Preservatives: class I natural (salt, sugar, vinegar, honey, edible oil) and class II chemical, for example benzoic acid (INS 210) and sodium benzoate in acidic foods, sorbic acid (INS 200) against moulds and yeasts, and sulphur dioxide (INS 220) in dried fruit and beverages.

Antioxidants: BHA (INS 320), BHT (INS 321), TBHQ (INS 319) and propyl gallate for fats, and ascorbic acid (INS 300) plus tocopherols (INS 307) as natural options; sequestrants such as EDTA (INS 385) bind pro-oxidant metals.

Permitted synthetic colours include tartrazine (INS 102), sunset yellow (INS 110), carmoisine (INS 122), ponceau 4R (INS 124) and brilliant blue (INS 133); natural colours include annatto (INS 160b), beta-carotene (INS 160a) and chlorophyll.

Sweeteners: nutritive (sucrose, glucose, fructose) and non-nutritive, for example saccharin (INS 954), aspartame (INS 951, not for phenylketonurics because it yields phenylalanine), sucralose (INS 955) and steviol glycosides (INS 960).

Adulteration is the addition of inferior, harmful or undeclared substances; common Indian examples are metanil yellow or lead chromate in turmeric, sawdust or chalk in chilli powder, starch in milk and ghee, and water in milk.

Simple detection tests: iodine gives a blue-black colour with starch in milk; concentrated hydrochloric acid gives a crimson colour with metanil yellow in turmeric; a drop on water spreading into a film indicates starch in ghee.

Macronutrients supply energy and building material; micronutrients (vitamins and minerals) do not supply energy but are essential cofactors; dietary fibre is non-digestible carbohydrate that aids bowel function and lowers cholesterol.

Recommended allowances in India are given by ICMR-NIN; protein energy ratio should be about 10–15% of energy, fat 20–30% and carbohydrate 50–60%, and protein quality is scored by PER, BV, NPU and PDCAAS.

A food business plan covers product description, market analysis, process and technology, plant location and layout, capital cost, working capital, projected profit and loss, break-even analysis and risk assessment.

Break-even point in units = fixed cost divided by (selling price per unit minus variable cost per unit); contribution margin is selling price minus variable cost.

Small Indian food enterprises can use schemes such as PMFME, the FSSAI's Eat Right and training initiatives, NABARD and MSME credit, and food parks or incubation centres for shared facilities.

Plant layout follows product flow to prevent cross-contamination: separate high-risk and low-risk zones, unidirectional movement from raw to cooked, hand-wash and foot-dip stations, and washable surfaces with coving.

Traceability means one step back and one step forward lot identification; a recall plan specifies recall committee, lot coding, communication, retrieval and mock-recall verification.

Cold chain stages are pre-cooling, cold storage, refrigerated transport, retail display and domestic storage; a break anywhere shortens shelf life and can allow pathogen growth.

Emerging technologies include high-pressure processing, pulsed electric field, cold plasma, ultrasound-assisted extraction, ohmic and microwave heating, 3D food printing, encapsulation, edible films and coatings, and plant-based and fermentation-derived proteins.

Industry 4.0 practices in food include IoT temperature sensors, automated vision inspection, blockchain traceability, predictive maintenance and digital twins for process control.

Sustainability practices include waste valorisation (peel, whey, pomace into pectin, fibre, antioxidants), water and energy audits, by-product recovery and biodegradable packaging.

Moisture: oven drying at 105 °C to constant weight; the loss in weight is expressed as a percentage of the original sample, and results are reported on a wet or dry basis as stated.

Kjeldahl protein: digest with sulphuric acid and catalyst, distil ammonia into boric acid, titrate with standard acid, then % protein = % N × 6.25 (6.38 for milk, 5.70 for wheat).

Soxhlet fat: extract dried sample with petroleum ether, evaporate the solvent, weigh the residue; crude fibre is the loss on ignition of the residue after acid and alkali digestion.

Ash: ignite the sample in a muffle furnace at 550 °C until constant weight; ash represents total mineral content, not the mineral composition.

Acidity and pH: titrate with standard sodium hydroxide using phenolphthalein to determine titratable acidity (as lactic acid for milk, citric for fruit products); measure pH with a calibrated glass electrode.

Peroxide value: titrate liberated iodine with sodium thiosulphate after reaction of the fat with potassium iodide; free fatty acid value is titration of extracted fat with alkali and is expressed as % oleic acid.

Microbiological practice: serial decimal dilutions in saline or peptone water, pour or spread plate on appropriate agar, incubate at 37 °C for 24–48 h for mesophiles, count plates with 30–300 colonies and report as CFU/g.

Aseptic technique essentials: flame-sterilise loops and mouths of tubes, work near a flame or in a laminar flow hood, never lay down a pipette or lid, and autoclave media at 121 °C for 15 minutes at 15 psi.

Sensory booth conditions: individual booths, controlled lighting, temperature about 20–25 °C, odour-free air, coded samples with random three-digit codes, water and plain crackers as palate cleansers, and standard score sheets.

Good laboratory practice: record raw data in a bound notebook, use calibrated instruments and traceable standards, replicate analyses (at least duplicates), and report mean with standard deviation and the method reference.

Food science applies chemistry, microbiology, engineering and nutrition to converting raw agricultural material into safe, stable, palatable food; food technology is the industrial application of those principles.

The six constituent classes are water, carbohydrates, proteins, lipids, vitamins and minerals; water plus the three macronutrients typically exceed 95% of fresh food mass.

Proximate analysis partitions a food into moisture, crude protein (Kjeldahl N × 6.25), crude fat (Soxhlet), crude fibre, ash and nitrogen-free extract (carbohydrate by difference).

Typical moisture: fruits and vegetables 80–95%, milk about 87%, meat 60–75%, cereals 10–14%, edible oils below 1% - water is the largest single component of most fresh foods.

Atwater energy factors: carbohydrate 4 kcal/g, protein 4 kcal/g, fat 9 kcal/g, alcohol 7 kcal/g; total energy is the sum of grams of each component multiplied by its factor.

Constituents are macro (gram quantities: water, carbohydrate, protein, lipid) or micro (vitamins, minerals, trace elements in milligram or microgram quantities).

Foods are grouped by function as energy-giving (cereals, fats), body-building (pulses, milk, meat, eggs) and protective (fruits, vegetables, milk).

Constituent interactions drive processing: Maillard browning needs a reducing sugar plus an amino group, gelatinisation needs starch plus heat and water, and emulsion stability needs protein or emulsifier at the interface.

Water activity aw = p/p0, the vapour pressure of the food divided by that of pure water at the same temperature; spoilage bacteria generally need aw above 0.90, yeasts above 0.88, and xerophilic moulds can grow near 0.60.

Bound water is hydrogen-bonded to solutes and unavailable as solvent; free water supports microbial growth and chemical reactions, so aw predicts stability better than total moisture content.

The sorption isotherm plots moisture content against aw at constant temperature; BET and GAB models describe the monolayer, and the monolayer value marks maximum stability.

Starch gelatinises on heating with water (irreversible swelling, loss of birefringence, about 60–75 °C for common starches); on cooling, amylose retrogrades, causing staling and syneresis.

Sugars caramelise on dry heating and undergo Maillard browning with amino groups; Maillard is fastest at aw 0.6–0.8 and pH 6–8 and reduces nutritional value.

Proteins are amino acid polymers joined by peptide bonds; primary, secondary (alpha-helix, beta-sheet), tertiary and quaternary structure determine function, and denaturation unfolds structure without breaking peptide bonds.

Protein functions include solubility, water- and fat-binding, emulsification, foaming, gelation and texturisation; the isoelectric point is the pH of minimum solubility and maximum precipitation (casein about pH 4.6).

Fats are triacylglycerols; saturated fatty acids raise melting point and oxidative stability, while each double bond lowers melting point and increases susceptibility to oxidation.

Lipid oxidation is a free-radical chain reaction (initiation, propagation, termination) accelerated by light, heat, metals and lipoxygenase; peroxide value measures hydroperoxides, free fatty acid value measures hydrolysis, and anisidine value measures secondary aldehydes.

Fat-soluble vitamins A, D, E and K are absorbed with lipid and stored in liver or adipose, and are heat-stable but oxygen- and light-sensitive; water-soluble B-complex and C vitamins leach into cooking water and are destroyed by heat and alkali.

Vitamin C is the most heat- and oxygen-labile vitamin; losses are minimised by blanching to inactivate ascorbic acid oxidase, excluding oxygen and avoiding copper and iron contact.

Minerals are not destroyed by heat, light or oxidation but are lost by leaching; phytate and oxalate reduce calcium, iron and zinc bioavailability, while ascorbic acid and animal protein enhance non-haem iron absorption.

Intrinsic factors: pH, aw, redox potential, nutrient content, antimicrobial constituents and biological structure; extrinsic factors: temperature, relative humidity, atmosphere and competing microorganisms.

Growth curve phases are lag, log (exponential), stationary and death; generation time is the doubling time, and spoilage becomes detectable at about 10^7–10^8 cells/g.

Cardinal temperatures: psychrotrophs grow at 0–7 °C, mesophiles at 20–45 °C (optimum about 30–37 °C) and thermophiles at 45–65 °C; most pathogens are mesophiles, so refrigeration slows but does not stop growth.

Clostridium botulinum is an obligate anaerobe forming heat-resistant spores that produce a neurotoxin; destruction needs 121 °C for at least 3 minutes (F0 = 12D at 121 °C), and growth is prevented below pH 4.6 or aw 0.93.

Staphylococcus aureus produces a heat-stable enterotoxin that survives boiling, so prevention means keeping food out of the 5–60 °C danger zone rather than reheating.

Salmonella, Escherichia coli O157:H7 and Listeria monocytogenes are vegetative pathogens destroyed by pasteurisation; Listeria is unusual in growing at refrigeration temperature and tolerating high salt.

Moulds tolerate lower aw and pH than bacteria and are aerobic; mycotoxins such as aflatoxin (Aspergillus flavus in groundnuts and cereals) and ochratoxin are heat-stable and survive normal cooking.

Spoilage types: putrefaction (anaerobic protein breakdown to amines and ammonia), rancidity (lipid oxidation or lipolysis), souring (lactic fermentation), flat sour (Bacillus thermoacidurans in canned low-acid foods) and can swelling from gas producers.

