The nutritional value of food depends not only on the nutritional content of the raw materials but also on the method used in the process of processing and cooking. Unreasonable processing will destroy and reduce the original nutritional content of the food. Therefore, it is usually necessary to choose the correct one. Cooking methods to maximize the retention of nutrients in food.
During the process of food processing, if some cooking methods are not correct, nutrients will be lost.
1. The food is prepared by salting and candying. Due to the action of hypertonic ions, the internal osmotic pressure of the food is changed, so that the water in the food overflows, and some nutrients, such as vitamins and inorganic salts, are lost with the overflow of the solution. nutrients suffer varying degrees of loss.
2. During the washing process of food, due to incorrect methods or prolonged stewing, protein, fat, vitamins, and inorganic salts are easily dissolved in water, and these nutrients are lost with washing water or unused soup, such as vegetables Improper cutting and washing can lose about 20% of vitamins, rice can lose about 43% of riboflavin and 5% of protein after repeated washing, and most of the fat and protein can be lost by cooking meat and discarding soup.
3. Under the condition of high-temperature heating, unstable nutrients are easily destroyed. Among various nutrients, the biggest loss is usually vitamins. For example, the loss of thiamine in fried food reaches 60%, and the loss of riboflavin is 40%. %, 50% of niacin is lost, and all vitamin C is destroyed.