I85PREP
⌘ K
HKDSE TL study materials
HKDSE TL study resources

HKDSE TL practice questions

One question at a time. Build your HKDSE TL understanding.

First 50 of 190 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Relevant subject foundations and applied reasoning

In the design process for a Technology and Living product, what is the main purpose of a design brief?

  1. To list every manufacturing machine that will be used
  2. To outline the design problem, client needs, and constraints that guide the project Correct answer.
  3. To provide the final evaluation report after the product is finished
  4. To replace the need for research and testing

Explanation

A design brief defines the problem to be solved, the intended users or client, and key constraints (time, cost, materials, safety). It steers research, idea generation, and development so later decisions stay focused on real needs.

Question 2Relevant subject foundations and applied reasoning

Which statement best describes design specifications in a Technology and Living project?

  1. Vague wishes that cannot be checked
  2. Measurable criteria the final product should meet so success can be judged Correct answer.
  3. Only aesthetic sketches with no functional targets
  4. A list of competitors' brand names

Explanation

Design specifications translate needs into clear, preferably measurable criteria (e.g. size, cost limit, wash temperature, nutritional target). They support objective evaluation against the brief.

Question 3Relevant subject foundations and applied reasoning

When identifying user needs for a kitchen gadget for elderly people with reduced grip strength, which research method is most appropriate first?

  1. Ignoring users and designing only from the designer's preference
  2. Interviewing or observing target users and reviewing similar products Correct answer.
  3. Selecting the most expensive materials without analysis
  4. Writing the final evaluation before any prototype exists

Explanation

User-centred design starts with learning from intended users-through interviews, observation, questionnaires, or product analysis-so needs such as grip, weight, and safety are real rather than assumed.

Question 4Relevant subject foundations and applied reasoning

Which activity belongs mainly to the idea generation stage of the design process?

  1. Mass production of the final product
  2. Brainstorming and sketching a range of possible solutions Correct answer.
  3. Calculating only the finished product's retail price
  4. Destroying all prototypes without recording results

Explanation

Idea generation (ideation) explores many possible solutions through techniques such as brainstorming, mind mapping, and thumbnail sketches before one concept is developed in detail.

Question 5Relevant subject foundations and applied reasoning

Why is iterative testing of prototypes important in design development?

  1. It guarantees zero manufacturing cost
  2. It reveals problems early so the design can be refined before final production Correct answer.
  3. It removes the need for any design specifications
  4. It is only used after products are already sold to consumers

Explanation

Prototypes allow functional, safety, and user-fit testing. Feedback drives modifications, reducing the risk of releasing a flawed final product and supporting continuous improvement.

Question 6Relevant subject foundations and applied reasoning

A student designs a school lunchbox that must stay cool for 4 hours, cost under HK$80 materials, and fit in a standard locker. These statements are best classified as:

  1. Marketing slogans only
  2. Design specifications derived from the brief and constraints Correct answer.
  3. Irrelevant details for evaluation
  4. Fashion trend forecasts

Explanation

Time, cost, and size targets are concrete specifications. They convert the design problem into checkable criteria used in development and evaluation.

Question 7Relevant subject foundations and applied reasoning

Which evaluation approach best checks whether a finished garment meets its design specifications?

  1. Comparing the product only to the designer's favourite colour
  2. Testing fit, function, construction quality, and care performance against the written criteria Correct answer.
  3. Counting how many people liked the social media post
  4. Ignoring user feedback after the first sample

Explanation

Valid evaluation systematically compares the outcome to specifications-fit, durability, safety, cost, aesthetics, and care-using tests and user feedback, then suggests improvements.

Question 8Relevant subject foundations and applied reasoning

How can technology support safer living in a modern home kitchen?

  1. By removing all need for food hygiene practices
  2. Through tools such as refrigerator temperature control, induction hobs with auto cut-off, and digital timers that reduce undercooking or fire risk Correct answer.
  3. By guaranteeing that any food stored indefinitely is safe
  4. Only by replacing all human cooking with robots

Explanation

Appropriate kitchen technology helps maintain cold-chain temperatures, control heat, and manage cooking time-reducing food safety and fire hazards-while good hygiene practices remain essential.

Question 9Relevant subject foundations and applied reasoning

In problem-solving for a clothing product that frays at seams, which step should come first?