Thermal death parameters: D-value is the time at a given temperature for a tenfold reduction in survivors; z-value is the temperature change giving a tenfold change in D; F-value is the equivalent time at a reference temperature.

Preservation uses hurdles: heat, cold, reduced aw, acidification, redox control, preservatives and competitive flora; the hurdle concept combines mild stresses so no single one damages quality.

Blanching (70–100 °C, 1–5 min) inactivates peroxidase, polyphenol oxidase and lipoxygenase, fixes colour, removes tissue gases and shrinks product before freezing or drying.

Pasteurisation stays below 100 °C (milk: 63 °C/30 min LTLT or 72 °C/15 s HTST) and kills vegetative pathogens; commercial sterility including spores needs UHT (135–150 °C for 2–5 s) or retorting.

Canning sequence: washing, blanching, filling, exhausting, seaming, retort processing and cooling; low-acid foods (pH above 4.6) need a botulinum cook, while acid foods (pH 4.6 or below) need only a boiling-water process.

Freezing preserves by lowering aw and temperature; quick freezing gives many small ice crystals and less drip loss, and storage is limited by ice recrystallisation, lipid oxidation and enzymatic browning unless blanched.

Drying removes water to aw below 0.60; the drying curve has constant-rate (surface evaporation) and falling-rate (internal diffusion) periods, and case-hardening retards drying when the surface dries too fast.

Concentration by evaporation (open pan, vacuum, multiple-effect) and membrane processes (reverse osmosis, ultrafiltration) removes water for heat-sensitive liquids; reverse osmosis needs higher pressure than ultrafiltration.

Irradiation doses: up to 1 kGy for sprout inhibition and insect disinfestation, 1–10 kGy for pathogen pasteurisation, above 10 kGy for sterilisation; the process is cold and leaves no radioactivity.

Emerging non-thermal methods include high-pressure processing (400–600 MPa), pulsed electric field, ohmic heating, microwave, ultrasound and cold plasma, which reduce thermal damage to nutrients and flavour.

HACCP's seven principles: hazard analysis, determination of critical control points, critical limits, monitoring, corrective actions, verification and record-keeping.

A critical control point is a step where control is essential to prevent, eliminate or reduce a significant hazard to an acceptable level; a critical limit is a measurable value such as 72 °C for 15 s or pH 4.6.

Pre-requisite programmes supporting HACCP include GMP, good hygiene practice, pest control, personnel hygiene, water quality, calibration, supplier approval, traceability and recall procedures.

Hazards are biological, chemical, physical and allergenic; major allergens such as milk, egg, peanut, soy, wheat, tree nuts, fish, shellfish and sesame need segregation and validated cleaning to prevent cross-contact.

FSSAI is India's statutory authority under the Food Safety and Standards Act, 2006, which consolidated earlier laws such as the PFA Act and the Fruit Products Order and covers licensing, standards, labelling and enforcement.

FSSAI licences are Central (manufacturers, importers, large turnover) and State (smaller units, distributors, retailers); petty food businesses register, and licences must be renewed periodically.

Codex Alimentarius (FAO/WHO) sets international standards, codes of practice and guidelines; ISO 22000 specifies food safety management systems, ISO 9001 quality management and ISO 17025 laboratory competence.

Mandatory label elements include name of food, ingredients in descending order of weight, net quantity, date of manufacture and best-before, nutritional information, veg/non-veg mark, FSSAI licence number and allergen declaration.

Quality assurance is process-oriented and preventive (systems, audits, documentation), while quality control is product-oriented and detective (sampling and testing finished product against specification).

Development stages: idea generation, screening, concept testing, prototype formulation, bench and pilot trials, sensory and shelf-life testing, scale-up, test marketing and launch.

Sensory tests are difference tests (triangle, duo-trio, paired comparison), descriptive tests (flavour profile, quantitative descriptive analysis) and affective tests (hedonic, preference, consumer acceptance).

The triangle test presents three coded samples, two identical and one different, and asks which is different; it detects a perceptible difference, not preference.

A 9-point hedonic scale runs from 1 (dislike extremely) through 5 (neither like nor dislike) to 9 (like extremely); samples are coded, randomised, temperature-controlled and served in individual booths, with red light used to mask colour bias.

Trained panels of 8–12 assessors suit descriptive profiling, whereas consumer panels need at least 60–100 untrained respondents for reliable acceptance data.

Packaging functions are containment, protection, preservation, communication, convenience and tamper evidence; barrier properties against oxygen, moisture, light and aroma drive material choice.

Materials: glass (inert, impermeable, heavy), tinplate and aluminium (hermetic, retortable), paper and board (low barrier, printable), plastics (PET, PP, PE, PS, PVC, EVOH) and laminates combining layers.

Modified atmosphere packaging uses a gas mix (typically 2–5% O2, 5–10% CO2, balance N2 for produce; higher CO2 for meat and fish) and works only with low temperature and suitable film permeability.

Active and intelligent packaging includes oxygen scavengers, ethylene absorbers, moisture regulators, antimicrobial films and time–temperature indicators that reveal cold-chain breaks.

Additive classes include preservatives, antioxidants, colours, emulsifiers, stabilisers, thickeners, sweeteners, flavour enhancers, anticaking agents, humectants, acidity regulators, leavening agents and sequestrants.

Additives carry INS (International Numbering System) and E numbers; each has permitted food categories and maximum levels, and use is justified only by a technological need.

Preservatives are class I natural (salt, sugar, vinegar, honey, edible oil) or class II chemical, such as benzoic acid (INS 210) in acidic foods, sorbic acid (INS 200) against moulds and yeasts, and sulphur dioxide (INS 220) in dried fruit.

Antioxidants: BHA (INS 320), BHT (INS 321), TBHQ (INS 319) and propyl gallate for fats, with ascorbic acid (INS 300) and tocopherols (INS 307) as natural options; sequestrants such as EDTA (INS 385) bind pro-oxidant metals.

Permitted synthetic colours include tartrazine (INS 102), sunset yellow (INS 110), carmoisine (INS 122), ponceau 4R (INS 124) and brilliant blue (INS 133); natural colours include annatto (INS 160b), beta-carotene (INS 160a) and chlorophyll.

Sweeteners are nutritive (sucrose, glucose, fructose) or non-nutritive, such as saccharin (INS 954), aspartame (INS 951, avoided in phenylketonuria because it yields phenylalanine), sucralose (INS 955) and steviol glycosides (INS 960).

Adulteration is adding inferior, harmful or undeclared substances; Indian examples include metanil yellow or lead chromate in turmeric, sawdust or chalk in chilli powder, starch in milk and ghee, and added water in milk.

Detection tests: iodine gives blue-black with starch in milk; concentrated hydrochloric acid gives crimson with metanil yellow in turmeric; a drop on water spreading into a film indicates starch in ghee.

Macronutrients supply energy and building material; micronutrients (vitamins and minerals) supply no energy but act as essential cofactors; dietary fibre is non-digestible carbohydrate aiding bowel function and lowering cholesterol.

ICMR-NIN gives Indian recommended allowances; protein should supply about 10–15% of energy, fat 20–30% and carbohydrate 50–60%, and protein quality is scored by PER, BV, NPU and PDCAAS.

A food business plan covers product description, market analysis, process and technology, plant location and layout, capital and working capital, projected profit and loss, break-even analysis and risk assessment.

Break-even point in units = fixed cost ÷ (selling price per unit − variable cost per unit); contribution margin is selling price minus variable cost.

Small Indian food enterprises can use PMFME, NABARD and MSME credit schemes, food parks and incubation centres for shared facilities, and FSSAI training initiatives.

Plant layout follows product flow to prevent cross-contamination: separate high-risk and low-risk zones, unidirectional movement from raw to cooked, hand-wash and foot-dip stations, and washable coving surfaces.

Traceability means one step back and one step forward lot identification; a recall plan specifies the recall committee, lot coding, communication, retrieval and mock-recall verification.

Cold chain stages are pre-cooling, cold storage, refrigerated transport, retail display and domestic storage; a break anywhere shortens shelf life and may allow pathogen growth.

Emerging technologies include high-pressure processing, pulsed electric field, cold plasma, ultrasound-assisted extraction, ohmic and microwave heating, 3D food printing, encapsulation, edible films and plant-based or fermentation-derived proteins.

Industry 4.0 practices in food include IoT temperature sensors, automated vision inspection, blockchain traceability, predictive maintenance and digital twins for process control.

Sustainability practices include waste valorisation (peel, whey and pomace into pectin, fibre and antioxidants), water and energy audits, by-product recovery and biodegradable packaging.

Moisture: oven drying at 105 °C to constant weight; the loss in weight is expressed as a percentage of the original sample, reported on a wet or dry basis as stated.

Kjeldahl protein: digest with sulphuric acid and catalyst, distil ammonia into boric acid, titrate with standard acid; % protein = % N × 6.25 (6.38 for milk, 5.70 for wheat).

Soxhlet fat: extract the dried sample with petroleum ether, evaporate the solvent and weigh the residue; crude fibre is the loss on ignition of the residue after acid and alkali digestion.

Ash: ignite in a muffle furnace at 550 °C to constant weight; ash represents total mineral content, not mineral composition.

Acidity and pH: titrate with standard sodium hydroxide using phenolphthalein for titratable acidity (as lactic acid for milk, citric for fruit products); measure pH with a calibrated glass electrode.

Peroxide value: titrate liberated iodine with sodium thiosulphate after reaction of the fat with potassium iodide; free fatty acid value is alkali titration of extracted fat, expressed as % oleic acid.

Microbiological practice: serial decimal dilutions in saline or peptone water, pour or spread plates, incubate at 37 °C for 24–48 h for mesophiles, count plates with 30–300 colonies and report as CFU/g.

Aseptic technique: flame-sterilise loops and tube mouths, work near a flame or in a laminar flow hood, never lay down a pipette or lid, and autoclave media at 121 °C for 15 minutes at 15 psi.

Sensory booth conditions: individual booths, controlled lighting, 20–25 °C, odour-free air, random three-digit sample codes, water and plain crackers as palate cleansers, and standard score sheets.

Good laboratory practice: record raw data in a bound notebook, use calibrated instruments and traceable standards, run at least duplicate analyses, and report mean with standard deviation and the method reference.

