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Punjab PSEB Matric NSQF Food Processing study materials
Punjab PSEB Matric NSQF Food Processing study resources

Punjab PSEB Matric NSQF Food Processing practice questions

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Question 1Introduction to Food Processing and Food Science

In food processing terminology, 'primary processing' of raw agricultural produce mainly involves which set of activities?

  1. Retail display and price labelling of packaged goods
  2. Formulating ready-to-eat snack blends with added flavours
  3. Designing national food safety legislation
  4. Cleaning, grading, sorting and basic preservation of the harvested material Correct answer.

Explanation

Primary processing converts harvested raw material into a stable, transportable form through operations such as cleaning, grading, sorting, drying and basic preservation. It sits at the first stage after harvest, before any product formulation or retail activity. Formulation, retail and regulation belong to later or non-processing stages.

Question 2Introduction to Food Processing and Food Science

Which change is the main reason food is processed by drying?

  1. Conversion of carbohydrates into vitamins
  2. Increase of moisture so enzymes become more active
  3. Reduction of water activity to slow microbial growth and spoilage reactions Correct answer.
  4. Removal of all protein from the food

Explanation

Drying removes water and lowers water activity, which limits the growth of bacteria, yeasts and moulds and slows enzymatic and chemical spoilage. This is why dried grains, pulses and spices keep for long periods without refrigeration. Drying does not remove protein or create vitamins.

Question 3Introduction to Food Processing and Food Science

A mango grower wants to reduce post-harvest losses before selling fruit to a distant market. Which practice best fits the principles of food science?

  1. Mix damaged and sound fruit in one crate to save space
  2. Harvest at the correct maturity, sort out damaged fruit, and cool the produce quickly Correct answer.
  3. Delay cooling for two days so the fruit can ripen fully
  4. Leave harvested fruit in direct sun to dry the surface

Explanation

Losses are reduced when fruit is harvested at proper maturity, injured fruit is removed to avoid spreading rot, and the produce is cooled promptly to slow respiration and microbial growth. Damaged fruit releases juices and spores that spoil sound fruit. Sun exposure and delayed cooling accelerate deterioration.

Question 4Introduction to Food Processing and Food Science

Which statement correctly describes the role of enzymes in foods?

  1. They are minerals that provide energy to the food
  2. They are proteins that catalyse reactions such as browning and ripening Correct answer.
  3. They are vitamins that stop all chemical reactions
  4. They are fats that form the cell wall of plants

Explanation

Enzymes are proteins that act as biological catalysts, speeding reactions such as enzymatic browning in cut fruit and ripening in stored produce. Their activity can be controlled by heat, pH and water activity. Enzymes are not minerals, fats or vitamins.

Question 5Introduction to Food Processing and Food Science

Blanching vegetables before freezing is done mainly to achieve which result?

  1. Removal of all vitamins to make the product more stable
  2. Inactivation of enzymes that cause off-flavours and colour loss during storage Correct answer.
  3. Complete sterilisation of the product so no cooling is needed
  4. Addition of salt to improve the taste of the vegetable

Explanation

Blanching uses hot water or steam to denature enzymes such as peroxidase and polyphenol oxidase, which otherwise cause off-flavours, browning and vitamin loss during frozen storage. It is not a sterilisation step, so the product still needs freezing. Blanching may cause some vitamin loss but that is not its purpose.

Question 6Introduction to Food Processing and Food Science

Which microorganism group is most likely to spoil a jar of fruit jam that has a high sugar content and low pH?

  1. Osmophilic yeasts and moulds Correct answer.
  2. Strictly anaerobic Clostridium botulinum
  3. Thermophilic spore-forming bacteria
  4. Pathogenic Salmonella species

Explanation

High sugar and low pH create a hostile environment for most bacteria, but osmophilic yeasts and moulds can tolerate high solute concentrations and spoil such products. Salmonella and Clostridium botulinum do not grow under these acidic, high-sugar conditions. Spoilage of jam is therefore usually fungal.

Question 7Introduction to Food Processing and Food Science

Which of the following is a unit operation commonly used in food processing?