  1. Mass-order new fabric without investigation
  2. Identify and analyse the cause (e.g. fabric type, stitch type, seam finish) before selecting a solution Correct answer.
  3. Blame the consumer and stop the project
  4. Change only the brand logo

Explanation

Effective problem-solving defines the problem and investigates root causes-construction method, fibre content, seam finish-then generates and tests solutions. Jumping to action without analysis wastes resources.

Question 10Relevant subject foundations and applied reasoning

Which practice best reflects sustainability in product design for Technology and Living?

  1. Designing for single use with non-recyclable mixed materials whenever convenient
  2. Selecting durable materials, enabling repair/reuse, reducing waste, and considering product life cycle impacts Correct answer.
  3. Using more packaging than needed to make the product look larger
  4. Ignoring energy use in production and care

Explanation

Sustainable design considers life-cycle impacts: material choice, longevity, repairability, efficient production, reduced waste, and responsible end-of-life. It aims to meet needs with less environmental harm.

Question 11Relevant subject foundations and applied reasoning

A design folio shows mood boards, fabric samples, toile fittings, and a final evaluation against specifications. What is the main purpose of this documentation?

  1. To hide failed experiments from assessors
  2. To communicate design thinking, justify decisions, and evidence development and evaluation Correct answer.
  3. To replace the need for any practical product
  4. To list only prices of luxury brands

Explanation

In HKDSE Technology and Living, the design folio/project records research, ideas, development, making, and evaluation. It shows how decisions link to the brief and specifications.

Question 12Relevant subject foundations and applied reasoning

Which statement about anthropometrics and ergonomics in product design is correct?

  1. Anthropometrics ignore human body measurements
  2. Ergonomics applies human body data and user capabilities so products are comfortable, safe, and efficient to use Correct answer.
  3. Ergonomics only concerns decorative patterns on fabric
  4. Human measurements are irrelevant for kitchen tools and clothing

Explanation

Anthropometrics supply body measurement data; ergonomics uses that data and human factors so tools, workspaces, and garments fit users, reduce strain, and improve safety and usability.

Question 13Relevant subject foundations and applied reasoning

When comparing two prototype food packaging designs for a chilled dessert, which evaluation criterion is MOST critical for food safety?

  1. Whether the logo uses three colours
  2. Ability to maintain cold-chain integrity, limit contamination, and provide clear storage/use-by information Correct answer.
  3. Whether the package is the tallest on the shelf
  4. How closely the colour matches last season's fashion trend

Explanation

Food packaging must protect product safety: barrier properties, seal integrity, temperature suitability, and clear labelling for storage and shelf life. Visual branding is secondary to safety performance.

Question 14Relevant subject foundations and applied reasoning

A student must choose between a natural fibre fabric and a recycled polyester for a school sports top. Which design analysis is most balanced?

  1. Choose cotton automatically because all natural fibres are always best in every performance category
  2. Compare moisture management, durability, care energy, cost, user comfort, and environmental life-cycle impacts against the brief Correct answer.
  3. Ignore performance and select only the cheapest option
  4. Select recycled polyester solely because it is synthetic

Explanation

Material selection should be multi-criteria: performance for the end use (sweat management, stretch, durability), user comfort, care requirements, cost, and sustainability trade-offs relative to specifications.

Question 15Relevant subject foundations and applied reasoning

Which sequence correctly represents a typical design process cycle used in Technology and Living?

  1. Evaluate → Manufacture mass stock → Ignore user needs → Design brief
  2. Identify needs/brief → Research → Generate ideas → Develop/prototype → Make → Evaluate/improve Correct answer.
  3. Make final product → Write brief → Research
  4. Only sketch once and never revise

Explanation

A standard school design cycle moves from problem identification and research through ideation, development and prototyping, making, then evaluation and modification. Iteration is expected.

Question 16Relevant subject foundations and applied reasoning

Smart home sensors that monitor fridge temperature and send alerts mainly support which design goal for living technology?

  1. Increasing food waste deliberately
  2. Improving food safety and reducing spoilage through better cold-chain monitoring Correct answer.
  3. Eliminating all need for cleaning
  4. Replacing nutritional knowledge entirely

Explanation

Temperature monitoring helps keep refrigerated food within safe ranges, limiting bacterial growth and spoilage. It is a technology application that supports safer, more efficient household living.