Food science applies chemistry, microbiology, engineering and nutrition to converting raw agricultural material into safe, stable, palatable food; food technology is the industrial application of those principles.

The six constituent classes are water, carbohydrates, proteins, lipids, vitamins and minerals; water plus the three macronutrients typically exceed 95% of fresh food mass.

Proximate analysis partitions a food into moisture, crude protein (Kjeldahl N × 6.25), crude fat (Soxhlet), crude fibre, ash and nitrogen-free extract (carbohydrate by difference).

Typical moisture: fruits and vegetables 80–95%, milk about 87%, meat 60–75%, cereals 10–14%, edible oils below 1% - water is the largest single component of most fresh foods.

Atwater energy factors: carbohydrate 4 kcal/g, protein 4 kcal/g, fat 9 kcal/g, alcohol 7 kcal/g; total energy is the sum of grams of each component multiplied by its factor.

Constituents are macro (gram quantities: water, carbohydrate, protein, lipid) or micro (vitamins, minerals, trace elements in milligram or microgram quantities).

Foods are grouped by function as energy-giving (cereals, fats), body-building (pulses, milk, meat, eggs) and protective (fruits, vegetables, milk).

Constituent interactions drive processing: Maillard browning needs a reducing sugar plus an amino group, gelatinisation needs starch plus heat and water, and emulsion stability needs protein or emulsifier at the interface.

Water activity aw = p/p0, the vapour pressure of the food divided by that of pure water at the same temperature; spoilage bacteria generally need aw above 0.90, yeasts above 0.88, and xerophilic moulds can grow near 0.60.

Bound water is hydrogen-bonded to solutes and unavailable as solvent; free water supports microbial growth and chemical reactions, so aw predicts stability better than total moisture content.

The sorption isotherm plots moisture content against aw at constant temperature; BET and GAB models describe the monolayer, and the monolayer value marks maximum stability.

Starch gelatinises on heating with water (irreversible swelling, loss of birefringence, about 60–75 °C for common starches); on cooling, amylose retrogrades, causing staling and syneresis.

Sugars caramelise on dry heating and undergo Maillard browning with amino groups; Maillard is fastest at aw 0.6–0.8 and pH 6–8 and reduces nutritional value.

Proteins are amino acid polymers joined by peptide bonds; primary, secondary (alpha-helix, beta-sheet), tertiary and quaternary structure determine function, and denaturation unfolds structure without breaking peptide bonds.

Protein functions include solubility, water- and fat-binding, emulsification, foaming, gelation and texturisation; the isoelectric point is the pH of minimum solubility and maximum precipitation (casein about pH 4.6).

Fats are triacylglycerols; saturated fatty acids raise melting point and oxidative stability, while each double bond lowers melting point and increases susceptibility to oxidation.

Lipid oxidation is a free-radical chain reaction (initiation, propagation, termination) accelerated by light, heat, metals and lipoxygenase; peroxide value measures hydroperoxides, free fatty acid value measures hydrolysis, and anisidine value measures secondary aldehydes.

Fat-soluble vitamins A, D, E and K are absorbed with lipid and stored in liver or adipose, and are heat-stable but oxygen- and light-sensitive; water-soluble B-complex and C vitamins leach into cooking water and are destroyed by heat and alkali.

Vitamin C is the most heat- and oxygen-labile vitamin; losses are minimised by blanching to inactivate ascorbic acid oxidase, excluding oxygen and avoiding copper and iron contact.

Minerals are not destroyed by heat, light or oxidation but are lost by leaching; phytate and oxalate reduce calcium, iron and zinc bioavailability, while ascorbic acid and animal protein enhance non-haem iron absorption.

Intrinsic factors: pH, aw, redox potential, nutrient content, antimicrobial constituents and biological structure; extrinsic factors: temperature, relative humidity, atmosphere and competing microorganisms.

Growth curve phases are lag, log (exponential), stationary and death; generation time is the doubling time, and spoilage becomes detectable at about 10^7–10^8 cells/g.

Cardinal temperatures: psychrotrophs grow at 0–7 °C, mesophiles at 20–45 °C (optimum about 30–37 °C) and thermophiles at 45–65 °C; most pathogens are mesophiles, so refrigeration slows but does not stop growth.

Clostridium botulinum is an obligate anaerobe forming heat-resistant spores that produce a neurotoxin; destruction needs 121 °C for at least 3 minutes (F0 = 12D at 121 °C), and growth is prevented below pH 4.6 or aw 0.93.

Staphylococcus aureus produces a heat-stable enterotoxin that survives boiling, so prevention means keeping food out of the 5–60 °C danger zone rather than reheating.

Salmonella, Escherichia coli O157:H7 and Listeria monocytogenes are vegetative pathogens destroyed by pasteurisation; Listeria is unusual in growing at refrigeration temperature and tolerating high salt.

Moulds tolerate lower aw and pH than bacteria and are aerobic; mycotoxins such as aflatoxin (Aspergillus flavus in groundnuts and cereals) and ochratoxin are heat-stable and survive normal cooking.

Spoilage types: putrefaction (anaerobic protein breakdown to amines and ammonia), rancidity (lipid oxidation or lipolysis), souring (lactic fermentation), flat sour (Bacillus thermoacidurans in canned low-acid foods) and can swelling from gas producers.

Thermal death parameters: D-value is the time at a given temperature for a tenfold reduction in survivors; z-value is the temperature change giving a tenfold change in D; F-value is the equivalent time at a reference temperature.

Preservation uses hurdles: heat, cold, reduced aw, acidification, redox control, preservatives and competitive flora; the hurdle concept combines mild stresses so no single one damages quality.

Blanching (70–100 °C, 1–5 min) inactivates peroxidase, polyphenol oxidase and lipoxygenase, fixes colour, removes tissue gases and shrinks product before freezing or drying.

Pasteurisation stays below 100 °C (milk: 63 °C/30 min LTLT or 72 °C/15 s HTST) and kills vegetative pathogens; commercial sterility including spores needs UHT (135–150 °C for 2–5 s) or retorting.

Canning sequence: washing, blanching, filling, exhausting, seaming, retort processing and cooling; low-acid foods (pH above 4.6) need a botulinum cook, while acid foods (pH 4.6 or below) need only a boiling-water process.

Freezing preserves by lowering aw and temperature; quick freezing gives many small ice crystals and less drip loss, and storage is limited by ice recrystallisation, lipid oxidation and enzymatic browning unless blanched.

Drying removes water to aw below 0.60; the drying curve has constant-rate (surface evaporation) and falling-rate (internal diffusion) periods, and case-hardening retards drying when the surface dries too fast.

Concentration by evaporation (open pan, vacuum, multiple-effect) and membrane processes (reverse osmosis, ultrafiltration) removes water for heat-sensitive liquids; reverse osmosis needs higher pressure than ultrafiltration.

Irradiation doses: up to 1 kGy for sprout inhibition and insect disinfestation, 1–10 kGy for pathogen pasteurisation, above 10 kGy for sterilisation; the process is cold and leaves no radioactivity.

Emerging non-thermal methods include high-pressure processing (400–600 MPa), pulsed electric field, ohmic heating, microwave, ultrasound and cold plasma, which reduce thermal damage to nutrients and flavour.

HACCP's seven principles: hazard analysis, determination of critical control points, critical limits, monitoring, corrective actions, verification and record-keeping.

A critical control point is a step where control is essential to prevent, eliminate or reduce a significant hazard to an acceptable level; a critical limit is a measurable value such as 72 °C for 15 s or pH 4.6.

Pre-requisite programmes supporting HACCP include GMP, good hygiene practice, pest control, personnel hygiene, water quality, calibration, supplier approval, traceability and recall procedures.

Hazards are biological, chemical, physical and allergenic; major allergens such as milk, egg, peanut, soy, wheat, tree nuts, fish, shellfish and sesame need segregation and validated cleaning to prevent cross-contact.

FSSAI is India's statutory authority under the Food Safety and Standards Act, 2006, which consolidated earlier laws such as the PFA Act and the Fruit Products Order and covers licensing, standards, labelling and enforcement.

FSSAI licences are Central (manufacturers, importers, large turnover) and State (smaller units, distributors, retailers); petty food businesses register, and licences must be renewed periodically.

Codex Alimentarius (FAO/WHO) sets international standards, codes of practice and guidelines; ISO 22000 specifies food safety management systems, ISO 9001 quality management and ISO 17025 laboratory competence.

Mandatory label elements include name of food, ingredients in descending order of weight, net quantity, date of manufacture and best-before, nutritional information, veg/non-veg mark, FSSAI licence number and allergen declaration.

Quality assurance is process-oriented and preventive (systems, audits, documentation), while quality control is product-oriented and detective (sampling and testing finished product against specification).

Development stages: idea generation, screening, concept testing, prototype formulation, bench and pilot trials, sensory and shelf-life testing, scale-up, test marketing and launch.

Sensory tests are difference tests (triangle, duo-trio, paired comparison), descriptive tests (flavour profile, quantitative descriptive analysis) and affective tests (hedonic, preference, consumer acceptance).

The triangle test presents three coded samples, two identical and one different, and asks which is different; it detects a perceptible difference, not preference.

A 9-point hedonic scale runs from 1 (dislike extremely) through 5 (neither like nor dislike) to 9 (like extremely); samples are coded, randomised, temperature-controlled and served in individual booths, with red light used to mask colour bias.

Trained panels of 8–12 assessors suit descriptive profiling, whereas consumer panels need at least 60–100 untrained respondents for reliable acceptance data.

Packaging functions are containment, protection, preservation, communication, convenience and tamper evidence; barrier properties against oxygen, moisture, light and aroma drive material choice.

Materials: glass (inert, impermeable, heavy), tinplate and aluminium (hermetic, retortable), paper and board (low barrier, printable), plastics (PET, PP, PE, PS, PVC, EVOH) and laminates combining layers.

Modified atmosphere packaging uses a gas mix (typically 2–5% O2, 5–10% CO2, balance N2 for produce; higher CO2 for meat and fish) and works only with low temperature and suitable film permeability.

Active and intelligent packaging includes oxygen scavengers, ethylene absorbers, moisture regulators, antimicrobial films and time–temperature indicators that reveal cold-chain breaks.

Additive classes include preservatives, antioxidants, colours, emulsifiers, stabilisers, thickeners, sweeteners, flavour enhancers, anticaking agents, humectants, acidity regulators, leavening agents and sequestrants.