  1. Profit calculation for a retail shop
  2. Writing a supply contract
  3. Size reduction by grinding Correct answer.
  4. Designing a food label font

Explanation

A unit operation is a single basic step such as grinding, mixing, heating, cooling or filtration that is combined with others to build a process. Grinding is a recognised size-reduction unit operation. Commercial and graphic tasks are not unit operations.

Question 8Introduction to Food Processing and Food Science

A processor wants to make clear apple juice from cloudy pressed juice. Which unit operation is most directly suitable?

  1. Fermenting the juice into vinegar
  2. Filtration after enzyme treatment and settling Correct answer.
  3. Adding more pulp to the juice
  4. Freezing the juice into blocks

Explanation

Clarification of cloudy juice involves treating with pectinase to break down pectin, allowing particles to settle, then filtering or centrifuging to obtain a clear product. Freezing, adding pulp or fermenting do not remove suspended solids. Filtration is the separation step that delivers clarity.

Question 9Introduction to Food Processing and Food Science

Which statement about the difference between food science and food technology is most accurate?

  1. Food science deals only with packaging design, while food technology deals only with accounting
  2. Food science and food technology are identical terms with no practical distinction
  3. Food science is limited to cooking at home, while food technology is limited to farming
  4. Food science studies the nature of food, while food technology applies that knowledge to manufacture and preserve it Correct answer.

Explanation

Food science is the study of the physical, chemical, microbiological and nutritional nature of foods and the changes they undergo. Food technology uses that scientific knowledge to develop processes, equipment and products for safe, large-scale manufacture. The two fields overlap but differ in emphasis.

Question 10Introduction to Food Processing and Food Science

A sealed can of low-acid vegetables is under-processed and then stored at room temperature. Which hazard is of greatest concern?

  1. Growth of Clostridium botulinum and production of a deadly neurotoxin Correct answer.
  2. Development of a bitter taste from added sugar
  3. Rapid growth of osmophilic yeasts on the surface
  4. Loss of colour due to light exposure

Explanation

Low-acid canned foods stored at room temperature provide the anaerobic, low-acid conditions in which Clostridium botulinum spores can germinate and produce a lethal neurotoxin. Adequate thermal processing is therefore essential. Yeast growth, sugar bitterness and light-induced colour change are minor quality issues by comparison.

Question 11Introduction to Food Processing and Food Science

Which property of water makes it important as a medium in food processing operations such as heating and washing?

  1. Very low boiling point
  2. Ability to act as a fat
  3. Complete absence of dissolved minerals
  4. High specific heat and good solvent power Correct answer.

Explanation

Water has a high specific heat, so it can carry and transfer large amounts of heat, and it is a strong solvent for salts, sugars and many food components. These properties make it useful as a heating medium and cleaning agent. Water is not a fat and does not have a low boiling point.

Question 12Introduction to Food Processing and Food Science

During storage, a sample of cooking oil develops a rancid smell. Which process best explains this change?

  1. Hydrolysis of starch into sugars
  2. Growth of lactic acid bacteria on the oil
  3. Oxidation of unsaturated fatty acids leading to rancidity Correct answer.
  4. Denaturation of protein by salt

Explanation

Rancidity in oils is mainly caused by oxidation of unsaturated fatty acids, producing aldehydes, ketones and other volatile compounds with unpleasant odours. Light, heat and trace metals accelerate this reaction. Starch hydrolysis, protein denaturation and lactic fermentation do not explain rancid oil.

Question 13Introduction to Food Processing and Food Science

Which packaging material property is most important for protecting light-sensitive foods such as edible oils and certain vitamins?

  1. Opacity to ultraviolet and visible light Correct answer.
  2. High water solubility
  3. High transparency to all wavelengths
  4. Low mechanical strength

Explanation

Light, especially ultraviolet, accelerates oxidation and destroys light-sensitive vitamins. Packaging that blocks or absorbs ultraviolet and visible light therefore protects these foods. Transparency, water solubility and low strength would all reduce protective performance.

