Protein.
Protein of pork is a complete protein, which contains a variety of essential amino acids. The proportion of essential amino acids is close to the needs of human body, which is easy to be fully utilized by human body and has high nutritional value. It belongs to high-quality protein. The average protein content of pork is about 13.2%, which varies with pig breed, age, fatness and origin. For example, the protein content of pork in different parts of pigs varies greatly due to the different degree of fatness. For example, the protein content of pork tenderloin is about 2 1%, the rear buttock tip is about 15%, the rib meat is about 10%, and the breast meat is only 8%. It can also be seen that the protein content of lean pork is higher than that of fat pork. The skin and tendons of pigs are mainly composed of connective tissue. The protein content of connective tissue is 35%-40%, and most of them are collagen and elastin. Because collagen and elastin lack essential amino acids such as tryptophan and methionine, the nutritional value of food with pig skin and tendon as the main raw materials is low. However, it is precisely because they are rich in collagen and elastin that these raw materials become the best products for women's beauty.
2. Lipids
The lipids in pork are mainly neutral fat and cholesterol. Among livestock meat, pork has the highest fat content, and the fat composition is mainly saturated fatty acids with high melting point. This is also the reason why lard is solid at low temperature. The cholesterol content in pork is lower in lean meat, higher in fat meat than lean meat, and higher in internal organs, which is generally about 3-5 times that of lean meat, and the highest in brain, reaching 2000mg/ 100g. Although cholesterol has a wide range of physiological functions in human body, it is also the main component of thrombosis and calculus. So eating too much high cholesterol food will lead to arteriosclerosis and increase the probability of hypertension.
3. carbohydrates
Carbohydrates in pork mainly exist in muscle and liver in the form of glycogen.
The nutrition of pork is very comprehensive. Besides protein and fat, it also contains calcium, phosphorus, iron, thiamine, riboflavin and nicotinic acid. Pig lean meat also contains hemoglobin, which can supplement iron and prevent anemia. Hemoglobin in meat is better absorbed than that in plants, so eating lean meat to supplement iron is better than eating vegetables.
Step 4 extract
When pork is cooked, some flavor substances can be dissolved, which are extracts, including nitrogen-containing extracts and non-nitrogen-containing extracts. Nitrogen-containing extracts include nucleotides, inosine, free amino acids and purine bases. The composition of extract is closely related to the flavor and taste of meat, especially the content of nitrogen-containing extract is very important to the thick and umami flavor of broth. Extracts can generally promote appetite and increase digestive juice.