Additives carry INS (International Numbering System) and E numbers; each has permitted food categories and maximum levels, and use is justified only by a technological need.

Preservatives are class I natural (salt, sugar, vinegar, honey, edible oil) or class II chemical, such as benzoic acid (INS 210) in acidic foods, sorbic acid (INS 200) against moulds and yeasts, and sulphur dioxide (INS 220) in dried fruit.

Antioxidants: BHA (INS 320), BHT (INS 321), TBHQ (INS 319) and propyl gallate for fats, with ascorbic acid (INS 300) and tocopherols (INS 307) as natural options; sequestrants such as EDTA (INS 385) bind pro-oxidant metals.

Permitted synthetic colours include tartrazine (INS 102), sunset yellow (INS 110), carmoisine (INS 122), ponceau 4R (INS 124) and brilliant blue (INS 133); natural colours include annatto (INS 160b), beta-carotene (INS 160a) and chlorophyll.

Sweeteners are nutritive (sucrose, glucose, fructose) or non-nutritive, such as saccharin (INS 954), aspartame (INS 951, avoided in phenylketonuria because it yields phenylalanine), sucralose (INS 955) and steviol glycosides (INS 960).

Adulteration is adding inferior, harmful or undeclared substances; Indian examples include metanil yellow or lead chromate in turmeric, sawdust or chalk in chilli powder, starch in milk and ghee, and added water in milk.

Detection tests: iodine gives blue-black with starch in milk; concentrated hydrochloric acid gives crimson with metanil yellow in turmeric; a drop on water spreading into a film indicates starch in ghee.

Macronutrients supply energy and building material; micronutrients (vitamins and minerals) supply no energy but act as essential cofactors; dietary fibre is non-digestible carbohydrate aiding bowel function and lowering cholesterol.

ICMR-NIN gives Indian recommended allowances; protein should supply about 10–15% of energy, fat 20–30% and carbohydrate 50–60%, and protein quality is scored by PER, BV, NPU and PDCAAS.

A food business plan covers product description, market analysis, process and technology, plant location and layout, capital and working capital, projected profit and loss, break-even analysis and risk assessment.

Break-even point in units = fixed cost ÷ (selling price per unit − variable cost per unit); contribution margin is selling price minus variable cost.

Small Indian food enterprises can use PMFME, NABARD and MSME credit schemes, food parks and incubation centres for shared facilities, and FSSAI training initiatives.

Plant layout follows product flow to prevent cross-contamination: separate high-risk and low-risk zones, unidirectional movement from raw to cooked, hand-wash and foot-dip stations, and washable coving surfaces.

Traceability means one step back and one step forward lot identification; a recall plan specifies the recall committee, lot coding, communication, retrieval and mock-recall verification.

Cold chain stages are pre-cooling, cold storage, refrigerated transport, retail display and domestic storage; a break anywhere shortens shelf life and may allow pathogen growth.

Emerging technologies include high-pressure processing, pulsed electric field, cold plasma, ultrasound-assisted extraction, ohmic and microwave heating, 3D food printing, encapsulation, edible films and plant-based or fermentation-derived proteins.

Industry 4.0 practices in food include IoT temperature sensors, automated vision inspection, blockchain traceability, predictive maintenance and digital twins for process control.

Sustainability practices include waste valorisation (peel, whey and pomace into pectin, fibre and antioxidants), water and energy audits, by-product recovery and biodegradable packaging.

Moisture: oven drying at 105 °C to constant weight; the loss in weight is expressed as a percentage of the original sample, reported on a wet or dry basis as stated.

Kjeldahl protein: digest with sulphuric acid and catalyst, distil ammonia into boric acid, titrate with standard acid; % protein = % N × 6.25 (6.38 for milk, 5.70 for wheat).

Soxhlet fat: extract the dried sample with petroleum ether, evaporate the solvent and weigh the residue; crude fibre is the loss on ignition of the residue after acid and alkali digestion.

Ash: ignite in a muffle furnace at 550 °C to constant weight; ash represents total mineral content, not mineral composition.

Acidity and pH: titrate with standard sodium hydroxide using phenolphthalein for titratable acidity (as lactic acid for milk, citric for fruit products); measure pH with a calibrated glass electrode.

Peroxide value: titrate liberated iodine with sodium thiosulphate after reaction of the fat with potassium iodide; free fatty acid value is alkali titration of extracted fat, expressed as % oleic acid.

Microbiological practice: serial decimal dilutions in saline or peptone water, pour or spread plates, incubate at 37 °C for 24–48 h for mesophiles, count plates with 30–300 colonies and report as CFU/g.

Aseptic technique: flame-sterilise loops and tube mouths, work near a flame or in a laminar flow hood, never lay down a pipette or lid, and autoclave media at 121 °C for 15 minutes at 15 psi.

Sensory booth conditions: individual booths, controlled lighting, 20–25 °C, odour-free air, random three-digit sample codes, water and plain crackers as palate cleansers, and standard score sheets.

Good laboratory practice: record raw data in a bound notebook, use calibrated instruments and traceable standards, run at least duplicate analyses, and report mean with standard deviation and the method reference.

Food science applies chemistry, microbiology, engineering and nutrition to converting raw agricultural material into safe, stable, palatable food; food technology is the industrial application of those principles.

The six constituent classes are water, carbohydrates, proteins, lipids, vitamins and minerals; water plus the three macronutrients typically exceed 95% of fresh food mass.

Proximate analysis partitions a food into moisture, crude protein (Kjeldahl N × 6.25), crude fat (Soxhlet), crude fibre, ash and nitrogen-free extract (carbohydrate by difference).

Typical moisture: fruits and vegetables 80–95%, milk about 87%, meat 60–75%, cereals 10–14%, edible oils below 1% - water is the largest single component of most fresh foods.

Atwater energy factors: carbohydrate 4 kcal/g, protein 4 kcal/g, fat 9 kcal/g, alcohol 7 kcal/g; total energy is the sum of grams of each component multiplied by its factor.

Constituents are macro (gram quantities: water, carbohydrate, protein, lipid) or micro (vitamins, minerals, trace elements in milligram or microgram quantities).

Foods are grouped by function as energy-giving (cereals, fats), body-building (pulses, milk, meat, eggs) and protective (fruits, vegetables, milk).

Constituent interactions drive processing: Maillard browning needs a reducing sugar plus an amino group, gelatinisation needs starch plus heat and water, and emulsion stability needs protein or emulsifier at the interface.

Water activity aw = p/p0, the vapour pressure of the food divided by that of pure water at the same temperature; spoilage bacteria generally need aw above 0.90, yeasts above 0.88, and xerophilic moulds can grow near 0.60.

Bound water is hydrogen-bonded to solutes and unavailable as solvent; free water supports microbial growth and chemical reactions, so aw predicts stability better than total moisture content.

The sorption isotherm plots moisture content against aw at constant temperature; BET and GAB models describe the monolayer, and the monolayer value marks maximum stability.

Starch gelatinises on heating with water (irreversible swelling, loss of birefringence, about 60–75 °C for common starches); on cooling, amylose retrogrades, causing staling and syneresis.

Sugars caramelise on dry heating and undergo Maillard browning with amino groups; Maillard is fastest at aw 0.6–0.8 and pH 6–8 and reduces nutritional value.

Proteins are amino acid polymers joined by peptide bonds; primary, secondary (alpha-helix, beta-sheet), tertiary and quaternary structure determine function, and denaturation unfolds structure without breaking peptide bonds.

Protein functions include solubility, water- and fat-binding, emulsification, foaming, gelation and texturisation; the isoelectric point is the pH of minimum solubility and maximum precipitation (casein about pH 4.6).

Fats are triacylglycerols; saturated fatty acids raise melting point and oxidative stability, while each double bond lowers melting point and increases susceptibility to oxidation.

Lipid oxidation is a free-radical chain reaction (initiation, propagation, termination) accelerated by light, heat, metals and lipoxygenase; peroxide value measures hydroperoxides, free fatty acid value measures hydrolysis, and anisidine value measures secondary aldehydes.

Fat-soluble vitamins A, D, E and K are absorbed with lipid and stored in liver or adipose, and are heat-stable but oxygen- and light-sensitive; water-soluble B-complex and C vitamins leach into cooking water and are destroyed by heat and alkali.

Vitamin C is the most heat- and oxygen-labile vitamin; losses are minimised by blanching to inactivate ascorbic acid oxidase, excluding oxygen and avoiding copper and iron contact.

Minerals are not destroyed by heat, light or oxidation but are lost by leaching; phytate and oxalate reduce calcium, iron and zinc bioavailability, while ascorbic acid and animal protein enhance non-haem iron absorption.

Intrinsic factors: pH, aw, redox potential, nutrient content, antimicrobial constituents and biological structure; extrinsic factors: temperature, relative humidity, atmosphere and competing microorganisms.

Growth curve phases are lag, log (exponential), stationary and death; generation time is the doubling time, and spoilage becomes detectable at about 10^7–10^8 cells/g.

Cardinal temperatures: psychrotrophs grow at 0–7 °C, mesophiles at 20–45 °C (optimum about 30–37 °C) and thermophiles at 45–65 °C; most pathogens are mesophiles, so refrigeration slows but does not stop growth.

Clostridium botulinum is an obligate anaerobe forming heat-resistant spores that produce a neurotoxin; destruction needs 121 °C for at least 3 minutes (F0 = 12D at 121 °C), and growth is prevented below pH 4.6 or aw 0.93.

Staphylococcus aureus produces a heat-stable enterotoxin that survives boiling, so prevention means keeping food out of the 5–60 °C danger zone rather than reheating.

Salmonella, Escherichia coli O157:H7 and Listeria monocytogenes are vegetative pathogens destroyed by pasteurisation; Listeria is unusual in growing at refrigeration temperature and tolerating high salt.

Moulds tolerate lower aw and pH than bacteria and are aerobic; mycotoxins such as aflatoxin (Aspergillus flavus in groundnuts and cereals) and ochratoxin are heat-stable and survive normal cooking.

Spoilage types: putrefaction (anaerobic protein breakdown to amines and ammonia), rancidity (lipid oxidation or lipolysis), souring (lactic fermentation), flat sour (Bacillus thermoacidurans in canned low-acid foods) and can swelling from gas producers.

