This set of Food Microbiology Multiple Choice Questions & Answers (MCQs) focuses on “Food Preservation – Chemical Preservatives”.
1. The first FDA approved chemical preservative was __________
a) Sodium pyruvate
b) Lithium chloride
c) Sodium Benzoate
d) Magnesium chloride
View Answer
Explanation: Benzoates are used in pickles, salad dressings etc. They are effective against yeast and molds. Its food preservative number is E211. It is formed due to a reaction of sodium hydroxide with benzoic acid.
2. Dehydroacetic acid is effective against ________
a) Insects
b) Molds
c) Yeast
d) Bacteria
View Answer
Explanation: Dehydroacetic acid can kill insects and pests. It is used as a pesticide for strawberries and squash. Its food preservative number is E265. It can also be used in toothpastes as an antienzyme.
3. The greatest antimicrobial activity of benzoate is at a low pH.
a) True
b) False
View Answer
Explanation: Undissociated molecules carry the antimicrobial activity. These are most active at low pHs. Acidic pH causes a decrease in anaerobic fermentation of glucose through phosphofructokinase. This inhibits the microbes.
4. Sorbates inhibit the _________ in molds.
a) Ribosomes
b) Dehydrogenase system
c) Hydrolase system
d) Invertase system
View Answer
Explanation: Sorbates are used as fungistats in the food industry. They inhibit molds by inhibiting the dehydrogenase system. As for the endospores, they prevent the outgrowth of vegetative cells.
5. _________ compounds of wood smoke have antimicrobial properties.
a) Acetic
b) Phenolic
c) Nitrate
d) Methyl
View Answer
Explanation: Phenolic compounds are found in wood smoke. Smoked sausages have a distinct flavor as well as anti-oxidative and antimicrobial properties. This improves their shelf life.
6. What is the full form of BHT?
a) Benzoate hydroxytoluene
b) Benzoate hydrotoluene
c) Butylated hydroxytoluene
d) Butylated hydroxyl triacetate
View Answer
Explanation: Butylated hydroxytoluene is used as an antioxidant. Its food preservative number is E321. It can be obtained from phytoplankton as well as cyanobacteria. BHT provides indirect antimicrobial properties to the food.
7. Which of the following is used as an antifoaming agent?
a) Menthol
b) Propyl Gallate
c) Sodium Citrate
d) Lauric Acid
View Answer
Explanation: Menthol is used for flavor and propyl gallate is used as an antioxidant. Sodium citrate is used as a buffer, whereas lauric acid is used as an antifoaming agent.
8. Phosphates are added to certain processes meats
a) True
b) False
View Answer
Explanation: Adding phosphate salts to processed meats increases their water holding capacity. There is an increase in the flavor. The salts also act as antioxidants.
9. _________ is used to improve feed efficiency in cattle.
a) Natamycin
b) Monensin
c) Choline
d) Tetracycline
View Answer
Explanation: Monensin is an antibiotic isolated from a bacterium. It was used as a cattle feed additive and was approved by the FDA. It inhibits Gram-positive bacteria.
10. Natamycin is not known as _______________
a) Choline
b) Pimaricin
c) Tennecetin
d) Myprozine
View Answer
Explanation: Natamycin is an antibiotic. Its food additive number is E235. It is effective against molds but does not inhibit bacteria. It is a polyene compound.
Sanfoundry Global Education & Learning Series – Food Microbiology.
To practice all areas of Food Microbiology, here is complete set of Multiple Choice Questions and Answers.
