Question

When you enjoyed having fried chicken.

a. Explain the process of catabolism with an overview of the product formed.

b. Identify the toxic substances generated from this process and what will be the natural mechanism over this toxic substance.

Answer 1

a) Fried Foods Are Typically High in Trans Fats.In fact, trans fats are associated with an increased risk of many diseases, including heart disease, cancer, diabetes and obesity.Deep‐fat frying produces desirable or undesirable flavor compounds and changes the flavor stability and quality of the oil by hydrolysis, oxidation, and polymerization. Tocopherols, essential amino acids, and fatty acids in foods are degraded during deep‐fat frying. The reactions in deep‐fat frying depend on factors such as replenishment of fresh oil, frying conditions, original quality of frying oil, food materials, type of fryer, antioxidants, and oxygen concentration. High frying temperature, the number of fryings, the contents of free fatty acids, polyvalent metals, and unsaturated fatty acids of oil decrease the oxidative stability and flavor quality of oil.

Antioxidant decreases the frying oil oxidation, but the effectiveness of antioxidant decreases with high frying temperature. Lignan compounds in sesame oil are effective antioxidants in deep‐fat frying.

b)

• Hydrolysis of oil

• Oxidation of oil

• Polymerization of oil

Deep‐fat frying causes the hydrolysis, oxidation, and polymerization of the oil. Hydrolysis increases the amount of free fatty acids, mono‐ and diacylglycerols, and glycerols in oils. Oxidation occurs at a greater rate than hydrolysis during deep‐fat frying. Oxidation produces hydroperoxides and then low molecular volatile compounds such as aldehydes, ketones, carboxylic acids, and short‐chain alkanes and alkenes. Dimers and polymers are also formed in oil by radical and Diels‐Alder reactions during deep‐fat frying. Replenishment of fresh oil, frying conditions, quality of frying oil, food materials, fryer, antioxidants, and oxygen concentration affect the quality and flavor of oil during deep‐fat frying. Intermittent frying with a lower turnover rate and higher temperature accelerates the oxidation and polymerization of oil during deep‐fat frying.

The major reaction products formed during deep-fat frying:

• Oxidized decomposition compound

• Hydrolysis products

• Oxidised TAGmonomers

• Cyclic fatty acid Monomers

• Trans Isomers.