Thermal death parameters: D-value is the time at a given temperature for a tenfold reduction in survivors; z-value is the temperature change giving a tenfold change in D; F-value is the equivalent time at a reference temperature.

Preservation uses hurdles: heat, cold, reduced aw, acidification, redox control, preservatives and competitive flora; the hurdle concept combines mild stresses so no single one damages quality.

Blanching (70–100 °C, 1–5 min) inactivates peroxidase, polyphenol oxidase and lipoxygenase, fixes colour, removes tissue gases and shrinks product before freezing or drying.

Pasteurisation stays below 100 °C (milk: 63 °C/30 min LTLT or 72 °C/15 s HTST) and kills vegetative pathogens; commercial sterility including spores needs UHT (135–150 °C for 2–5 s) or retorting.

Canning sequence: washing, blanching, filling, exhausting, seaming, retort processing and cooling; low-acid foods (pH above 4.6) need a botulinum cook, while acid foods (pH 4.6 or below) need only a boiling-water process.

Freezing preserves by lowering aw and temperature; quick freezing gives many small ice crystals and less drip loss, and storage is limited by ice recrystallisation, lipid oxidation and enzymatic browning unless blanched.

Drying removes water to aw below 0.60; the drying curve has constant-rate (surface evaporation) and falling-rate (internal diffusion) periods, and case-hardening retards drying when the surface dries too fast.

Concentration by evaporation (open pan, vacuum, multiple-effect) and membrane processes (reverse osmosis, ultrafiltration) removes water for heat-sensitive liquids; reverse osmosis needs higher pressure than ultrafiltration.

Irradiation doses: up to 1 kGy for sprout inhibition and insect disinfestation, 1–10 kGy for pathogen pasteurisation, above 10 kGy for sterilisation; the process is cold and leaves no radioactivity.

Emerging non-thermal methods include high-pressure processing (400–600 MPa), pulsed electric field, ohmic heating, microwave, ultrasound and cold plasma, which reduce thermal damage to nutrients and flavour.

HACCP's seven principles: hazard analysis, determination of critical control points, critical limits, monitoring, corrective actions, verification and record-keeping.

A critical control point is a step where control is essential to prevent, eliminate or reduce a significant hazard to an acceptable level; a critical limit is a measurable value such as 72 °C for 15 s or pH 4.6.

Pre-requisite programmes supporting HACCP include GMP, good hygiene practice, pest control, personnel hygiene, water quality, calibration, supplier approval, traceability and recall procedures.

Hazards are biological, chemical, physical and allergenic; major allergens such as milk, egg, peanut, soy, wheat, tree nuts, fish, shellfish and sesame need segregation and validated cleaning to prevent cross-contact.

FSSAI is India's statutory authority under the Food Safety and Standards Act, 2006, which consolidated earlier laws such as the PFA Act and the Fruit Products Order and covers licensing, standards, labelling and enforcement.

FSSAI licences are Central (manufacturers, importers, large turnover) and State (smaller units, distributors, retailers); petty food businesses register, and licences must be renewed periodically.

Codex Alimentarius (FAO/WHO) sets international standards, codes of practice and guidelines; ISO 22000 specifies food safety management systems, ISO 9001 quality management and ISO 17025 laboratory competence.

Mandatory label elements include name of food, ingredients in descending order of weight, net quantity, date of manufacture and best-before, nutritional information, veg/non-veg mark, FSSAI licence number and allergen declaration.

Quality assurance is process-oriented and preventive (systems, audits, documentation), while quality control is product-oriented and detective (sampling and testing finished product against specification).

Development stages: idea generation, screening, concept testing, prototype formulation, bench and pilot trials, sensory and shelf-life testing, scale-up, test marketing and launch.

Sensory tests are difference tests (triangle, duo-trio, paired comparison), descriptive tests (flavour profile, quantitative descriptive analysis) and affective tests (hedonic, preference, consumer acceptance).

The triangle test presents three coded samples, two identical and one different, and asks which is different; it detects a perceptible difference, not preference.

A 9-point hedonic scale runs from 1 (dislike extremely) through 5 (neither like nor dislike) to 9 (like extremely); samples are coded, randomised, temperature-controlled and served in individual booths, with red light used to mask colour bias.

Trained panels of 8–12 assessors suit descriptive profiling, whereas consumer panels need at least 60–100 untrained respondents for reliable acceptance data.

Packaging functions are containment, protection, preservation, communication, convenience and tamper evidence; barrier properties against oxygen, moisture, light and aroma drive material choice.

Materials: glass (inert, impermeable, heavy), tinplate and aluminium (hermetic, retortable), paper and board (low barrier, printable), plastics (PET, PP, PE, PS, PVC, EVOH) and laminates combining layers.

Modified atmosphere packaging uses a gas mix (typically 2–5% O2, 5–10% CO2, balance N2 for produce; higher CO2 for meat and fish) and works only with low temperature and suitable film permeability.

Active and intelligent packaging includes oxygen scavengers, ethylene absorbers, moisture regulators, antimicrobial films and time–temperature indicators that reveal cold-chain breaks.

Additive classes include preservatives, antioxidants, colours, emulsifiers, stabilisers, thickeners, sweeteners, flavour enhancers, anticaking agents, humectants, acidity regulators, leavening agents and sequestrants.

Additives carry INS (International Numbering System) and E numbers; each has permitted food categories and maximum levels, and use is justified only by a technological need.

Preservatives are class I natural (salt, sugar, vinegar, honey, edible oil) or class II chemical, such as benzoic acid (INS 210) in acidic foods, sorbic acid (INS 200) against moulds and yeasts, and sulphur dioxide (INS 220) in dried fruit.

Antioxidants: BHA (INS 320), BHT (INS 321), TBHQ (INS 319) and propyl gallate for fats, with ascorbic acid (INS 300) and tocopherols (INS 307) as natural options; sequestrants such as EDTA (INS 385) bind pro-oxidant metals.

Permitted synthetic colours include tartrazine (INS 102), sunset yellow (INS 110), carmoisine (INS 122), ponceau 4R (INS 124) and brilliant blue (INS 133); natural colours include annatto (INS 160b), beta-carotene (INS 160a) and chlorophyll.

Sweeteners are nutritive (sucrose, glucose, fructose) or non-nutritive, such as saccharin (INS 954), aspartame (INS 951, avoided in phenylketonuria because it yields phenylalanine), sucralose (INS 955) and steviol glycosides (INS 960).

Adulteration is adding inferior, harmful or undeclared substances; Indian examples include metanil yellow or lead chromate in turmeric, sawdust or chalk in chilli powder, starch in milk and ghee, and added water in milk.

Detection tests: iodine gives blue-black with starch in milk; concentrated hydrochloric acid gives crimson with metanil yellow in turmeric; a drop on water spreading into a film indicates starch in ghee.

Macronutrients supply energy and building material; micronutrients (vitamins and minerals) supply no energy but act as essential cofactors; dietary fibre is non-digestible carbohydrate aiding bowel function and lowering cholesterol.

ICMR-NIN gives Indian recommended allowances; protein should supply about 10–15% of energy, fat 20–30% and carbohydrate 50–60%, and protein quality is scored by PER, BV, NPU and PDCAAS.

A food business plan covers product description, market analysis, process and technology, plant location and layout, capital and working capital, projected profit and loss, break-even analysis and risk assessment.

Break-even point in units = fixed cost ÷ (selling price per unit − variable cost per unit); contribution margin is selling price minus variable cost.

Small Indian food enterprises can use PMFME, NABARD and MSME credit schemes, food parks and incubation centres for shared facilities, and FSSAI training initiatives.

Plant layout follows product flow to prevent cross-contamination: separate high-risk and low-risk zones, unidirectional movement from raw to cooked, hand-wash and foot-dip stations, and washable coving surfaces.

Traceability means one step back and one step forward lot identification; a recall plan specifies the recall committee, lot coding, communication, retrieval and mock-recall verification.

Cold chain stages are pre-cooling, cold storage, refrigerated transport, retail display and domestic storage; a break anywhere shortens shelf life and may allow pathogen growth.

Emerging technologies include high-pressure processing, pulsed electric field, cold plasma, ultrasound-assisted extraction, ohmic and microwave heating, 3D food printing, encapsulation, edible films and plant-based or fermentation-derived proteins.

Industry 4.0 practices in food include IoT temperature sensors, automated vision inspection, blockchain traceability, predictive maintenance and digital twins for process control.

Sustainability practices include waste valorisation (peel, whey and pomace into pectin, fibre and antioxidants), water and energy audits, by-product recovery and biodegradable packaging.

Moisture: oven drying at 105 °C to constant weight; the loss in weight is expressed as a percentage of the original sample, reported on a wet or dry basis as stated.

Kjeldahl protein: digest with sulphuric acid and catalyst, distil ammonia into boric acid, titrate with standard acid; % protein = % N × 6.25 (6.38 for milk, 5.70 for wheat).

Soxhlet fat: extract the dried sample with petroleum ether, evaporate the solvent and weigh the residue; crude fibre is the loss on ignition of the residue after acid and alkali digestion.

Ash: ignite in a muffle furnace at 550 °C to constant weight; ash represents total mineral content, not mineral composition.

Acidity and pH: titrate with standard sodium hydroxide using phenolphthalein for titratable acidity (as lactic acid for milk, citric for fruit products); measure pH with a calibrated glass electrode.

Peroxide value: titrate liberated iodine with sodium thiosulphate after reaction of the fat with potassium iodide; free fatty acid value is alkali titration of extracted fat, expressed as % oleic acid.

Microbiological practice: serial decimal dilutions in saline or peptone water, pour or spread plates, incubate at 37 °C for 24–48 h for mesophiles, count plates with 30–300 colonies and report as CFU/g.

Aseptic technique: flame-sterilise loops and tube mouths, work near a flame or in a laminar flow hood, never lay down a pipette or lid, and autoclave media at 121 °C for 15 minutes at 15 psi.

Sensory booth conditions: individual booths, controlled lighting, 20–25 °C, odour-free air, random three-digit sample codes, water and plain crackers as palate cleansers, and standard score sheets.

Good laboratory practice: record raw data in a bound notebook, use calibrated instruments and traceable standards, run at least duplicate analyses, and report mean with standard deviation and the method reference.