Question 14Introduction to Food Processing and Food Science

A product labelled as containing 12 g of carbohydrate per 100 g. Which statement about this value is correct?

  1. It describes the carbohydrate content per 100 g of protein
  2. It expresses the carbohydrate content on a per-100-gram basis of the food as sold Correct answer.
  3. It means 12 g of carbohydrate must be eaten daily
  4. It refers to 12 g of carbohydrate in the whole package regardless of size

Explanation

Nutrition information stated per 100 g expresses the amount of the nutrient in 100 g of the food as sold, allowing comparison between products. It is not a daily requirement, does not depend on package size, and is not measured against protein. The reference quantity is the food itself.

Question 15Introduction to Food Processing and Food Science

Which factor most strongly determines whether a given microorganism can grow in a food?

  1. The shape of the food container
  2. Combined intrinsic factors such as pH, water activity, nutrients and temperature Correct answer.
  3. The brand name printed on the label
  4. The colour of the packaging

Explanation

Microbial growth depends on intrinsic factors such as pH, water activity, nutrient availability and redox potential, together with extrinsic factors such as temperature and atmosphere. These conditions determine which organisms can multiply. Packaging colour, brand names and container shape do not control microbial growth.

Question 16Introduction to Food Processing and Food Science

Which statement about the Maillard reaction is correct?

  1. It is the same reaction as starch gelatinisation
  2. It requires the presence of fat and produces green pigments
  3. It occurs between reducing sugars and amino groups and produces brown pigments and aroma compounds Correct answer.
  4. It occurs only at temperatures below freezing

Explanation

The Maillard reaction is a non-enzymatic browning reaction between reducing sugars and amino compounds such as amino acids or proteins. It produces brown melanoidins and many aroma compounds and is favoured by heat and low moisture. It does not need fat, is not gelatinisation, and does not occur at freezing temperatures.

Question 17Introduction to Food Processing and Food Science

A dairy plant heats milk to about 72 degrees Celsius for 15 seconds and then cools it rapidly. Which treatment has been applied?

  1. High-temperature short-time pasteurisation Correct answer.
  2. Spray drying
  3. Freeze-drying
  4. Commercial sterilisation in a retort

Explanation

Heating to about 72 degrees Celsius for 15 seconds followed by rapid cooling is the standard high-temperature short-time pasteurisation process for milk. It destroys vegetative pathogens such as Coxiella burnetii while retaining much of the sensory quality. Sterilisation, freeze-drying and spray drying use very different conditions.

Question 18Introduction to Food Processing and Food Science

Which statement best explains why salt is used in traditional preservation of fish and meat?

  1. It lowers water activity, making water unavailable to spoilage microorganisms Correct answer.
  2. It raises the pH above 10, killing all bacteria
  3. It provides a nitrogen source that microorganisms cannot use
  4. It increases the moisture content of the tissue

Explanation

Salt dissolves in the tissue water and lowers water activity, so spoilage microorganisms cannot obtain the water they need for growth. This is why curing extends shelf life. Salt does not raise pH to alkaline levels, act as a nitrogen source in this way, or increase moisture.

Question 19Introduction to Food Processing and Food Science

A food scientist compares two samples of wheat flour and finds that one has higher gluten strength. Which quality difference is most likely?

  1. The stronger flour has no protein content
  2. The stronger flour dissolves completely in cold water
  3. The stronger flour gives a more elastic dough suitable for bread Correct answer.
  4. The stronger flour gives a crumbly dough suitable only for biscuits

Explanation

Gluten strength depends on the glutenin and gliadin proteins, which form an elastic network when hydrated and kneaded. Stronger flour produces a more elastic, gas-retaining dough suited to bread. Weak flour is used for biscuits and cakes. Gluten does not dissolve in cold water, and strength reflects protein quality, not absence.

Question 20Introduction to Food Processing and Food Science

Which combination correctly pairs a preservation method with its main principle?

