CFS Food Chemistry & Biochemistry Flashcards

The Maillard reaction in food processing involves a reaction between which two types of compounds?

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.

Water activity (a_w) of 0.85 is most closely associated with which type of food preservation concern?

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.

Which term describes the temperature at which a protein loses its native three-dimensional structure due to disruption of non-covalent bonds?

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.

Lipid oxidation in food products is primarily initiated by which mechanism?

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.

Which of the following is a reducing sugar commonly involved in non-enzymatic browning reactions?

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.

The peroxide value (PV) of a fat is used to measure which stage of oxidation?

Answer: Primary oxidation (hydroperoxide formation)

Peroxide value measures hydroperoxides, which are primary oxidation products formed in the early stages of lipid autoxidation.