Food Science Quiz 20
What this quiz covers
Cheese exists because of an enzyme from a calf’s stomach. Bread rises because a single-celled fungus exhales. And a cup of coffee carries roughly 95 milligrams of the world’s most popular psychoactive drug. Food Science Quiz 20 is built from these concrete, checkable facts — the enzymes, temperatures, organisms, and molecules that working food scientists carry in their heads. It is less about theory and more about the working knowledge that separates someone who studied food from someone who works in it.
Twenty questions spanning dairy, bakery, beverages, and food chemistry. Dairy: rennin in cheesemaking, the 10% fat line for economy ice cream, lysozyme as milk’s built-in antimicrobial, and why colostrum runs low on lactose. Bakery and cereals: yeast’s double duty on flavour and volume, waxy wheat’s missing amylose, ropiness from Bacillus, and the maturing agent the industry abandoned. Physical chemistry you can measure: the triple point of water, HTST conditions, what aspartame is actually made of, and non-enzymatic browning behind caramel flavour in heated milk. Plus fermentation gone sideways — scum on pickles — and the industrial end: single-cell protein from starch waste.
Facts worth carrying
Several answers here are the kind professionals quote from memory. HTST pasteurization: 72 °C for 15 seconds — the time-temperature pair behind most of the world’s milk supply. Water’s triple point: 0.01 °C at 4.58 mm Hg, where ice, liquid, and vapour coexist. Aspartame: aspartic acid plus phenylalanine, which is exactly why products carrying it warn phenylketonurics. One cup of coffee: about 95 mg of caffeine. These are not trivia; they are the constants of the trade, the numbers that come up in audits, formulations, and interviews without warning.
How to use this quiz
You get 20 seconds per question and one attempt at each answer. Treat the numbers as flashcards — triple point, HTST, caffeine, ICMR’s 8-to-1 beta-carotene conversion — and drill them until they are instant. For the organism questions (ropiness, scum, ropiness again), picture the spoilage: ropy bread stretches into strings, pickle scum is a mould mat on brine. Miss one, learn the organism’s signature, and move on.
Answer explanations
Worked through the quiz? Here is why each correct answer is correct — the concept behind it, in plain terms.
- Which of the following is a proteolytic enzyme
Correct answer: all — Ficin from figs, papain from papaya, and actinidin from kiwifruit are all cysteine proteases — plant enzymes that cleave proteins, which is why they tenderize meat and clarify beverages. - Enzyme used in cheese manufacturing is
Correct answer: Rennin — Rennin (chymosin) clips kappa-casein on the micelle surface, collapsing the micelles’ stability so milk sets into curd — the enzymatic step every rennet cheese depends on. - Fat content in economy ice cream is
Correct answer: 10% — Economy ice cream is formulated at about 10% milk fat — the regulatory and cost line that separates it from premium grades carrying 14–16% or more. - Beta glucan, a soluble fiber is present in
Correct answer: Oats — Oats are the signature source of beta-glucan, the soluble fibre that forms viscous gels in the gut, blunts cholesterol absorption, and earned oats their heart-health claim. - Yeast in bread making is responsible for
Correct answer: both — Yeast ferments sugars to CO₂ that leavens the loaf and simultaneously generates the alcohols, acids, and esters behind bread’s flavour — volume and taste from the same organism. - The triple point of water is
Correct answer: 0.01°C and 4.58mm Hg — At 0.01 °C and 4.58 mm Hg, ice, liquid water, and vapour coexist in equilibrium — the triple point, a fundamental fixed point of thermometry and the reference behind freeze-drying’s operating window. - LTLT process for pasteurization of milk is at 63°C for 30 mins, HTST process
Correct answer: 72°C/15 sec — HTST — high temperature, short time — runs milk at 72 °C for just 15 seconds, delivering the same pathogen kill as 30 minutes at 63 °C with far less cooked flavour. - Aspartame, an artificial sweetener is made of
Correct answer: Aspartic acid & phenylalanine — Aspartame is a dipeptide of aspartic acid and phenylalanine — which is precisely why its labels warn people with phenylketonuria, who cannot metabolize phenylalanine. - Waxy wheat has a low content of
Correct answer: Amylose — Waxy wheats are amylose-deficient, nearly all amylopectin — which is why their starch pastes stay clear and stable instead of gelling firmly on cooling. - Ropiness in bread is due to
Correct answer: Bacillus mesentaricus — Bacillus mesentericus (now reclassified within the Bacillus subtilis group) survives baking as spores, then grows in the moist crumb producing slimy, rope-like strands — the classic rope spoilage of bread. - Antimicrobial component of milk is
Correct answer: lysozyme — Lysozyme in milk attacks bacterial cell walls by cleaving peptidoglycan — part of milk’s innate antimicrobial system alongside lactoferrin and the lactoperoxidase system. - One cup of coffee has a caffeine content of
Correct answer: 95 mg — A standard brewed cup carries roughly 95 mg of caffeine — the reference figure behind dietary guidance that caps most adults around 400 mg per day. - Caramelized flavor in milk is due to
Correct answer: Non-enzymatic browning — Heated milk browns through the Maillard reaction and caramelization — non-enzymatic chemistry between lactose and proteins — producing the cooked, caramel notes of sterilized and evaporated milks. - The scum formation in pickles is due to the growth of
Correct answer: Molds — A surface scum on pickle brine is typically oxidative moulds or film yeasts growing where air meets the liquid — a sign the vegetables were exposed above the brine. - Which of the following maturing agent is no longer used in wheat flour maturation
Correct answer: Potassium bromate — Potassium bromate, once a standard flour oxidizer for dough strength, was abandoned over its carcinogenicity — classified as a possible human carcinogen and banned in food use across many countries. - Flavor reversion in food is due to
Correct answer: Linolenic acid — Linolenic acid’s three double bonds oxidize into the grassy, fishy off-notes called flavour reversion in soybean and other linolenate-rich oils — the industry’s long war against it drove low-linolenic breeding. - The flavor of wine is not be affected by
Correct answer: none — Ageing, maturation, and container type all shape wine flavour — oak adds tannin and vanilla, time softens and integrates — so ‘none’ is correct: there is no listed factor that leaves flavour untouched. - Colostrum has lower content of ______ than normal bovine milk
Correct answer: Lactose — Colostrum is built for immunity, not energy: it runs rich in protein and antibodies but lower in lactose than mature milk, since the newborn gut is not yet ready for a full lactose load. - According to ICMR, 1 mcg of retinol is equivalent to
Correct answer: 8 mcg of beta carotene — ICMR sets the conversion at 8 mcg of dietary beta-carotene per 1 mcg of retinol — plant carotenoids convert inefficiently, so you need far more of them to match preformed vitamin A. - Symba process utilizes ____________ wastes in SCP production
Correct answer: Starch — The Symba process ferments starch-rich wastes — such as potato processing effluent — into single-cell protein, turning a disposal problem into feed.