Advanced Preservation Quiz

Answer explanations

All twenty done? Below is why each correct answer is right — the quality science or process logic behind it.

1. At high irradiation doses, fruits and vegetables soften because the radiation does what?
   Correct answer: Breaks down long-chain polysaccharides such as pectin — High doses cleave the long pectin chains that cement plant cell walls, so the texture collapses.
2. During cocoa fermentation, what is removed?
   Correct answer: Beans from the pulp — Fermentation breaks down the mucilaginous pulp so the beans can be separated, dried, and flavour-developed.
3. Which methods are used for fermenting cocoa beans?
   Correct answer: Box, heap and tray methods — Box, heap, and tray are the three traditional cocoa fermentation systems, differing in scale and aeration.
4. Which process variable cannot be changed while the extruder is running?
   Correct answer: Screw configuration — Screw geometry is fixed hardware; speed, feed rate, and water injection are all adjustable on the fly.
5. A shelf-life study run over a shorter interval under more adverse storage conditions is known as which type of testing?
   Correct answer: Accelerated testing — ASLT deliberately stresses the product to predict shelf life far faster than real-time storage.
6. Which model is used to explain the theory behind accelerated shelf-life testing?
   Correct answer: Arrhenius model — Reaction rates rise exponentially with temperature — Arrhenius kinetics lets testers extrapolate from hot storage to ambient.
7. Accelerated shelf-life studies are generally conducted under which conditions?
   Correct answer: Elevated constant temperatures — Steady heat accelerates the chemistry; freezing or cycling would change the degradation pathways being measured.
8. In slow freezing, the ice crystals that form are typically:
   Correct answer: Big — Slow heat removal grows a few large, often extracellular crystals that rupture cells — the texture damage fast freezing avoids.
9. Chilling injury is most common in:
   Correct answer: Banana — Tropical fruits like banana suffer physiological damage at refrigerator temperatures that temperate fruits tolerate.
10. At what temperature is cheese cured (ripened)?
    Correct answer: 16 °C — This is the cited ripening temperature for the cheese-curing context in the quiz — warm enough for flavour development to proceed.
11. In cured-meat manufacture, smoking is carried out
    Correct answer: After curing — Smoke follows the cure: salt first stabilizes and flavours the meat, then smoke adds its preservative and flavour compounds.
12. The primary purpose of adding alkaline phosphates in meat curing is to
    Correct answer: Decrease shrinkage in meat — Phosphates raise the meat’s water-holding capacity, so it loses less weight in cooking.
13. Eggs are pasteurized mainly to destroy
    Correct answer: Salmonella organisms — Liquid egg is pasteurized principally to destroy Salmonella, the pathogen of concern.
14. During blanching, shrimps are heated for such a time that
    Correct answer: The surface of the product reaches a temperature adequate to coagulate the protein — The endpoint is a set, coagulated surface — not full cooking and not complete pathogen kill.
15. Read the two statements about fish stability and glazing below, then choose the correct option: (1) Whole and eviscerated fish have longer shelf stability than fillets. (2) Glazing provides a continuous film that adheres to the frozen product, thereby reducing moisture loss and the rate of oxidation.
    Correct answer: Both given statements are correct — Whole eviscerated fish outlasts fillets because less surface is exposed, and glaze films cut moisture loss and oxidation.
16. Which of the following statements about frozen fish is correct?
    Correct answer: Frozen fish gradually loses its juiciness and succulence during frozen storage — Protein denaturation and drip loss during frozen storage steadily reduce succulence over time.
17. Which of the following statements regarding the curing of vanilla is/are correct?
    Correct answer: Glucovanillin converts to vanillin, vanillin content rises, β-glucosidase drives it — β-glucosidase hydrolyzes glucovanillin to vanillin plus glucose, so vanillin content rises through curing.
18. Which of these cannot make lactic acid at high temperatures?
    Correct answer: Lactococcus lactis subsp. lactis — A mesophile, unlike Strep. thermophilus and Lb. bulgaricus — it cannot make lactic acid at high temperatures.
19. Direct-immersion freezing of foods is normally carried out at a temperature of about
    Correct answer: −62 °C — This is the cited operating temperature for direct-immersion freezing systems.
20. Pasteurization is carried out mainly to destroy
    Correct answer: Harmful bacteria — Pasteurization’s purpose is destroying pathogens (and cutting spoilage flora) — it was never meant to sterilize.