Currently, fried food has grown into one of the major segments of the food processing industry. The deep frying is a process where food is heated for a short time at a high temperature.
Meat, fish, doughnuts, potato chips or french fries are dipped into fat (oil) heated to about 180 ° C. Deep frying will color the food and give it a crunchy texture on the outside, inside the remains moist.
During deep fat frying, three types of chemical reactions process in the deep frying medium, influencing the flavor:
*hydrolytic processes
*oxidative processes
*pyrolytic processes
The frying fat or oil substantially in its chemical and physical properties after prolonged use.
During deep frying, heat transferred from oil is carried off as latent heat of vaporization and thus maintains the temperature of the food/oil interface virtually at 100° C, preventing charring or burning of the food.
As water content decreases, the amount of thermal energy carried off as latent heat of vaporization starts to decline and the food/oil interface temperature begins to increase, leading potentially to charring or burning of the food.
Frying oils not only transfer heat to cook foods but also help produce distinct fried food flavor and unfortunately, undesirable off-flavors if the oil is deteriorated.
In the deep frying antioxidants in the oils such as vitamin E and carotene are used up. Then it produce free radicals that start chain reactions in oil molecules.
Deep frying also produce some trans-fatty acids.
Process of deep frying