  1. Canning with removal of protein; refrigeration with exposure to light
  2. Canning with heat sterilisation; refrigeration with lowered temperature Correct answer.
  3. Canning with reduced water activity; refrigeration with added salt
  4. Canning with increased pH; refrigeration with added sugar

Explanation

Canning relies on heat sterilisation to destroy microorganisms and inactivate enzymes inside a sealed container, while refrigeration slows microbial growth and enzyme activity by lowering temperature. The other pairings misstate the principle behind each method.

Question 21Food Safety, Hygiene and Sanitation

In a small fruit-processing unit, a worker has a fresh cut on the hand while packing dried mango slices. What is the most appropriate first action before continuing work?

  1. Cover the cut with a brightly coloured waterproof dressing and a glove, then continue packing
  2. Wash the hand, apply a waterproof plaster, and if the cut is on a hand that touches food, move the worker to a non-food-contact task Correct answer.
  3. Rinse the cut with water and continue packing because dried fruit has low moisture and spoilage risk
  4. Ask the supervisor for permission to keep working and report the cut at the end of the shift

Explanation

Open wounds on food handlers can carry Staphylococcus and other pathogens onto food, so a waterproof dressing is mandatory and the worker should be excluded from direct food contact until healed. Simply covering with a glove over an uncovered wound does not control leakage, and dried fruit is not sterile. Reporting only at shift end leaves the hazard uncontrolled during production.

Question 22Food Safety, Hygiene and Sanitation

Which practice best describes correct handwashing for a food handler in a PSEB-registered food processing unit?

  1. Wash hands only at the start of the shift and after using the toilet
  2. Wet hands, apply soap, rub for at least 20 seconds including between fingers and under nails, rinse and dry with a clean towel or air dryer Correct answer.
  3. Rinse hands quickly under running water for five seconds before touching food
  4. Use a hand sanitizer alone when hands are visibly soiled with fruit pulp

Explanation

Effective handwashing requires soap, mechanical friction for about 20 seconds covering all surfaces of the hands, thorough rinsing and proper drying. Rinsing alone does not remove oils and microorganisms, and sanitizers are ineffective on visibly soiled hands. Handwashing must be repeated frequently, not just twice a day.

Question 23Food Safety, Hygiene and Sanitation

A food processing hall has a foot-operated washbasin, a hand-wash notice and liquid soap, but no disposable towels and no hand dryer. What is the main hygiene problem?

  1. The foot-operated basin wastes too much water during peak production
  2. Without a proper drying method, hands may be recontaminated or workers may dry them on aprons, so drying facilities must be provided Correct answer.
  3. Liquid soap is less effective than bar soap in food units
  4. Hand-wash notices are unnecessary if workers have been trained once

Explanation

Drying is a required part of handwashing because wet hands transfer microorganisms more readily and workers may improvise by wiping on clothing. Disposable towels or a working air dryer must therefore be available at every washbasin. Water use, soap type and signage are separate issues and do not replace the missing drying step.

Question 24Food Safety, Hygiene and Sanitation

Which of the following is the correct order for cleaning a stainless-steel table used for cutting vegetables?

  1. Rinse, dry, clean with detergent, sanitize
  2. Dry, sanitize, clean with detergent, rinse
  3. Sanitize, rinse, clean with detergent, dry
  4. Clean with detergent, rinse, sanitize, air-dry Correct answer.

Explanation

The standard sequence is dry removal of debris, detergent cleaning to lift soil, rinsing to remove detergent and loosened soil, then sanitizing and air-drying. Sanitizer applied before cleaning is wasted because soil shields microorganisms. Drying after sanitizing prevents recontamination from cloths and allows the sanitizer contact time.

Question 25Food Safety, Hygiene and Sanitation

A sanitiser is labelled for use at 100 ppm available chlorine with a contact time of one minute. A worker dilutes it to 50 ppm to save chemical. What is the most likely consequence?

  1. The sanitiser will become more effective because microorganisms are less stressed
  2. The sanitiser will work faster because the solution is less corrosive
  3. There is no effect because contact time alone determines sanitising power
  4. The reduced concentration may fail to kill pathogens within the stated contact time, leaving a false sense of safety Correct answer.

