1. : The main cause of food spoilage is:
(A) Enzymatic activity
(B) Microbial growth
(C) Physical damage
(D) Chemical oxidation
2. : Which microorganism is mainly responsible for souring of milk?
(A) Yeast
(B) Lactic acid bacteria
(C) Mold
(D) Coliform bacteria
3. : The term “putrefaction” refers to:
(A) Breakdown of carbohydrates
(B) Decomposition of proteins
(C) Oxidation of fats
(D) Formation of alcohols
4. : Slime formation on meat is mainly caused by:
(A) Molds
(B) Yeasts
(C) Bacteria
(D) Viruses
5. : Which bacteria are most common in refrigerated spoilage of meat?
(A) Pseudomonas species
(B) Clostridium species
(C) Lactobacillus species
(D) Bacillus species
6. : “Flat sour spoilage” in canned food is caused by:
(A) Clostridium botulinum
(B) Bacillus stearothermophilus
(C) Bacillus coagulans
(D) Clostridium sporogenes
7. : The “swelling” of canned foods is due to:
(A) Gas formation by microorganisms
(B) Moisture loss
(C) Chemical reaction
(D) Freezing
8. : Yeasts spoil food primarily by:
(A) Producing toxins
(B) Fermentation of sugars
(C) Breaking down proteins
(D) Oxidizing fats
9. : Mold spoilage in bread is commonly caused by:
(A) Penicillium and Aspergillus
(B) Clostridium and Bacillus
(C) Lactobacillus and Leuconostoc
(D) Salmonella and Shigella
10. : Which type of microorganism causes “ropiness” in bread?
(A) Bacillus subtilis
(B) Pseudomonas fluorescens
(C) Rhizopus stolonifer
(D) Penicillium expansum
11. : “Black rot” in eggs is caused by:
(A) Pseudomonas
(B) Proteus
(C) Clostridium
(D) Salmonella
12. : The spoilage of canned acidic foods is mostly caused by:
(A) Bacillus coagulans
(B) Clostridium botulinum
(C) Lactobacillus
(D) Yeasts and molds
13. : The microorganism responsible for butter rancidity is:
(A) Pseudomonas putida
(B) Lactobacillus casei
(C) Clostridium butyricum
(D) Bacillus cereus
14. : “Surface taint” on butter is caused by:
(A) Pseudomonas putrefaciens
(B) Bacillus cereus
(C) Saccharomyces cerevisiae
(D) Penicillium glaucum
15. : “Green rot” in eggs is caused by:
(A) Pseudomonas fluorescens
(B) Bacillus subtilis
(C) Aspergillus niger
(D) Clostridium botulinum
16. : The “souring” of canned food without gas production is called:
(A) Putrefaction
(B) Flat sour spoilage
(C) Swelling
(D) Ropiness
17. : The “cloudiness” in fruit juices is caused by:
(A) Yeasts
(B) Bacteria
(C) Molds
(D) Coliforms
18. : Meat slime develops faster at:
(A) Low humidity
(B) High humidity
(C) Freezing temperature
(D) Dry conditions
19. : The bacteria that cause “sweet curdling” of milk are:
(A) Bacillus cereus
(B) Alcaligenes viscolactis
(C) Lactobacillus bulgaricus
(D) Streptococcus lactis
20. : “Sour cream” is produced by:
(A) Lactic acid bacteria
(B) Yeasts
(C) Molds
(D) Coliforms
21. : “Pink discoloration” in cheese is due to:
(A) Serratia marcescens
(B) Bacillus subtilis
(C) Lactobacillus plantarum
(D) Rhizopus nigricans
22. : The spoilage of canned meat by hydrogen swell is due to:
(A) Clostridium species
(B) Bacillus species
(C) Lactic acid bacteria
(D) Molds
23. : “Rancidity” in fats and oils is caused mainly by:
(A) Yeasts
(B) Lipolytic bacteria
(C) Lactic acid bacteria
(D) Proteolytic molds
24. : The “rope spoilage” of pasteurized milk is caused by:
(A) Bacillus subtilis
(B) Clostridium sporogenes
(C) Pseudomonas fluorescens
(D) Micrococcus luteus
25. : “Black spot” on cured meat is caused by:
(A) Penicillium
