What this quiz covers
A single molecule — isoamyl acetate — is why a candy tastes like banana though no banana came near the factory. A twelve-log reduction in Clostridium botulinum spores is why canned vegetables don’t kill people. And a nitroso compound forming quietly in cured meat is why regulators cap nitrite. Food Science Quiz 21 moves between the physics, the chemistry, and the microbiology of food, and its best questions are the ones where all three collide in a single product.
Twenty questions across the physical and chemical core. Physics in the plant: Stokes’ law for settling velocity, which starch gelatinizes coolest, and why water hogs microwave energy. Chemistry of flavour and spoilage: rancidity’s definition, the banana note of isoamyl acetate, methionine as the limiting amino acid in legumes, and the carcinogenic nitroso compounds of cured meats. Microbiology and fermentation: lactic acid bacteria in yoghurt, pickles, and sauerkraut; Acetobacter turning alcohol to vinegar; yeast’s mostly harmless reputation; and the 12D concept that anchors thermal processing against botulinum. It closes with the big picture — Codex Alimentarius, the food code the world trades by.
From molecules to regulations
Watch the scale shift as you work through these questions. At the bottom sit molecules: isoamyl acetate, nitroso compounds, methionine — small structures with outsized effects on flavour, safety, and nutrition. One level up are the organisms doing chemistry for us: Lactobacillus souring pickles, Acetobacter oxidizing ethanol to acetic acid, beta-amylase saccharifying starch into maltose. And at the top sits the regulatory frame — Codex, the 12D standard — translating all that science into rules plants must follow. The quiz rewards people who can travel that ladder in both directions.
How to use this quiz
You get 20 seconds per question and one attempt at each answer. When a fermentation question appears, name the organism and its product before looking at the options — Lactobacillus makes lactic acid, Acetobacter makes acetic acid, yeast makes ethanol and CO₂. When a chemistry question appears, picture the functional group. And give the Codex question the respect it deserves: if you work in food anywhere on earth, that answer should be instant.
Answer explanations
Worked through the quiz? Here is why each correct answer is correct — the concept behind it, in plain terms.
- Stoke’s law is used to find out
Correct answer: Terminal velocity — Stokes’ law balances drag against gravity for a small sphere falling through a viscous fluid, giving its terminal settling velocity — the calculation behind sedimentation, clarification, and particle-size analysis. - Carcinogenic compound formed in cured meat is
Correct answer: Nitroso compound — Nitrite in cured meats can react with secondary amines to form nitrosamines, which are carcinogenic — the reason nitrite levels are regulated and ascorbate is added to block the reaction. - Which container should not be used for wine maturation
Correct answer: New oak — New oak barrels flood a maturing wine with tannins, vanillin, and toast character that can overwhelm it; maturation favours neutral vessels like seasoned or older oak that let the wine evolve without being dominated by wood. - Which of the following is not a universal taste
Correct answer: None — Salt, sweet, and sour are all universally recognized basic tastes (alongside bitter and umami), so ‘none’ is correct — every item listed is a genuine universal taste. - The deterioration of fat due to oxidation and hydrolysis is called
Correct answer: Rancidity — Rancidity is the umbrella term for fat spoilage: oxidative rancidity from radical attack on double bonds, and hydrolytic rancidity from lipases freeing short-chain fatty acids with soapy, goaty notes. - Which of the following has a higher protein content among the following
Correct answer: Oats — Oats carry roughly 13% protein, ahead of sorghum, pearl millet, and maize — plus the soluble fibre beta-glucan that made oats a health-food staple. - Milk gets coagulated upon
Correct answer: all — Acid (lowered pH), heat, and enzymatic action all coagulate milk: each destabilizes the casein micelle — by neutralizing its charge, denaturing whey proteins onto it, or clipping its stabilizing hairs — until the micelles aggregate. - Which of the following is regarded as saccharifying enzyme
Correct answer: beta amylase — Beta-amylase is the saccharifying enzyme: it clips maltose units from the non-reducing ends of starch chains, which is how brewing and baking get their fermentable sugars. - Which one is similar to functional foods
Correct answer: both (a) & (b) — Nutraceuticals and therapeutic foods both overlap functional foods — all three describe foods positioned for a health benefit beyond basic nutrition, differing mainly in regulatory framing and marketing. - Which of the following is an example of natural emulsifier
Correct answer: Lecithin — Lecithin — phospholipids from egg yolk or soy — is the classic natural emulsifier, with a water-loving head and fat-loving tails that stabilize oil-in-water emulsions like mayonnaise. - Which of the following is a Lab fermented product
Correct answer: all — Yoghurt, kefir, and sauerkraut are all lactic acid bacteria fermentations: different genera and substrates, same metabolic signature — lactose or sugars converted to lactic acid. - Maximum microwaves absorbed by
Correct answer: Water — Water’s polar molecules rotate to follow the oscillating microwave field, converting that motion to heat — which is why high-moisture foods heat fastest and salt or sugar solutions absorb less per unit volume. - Pickles commonly contains
Correct answer: all — Lactobacillus, Leuconostoc, and Pediococcus all participate in vegetable fermentations like pickles, succeeding each other as acidity rises and each contributing flavour notes along the way. - Which of the following is mostly nonpathogenic
Correct answer: yeast — Yeasts are overwhelmingly nonpathogenic — humanity’s fermentation partners for millennia — while bacteria, moulds, and viruses each include major foodborne and clinical pathogens. - Concept used for killing of most resistant spores of Clostridium botulinum in vegetables
Correct answer: 12D — The 12D concept demands a process delivering twelve decimal reductions of C. botulinum spores — the ‘botulinum cook’ — reducing the survival probability to one spore in a trillion containers. - Compound having flavour similar to banana
Correct answer: Isoamyl acetate — Isoamyl acetate is the signature volatile of banana aroma; the flavour industry synthesizes it pure, which is why banana candy tastes like banana without containing any. - Essential amino acid present in low amount in legumes
Correct answer: methionine — Legumes are rich in lysine but short on the sulfur amino acids, with methionine the limiting one — the classic nutritional argument for pairing beans with cereals, which supply what legumes lack. - Which of the following starch have lowest gelatinization temperature
Correct answer: potato — Potato starch gelatinizes around 60–65 °C, lower than rice, maize, or sorghum — its large granules and phosphate groups let water in early, which is why potato-thickened sauces turn glossy fast. - Micro-organism responsible for production of vinegar from alcohol
Correct answer: Acetobacter — Acetobacter oxidizes ethanol to acetic acid in the presence of oxygen — the second fermentation of vinegar-making, following the yeast fermentation that made the alcohol. - Codex Alimentarius means
Correct answer: Food code — Codex Alimentarius is Latin for ‘food code’: the FAO/WHO collection of international food standards that harmonizes safety and trade rules across member countries.