FSN 230 Midterm 2 Questions With Complete Solutions

Enzymes correct answer: Catalyze chemical reactions to convert proteins, fats and carbohydrates to less complex compounds Enzymes are responsible for changes in flavore, color, texture and nutritional properties Enzyme Temperature correct answer: 60-150 F OPTIMAL ACTIVITY 160-200 F Inactiviated Enzyme pH correct answer: Most enzymes activate only over a narrow range Optimum pH varies Affects both catalytic activity and enzyme stability Protease correct answer: All enzymes that hydrolyze peptide bonds Meat tenderizing, cheese manufacturing, textural modification Used to chill-proof beer by removing proteins that can cause clouding Oxidation correct answer: Loss of an electron by an atom or chemical combination with oxygen Many oxidizing enzymes in food but they do not cause deteriorating in intact tissues Cheese Polyphenoloxidase (oxidizing) correct answer: Reacts with phenolic compounds Responsible for browning in fruits and vegetables Ascorbic Acid (oxidizing) correct answer: Oxides vitamin C (can't be used by humans) Tyrosinase (oxidizing) correct answer: Oxidizes compounds related to Tyrosine Causes black spotting (lobster, shrimp) Lipases (fat-splitting) correct answer: Breaks fats into glycerin and fatty acids (Large chain fatty acid >10 = Smoking while heating Short chain fatty acid - odor and flavor)