(B) Aspergillus niger
(C) Rhizopus
(D) Mucor
26. : The “musty odor” in spoiled grains is due to:
(A) Molds
(B) Yeasts
(C) Bacteria
(D) Protozoa
27. : Fish spoil rapidly because:
(A) High water activity and neutral pH
(B) Low protein content
(C) High salt content
(D) Low microbial load
28. : “Sulphide spoilage” in canned foods produces:
(A) Rotten egg smell
(B) Sweet taste
(C) Sour odor
(D) No smell
29. : “Mold bloom” on cheese surface is due to:
(A) Penicillium and Aspergillus
(B) Lactobacillus
(C) Bacillus
(D) Clostridium
30. : “Soft rot” in vegetables is caused by:
(A) Erwinia carotovora
(B) Pseudomonas aeruginosa
(C) Clostridium botulinum
(D) Bacillus cereus
31. : The main cause of microbial spoilage in frozen foods is:
(A) Psychrotrophic bacteria
(B) Thermophilic bacteria
(C) Mesophilic bacteria
(D) Yeasts only
32. : “Sticky surface” of cured meat is due to:
(A) Micrococcus and Staphylococcus
(B) Clostridium
(C) Pseudomonas
(D) Lactobacillus
33. : The presence of coliforms in food indicates:
(A) Poor hygiene or contamination
(B) Presence of toxin
(C) Pasteurization
(D) High acidity
34. : “Blue mold rot” on citrus fruits is caused by:
(A) Penicillium italicum
(B) Aspergillus flavus
(C) Rhizopus stolonifer
(D) Fusarium oxysporum
35. : “Black mold rot” on fruits is caused by:
(A) Aspergillus niger
(B) Rhizopus stolonifer
(C) Penicillium digitatum
(D) Mucor pusillus
36. : “Souring” of canned foods is mostly due to:
(A) Lactic acid bacteria
(B) Yeasts
(C) Molds
(D) Clostridium
37. : “Swelling” of cans without spoilage odor indicates:
(A) Chemical reaction
(B) Microbial contamination
(C) Mold growth
(D) Physical damage
38. : “Gassy spoilage” in canned vegetables is caused by:
(A) Clostridium species
(B) Bacillus subtilis
(C) Lactobacillus species
(D) Yeast
39. : “White patches” on bread are caused by:
(A) Rhizopus stolonifer
(B) Penicillium expansum
(C) Aspergillus flavus
(D) Mucor mucedo
40. : “Slimy” spoilage of cooked meat is caused by:
(A) Lactic acid bacteria
(B) Pseudomonas species
(C) Staphylococcus aureus
(D) Yeasts
41. : “Souring” of meat is caused by:
(A) Lactic acid bacteria
(B) Clostridium
(C) Bacillus
(D) Yeast
42. : The spoilage of canned foods without visible microbial growth is called:
(A) Flat sour spoilage
(B) Hidden spoilage
(C) Swelling
(D) Putrefaction
43. : “Pink slime” in bottled beverages is due to:
(A) Serratia marcescens
(B) Pseudomonas fluorescens
(C) Bacillus subtilis
(D) Aspergillus niger
44. : The spoilage of pickles is mainly due to:
(A) Yeasts and molds
(B) Lactic acid bacteria
(C) Coliform bacteria
(D) Clostridium
45. : “Ropy” slime formation in beer is due to:
(A) Pediococcus
(B) Listeria
(C) Bacillus
(D) Pseudomonas
46. : Spoilage in butter often begins on:
(A) Surface
(B) Core
(C) Bottom
(D) Sides
47. : The main spoilage organisms in vacuum-packed meats are:
(A) Lactic acid bacteria
(B) Aerobic molds
(C) Yeasts
(D) Pseudomonas species
48. : “Sulfur stinker” spoilage in canned foods is caused by:
(A) Clostridium nigrificans
(B) Bacillus coagulans
(C) Listeria monocytogenes
(D) Lactobacillus plantarum
49. : “Fruity odor” in spoiled wine is due to:
(A) Yeasts producing esters
(B) Lactic acid bacteria
(C) Molds
(D) Bacillus species
50. : “Putrid odor” in spoiled fish is mainly due to:
(A) Production of trimethylamine
(B) Yeast fermentation
(C) Mold growth
(D) Lactic acid formation