Question 17Relevant subject foundations and applied reasoning

Inclusive design for a family living product means the designer should primarily:

  1. Design only for a single ideal average user and ignore diversity
  2. Consider a wide range of users (age, ability, culture) so more people can use the product safely and effectively Correct answer.
  3. Make products deliberately difficult for elderly users
  4. Exclude children from any consideration in family products

Explanation

Inclusive design anticipates diverse body sizes, abilities, languages, and contexts so products serve more users with fewer barriers-important for family and community living contexts.

Question 18Relevant subject foundations and applied reasoning

A garment design meets all aesthetic goals but fails a 30-wash durability specification and shrinks 12% after one hot wash. The best next design action is to:

  1. Market it as a premium product without changes
  2. Revise fibre/fabric choice, construction, and care labelling, then retest against the durability and dimensional stability criteria Correct answer.
  3. Delete the durability specification from the folio
  4. Increase only the selling price to cover returns

Explanation

When a product fails measurable specifications, designers diagnose causes (fibre, construction, finishing, care instructions), modify the design, and retest. Hiding failures or only raising price does not solve the problem.

Question 19Relevant subject foundations and applied reasoning

Which group correctly lists the three macronutrients that provide energy in the diet?

  1. Vitamins, minerals, and water
  2. Carbohydrates, proteins, and fats Correct answer.
  3. Fibre, sodium, and cholesterol only
  4. Iron, calcium, and vitamin C

Explanation

Carbohydrates, proteins, and fats (lipids) are the energy-yielding macronutrients. Vitamins and minerals are micronutrients; water is essential but not an energy source.

Question 20Relevant subject foundations and applied reasoning

What is a primary physiological function of dietary protein?

  1. Sole source of dietary fibre
  2. Growth, repair, and maintenance of body tissues; also provides energy when needed Correct answer.
  3. Carrying oxygen as haemoglobin without amino acids
  4. Preventing all infections without immune cells

Explanation

Proteins supply amino acids for building and repairing tissues, enzymes, and some hormones. They can also contribute energy (about 4 kcal/g) if required, but their distinctive role is structural and functional tissue maintenance.

Question 21Relevant subject foundations and applied reasoning

Which food is the richest common source of high-quality complete protein among the options?

  1. White sugar
  2. Egg Correct answer.
  3. Vegetable oil
  4. Plain black tea

Explanation

Eggs provide high-quality complete protein with a good essential amino acid profile. Sugar and oil are mainly carbohydrate and fat; plain tea contributes negligible protein.

Question 22Relevant subject foundations and applied reasoning

Iron deficiency is most closely associated with which health problem?

  1. Scurvy
  2. Iron-deficiency anaemia with fatigue and reduced oxygen transport Correct answer.
  3. Night blindness only from vitamin A excess
  4. Goitre from excess iodine

Explanation

Insufficient iron impairs haemoglobin synthesis, reducing oxygen delivery and causing iron-deficiency anaemia with tiredness and reduced work capacity. Scurvy is vitamin C deficiency; goitre relates to iodine.

Question 23Relevant subject foundations and applied reasoning

Using the Atwater factors commonly taught at secondary level, how much energy is provided by 10 g of pure carbohydrate?

  1. 10 kcal
  2. 40 kcal Correct answer.
  3. 70 kcal
  4. 90 kcal

Explanation

Carbohydrate yields about 4 kcal per gram. Therefore 10 g × 4 kcal/g = 40 kcal. Fat is about 9 kcal/g and protein about 4 kcal/g in the same simplified model.

Question 24Relevant subject foundations and applied reasoning

A snack contains 5 g protein, 10 g carbohydrate, and 8 g fat. Using 4, 4, and 9 kcal/g respectively, what is the approximate total energy?

  1. 92 kcal
  2. 132 kcal Correct answer.
  3. 172 kcal
  4. 212 kcal

Explanation

Energy = (5 × 4) + (10 × 4) + (8 × 9) = 20 + 40 + 72 = 132 kcal. This is a standard secondary-level nutrition calculation using Atwater factors.

Question 25Relevant subject foundations and applied reasoning

What is the main role of dietary fibre in a balanced diet?

  1. It is fully digested to provide 9 kcal/g like fat
  2. It aids digestive health, promotes satiety, and helps regulate bowel function Correct answer.
  3. It is identical to pure sucrose
  4. It is the primary source of vitamin B12 in vegan diets

Explanation

Dietary fibre (mostly non-digestible plant carbohydrate) supports bowel regularity, contributes to satiety, and is associated with better long-term health when intakes are adequate from whole grains, fruits, vegetables, and legumes.