Explanation

Sanitiser efficacy depends on concentration, contact time, temperature and cleanliness, so halving the concentration can drop killing power below the required level. The user then believes the surface is sanitised when pathogens may survive. Concentration must be checked, for example with test strips, and the label instructions followed.

Question 26Food Safety, Hygiene and Sanitation

Why should colour-coded chopping boards be used in a food processing unit?

  1. To make the kitchen look attractive to visiting customers
  2. To allow workers to identify which board belongs to which employee
  3. To separate boards used for raw meat, cooked food and vegetables so cross-contamination is prevented Correct answer.
  4. To reduce the cost of replacing worn boards

Explanation

Colour coding links each board to a food category, which stops raw meat or poultry juices from contacting ready-to-eat foods through shared equipment. This is a recognised control for cross-contamination. Appearance, personal ownership and replacement cost are not the purpose of the system.

Question 27Food Safety, Hygiene and Sanitation

A worker finishes trimming raw chicken and then picks up washed salad leaves with bare hands. Which hazard pathway is created?

  1. Chemical contamination from detergent residue
  2. Physical contamination from bone fragments
  3. Allergenic contamination from the chicken protein
  4. Cross-contamination with pathogens such as Salmonella from raw poultry to the ready-to-eat salad Correct answer.

Explanation

Raw poultry commonly carries Salmonella and Campylobacter, and unwashed hands transfer these organisms to ready-to-eat food that will not be cooked again. This is a classic cross-contamination route. Bone, detergent and allergen issues are different hazards and are not created by this handling sequence.

Question 28Food Safety, Hygiene and Sanitation

Which temperature range is commonly called the danger zone for bacterial growth in foods?

  1. Between 63 °C and 100 °C
  2. Between 5 °C and 63 °C Correct answer.
  3. Between -18 °C and 0 °C
  4. Between 0 °C and 5 °C

Explanation

Most foodborne bacteria multiply rapidly between about 5 °C and 63 °C, so chilled food is held at or below 5 °C and hot food at or above 63 °C. Keeping food out of this range limits growth. Freezing and near-boiling temperatures are outside the main growth zone.

Question 29Food Safety, Hygiene and Sanitation

Cooked rice is prepared at 11 a.m. and left in a covered vessel at room temperature until 4 p.m. before being served. What is the best assessment?

  1. The rice is safe because rice is a low-risk cereal product
  2. The rice is safe because it was covered and no dust entered
  3. The rice is safe if it is reheated briefly just before serving
  4. The rice has spent several hours in the danger zone and may contain Bacillus cereus toxin, so it should be discarded Correct answer.

Explanation

Cooked rice is a well-known vehicle for Bacillus cereus, whose spores survive cooking and produce toxin when rice cools slowly at ambient temperature. Five hours in the danger zone is excessive, and reheating does not reliably destroy the pre-formed toxin. Covering does not prevent bacterial growth.

Question 30Food Safety, Hygiene and Sanitation

Which statement correctly describes the difference between cleaning and disinfection?

  1. Cleaning removes visible soil, while disinfection reduces microorganisms to a safe level on a clean surface Correct answer.
  2. Disinfection removes food debris, while cleaning sterilises the surface
  3. Cleaning kills all microorganisms, while disinfection only removes dust
  4. Cleaning and disinfection are the same process performed with hot water

Explanation

Cleaning physically removes grease, food residues and dirt, whereas disinfection uses a chemical or heat treatment to reduce microorganisms. Disinfection works only after cleaning because soil protects microbes. Neither step necessarily achieves sterilisation, which is a much higher level of treatment.

Question 31Food Safety, Hygiene and Sanitation

A mixer used for dough containing milk powder is cleaned only with a water rinse at the end of the shift. Why is this inadequate?

  1. Milk powder does not dissolve in water and therefore cannot be cleaned
  2. Water rinsing is too expensive for small units
  3. Water rinsing leaves milk protein and fat films that support microbial growth and can harbour allergens Correct answer.
  4. Rinsing is adequate provided the mixer is covered overnight

Explanation

Milk residues form protein and fat films that adhere to surfaces, feed bacteria and remain as allergenic material for the next product. Detergent cleaning followed by rinsing and disinfection is required. Cost, solubility and overnight covering are not valid reasons to skip proper cleaning.