Food science applies chemistry, microbiology, engineering and nutrition to converting raw agricultural material into safe, stable, palatable food; food technology is the industrial application of those principles.

The six constituent classes are water, carbohydrates, proteins, lipids, vitamins and minerals; water plus the three macronutrients typically exceed 95% of fresh food mass.

Proximate analysis partitions a food into moisture, crude protein (Kjeldahl N × 6.25), crude fat (Soxhlet), crude fibre, ash and nitrogen-free extract (carbohydrate by difference).

Typical moisture: fruits and vegetables 80–95%, milk about 87%, meat 60–75%, cereals 10–14%, edible oils below 1% - water is the largest single component of most fresh foods.

Atwater energy factors: carbohydrate 4 kcal/g, protein 4 kcal/g, fat 9 kcal/g, alcohol 7 kcal/g; total energy is the sum of grams of each component multiplied by its factor.

Constituents are macro (gram quantities: water, carbohydrate, protein, lipid) or micro (vitamins, minerals, trace elements in milligram or microgram quantities).

Foods are grouped by function as energy-giving (cereals, fats), body-building (pulses, milk, meat, eggs) and protective (fruits, vegetables, milk).

Constituent interactions drive processing: Maillard browning needs a reducing sugar plus an amino group, gelatinisation needs starch plus heat and water, and emulsion stability needs protein or emulsifier at the interface.

Water activity aw = p/p0, the vapour pressure of the food divided by that of pure water at the same temperature; spoilage bacteria generally need aw above 0.90, yeasts above 0.88, and xerophilic moulds can grow near 0.60.

Bound water is hydrogen-bonded to solutes and unavailable as solvent; free water supports microbial growth and chemical reactions, so aw predicts stability better than total moisture content.

The sorption isotherm plots moisture content against aw at constant temperature; BET and GAB models describe the monolayer, and the monolayer value marks maximum stability.

Starch gelatinises on heating with water (irreversible swelling, loss of birefringence, about 60–75 °C for common starches); on cooling, amylose retrogrades, causing staling and syneresis.

Sugars caramelise on dry heating and undergo Maillard browning with amino groups; Maillard is fastest at aw 0.6–0.8 and pH 6–8 and reduces nutritional value.

Proteins are amino acid polymers joined by peptide bonds; primary, secondary (alpha-helix, beta-sheet), tertiary and quaternary structure determine function, and denaturation unfolds structure without breaking peptide bonds.

Protein functions include solubility, water- and fat-binding, emulsification, foaming, gelation and texturisation; the isoelectric point is the pH of minimum solubility and maximum precipitation (casein about pH 4.6).

Fats are triacylglycerols; saturated fatty acids raise melting point and oxidative stability, while each double bond lowers melting point and increases susceptibility to oxidation.

Lipid oxidation is a free-radical chain reaction (initiation, propagation, termination) accelerated by light, heat, metals and lipoxygenase; peroxide value measures hydroperoxides, free fatty acid value measures hydrolysis, and anisidine value measures secondary aldehydes.

Fat-soluble vitamins A, D, E and K are absorbed with lipid and stored in liver or adipose, and are heat-stable but oxygen- and light-sensitive; water-soluble B-complex and C vitamins leach into cooking water and are destroyed by heat and alkali.

Vitamin C is the most heat- and oxygen-labile vitamin; losses are minimised by blanching to inactivate ascorbic acid oxidase, excluding oxygen and avoiding copper and iron contact.

Minerals are not destroyed by heat, light or oxidation but are lost by leaching; phytate and oxalate reduce calcium, iron and zinc bioavailability, while ascorbic acid and animal protein enhance non-haem iron absorption.

Intrinsic factors: pH, aw, redox potential, nutrient content, antimicrobial constituents and biological structure; extrinsic factors: temperature, relative humidity, atmosphere and competing microorganisms.

Growth curve phases are lag, log (exponential), stationary and death; generation time is the doubling time, and spoilage becomes detectable at about 10^7–10^8 cells/g.

Cardinal temperatures: psychrotrophs grow at 0–7 °C, mesophiles at 20–45 °C (optimum about 30–37 °C) and thermophiles at 45–65 °C; most pathogens are mesophiles, so refrigeration slows but does not stop growth.

Clostridium botulinum is an obligate anaerobe forming heat-resistant spores that produce a neurotoxin; destruction needs 121 °C for at least 3 minutes (F0 = 12D at 121 °C), and growth is prevented below pH 4.6 or aw 0.93.

Staphylococcus aureus produces a heat-stable enterotoxin that survives boiling, so prevention means keeping food out of the 5–60 °C danger zone rather than reheating.

Salmonella, Escherichia coli O157:H7 and Listeria monocytogenes are vegetative pathogens destroyed by pasteurisation; Listeria is unusual in growing at refrigeration temperature and tolerating high salt.

Moulds tolerate lower aw and pH than bacteria and are aerobic; mycotoxins such as aflatoxin (Aspergillus flavus in groundnuts and cereals) and ochratoxin are heat-stable and survive normal cooking.

Spoilage types: putrefaction (anaerobic protein breakdown to amines and ammonia), rancidity (lipid oxidation or lipolysis), souring (lactic fermentation), flat sour (Bacillus thermoacidurans in canned low-acid foods) and can swelling from gas producers.

Thermal death parameters: D-value is the time at a given temperature for a tenfold reduction in survivors; z-value is the temperature change giving a tenfold change in D; F-value is the equivalent time at a reference temperature.

Preservation uses hurdles: heat, cold, reduced aw, acidification, redox control, preservatives and competitive flora; the hurdle concept combines mild stresses so no single one damages quality.

Blanching (70–100 °C, 1–5 min) inactivates peroxidase, polyphenol oxidase and lipoxygenase, fixes colour, removes tissue gases and shrinks product before freezing or drying.

Pasteurisation stays below 100 °C (milk: 63 °C/30 min LTLT or 72 °C/15 s HTST) and kills vegetative pathogens; commercial sterility including spores needs UHT (135–150 °C for 2–5 s) or retorting.

Canning sequence: washing, blanching, filling, exhausting, seaming, retort processing and cooling; low-acid foods (pH above 4.6) need a botulinum cook, while acid foods (pH 4.6 or below) need only a boiling-water process.

Freezing preserves by lowering aw and temperature; quick freezing gives many small ice crystals and less drip loss, and storage is limited by ice recrystallisation, lipid oxidation and enzymatic browning unless blanched.

Drying removes water to aw below 0.60; the drying curve has constant-rate (surface evaporation) and falling-rate (internal diffusion) periods, and case-hardening retards drying when the surface dries too fast.

Concentration by evaporation (open pan, vacuum, multiple-effect) and membrane processes (reverse osmosis, ultrafiltration) removes water for heat-sensitive liquids; reverse osmosis needs higher pressure than ultrafiltration.

Irradiation doses: up to 1 kGy for sprout inhibition and insect disinfestation, 1–10 kGy for pathogen pasteurisation, above 10 kGy for sterilisation; the process is cold and leaves no radioactivity.

Emerging non-thermal methods include high-pressure processing (400–600 MPa), pulsed electric field, ohmic heating, microwave, ultrasound and cold plasma, which reduce thermal damage to nutrients and flavour.

HACCP's seven principles: hazard analysis, determination of critical control points, critical limits, monitoring, corrective actions, verification and record-keeping.

A critical control point is a step where control is essential to prevent, eliminate or reduce a significant hazard to an acceptable level; a critical limit is a measurable value such as 72 °C for 15 s or pH 4.6.

Pre-requisite programmes supporting HACCP include GMP, good hygiene practice, pest control, personnel hygiene, water quality, calibration, supplier approval, traceability and recall procedures.

Hazards are biological, chemical, physical and allergenic; major allergens such as milk, egg, peanut, soy, wheat, tree nuts, fish, shellfish and sesame need segregation and validated cleaning to prevent cross-contact.

FSSAI is India's statutory authority under the Food Safety and Standards Act, 2006, which consolidated earlier laws such as the PFA Act and the Fruit Products Order and covers licensing, standards, labelling and enforcement.

FSSAI licences are Central (manufacturers, importers, large turnover) and State (smaller units, distributors, retailers); petty food businesses register, and licences must be renewed periodically.

Codex Alimentarius (FAO/WHO) sets international standards, codes of practice and guidelines; ISO 22000 specifies food safety management systems, ISO 9001 quality management and ISO 17025 laboratory competence.

Mandatory label elements include name of food, ingredients in descending order of weight, net quantity, date of manufacture and best-before, nutritional information, veg/non-veg mark, FSSAI licence number and allergen declaration.

Quality assurance is process-oriented and preventive (systems, audits, documentation), while quality control is product-oriented and detective (sampling and testing finished product against specification).

Development stages: idea generation, screening, concept testing, prototype formulation, bench and pilot trials, sensory and shelf-life testing, scale-up, test marketing and launch.

Sensory tests are difference tests (triangle, duo-trio, paired comparison), descriptive tests (flavour profile, quantitative descriptive analysis) and affective tests (hedonic, preference, consumer acceptance).

The triangle test presents three coded samples, two identical and one different, and asks which is different; it detects a perceptible difference, not preference.

A 9-point hedonic scale runs from 1 (dislike extremely) through 5 (neither like nor dislike) to 9 (like extremely); samples are coded, randomised, temperature-controlled and served in individual booths, with red light used to mask colour bias.

Trained panels of 8–12 assessors suit descriptive profiling, whereas consumer panels need at least 60–100 untrained respondents for reliable acceptance data.

Packaging functions are containment, protection, preservation, communication, convenience and tamper evidence; barrier properties against oxygen, moisture, light and aroma drive material choice.

Materials: glass (inert, impermeable, heavy), tinplate and aluminium (hermetic, retortable), paper and board (low barrier, printable), plastics (PET, PP, PE, PS, PVC, EVOH) and laminates combining layers.

Modified atmosphere packaging uses a gas mix (typically 2–5% O2, 5–10% CO2, balance N2 for produce; higher CO2 for meat and fish) and works only with low temperature and suitable film permeability.

Active and intelligent packaging includes oxygen scavengers, ethylene absorbers, moisture regulators, antimicrobial films and time–temperature indicators that reveal cold-chain breaks.

Additive classes include preservatives, antioxidants, colours, emulsifiers, stabilisers, thickeners, sweeteners, flavour enhancers, anticaking agents, humectants, acidity regulators, leavening agents and sequestrants.

