1. The main purpose of food preservation is to:
(A) Improve color of food
(B) Increase shelf life and prevent spoilage
(C) Enhance taste only
(D) Reduce food value
2. The process of heating food to destroy microorganisms is called:
(A) Pasteurization
(B) Sterilization
(C) Dehydration
(D) Blanching
3. The method of preservation that removes moisture from food is:
(A) Drying
(B) Canning
(C) Freezing
(D) Fermentation
4. The primary agent responsible for spoilage of food is:
(A) Minerals
(B) Vitamins
(C) Microorganisms
(D) Preservatives
5. Freezing preserves food mainly by:
(A) Destroying enzymes completely
(B) Inhibiting microbial growth
(C) Removing nutrients
(D) Increasing oxidation
6. Canning was first developed by:
(A) Louis Pasteur
(B) John Tyndall
(C) Robert Koch
(D) Nicolas Appert
7. The temperature used for pasteurization of milk by LTLT method is:
(A) 63°C for 30 minutes
(B) 72°C for 15 seconds
(C) 80°C for 5 minutes
(D) 100°C for 10 minutes
8. The main principle of food preservation by refrigeration is:
(A) Removing moisture
(B) Killing all microorganisms
(C) Slowing down microbial and enzymatic activity
(D) Increasing pH
9. The addition of salt or sugar to food preserves it by:
(A) Increasing pH
(B) Lowering water activity
(C) Enhancing enzyme activity
(D) Increasing oxidation
10. The process of sterilizing food in sealed containers is called:
(A) Irradiation
(B) Freezing
(C) Dehydration
(D) Canning
11. The enzyme responsible for browning in fruits and vegetables is:
(A) Amylase
(B) Lipase
(C) Polyphenol oxidase
(D) Protease
12. The preservation method that involves exposure to ionizing radiation is known as:
(A) Lyophilization
(B) Osmosis
(C) Irradiation
(D) Blanching
13. Chemical preservatives are used in food to:
(A) Enhance color
(B) Destroy or inhibit microorganisms
(C) Add flavor
(D) Provide nutrition
14. Sodium benzoate is most effective in:
(A) Frozen foods
(B) Alkaline foods
(C) Neutral foods
(D) Acidic foods
15. The main principle of dehydration is to:
(A) Improve taste
(B) Increase enzyme activity
(C) Reduce moisture content
(D) Increase fat content
16. The process of removing water by sublimation from frozen food is:
(A) Filtration
(B) Dehydration
(C) Freeze drying
(D) Osmosis
17. Fermentation helps in preservation by:
(A) Increasing sugar
(B) Lowering pH and producing acids
(C) Raising temperature
(D) Removing oxygen
18. The bacteria mainly responsible for fermentation are:
(A) Bacillus subtilis
(B) Salmonella species
(C) Pseudomonas
(D) Lactic acid bacteria
19. The principle of pickling is based on:
(A) High temperature
(B) Low temperature
(C) High salt or acid concentration
(D) Removing oxygen
20. The process of briefly immersing food in hot water or steam is:
(A) Steaming
(B) Pasteurization
(C) Blanching
(D) Boiling
21. The pH range at which most bacteria cannot grow is:
(A) 7.5–8.5
(B) 6.0–8.0
(C) Above 9.0
(D) Below 4.5
22. The common preservative used in fruit juices is:
(A) Calcium chloride
(B) Sodium carbonate
(C) Potassium metabisulfite
(D) Sodium hydroxide
23. The use of vinegar in pickles helps in preservation by:
(A) Increasing sugar content
(B) Lowering pH
(C) Reducing oxygen
(D) Increasing temperature
24. The preservation method involving storage at −18°C or below is:
(A) Canning
(B) Refrigeration
(C) Blanching
(D) Freezing
25. The process that kills all microorganisms including spores is:
(A) Refrigeration
(B) Pasteurization
(C) Sterilization
(D) Blanching
26. The preservative commonly used in bakery products is:
(A) Sodium carbonate
(B) Calcium propionate
(C) Potassium nitrate
(D) Citric acid
27. The use of carbon dioxide for preservation is found in:
(A) Modified atmosphere packaging
(B) Pasteurization
(C) Blanching
(D) Filtration
28. Which of the following is not a physical method of food preservation?
(A) Irradiation
(B) Canning
(C) Use of preservatives
(D) Freezing
29. Lyophilization is another term for:
(A) Freeze drying
(B) Osmotic dehydration
(C) Sun drying
(D) Blanching
30. The purpose of blanching before freezing vegetables is to:
(A) Increase water activity
(B) Add flavor
(C) Improve color
(D) Inactivate enzymes
31. The most heat-resistant microorganisms are:
(A) Yeasts
(B) Bacterial spores
(C) Molds
(D) Viruses
32. The temperature used for sterilization in an autoclave is:
(A) 90°C
(B) 121°C
(C) 60°C
(D) 100°C
33. The principle of food preservation by smoking includes:
(A) Raising the pH
(B) Absorption of moisture
(C) Increase in fat content
(D) Dehydration and antimicrobial action of smoke
34. The chemical preservative used in soft drinks is:
(A) Calcium carbonate
(B) Citric acid
(C) Sodium benzoate
(D) Ascorbic acid
35. The low temperature storage that maintains food above freezing point is:
(A) Canning
(B) Deep freezing
(C) Refrigeration
(D) Sterilization
36. The principle of preservation by sugar is:
(A) Enzyme inactivation
(B) Osmotic dehydration
(C) pH reduction
(D) Oxidation
37. The spoilage of canned food is mainly due to:
(A) Improper sealing or under-processing
(B) Excess acid
(C) Too much salt
(D) Freezing temperature
38. The best preservation method for leafy vegetables is:
(A) Dehydration
(B) Smoking
(C) Canning
(D) Freezing
39. The microorganism used in yogurt production is:
(A) Lactobacillus bulgaricus
(B) Penicillium roqueforti
(C) Aspergillus oryzae
(D) Bacillus subtilis
40. The process of preservation by heating food in sealed containers is:
(A) Freezing
(B) Canning
(C) Blanching
(D) Drying
41. Food irradiation uses which type of radiation?
(A) Gamma rays
(B) Ultraviolet rays
(C) X-rays
(D) Infrared rays
42. The main disadvantage of dehydration is:
(A) Loss of flavor and texture
(B) Microbial growth increases
(C) Water activity increases
(D) Nutrient enrichment
43. The enzyme inactivation in fruits is achieved by:
(A) Salting
(B) Freezing
(C) Blanching
(D) Smoking
44. The most suitable packaging for frozen foods is:
(A) Paper bag
(B) Moisture-proof and air-tight
(C) Cloth wrap
(D) Wooden box
45. The chemical preservative used in meat products is:
(A) Potassium sorbate
(B) Sodium benzoate
(C) Citric acid
(D) Sodium nitrite
46. The common cause of food spoilage during storage is:
(A) Freezing
(B) Vacuum packaging
(C) Microbial growth and enzyme activity
(D) Irradiation
47. The preservation method that maintains both texture and nutrients effectively is:
(A) Canning
(B) Freeze drying
(C) Blanching
(D) Smoking
48. The principle of cold storage depends on:
(A) Enhancing oxidation
(B) Killing microbes completely
(C) Increasing enzyme activity
(D) Slowing biochemical and microbial reactions
49. The method suitable for long-term preservation of meat is:
(A) Pasteurization
(B) Boiling
(C) Freezing
(D) Blanching
50. The main advantage of food preservation is:
(A) Making food perishable
(B) Increasing cost
(C) Reducing nutrition
(D) Availability of seasonal foods year-round