Question 26Relevant subject foundations and applied reasoning

Which statement best describes energy balance?

  1. Body weight is unrelated to energy intake and expenditure
  2. When long-term energy intake exceeds expenditure, excess energy is stored and body weight tends to increase Correct answer.
  3. Only protein intake affects energy balance
  4. Energy balance means eating only one food group

Explanation

Energy balance compares dietary energy intake with expenditure (basal metabolism, physical activity, thermic effect of food). Sustained surplus leads to weight gain; sustained deficit to weight loss.

Question 27Relevant subject foundations and applied reasoning

Compared with adults, adolescents typically need relatively more of which nutrient priority for growth?

  1. Only pure sugar for rapid growth
  2. Adequate energy, protein, calcium, and iron to support growth spurts and increased needs Correct answer.
  3. Zero fat in the diet
  4. No additional nutrients beyond toddler requirements

Explanation

Adolescence involves rapid growth and often higher needs for energy, protein, calcium (bone), and iron (especially for menstruating girls). Balanced meals-not sugar-only or zero-fat diets-support healthy development.

Question 28Relevant subject foundations and applied reasoning

Which nutritional concern is especially important during pregnancy?

  1. Avoiding all protein foods
  2. Adequate folate/folic acid, iron, and overall balanced energy and nutrients to support maternal and fetal health Correct answer.
  3. Consuming only soft drinks for hydration
  4. Eliminating all calcium-containing foods

Explanation

Pregnancy increases needs for several nutrients. Folate helps reduce neural tube defect risk; iron supports expanded blood volume; balanced diet supports fetal growth. Extreme restrictions are inappropriate without medical advice.

Question 29Relevant subject foundations and applied reasoning

For many older adults, which dietary adjustment is often appropriate?

  1. Ignoring protein because muscle loss is inevitable and diet-proof
  2. Nutrient-dense foods with adequate protein, calcium, vitamin D, and fibre, adjusted for lower energy needs and chewing/appetite changes Correct answer.
  3. Only high-sugar snacks to maximise calories
  4. Complete avoidance of fluids

Explanation

Older adults often need fewer calories but still require high nutrient density. Protein helps limit sarcopenia; calcium and vitamin D support bone health; fibre and fluids aid bowel function. Texture may need adaptation.

Question 30Relevant subject foundations and applied reasoning

What happens during gelatinisation of starch in cooking?

  1. Starch granules absorb water, swell, and thicken the mixture when heated Correct answer.
  2. Proteins form a permanent ice crystal network
  3. Fat molecules turn into pure protein
  4. Vitamin C is synthesised from oil

Explanation

When starch is heated in water, granules absorb water, swell, and eventually disrupt, releasing amylose and thickening sauces, custards, and gravies-this is gelatinisation.

Question 31Relevant subject foundations and applied reasoning

Protein denaturation during cooking is best described as:

  1. A change in protein structure that can alter texture and solubility, as when egg white coagulates on heating Correct answer.
  2. Conversion of protein entirely into sugar
  3. Removal of all amino acids from food
  4. Freezing food without any structural change

Explanation

Denaturation unfolds protein molecules (heat, acid, mechanical action). In cooking, this can lead to coagulation (e.g. eggs, meat), changing texture and water-holding properties.

Question 32Relevant subject foundations and applied reasoning

Mayonnaise stays as a stable semi-solid because of which food chemistry principle?

  1. Complete separation of oil and water with no emulsifier
  2. Emulsification, in which egg yolk lecithin helps disperse oil droplets in water Correct answer.
  3. Only gelatinisation of starch from flour
  4. Caramelisation of sucrose alone

Explanation

Mayonnaise is an oil-in-water emulsion stabilised by emulsifiers in egg yolk (notably lecithin), which reduce interfacial tension and keep oil droplets dispersed.

Question 33Relevant subject foundations and applied reasoning

The brown colour and flavour on the surface of baked bread or seared meat is mainly due to:

  1. Maillard reaction between reducing sugars and amino acids at high heat Correct answer.
  2. Freezing of surface water only
  3. Addition of pure vitamin C crystals
  4. Complete removal of all proteins

Explanation

The Maillard reaction is a non-enzymatic browning reaction between reducing sugars and amino compounds under dry heat, producing brown pigments and complex flavours in baked and roasted foods.