Additives carry INS (International Numbering System) and E numbers; each has permitted food categories and maximum levels, and use is justified only by a technological need.

Preservatives are class I natural (salt, sugar, vinegar, honey, edible oil) or class II chemical, such as benzoic acid (INS 210) in acidic foods, sorbic acid (INS 200) against moulds and yeasts, and sulphur dioxide (INS 220) in dried fruit.

Antioxidants: BHA (INS 320), BHT (INS 321), TBHQ (INS 319) and propyl gallate for fats, with ascorbic acid (INS 300) and tocopherols (INS 307) as natural options; sequestrants such as EDTA (INS 385) bind pro-oxidant metals.

Permitted synthetic colours include tartrazine (INS 102), sunset yellow (INS 110), carmoisine (INS 122), ponceau 4R (INS 124) and brilliant blue (INS 133); natural colours include annatto (INS 160b), beta-carotene (INS 160a) and chlorophyll.

Sweeteners are nutritive (sucrose, glucose, fructose) or non-nutritive, such as saccharin (INS 954), aspartame (INS 951, avoided in phenylketonuria because it yields phenylalanine), sucralose (INS 955) and steviol glycosides (INS 960).

Adulteration is adding inferior, harmful or undeclared substances; Indian examples include metanil yellow or lead chromate in turmeric, sawdust or chalk in chilli powder, starch in milk and ghee, and added water in milk.

Detection tests: iodine gives blue-black with starch in milk; concentrated hydrochloric acid gives crimson with metanil yellow in turmeric; a drop on water spreading into a film indicates starch in ghee.

Macronutrients supply energy and building material; micronutrients (vitamins and minerals) supply no energy but act as essential cofactors; dietary fibre is non-digestible carbohydrate aiding bowel function and lowering cholesterol.

ICMR-NIN gives Indian recommended allowances; protein should supply about 10–15% of energy, fat 20–30% and carbohydrate 50–60%, and protein quality is scored by PER, BV, NPU and PDCAAS.

A food business plan covers product description, market analysis, process and technology, plant location and layout, capital and working capital, projected profit and loss, break-even analysis and risk assessment.

Break-even point in units = fixed cost ÷ (selling price per unit − variable cost per unit); contribution margin is selling price minus variable cost.

Small Indian food enterprises can use PMFME, NABARD and MSME credit schemes, food parks and incubation centres for shared facilities, and FSSAI training initiatives.

Plant layout follows product flow to prevent cross-contamination: separate high-risk and low-risk zones, unidirectional movement from raw to cooked, hand-wash and foot-dip stations, and washable coving surfaces.

Traceability means one step back and one step forward lot identification; a recall plan specifies the recall committee, lot coding, communication, retrieval and mock-recall verification.

Cold chain stages are pre-cooling, cold storage, refrigerated transport, retail display and domestic storage; a break anywhere shortens shelf life and may allow pathogen growth.

Emerging technologies include high-pressure processing, pulsed electric field, cold plasma, ultrasound-assisted extraction, ohmic and microwave heating, 3D food printing, encapsulation, edible films and plant-based or fermentation-derived proteins.

Industry 4.0 practices in food include IoT temperature sensors, automated vision inspection, blockchain traceability, predictive maintenance and digital twins for process control.

Sustainability practices include waste valorisation (peel, whey and pomace into pectin, fibre and antioxidants), water and energy audits, by-product recovery and biodegradable packaging.

Moisture: oven drying at 105 °C to constant weight; the loss in weight is expressed as a percentage of the original sample, reported on a wet or dry basis as stated.

Kjeldahl protein: digest with sulphuric acid and catalyst, distil ammonia into boric acid, titrate with standard acid; % protein = % N × 6.25 (6.38 for milk, 5.70 for wheat).

Soxhlet fat: extract the dried sample with petroleum ether, evaporate the solvent and weigh the residue; crude fibre is the loss on ignition of the residue after acid and alkali digestion.

Ash: ignite in a muffle furnace at 550 °C to constant weight; ash represents total mineral content, not mineral composition.

Acidity and pH: titrate with standard sodium hydroxide using phenolphthalein for titratable acidity (as lactic acid for milk, citric for fruit products); measure pH with a calibrated glass electrode.

Peroxide value: titrate liberated iodine with sodium thiosulphate after reaction of the fat with potassium iodide; free fatty acid value is alkali titration of extracted fat, expressed as % oleic acid.

Microbiological practice: serial decimal dilutions in saline or peptone water, pour or spread plates, incubate at 37 °C for 24–48 h for mesophiles, count plates with 30–300 colonies and report as CFU/g.

Aseptic technique: flame-sterilise loops and tube mouths, work near a flame or in a laminar flow hood, never lay down a pipette or lid, and autoclave media at 121 °C for 15 minutes at 15 psi.

Sensory booth conditions: individual booths, controlled lighting, 20–25 °C, odour-free air, random three-digit sample codes, water and plain crackers as palate cleansers, and standard score sheets.

Good laboratory practice: record raw data in a bound notebook, use calibrated instruments and traceable standards, run at least duplicate analyses, and report mean with standard deviation and the method reference.

Food science applies chemistry, microbiology, engineering and nutrition to converting raw agricultural material into safe, stable, palatable food; food technology is the industrial application of those principles.

The six constituent classes are water, carbohydrates, proteins, lipids, vitamins and minerals; water plus the three macronutrients typically exceed 95% of fresh food mass.

Proximate analysis partitions a food into moisture, crude protein (Kjeldahl N × 6.25), crude fat (Soxhlet), crude fibre, ash and nitrogen-free extract (carbohydrate by difference).

Typical moisture: fruits and vegetables 80–95%, milk about 87%, meat 60–75%, cereals 10–14%, edible oils below 1% - water is the largest single component of most fresh foods.

Atwater energy factors: carbohydrate 4 kcal/g, protein 4 kcal/g, fat 9 kcal/g, alcohol 7 kcal/g; total energy is the sum of grams of each component multiplied by its factor.

Constituents are macro (gram quantities: water, carbohydrate, protein, lipid) or micro (vitamins, minerals, trace elements in milligram or microgram quantities).

Foods are grouped by function as energy-giving (cereals, fats), body-building (pulses, milk, meat, eggs) and protective (fruits, vegetables, milk).

Constituent interactions drive processing: Maillard browning needs a reducing sugar plus an amino group, gelatinisation needs starch plus heat and water, and emulsion stability needs protein or emulsifier at the interface.

Water activity aw = p/p0, the vapour pressure of the food divided by that of pure water at the same temperature; spoilage bacteria generally need aw above 0.90, yeasts above 0.88, and xerophilic moulds can grow near 0.60.

Bound water is hydrogen-bonded to solutes and unavailable as solvent; free water supports microbial growth and chemical reactions, so aw predicts stability better than total moisture content.

The sorption isotherm plots moisture content against aw at constant temperature; BET and GAB models describe the monolayer, and the monolayer value marks maximum stability.

Starch gelatinises on heating with water (irreversible swelling, loss of birefringence, about 60–75 °C for common starches); on cooling, amylose retrogrades, causing staling and syneresis.

Sugars caramelise on dry heating and undergo Maillard browning with amino groups; Maillard is fastest at aw 0.6–0.8 and pH 6–8 and reduces nutritional value.

Proteins are amino acid polymers joined by peptide bonds; primary, secondary (alpha-helix, beta-sheet), tertiary and quaternary structure determine function, and denaturation unfolds structure without breaking peptide bonds.

Protein functions include solubility, water- and fat-binding, emulsification, foaming, gelation and texturisation; the isoelectric point is the pH of minimum solubility and maximum precipitation (casein about pH 4.6).

Fats are triacylglycerols; saturated fatty acids raise melting point and oxidative stability, while each double bond lowers melting point and increases susceptibility to oxidation.

Lipid oxidation is a free-radical chain reaction (initiation, propagation, termination) accelerated by light, heat, metals and lipoxygenase; peroxide value measures hydroperoxides, free fatty acid value measures hydrolysis, and anisidine value measures secondary aldehydes.

Fat-soluble vitamins A, D, E and K are absorbed with lipid and stored in liver or adipose, and are heat-stable but oxygen- and light-sensitive; water-soluble B-complex and C vitamins leach into cooking water and are destroyed by heat and alkali.

Vitamin C is the most heat- and oxygen-labile vitamin; losses are minimised by blanching to inactivate ascorbic acid oxidase, excluding oxygen and avoiding copper and iron contact.

Minerals are not destroyed by heat, light or oxidation but are lost by leaching; phytate and oxalate reduce calcium, iron and zinc bioavailability, while ascorbic acid and animal protein enhance non-haem iron absorption.

Intrinsic factors: pH, aw, redox potential, nutrient content, antimicrobial constituents and biological structure; extrinsic factors: temperature, relative humidity, atmosphere and competing microorganisms.

Growth curve phases are lag, log (exponential), stationary and death; generation time is the doubling time, and spoilage becomes detectable at about 10^7–10^8 cells/g.

Cardinal temperatures: psychrotrophs grow at 0–7 °C, mesophiles at 20–45 °C (optimum about 30–37 °C) and thermophiles at 45–65 °C; most pathogens are mesophiles, so refrigeration slows but does not stop growth.

Clostridium botulinum is an obligate anaerobe forming heat-resistant spores that produce a neurotoxin; destruction needs 121 °C for at least 3 minutes (F0 = 12D at 121 °C), and growth is prevented below pH 4.6 or aw 0.93.

Staphylococcus aureus produces a heat-stable enterotoxin that survives boiling, so prevention means keeping food out of the 5–60 °C danger zone rather than reheating.

Salmonella, Escherichia coli O157:H7 and Listeria monocytogenes are vegetative pathogens destroyed by pasteurisation; Listeria is unusual in growing at refrigeration temperature and tolerating high salt.

Moulds tolerate lower aw and pH than bacteria and are aerobic; mycotoxins such as aflatoxin (Aspergillus flavus in groundnuts and cereals) and ochratoxin are heat-stable and survive normal cooking.

Spoilage types: putrefaction (anaerobic protein breakdown to amines and ammonia), rancidity (lipid oxidation or lipolysis), souring (lactic fermentation), flat sour (Bacillus thermoacidurans in canned low-acid foods) and can swelling from gas producers.