Question 32Food Safety, Hygiene and Sanitation

Which of these is an example of a physical hazard in a food processing line?

  1. Peanut protein in a product without an allergen label
  2. Listeria monocytogenes on a slicing blade
  3. Broken glass from a light fitting falling onto an open product tray Correct answer.
  4. Cleaning detergent left on a conveyor belt

Explanation

Physical hazards are foreign objects such as glass, metal, stones, bone or plastic that can injure consumers. Glass from an unprotected light above exposed food is a classic example, which is why shatterproof covers are used. Bacteria, chemicals and undeclared allergens belong to other hazard categories.

Question 33Food Safety, Hygiene and Sanitation

A metal detector at the end of a snack-frying line rejects a packet. What is the correct action according to good manufacturing practice?

  1. Put the packet back on the line after checking it by hand for metal
  2. Discard the packet immediately without investigation
  3. Increase the detector sensitivity so the packet passes automatically
  4. Isolate the rejected packet, re-test it, and investigate the source of contamination before releasing any product Correct answer.

Explanation

Rejects must be quarantined and re-tested to confirm the signal, and the source of metal must be traced because it may indicate equipment wear or damage. Product from the affected period may need to be held. Hand checking, blind discarding or adjusting sensitivity to force a pass all defeat the control.

Question 34Food Safety, Hygiene and Sanitation

What is the main purpose of a pest control programme in a food processing unit?

  1. To reduce the amount of cleaning chemicals used
  2. To prevent rodents, insects and birds from entering, sheltering and contaminating food or surfaces Correct answer.
  3. To satisfy visitors who ask about environmental protection
  4. To improve the appearance of the factory boundary

Explanation

Pests carry pathogens and contaminate food, packaging and equipment with droppings, hair and body parts, so proofing, baiting and monitoring are food safety controls. Appearance, visitor perception and chemical savings are not the objective. Pest control also protects against product recalls and legal action.

Question 35Food Safety, Hygiene and Sanitation

A food unit finds rodent droppings near a sack of wheat flour. Which response is most appropriate?

  1. Sprinkle insecticide powder around the sack and continue production
  2. Move the sack to another store room and take no further action
  3. Sweep up the droppings and use the flour as normal after sieving
  4. Segregate and condemn affected material, clean and disinfect the area, and investigate entry points and the pest control records Correct answer.

Explanation

Rodent droppings indicate active infestation and can carry Salmonella and other pathogens, so affected material must be condemned and the area cleaned and disinfected. Entry points must be sealed and monitoring records reviewed to find the source. Sieving, insecticide near food or simply relocating the sack does not remove the hazard.

Question 36Food Safety, Hygiene and Sanitation

Which of the following best describes the role of a food handler medical fitness check at recruitment?

  1. It replaces the need for handwashing and protective clothing
  2. It is only needed for workers who handle raw meat
  3. It guarantees the worker will never contaminate food
  4. It identifies workers who may transmit disease through food so they can be excluded or treated before handling food Correct answer.

Explanation

Pre-employment and periodic medical checks help detect conditions such as typhoid carriers, infected skin lesions or gastrointestinal infection that could be transmitted through food. They support, but never replace, hygiene practices. No check can guarantee freedom from contamination, and all food handlers need clearance.

Question 37Food Safety, Hygiene and Sanitation

A worker develops vomiting and diarrhoea during a shift. What should happen under good food hygiene practice?

  1. The worker should continue but wear double gloves
  2. The worker should take an anti-diarrhoeal tablet and finish the shift
  3. The worker should be excluded from food handling and food areas, report to the supervisor, and return only after being symptom-free for the required period Correct answer.
  4. The worker should be moved to packing dry goods because dry food cannot transmit infection

Explanation

Gastrointestinal symptoms may indicate infection with organisms such as Salmonella, norovirus or Shiga-toxin-producing E. coli, which spread easily through food. Exclusion and reporting protect consumers and allow investigation. Gloves, medication or transfer to dry packing do not remove the risk of contamination.