Question 34Relevant subject foundations and applied reasoning

Vitamin C (ascorbic acid) is especially important because it:

  1. Provides 9 kcal per gram like fat
  2. Acts as an antioxidant and is needed for collagen formation; deficiency causes scurvy Correct answer.
  3. Is stored in unlimited amounts in body fat for decades
  4. Is only found in animal muscle foods

Explanation

Vitamin C supports collagen synthesis and antioxidant defence. Prolonged deficiency causes scurvy. It is water-soluble, not an energy nutrient, and is abundant in many fruits and vegetables.

Question 35Relevant subject foundations and applied reasoning

Which description best matches a balanced diet concept taught via food guide models (pyramid/plate)?

  1. Eating only one food type each day
  2. Consuming a variety of foods in appropriate proportions, emphasising grains/vegetables/fruits with moderated fats, sugars, and salt Correct answer.
  3. Eliminating all carbohydrates permanently
  4. Relying solely on dietary supplements without food

Explanation

Food guides promote variety and proportion-plenty of plant foods and whole grains, adequate protein foods and dairy/alternatives, and limited free sugars, saturated fat, and salt-for overall nutrient adequacy.

Question 36Relevant subject foundations and applied reasoning

Calcium is most closely associated with which body function?

  1. Formation and maintenance of bones and teeth, plus roles in muscle and nerve function Correct answer.
  2. Carrying oxygen in red blood cells as the main component of haemoglobin iron centres
  3. Producing melanin only
  4. Acting as the only source of dietary energy

Explanation

About 99% of body calcium is in bones and teeth. Calcium also supports muscle contraction and nerve signalling. Iron, not calcium, is central to haemoglobin oxygen transport.

Question 37Relevant subject foundations and applied reasoning

A recipe for 4 people uses 200 g flour. How much flour is needed for 10 people if scaled proportionally?

  1. 200 g
  2. 400 g
  3. 500 g Correct answer.
  4. 800 g

Explanation

Scale factor = 10/4 = 2.5. Flour needed = 200 g × 2.5 = 500 g. Proportional recipe scaling multiplies each ingredient by the same factor.

Question 38Relevant subject foundations and applied reasoning

If fat provides 54 kcal in a snack and fat is counted as 9 kcal/g, how many grams of fat are present?

  1. 3 g
  2. 6 g Correct answer.
  3. 9 g
  4. 12 g

Explanation

Mass of fat = energy from fat ÷ 9 kcal/g = 54 ÷ 9 = 6 g.

Question 39Relevant subject foundations and applied reasoning

Which pair correctly matches a nutrient with a good common food source?

  1. Vitamin A precursor (beta-carotene) - orange vegetables such as carrot Correct answer.
  2. Vitamin C - pure vegetable oil
  3. Calcium - white sugar
  4. Iron - soft drinks

Explanation

Deep orange vegetables like carrots are rich in beta-carotene, which the body can convert to vitamin A. Oils, sugar, and soft drinks are poor sources of the other listed micronutrients.

Question 40Relevant subject foundations and applied reasoning

Unsaturated fats are generally recommended in preference to excess saturated fat because they:

  1. Are chemically identical to pure sugar
  2. Are associated with more favourable blood lipid profiles when they replace excess saturated fat within a balanced diet Correct answer.
  3. Provide no energy at all
  4. Must be completely avoided in all healthy diets

Explanation

Dietary guidance typically encourages replacing excess saturated fat with unsaturated fats (e.g. from nuts, seeds, vegetable oils, oily fish) as part of heart-healthy eating patterns. All fats still provide energy.

Question 41Relevant subject foundations and applied reasoning

A lunch provides 600 kcal. Protein contributes 15% of energy. How many grams of protein is that (using 4 kcal/g)?

  1. 15 g
  2. 22.5 g Correct answer.
  3. 30 g
  4. 45 g

Explanation

Energy from protein = 0.15 × 600 = 90 kcal. Protein mass = 90 ÷ 4 = 22.5 g.

Question 42Relevant subject foundations and applied reasoning

Why might prolonged boiling of green vegetables in large volumes of water reduce their vitamin C content more than brief steaming?

