Maharashtra HSC Food Science and Technology flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Water activity (aw)

The ratio of the vapour pressure of water in a food to that of pure water at the same temperature. It predicts microbial growth and chemical stability better than total moisture content does.

Proximate analysis

A scheme that partitions food into moisture, crude protein, crude fat, crude fibre, ash and nitrogen-free extract. Carbohydrate is usually obtained by difference rather than measured directly.

Atwater energy factors

Calorie conversion values applied to macronutrients: carbohydrate 4 kcal/g, protein 4 kcal/g, fat 9 kcal/g and alcohol 7 kcal/g. Multiplying grams by these factors gives the energy content of a food.

Starch gelatinisation

Irreversible swelling and disruption of starch granules on heating in water, with loss of birefringence, typically between 60 and 75 degrees Celsius. It thickens foods and makes starch digestible.

Isoelectric point of protein

The pH at which a protein carries no net charge, so electrostatic repulsion is minimal. Solubility is lowest there and the protein precipitates most readily, as casein does near pH 4.6.

Lipid auto-oxidation

A free-radical chain reaction in fats with initiation, propagation and termination phases. Light, heat, metals and lipoxygenase accelerate it, producing hydroperoxides that break down into rancid aldehydes and ketones.

Peroxide value

A measure of hydroperoxides in a fat, found by liberating iodine from potassium iodide and titrating with sodium thiosulphate. It is an early indicator of oxidative rancidity in edible oils and fried products.

Maillard browning

Non-enzymatic browning between a reducing sugar and an amino group, producing brown pigments and aroma compounds. It is fastest at water activity 0.6 to 0.8 and at pH 6 to 8.

D-value

The decimal reduction time, meaning the heating time at a stated temperature that reduces a microbial population by 90 percent, or one log cycle. It quantifies the heat resistance of a specific organism.

Botulinum cook (F0 = 12D)

A heat process at 121 degrees Celsius for at least three minutes, designed to reduce Clostridium botulinum spores twelvefold in decimal terms. It is required for canned low-acid foods above pH 4.6.

Danger zone temperatures

The range of roughly 5 to 60 degrees Celsius in which foodborne pathogens multiply rapidly. Food should spend minimal time in this range, and reheating does not destroy preformed heat-stable toxins.

Aflatoxin

A heat-stable mycotoxin produced mainly by Aspergillus flavus in groundnuts, cereals and spices under warm humid storage. It is not removed by ordinary cooking and is regulated because it is hepatotoxic and carcinogenic.

Flat sour spoilage

Spoilage of canned low-acid foods by Bacillus thermoacidurans, which produces acid without gas. The can remains flat but the product turns sour, distinguishing it from gas-swelling spoilage.

Blanching

A mild heat treatment, roughly 70 to 100 degrees Celsius for one to five minutes, applied before freezing or drying. It inactivates enzymes such as peroxidase and polyphenol oxidase, fixes colour and shrinks tissue.

HTST pasteurisation

High-temperature short-time pasteurisation of milk at 72 degrees Celsius for 15 seconds, followed by rapid cooling. It destroys vegetative pathogens such as Salmonella while causing less nutritional and flavour damage than LTLT.

UHT processing

Ultra-high-temperature treatment at about 135 to 150 degrees Celsius for two to five seconds, giving commercial sterility. Combined with aseptic packaging it yields shelf-stable milk without refrigeration until opening.

Hurdle technology

Combining several mild preservation stresses, such as reduced water activity, lowered pH, refrigeration and added preservatives, so that no single treatment must be severe. It improves safety while retaining sensory quality.

Freeze concentration and recrystallisation

During frozen storage small ice crystals grow into larger ones, damaging cell structure and increasing drip loss on thawing. Rapid freezing and stable low temperatures limit this quality defect.

HACCP principles

Seven principles: hazard analysis, critical control point determination, critical limits, monitoring, corrective actions, verification and record-keeping. They form the systematic preventive framework for food safety management.

Critical control point

A process step where control can prevent, eliminate or reduce a significant food safety hazard to an acceptable level. Each CCP has measurable critical limits, monitoring frequency and a defined corrective action.

FSSAI

India's Food Safety and Standards Authority, established under the Food Safety and Standards Act, 2006. It sets standards, issues Central and State licences, regulates labelling and enforces food safety law.

Quality assurance versus quality control

Quality assurance is preventive and system-based, covering procedures, audits and documentation. Quality control is detective and product-based, testing samples against specifications. Both are needed in a food safety management system.

Triangle sensory test

A difference test presenting three coded samples, two identical and one different, and asking the panelist to identify the odd one. It establishes whether a perceptible difference exists, not which sample is preferred.

Nine-point hedonic scale

An affective rating scale from 1, dislike extremely, through 5, neither like nor dislike, to 9, like extremely. It measures consumer acceptance and preference rather than trained analytical description.

Modified atmosphere packaging

Replacing air in a package with a controlled gas mixture, commonly 2 to 5 percent oxygen, 5 to 10 percent carbon dioxide and balance nitrogen. It extends shelf life only when combined with low temperature.

Active packaging

Packaging that deliberately interacts with the food or headspace, for example oxygen scavengers, ethylene absorbers, moisture regulators and antimicrobial films. It extends shelf life beyond the passive barrier function.

Class I preservatives

Naturally occurring preservatives such as salt, sugar, vinegar, honey and edible oil. They act mainly by lowering water activity or pH and are permitted without the maximum-level restrictions applied to class II chemical preservatives.

Metanil yellow adulteration

A non-permitted synthetic dye sometimes added to turmeric to brighten colour. Concentrated hydrochloric acid gives a crimson colour with it, and it is prohibited because of its toxicity.

Aspartame and phenylketonuria

Aspartame, INS 951, is a non-nutritive sweetener that releases phenylalanine on digestion. Foods containing it must carry a warning for people with phenylketonuria, who cannot metabolise phenylalanine normally.

Break-even point

The sales volume at which total revenue equals total cost, calculated as fixed cost divided by selling price minus variable cost per unit. Above it the food business earns profit; below it, it makes a loss.

Cold chain

The continuous refrigerated sequence from pre-cooling and cold storage through refrigerated transport to retail display. Any break raises temperature, shortens shelf life and may permit pathogen growth.

Kjeldahl protein determination

Digestion of the sample with sulphuric acid and catalyst, distillation of ammonia into boric acid and titration with standard acid. Percentage protein equals percentage nitrogen multiplied by a factor, 6.25 for most foods.