Food Science Quiz 11
What this quiz covers
Every food scientist carries a mental drawer of facts that seem small until the day they matter: the angle wheat grain rests at in a silo, which enzyme must die the moment milk is homogenized, who invented canning, where saffron actually comes from on the flower. This quiz is that drawer, opened and shaken out. Twenty questions, each one a compact fact with a real job behind it — the lipase that must be inactivated after homogenization will turn milk rancid if it survives, and the angle of repose decides whether grain flows or bridges in a bin.
The questions range across cookie spread ratios, sorption isotherms, jelly formulation, methyl bromide as a grain fumigant, mycotoxins from Aspergillus flavus, rennin as an enzyme, anthocyanin turning red at low pH, Nicholas Appert’s canning, the visible range of a spectrophotometer, whey as the liquid left when milk coagulates, alcohol precipitating pectin, egg’s biological value of 93, saffron’s stigma, the fifteen-day life of a taste bud, rhodopsin in the eye, the banana note of isoamyl alcohol, and which radiation penetrates least.
Small facts, real consequences
The trick to a quiz like this is not memorizing harder but connecting each fact to its consequence. Lipase after homogenization: consequence, rancid milk. Anthocyanin at low pH: consequence, the color of your jam tells you its acidity. The spectrophotometer’s 400–800 nm range: consequence, that is the visible band you can actually see. Standard deviation is not a central tendency — consequence, you will misread every QC chart if you think it is. Tie each answer to something physical and the facts stop sliding off.
How to use this quiz
You get 20 seconds per question and one attempt at each answer. This is a recall quiz, so treat misses as flashcards: write the question on one side, the mechanism on the other, and drill them until the pairs are instant. Pay special attention to the numbers — 27 degrees, 400 to 800 nanometers, 93, 15 days — because number questions are the ones that separate a pass from a fail. Then retake it cold and count how many stuck.
Answer explanations
Worked through the quiz? Here is why each correct answer is correct — the concept behind it, in plain terms.
- What is the ratio of diameter to thickness of cookie called
Correct answer: both (a) & (c) — Diameter ÷ thickness of a cookie is called the spread ratio — also termed the spread factor — a key quality check in biscuit baking. - Sorption isotherm is plotted between moisture content and
Correct answer: aw of food product — A sorption isotherm plots moisture content against water activity (aw) at constant temperature — the curve behind drying calculations and shelf-life prediction. - The preparation of jelly does not require
Correct answer: salt — Jelly needs pectin, acid, and sugar to set; salt plays no structural role, so it is the odd ingredient out. - An effective fumigant in grain storage is
Correct answer: Methyl bromide — Methyl bromide was the standard grain-storage fumigant — penetrating and effective — before ozone-layer concerns phased it out. - Which enzyme should be inactivated immediately after homogenization of milk
Correct answer: lipase — Homogenization shreds fat globules and exposes them to lipase; the enzyme must be inactivated immediately or it will hydrolyze the fat and turn the milk rancid. - Mycotoxin is produced by
Correct answer: Aspergillus flavus — Mycotoxins such as aflatoxins are produced by Aspergillus flavus growing on grains and nuts — the textbook mycotoxin example this question is built on. - Rennin is a
Correct answer: enzyme — Rennin (chymosin) is the milk-clotting enzyme of cheese making — a protein catalyst, not a structural protein or a fat. - The color of anthocyanin at low pH is
Correct answer: red — Anthocyanins are red in acid, shifting toward blue and purple as pH rises — the color change behind red-cabbage indicator chemistry. - Angle of repose of wheat grain is
Correct answer: 27° — Wheat’s angle of repose is about 27° — the slope a grain pile naturally rests at, which sets silo and conveyor design. - Father of canning is
Correct answer: Nicholas Appert — Nicolas Appert won Napoleon’s prize around 1810 with heat-sealed glass jars — the birth of canning, decades before Pasteur explained why it worked. - The visible range of spectrophotometer is
Correct answer: 400-800nm — A spectrophotometer’s visible range spans roughly 400–800 nm (violet to red); 200–400 nm is the UV band. - When milk is coagulated, the part that remains is called
Correct answer: whey — Coagulate the casein out of milk and the remaining liquid is whey — the protein-rich stream behind whey powder and sports nutrition. - Pectin is precipitated by
Correct answer: alcohol — Pectin precipitates in alcohol — the basis of lab pectin assays, since alcohol dehydrates the pectin chains out of solution. - The biological value of egg is
Correct answer: 93 — Egg protein’s biological value of 93 makes it the reference standard — the most completely utilized common protein. - Saffron is obtained from ____ of flower
Correct answer: stigma — Saffron is the dried stigmas of Crocus sativus — three threads per flower, which is why it is the world’s costliest spice. - The taste buds have a life cycle of ________ days
Correct answer: 15 — Taste bud cells renew roughly every 10–15 days — the quiz’s 15-day figure — which is why a burned tongue recovers fast. - Rhodopsin is a mixture of
Correct answer: opsin and 11-cis-retinal — Rhodopsin, the rod cells’ light sensor, is opsin protein bound to 11-cis-retinal; light flips the retinal and fires the visual signal. - Banana like flavor
Correct answer: iso amyl alcohol — Isoamyl acetate/alcohol carries the unmistakable banana note — the ester behind banana flavorings and some fermentations. - Which of the following is not central tendency
Correct answer: standard deviation — Mean, median, and mode locate the center; standard deviation measures spread — a different job entirely. - Which among the following has the lowest penetration power
Correct answer: microwaves — Penetrating power rises with frequency, so among gamma rays, X-rays, microwaves, and infrared, low-frequency microwaves penetrate least.