Agricultural/Bioengineering: Food Engineering Flashcards
7 cards from real Agricultural/Bioengineering practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Agricultural/Bioengineering: Food Engineering flashcards as text
The 'glass transition temperature' (Tg) of a food system is important because below Tg:
Answer: Molecular mobility is greatly reduced, improving stability
Below Tg, the amorphous food matrix becomes a rigid glass with very low molecular mobility, dramatically slowing diffusion-limited deterioration reactions and microbial growth.
In the context of frying, the 'oil uptake' by a fried food product is primarily driven by:
Answer: Condensation vacuum created as steam exits and the product cools after frying
Most oil uptake occurs post-frying as the product cools: steam that had been escaping condenses, creating a partial vacuum that draws surface oil into the porous crust.
Which analytical technique is most commonly used to determine fat content in food products by solvent extraction?
Answer: Soxhlet extraction
The Soxhlet method uses repeated cycling of an organic solvent (e.g., hexane or petroleum ether) to continuously extract fat from a dried food sample.
The pasteurization of egg products at 60°C for 3.5 minutes is designed primarily to destroy:
Answer: Salmonella species
Liquid egg pasteurization targets Salmonella, the primary pathogen of concern in shell eggs, using the minimum time-temperature combination that achieves a sufficient log reduction.
In food fermentation, heterofermentative lactic acid bacteria (LAB) produce lactic acid and also:
Answer: CO2 and ethanol or acetic acid as byproducts
Heterofermentative LAB use the phosphoketolase pathway, producing equimolar amounts of lactic acid, CO2, and either ethanol or acetic acid from glucose.
The Fickian diffusion model is applied in food engineering primarily to predict:
Answer: Mass transfer of solutes or moisture within food matrices
Fick's second law describes transient diffusion of moisture or solutes through food, enabling prediction of drying curves, salt penetration, and flavor migration.
Which statement best describes the function of transglutaminase (TG) enzyme in food processing?
Answer: It crosslinks glutamine and lysine residues to restructure proteins
Transglutaminase catalyzes covalent isopeptide bonds between glutamine and lysine residues in proteins, enabling restructured meat production and improved gel texture.