CFS CFS Food Chemistry & Biochemistry 1 — Questions and Answers
Question 1: The Maillard reaction in food processing involves a reaction between which two types of compounds?
- Reducing sugars and amino acids (Correct answer)
- Fatty acids and glycerol
- Starch and water
- Vitamins and minerals
Correct answer: Reducing sugars and amino acids
The Maillard reaction occurs between reducing sugars and amino acids, producing the characteristic brown color and flavor in cooked foods such as bread crust and roasted meats.
Question 2: Water activity (a_w) of 0.85 is most closely associated with which type of food preservation concern?
- Clostridium botulinum growth
- Mold and yeast growth only
- Staphylococcus aureus growth becoming possible (Correct answer)
- Complete microbial inhibition
Correct answer: Staphylococcus aureus growth becoming possible
At a_w of 0.85, Staphylococcus aureus can grow and produce toxin, making this a critical threshold for intermediate-moisture food safety.
Question 3: Which term describes the temperature at which a protein loses its native three-dimensional structure due to disruption of non-covalent bonds?
- Gelatinization point
- Denaturation temperature (Correct answer)
- Isoelectric point
- Saponification value
Correct answer: Denaturation temperature
Denaturation temperature is the point at which a protein unfolds and loses its functional native structure due to heat, pH change, or chemical agents.
Question 4: Lipid oxidation in food products is primarily initiated by which mechanism?
- Hydrolysis of ester bonds
- Free radical chain reaction (Correct answer)
- Enzymatic esterification
- Glycolysis
Correct answer: Free radical chain reaction
Lipid oxidation (autoxidation) proceeds via a free radical chain reaction involving initiation, propagation, and termination stages, producing off-flavors and rancidity.
Question 5: Which of the following is a reducing sugar commonly involved in non-enzymatic browning reactions?
- Sucrose
- Glucose (Correct answer)
- Sorbitol
- Mannitol
Correct answer: Glucose
Glucose is a reducing sugar with a free aldehyde group that participates in the Maillard reaction; sucrose is a non-reducing sugar and must be hydrolyzed first.
Question 6: The peroxide value (PV) of a fat is used to measure which stage of oxidation?
- Secondary oxidation products
- Primary oxidation (hydroperoxide formation) (Correct answer)
- Rancidity endpoint
- Acidity from hydrolysis
Correct answer: Primary oxidation (hydroperoxide formation)
Peroxide value measures hydroperoxides, which are primary oxidation products formed in the early stages of lipid autoxidation.
CFS CFS Food Chemistry & Biochemistry 1
The Maillard reaction in food processing involves a reaction between which two types of compounds?