  1. Vitamin C is heat-sensitive and water-soluble, so heat plus leaching into cooking water increase losses Correct answer.
  2. Vitamin C is a fat that evaporates only in steam
  3. Steaming always destroys 100% of vitamin C while boiling preserves it
  4. Vitamin C is created by boiling water

Explanation

Ascorbic acid is water-soluble and heat-labile. Boiling can leach vitamin C into discarded water and expose it longer to heat; steaming or short cooking with less water better retains it.

Question 43Relevant subject foundations and applied reasoning

In food hygiene teaching, the temperature 'danger zone' in which many pathogenic bacteria grow rapidly is commonly described as approximately:

  1. Below −18°C only
  2. About 4°C to 60°C Correct answer.
  3. Above 100°C only
  4. Exactly 0°C only

Explanation

Secondary-level food safety commonly teaches a danger zone of roughly 4–60°C (sometimes stated as 5–63°C), where mesophilic pathogens multiply quickly. Keep cold foods cold and hot foods hot.

Question 44Relevant subject foundations and applied reasoning

Which is an example of cross-contamination in a kitchen?

  1. Washing hands before food preparation
  2. Using the same unwashed cutting board for raw chicken and then for salad vegetables Correct answer.
  3. Cooking poultry to a safe internal temperature
  4. Storing raw meat on the bottom shelf of the fridge in a sealed container

Explanation

Cross-contamination transfers harmful microbes from one food or surface to another. Raw poultry juices on a board can contaminate ready-to-eat salad if boards and knives are not cleaned and separated.

Question 45Relevant subject foundations and applied reasoning

Salmonella contamination of food is classified primarily as which type of hazard?

  1. Physical hazard (e.g. glass)
  2. Biological hazard Correct answer.
  3. Chemical hazard from pesticide only
  4. Radiological hazard

Explanation

Pathogenic bacteria such as Salmonella are biological hazards. Physical hazards include glass or metal; chemical hazards include cleaning agents or pesticide residues.

Question 46Relevant subject foundations and applied reasoning

Which preservation method mainly works by lowering temperature to slow microbial growth and enzyme activity?

  1. Deep frying only
  2. Chilling/refrigeration Correct answer.
  3. Adding large amounts of air at room temperature
  4. Leaving food in the danger zone

Explanation

Refrigeration (typically about 0–4°C for chilled storage) slows bacterial growth and enzymatic spoilage. It does not sterilise food, so hygiene and time limits still matter.

Question 47Relevant subject foundations and applied reasoning

Freezing food preserves quality and safety mainly by:

  1. Killing all bacteria instantly in every food at −1°C
  2. Converting free water to ice, lowering water activity available for microbial growth and greatly slowing reactions Correct answer.
  3. Increasing water activity to promote fermentation
  4. Raising pH above 14

Explanation

Freezing immobilises water as ice, limiting microbial growth and slowing chemical/enzymatic changes. Many microbes survive freezing and can grow again on thawing if mishandled.

Question 48Relevant subject foundations and applied reasoning

Commercial canning preserves low-acid foods primarily by:

  1. Leaving them raw at room temperature in open jars
  2. Heat sterilisation in sealed containers to destroy spoilage organisms and pathogens (including spores under correct processes) Correct answer.
  3. Only adding raw egg as a preservative
  4. Short microwave heating without sealing

Explanation

Canning seals food and applies controlled heat to destroy microbes that cause spoilage and foodborne illness. Low-acid foods require validated thermal processes because of spore-forming pathogens such as Clostridium botulinum.

Question 49Relevant subject foundations and applied reasoning

Dehydration preserves foods mainly because:

  1. Water activity is reduced so microbes cannot grow easily Correct answer.
  2. Moisture content is increased to 90%
  3. Foods are kept permanently in the danger zone
  4. Salt is always removed completely

Explanation

Drying removes water, lowering water activity (aw). Most bacteria need available water to multiply. Proper packaging then prevents moisture regain.

Question 50Relevant subject foundations and applied reasoning

Fermentation can preserve foods such as yoghurt and kimchi mainly by:

  1. Raising pH to strongly alkaline levels that kill all spores instantly
  2. Beneficial microbes producing acids (and sometimes other antimicrobials) that inhibit pathogens and spoilage organisms Correct answer.
  3. Removing all microorganisms including starter cultures
  4. Storing at 50°C continuously

Explanation

Lactic acid bacteria and other fermentative microbes convert sugars to organic acids, lowering pH and creating conditions less favourable for many pathogens, while developing characteristic flavours and textures.