Thermal death parameters: D-value is the time at a given temperature for a tenfold reduction in survivors; z-value is the temperature change giving a tenfold change in D; F-value is the equivalent time at a reference temperature.

Preservation uses hurdles: heat, cold, reduced aw, acidification, redox control, preservatives and competitive flora; the hurdle concept combines mild stresses so no single one damages quality.

Blanching (70–100 °C, 1–5 min) inactivates peroxidase, polyphenol oxidase and lipoxygenase, fixes colour, removes tissue gases and shrinks product before freezing or drying.

Pasteurisation stays below 100 °C (milk: 63 °C/30 min LTLT or 72 °C/15 s HTST) and kills vegetative pathogens; commercial sterility including spores needs UHT (135–150 °C for 2–5 s) or retorting.

Canning sequence: washing, blanching, filling, exhausting, seaming, retort processing and cooling; low-acid foods (pH above 4.6) need a botulinum cook, while acid foods (pH 4.6 or below) need only a boiling-water process.

Freezing preserves by lowering aw and temperature; quick freezing gives many small ice crystals and less drip loss, and storage is limited by ice recrystallisation, lipid oxidation and enzymatic browning unless blanched.

Drying removes water to aw below 0.60; the drying curve has constant-rate (surface evaporation) and falling-rate (internal diffusion) periods, and case-hardening retards drying when the surface dries too fast.

Concentration by evaporation (open pan, vacuum, multiple-effect) and membrane processes (reverse osmosis, ultrafiltration) removes water for heat-sensitive liquids; reverse osmosis needs higher pressure than ultrafiltration.

Irradiation doses: up to 1 kGy for sprout inhibition and insect disinfestation, 1–10 kGy for pathogen pasteurisation, above 10 kGy for sterilisation; the process is cold and leaves no radioactivity.

Emerging non-thermal methods include high-pressure processing (400–600 MPa), pulsed electric field, ohmic heating, microwave, ultrasound and cold plasma, which reduce thermal damage to nutrients and flavour.

HACCP's seven principles: hazard analysis, determination of critical control points, critical limits, monitoring, corrective actions, verification and record-keeping.

A critical control point is a step where control is essential to prevent, eliminate or reduce a significant hazard to an acceptable level; a critical limit is a measurable value such as 72 °C for 15 s or pH 4.6.

Pre-requisite programmes supporting HACCP include GMP, good hygiene practice, pest control, personnel hygiene, water quality, calibration, supplier approval, traceability and recall procedures.

Hazards are biological, chemical, physical and allergenic; major allergens such as milk, egg, peanut, soy, wheat, tree nuts, fish, shellfish and sesame need segregation and validated cleaning to prevent cross-contact.

FSSAI is India's statutory authority under the Food Safety and Standards Act, 2006, which consolidated earlier laws such as the PFA Act and the Fruit Products Order and covers licensing, standards, labelling and enforcement.

FSSAI licences are Central (manufacturers, importers, large turnover) and State (smaller units, distributors, retailers); petty food businesses register, and licences must be renewed periodically.

Codex Alimentarius (FAO/WHO) sets international standards, codes of practice and guidelines; ISO 22000 specifies food safety management systems, ISO 9001 quality management and ISO 17025 laboratory competence.

Mandatory label elements include name of food, ingredients in descending order of weight, net quantity, date of manufacture and best-before, nutritional information, veg/non-veg mark, FSSAI licence number and allergen declaration.

Quality assurance is process-oriented and preventive (systems, audits, documentation), while quality control is product-oriented and detective (sampling and testing finished product against specification).

Development stages: idea generation, screening, concept testing, prototype formulation, bench and pilot trials, sensory and shelf-life testing, scale-up, test marketing and launch.

Sensory tests are difference tests (triangle, duo-trio, paired comparison), descriptive tests (flavour profile, quantitative descriptive analysis) and affective tests (hedonic, preference, consumer acceptance).

The triangle test presents three coded samples, two identical and one different, and asks which is different; it detects a perceptible difference, not preference.

A 9-point hedonic scale runs from 1 (dislike extremely) through 5 (neither like nor dislike) to 9 (like extremely); samples are coded, randomised, temperature-controlled and served in individual booths, with red light used to mask colour bias.

Trained panels of 8–12 assessors suit descriptive profiling, whereas consumer panels need at least 60–100 untrained respondents for reliable acceptance data.

Packaging functions are containment, protection, preservation, communication, convenience and tamper evidence; barrier properties against oxygen, moisture, light and aroma drive material choice.

Materials: glass (inert, impermeable, heavy), tinplate and aluminium (hermetic, retortable), paper and board (low barrier, printable), plastics (PET, PP, PE, PS, PVC, EVOH) and laminates combining layers.

Modified atmosphere packaging uses a gas mix (typically 2–5% O2, 5–10% CO2, balance N2 for produce; higher CO2 for meat and fish) and works only with low temperature and suitable film permeability.

Active and intelligent packaging includes oxygen scavengers, ethylene absorbers, moisture regulators, antimicrobial films and time–temperature indicators that reveal cold-chain breaks.

Additive classes include preservatives, antioxidants, colours, emulsifiers, stabilisers, thickeners, sweeteners, flavour enhancers, anticaking agents, humectants, acidity regulators, leavening agents and sequestrants.

Additives carry INS (International Numbering System) and E numbers; each has permitted food categories and maximum levels, and use is justified only by a technological need.

Preservatives are class I natural (salt, sugar, vinegar, honey, edible oil) or class II chemical, such as benzoic acid (INS 210) in acidic foods, sorbic acid (INS 200) against moulds and yeasts, and sulphur dioxide (INS 220) in dried fruit.

Antioxidants: BHA (INS 320), BHT (INS 321), TBHQ (INS 319) and propyl gallate for fats, with ascorbic acid (INS 300) and tocopherols (INS 307) as natural options; sequestrants such as EDTA (INS 385) bind pro-oxidant metals.

Permitted synthetic colours include tartrazine (INS 102), sunset yellow (INS 110), carmoisine (INS 122), ponceau 4R (INS 124) and brilliant blue (INS 133); natural colours include annatto (INS 160b), beta-carotene (INS 160a) and chlorophyll.

Sweeteners are nutritive (sucrose, glucose, fructose) or non-nutritive, such as saccharin (INS 954), aspartame (INS 951, avoided in phenylketonuria because it yields phenylalanine), sucralose (INS 955) and steviol glycosides (INS 960).

Adulteration is adding inferior, harmful or undeclared substances; Indian examples include metanil yellow or lead chromate in turmeric, sawdust or chalk in chilli powder, starch in milk and ghee, and added water in milk.

Detection tests: iodine gives blue-black with starch in milk; concentrated hydrochloric acid gives crimson with metanil yellow in turmeric; a drop on water spreading into a film indicates starch in ghee.

Macronutrients supply energy and building material; micronutrients (vitamins and minerals) supply no energy but act as essential cofactors; dietary fibre is non-digestible carbohydrate aiding bowel function and lowering cholesterol.

ICMR-NIN gives Indian recommended allowances; protein should supply about 10–15% of energy, fat 20–30% and carbohydrate 50–60%, and protein quality is scored by PER, BV, NPU and PDCAAS.

A food business plan covers product description, market analysis, process and technology, plant location and layout, capital and working capital, projected profit and loss, break-even analysis and risk assessment.

Break-even point in units = fixed cost ÷ (selling price per unit − variable cost per unit); contribution margin is selling price minus variable cost.

Small Indian food enterprises can use PMFME, NABARD and MSME credit schemes, food parks and incubation centres for shared facilities, and FSSAI training initiatives.

Plant layout follows product flow to prevent cross-contamination: separate high-risk and low-risk zones, unidirectional movement from raw to cooked, hand-wash and foot-dip stations, and washable coving surfaces.

Traceability means one step back and one step forward lot identification; a recall plan specifies the recall committee, lot coding, communication, retrieval and mock-recall verification.

Cold chain stages are pre-cooling, cold storage, refrigerated transport, retail display and domestic storage; a break anywhere shortens shelf life and may allow pathogen growth.

Emerging technologies include high-pressure processing, pulsed electric field, cold plasma, ultrasound-assisted extraction, ohmic and microwave heating, 3D food printing, encapsulation, edible films and plant-based or fermentation-derived proteins.

Industry 4.0 practices in food include IoT temperature sensors, automated vision inspection, blockchain traceability, predictive maintenance and digital twins for process control.

Sustainability practices include waste valorisation (peel, whey and pomace into pectin, fibre and antioxidants), water and energy audits, by-product recovery and biodegradable packaging.

Moisture: oven drying at 105 °C to constant weight; the loss in weight is expressed as a percentage of the original sample, reported on a wet or dry basis as stated.

Kjeldahl protein: digest with sulphuric acid and catalyst, distil ammonia into boric acid, titrate with standard acid; % protein = % N × 6.25 (6.38 for milk, 5.70 for wheat).

Soxhlet fat: extract the dried sample with petroleum ether, evaporate the solvent and weigh the residue; crude fibre is the loss on ignition of the residue after acid and alkali digestion.

Ash: ignite in a muffle furnace at 550 °C to constant weight; ash represents total mineral content, not mineral composition.

Acidity and pH: titrate with standard sodium hydroxide using phenolphthalein for titratable acidity (as lactic acid for milk, citric for fruit products); measure pH with a calibrated glass electrode.

Peroxide value: titrate liberated iodine with sodium thiosulphate after reaction of the fat with potassium iodide; free fatty acid value is alkali titration of extracted fat, expressed as % oleic acid.

Microbiological practice: serial decimal dilutions in saline or peptone water, pour or spread plates, incubate at 37 °C for 24–48 h for mesophiles, count plates with 30–300 colonies and report as CFU/g.

Aseptic technique: flame-sterilise loops and tube mouths, work near a flame or in a laminar flow hood, never lay down a pipette or lid, and autoclave media at 121 °C for 15 minutes at 15 psi.

Sensory booth conditions: individual booths, controlled lighting, 20–25 °C, odour-free air, random three-digit sample codes, water and plain crackers as palate cleansers, and standard score sheets.

Good laboratory practice: record raw data in a bound notebook, use calibrated instruments and traceable standards, run at least duplicate analyses, and report mean with standard deviation and the method reference.