first, correct and reasonable initial processing

in the initial processing of cooking materials, we should insist on washing before cutting, and it is not suitable to soak fresh vegetables after cutting. Try not to blanch them, because more water-soluble vitamins will be lost after blanching. Fresh beans, tender stems, leaves, liverworts, root vegetables and solanaceous fruits should be cleaned, sorted and peeled with mud and necrotic parts. Finishing and chipping raw materials will destroy the integrity of the tissue, and at this time, the water-soluble inorganic salts and vitamins are the most easily lost. Therefore, washing before finishing can reduce their losses and achieve the degree of not rotting their organizational structure. Fish scraping scales requires correct and skillful knife skills, which not only removes clean materials, but also does not waste raw materials.

Each raw material contains various nutrients, so these nutrients should be preserved as much as possible during the initial processing, and the most essential parts containing vitamins should not be discarded. For example, soybean sprouts, mung bean sprouts, etc., some people only eat the above stem buds and throw away the beans when eating. In fact, the vitamin C in beans is 2-3 times more than that in buds, so they can't be lost in vain.

In short, four principles must be followed in the initial processing of raw materials: ① raw materials must be kept clean and hygienic; (2) Care must be taken to keep the nutrients of raw materials; ③ Does not affect the color, aroma, taste and shape of dishes; (4) to save for the principle.

second, the types of food are combined with nutrition.

The combination of nutrition is to select and match foods, so that all kinds of foods are nutritionally complementary. In reasonable cooking, reasonable side dishes are also the key. Choose food according to season and physique. People's diet is closely related to climate and environment. There are four seasons: warm in spring, hot in summer, cool in autumn and cold in winter. The human body is divided into yin and yang, and food is also cold, hot, warm and cool. The so-called "heat is cold, cold is hot" in Chinese medicine is the dialectical balance between cold and heat.

In the collocation of daily diet, we should pay attention to the reasonable matching of seasons and human body changes, so as to achieve a balanced diet among the four seasons. After reasonable collocation of raw materials, the nutritional proportion of dishes is relatively balanced, and it meets the requirements of perfect color, fragrance, taste and shape. The selection of raw materials of dishes not only meets the different tastes of different people, but also enhances human nutrition, with balanced proportion of meat and vegetables and diversified collocation of multiple varieties, which complement each other.

For example, in the dish of Fried Silver Bud with Dried Pork, the dried Pork contains more nutrients such as protein, iron, phosphorus and calcium, and the Silver Bud (mung bean sprouts) is rich in vitamin C, so the combination of the two is also perfect.

Although tofu is rich in protein, it lacks methionine, an essential amino acid for human body. If it is cooked alone, the utilization rate of protein is very low. If tofu is mixed with other meat and egg foods, such as "roasted tofu with minced meat", "Mapo tofu", "home-cooked tofu" and "fried tofu", it will not only enrich the color, fragrance and taste, but also improve the nutritional utilization rate of protein in tofu.

Another example is some high-grade raw materials, such as red ham, pale yellow winter bamboo shoots, green green beans or Chinese cabbage; It is not only harmonious in color and delicious in taste, but also conforms to the principle of reasonable nutrition by combining various nutrients.

Using scientific and reasonable methods to choose all kinds of foods can get rid of diseases and keep fit. Knowing the nature and taste of foods is the basis of scientific and reasonable diet. Nature provides us with abundant foods, which not only improves our life, but also meets the needs of people with different tastes.

Third, scientific cooking and nutrition and hygiene

Cooking methods and food hygiene are important links to ensure the quality of diet, and both families and restaurants deserve great attention. Having good raw materials does not mean that you can eat well; Washing vegetables and rice is not the whole of food hygiene. The key is to understand the characteristics of food itself and to cook scientifically.

Cooking can achieve the goal of eliminating germs. Generally speaking, raw materials, no matter how fresh, will inevitably contain microorganisms, parasitic eggs or toxic protein. These substances that are harmful to human health are all made of protein. protein denatures after heating and loses its biological activity, so cooking can achieve the purpose of disinfection and sterilization. But different bacteria have different resistance to high temperature. Generally, intestinal bacteria need 81-111 degrees, or even higher temperature to be killed. Therefore, the cooking method should be selected according to the variety of food and the degree of hygiene.

The selection of cooking methods should be based on the attributes of dishes and the texture of raw materials. In the cooking process, the changes of raw materials of dishes are extremely complicated, which can be divided into two types according to their nature: favorable changes and unfavorable changes. Only by thoroughly understanding these two changes can we choose the correct cooking methods, promote favorable changes and reduce unfavorable changes in cooking. The adverse changes in the cooking process of raw materials of dishes are mainly as follows: some water-soluble vitamins are damaged to varying degrees after being heated, some inorganic salts and vitamins are lost in water during the initial processing such as washing, cutting, soaking, scalding and soaking, and some raw materials are cooked at high temperature such as roasting, roasting and frying, and vitamin B family is lost. When the oil temperature exceeds 1.81 degrees, high temperature is easy to produce lipid peroxide, which is easy to cause cancer. In the process of cooking dishes, we should try our best to reduce adverse changes and increase favorable changes, so as to make the dishes delicious and palatable and beneficial to human health.

Before cooking, the tastes of various raw materials are independent and incompatible with each other. Choose the best cooking method, and several raw materials are heated together. With the increase of temperature, the molecules in various foods will move violently, and the molecules in one raw material will move into another raw material, especially through the action of boiling water and oil in the pot, so that the molecules in various raw materials can easily penetrate each other and form a compound delicious food. Some foods need big fire, which can fully extract all kinds of nutrients and improve the digestion and absorption rate. Experiments show that different conditions are very different for the preservation of food nutritional value, so it is the most ideal to choose a cooking method to improve the taste and less destroy nutrients.