The effect of frying on the nutritional value of food is related to the frying process conditions. Generally, frying does not reduce the nutritional value of many foods.
Changes in nutritional value :
When the frying temperature is high, a dry layer is formed on the surface of the food. This hard shell prevents the transfer of heat into the food and the escape of water vapor. Therefore, the nutrients in the food are better preserved and the water content is higher (table below). At the same time, the oil content of the products is significantly increased.
When frying food, changes in retinol, carotenoids, and tocopherols can cause changes in flavor and color. The oxidation of vitamin C protects the oxidation of oil, that is, it acts as an oil antioxidant. The nutritional value of fried peanuts can provide the protein and unsaturated fatty acids needed by the human body, as well as various vitamins and dietary fiber.
Protein digestibility coefficient is one of the important indicators to evaluate the nutritional value of food. The effect of frying on the protein digestibility coefficient is related to the composition of the product and the type of meat. For example, if the meat products such as beef and pork are fried without adjuncts, the protein digestibility of the products will generally not change. However, if the meat is fried with adjuncts (such as starch), the protein digestibility of the product will be reduced.
Safety of fried food:
In general cooking and processing, the heating temperature is not high and the time is short, which has little impact on the hygiene and safety of frying oil. However, if the heating temperature is high in the frying process, the frying oil is used repeatedly, resulting in thermal polymerization of the oil at high temperature, which may form harmful polycyclic aromatic hydrocarbons, such as cyclic monomers, dimers and polymers. body. These substances can cause paralysis in the body.