CCS Food Chemistry & Biochemistry 2

Question 1

Which enzyme causes enzymatic browning in cut apples and potatoes when exposed to oxygen?

Accepted Answer

Polyphenol oxidase

Answer

Polyphenol oxidase (PPO) catalyzes the oxidation of phenolic substrates in the presence of molecular oxygen, producing brown quinone pigments.

Question 2

What is a protein's isoelectric point (pI)?

Accepted Answer

The pH at which a protein has no net electrical charge

Answer

At the isoelectric point, the number of positive charges equals negative charges on a protein, resulting in zero net charge and minimal solubility.

Question 3

Which type of dietary fiber is fermented by colonic bacteria to yield beneficial short-chain fatty acids (SCFAs)?

Accepted Answer

Soluble prebiotic fiber

Answer

Soluble fibers such as inulin, pectin, and beta-glucan are fermented by gut microbiota to produce SCFAs (butyrate, propionate, acetate) that nourish colonocytes.

Question 4

What is the primary antioxidant function of ascorbic acid (Vitamin C) in food systems?

Accepted Answer

It donates electrons to free radicals, preventing oxidation

Answer

Ascorbic acid is a reducing agent that donates electrons to reactive oxygen species, preventing the oxidative degradation of lipids, pigments, and vitamins.

Question 5

Which monosaccharide is the primary circulating sugar in human blood and the central fuel for cellular metabolism?

Accepted Answer

Glucose

Answer

Glucose is the principal monosaccharide in blood (blood sugar) and the preferred substrate for glycolysis and ATP production in all cells.

(CCS) Certified Culinary Scientist Practice Test

(CCS) Certified Culinary Scientist Practice Test

CCS Food Chemistry & Biochemistry 2