Question 38Food Safety, Hygiene and Sanitation

Why are protective clothing items such as aprons, hairnets and beard snoods required in a food processing hall?

  1. To keep workers warm in cold storage rooms
  2. To identify which department a worker belongs to
  3. To reduce the need for handwashing during the shift
  4. To prevent hair, skin flakes and street clothing from contaminating food and to keep work clothes clean Correct answer.

Explanation

Protective clothing acts as a barrier so hair, skin cells, fibres and dirt from personal clothing do not fall into food. Hairnets and snoods also stop loose hair from becoming a physical hazard. Clothing colour may aid identification but that is not the hygiene purpose, and it never replaces handwashing.

Question 39Food Safety, Hygiene and Sanitation

In a hazard analysis, a step where a significant hazard can be prevented, eliminated or reduced to an acceptable level is called what?

  1. A traceability record
  2. A verification activity
  3. A good hygiene practice
  4. A critical control point Correct answer.

Explanation

A critical control point is a step at which control can be applied and is essential to prevent, eliminate or reduce a food safety hazard to an acceptable level. Good hygiene practices are the foundation but are not, by definition, critical control points. Verification and traceability support the system but do not control the hazard at that step.

Question 40Food Safety, Hygiene and Sanitation

A milk-processing unit sets a pasteurisation step at 72 °C for 15 seconds. Which is the most appropriate critical limit monitoring method?

  1. Testing the final product for colour change
  2. Checking the pasteuriser once a month during maintenance
  3. Asking the operator to taste the milk after treatment
  4. Recording the temperature and holding time continuously with an automatic chart and alarm Correct answer.

Explanation

A critical limit must be monitored in real time so that any deviation is detected immediately, which is why continuous temperature and time recording with alarms is used. Monthly checks, taste and colour are not objective or timely measures of pasteurisation. Monitoring records also provide evidence for verification.

Question 41Food Safety, Hygiene and Sanitation

What does the 'one-step-forward, one-step-back' principle require in a food processing unit?

  1. That every ingredient is tested twice before use
  2. That products are stored one step above the floor and one step away from the wall
  3. That workers take one step forward and one step back while cleaning
  4. That each batch can be traced to the immediate supplier and to the immediate customer Correct answer.

Explanation

Traceability requires that a unit can identify where each batch came from and where it went, so a recall can be limited and effective. Storage clearance from floor and walls is a separate hygiene rule. Worker movement and double testing are not what the principle means.

Question 42Food Safety, Hygiene and Sanitation

Water used in a food processing unit for washing vegetables and for cleaning equipment must meet which standard?

  1. It must be distilled water in all cases
  2. It only needs to be clear and free of visible dirt
  3. It must be potable or of equivalent microbiological quality so it does not introduce contamination Correct answer.
  4. It may be any water as long as detergent is added

Explanation

Water that contacts food or food-contact surfaces must be safe and of potable quality, because contaminated water can introduce pathogens such as E. coli and Vibrio. Clarity is not a microbiological test, detergent does not sterilise water, and distilled water is unnecessary where potable supply is available.

Question 43Food Safety, Hygiene and Sanitation

A drain in a vegetable-washing area is blocked and wastewater is pooling on the floor. Why is this a significant food safety issue?

  1. The water will make the floor slippery only
  2. The blocked drain will increase the electricity bill
  3. Pooled wastewater can spread pathogens and attract pests, and aerosols may contaminate nearby food and surfaces Correct answer.
  4. The floor will look untidy to visitors

Explanation

Standing wastewater harbours bacteria and can splash or aerosolise onto food, equipment and workers' boots, and it attracts flies and rodents. Drainage must therefore be maintained and floors sloped to drain freely. Tidiness, slip risk and energy cost do not capture the contamination risk.

Question 44Food Safety, Hygiene and Sanitation

Which practice is correct for storing cleaning chemicals in a food processing unit?

  1. Decant them into soft-drink bottles so workers do not confuse them with sanitiser
  2. Keep them in unlabelled bottles near the production line for quick access
  3. Store them beside open ingredients so spills can be wiped immediately
  4. Store them in a locked, labelled area away from food, with original labels and safety data sheets available Correct answer.

Explanation

Chemicals must be kept in clearly labelled containers in a separate locked store to prevent accidental contamination of food and to control access. Safety data sheets give first-aid and handling information. Unlabelled or drinks bottles create a serious poisoning risk, and storing chemicals beside ingredients invites contamination.

Question 45Food Preservation Principles and Methods

In food preservation, the term 'water activity' (aw) refers to which property of a food?

  1. The rate at which water evaporates from the food surface during drying
  2. The temperature at which free water in the food begins to freeze
  3. The ratio of free water vapour pressure in the food to that of pure water at the same temperature Correct answer.
  4. The total moisture content measured in grams per 100 g of food

Explanation

Water activity is defined as the vapour pressure of water in the food divided by the vapour pressure of pure water at the same temperature. It measures the fraction of water that is available for microbial growth and chemical reactions, not the total moisture. Most spoilage bacteria are inhibited below aw 0.91, while many moulds tolerate lower values.

Question 46Food Preservation Principles and Methods

Which preservation method works primarily by lowering water activity through the addition of solutes?

  1. Vacuum packing fresh fish
  2. Irradiating spices with gamma rays
  3. Preparing a sweet fruit jam with high sugar concentration Correct answer.
  4. Blanching vegetables in hot water

Explanation

Adding high concentrations of sugar binds free water, lowering water activity so that microbial growth is inhibited; this is the principle behind jams, jellies and murabba. Blanching, vacuum packing and irradiation act through heat, oxygen exclusion and radiation respectively, not through solute-driven aw reduction.

Question 47Food Preservation Principles and Methods

Commercial sterilisation of canned low-acid foods is designed mainly to destroy which organism and its spores?

  1. Clostridium botulinum Correct answer.
  2. Leuconostoc mesenteroides
  3. Lactobacillus plantarum
  4. Saccharomyces cerevisiae

Explanation

Clostridium botulinum forms heat-resistant spores and can produce a deadly neurotoxin in anaerobic low-acid canned foods. Commercial sterilisation targets a 12-log reduction of these spores (the 12D concept). The other organisms listed are acid-tolerant spoilage or fermentation microbes that do not drive the sterilisation schedule for low-acid cans.

Question 48Food Preservation Principles and Methods

Which of the following best describes the purpose of blanching vegetables before freezing?

  1. To add a protective sugar coating to the surface
  2. To sterilise the product so that no microorganisms remain
  3. To inactivate enzymes that cause off-flavours and colour loss during frozen storage Correct answer.
  4. To increase the water activity of the tissue

Explanation

Blanching with hot water or steam denatures enzymes such as peroxidase and polyphenol oxidase that would otherwise cause browning, off-flavours and vitamin loss during frozen storage. It is not a sterilisation step and does not alter water activity or add a coating.

Question 49Food Preservation Principles and Methods

Refrigeration at 4 degrees Celsius slows spoilage mainly because it:

  1. Reduces the metabolic and enzymatic activity of microorganisms and the food itself Correct answer.
  2. Removes oxygen from the food package
  3. Increases the water activity of the food
  4. Kills all pathogenic bacteria present in the food

Explanation

Low temperature slows the growth rate of most microorganisms and the rate of enzymatic and chemical reactions in the food, extending shelf life. Refrigeration is not lethal to most microbes and does not remove oxygen or raise aw.

Question 50Food Preservation Principles and Methods

Drying of foods preserves them because the reduction in moisture:

  1. Raises the pH of the food to alkaline levels
  2. Adds antimicrobial chemicals to the food
  3. Increases the availability of free water for microbial growth
  4. Lowers water activity below the level needed by most spoilage microorganisms Correct answer.

Explanation

Removing water lowers water activity, so most bacteria, yeasts and moulds can no longer grow or multiply. Drying does not raise pH or add antimicrobial agents; it simply deprives microbes of available water.