Milk, one of the oldest natural drinks, is as its name implies, squeezed out of a female cow. In different countries, milk is also divided into different grades. The most common ones are full-fat, low-fat and skim milk. There are also many milk additives on the market, such as high-calcium and low-fat milk, which emphasizes the addition of calcium.
Nutritional analysis contains nutrients per 100 grams of milk as follows:
Heat (54.00 kcal), Protein (3.00 g), Fat (3.20 g), Carbohydrate (3.40 g), Vitamin A (24.00 μg), Thiamine (0.03 mg), Riboflavin (0.14 mg), Nick Acid (0.10 mg), Vitamin C (1.00 mg), Vitamin E (0.21 mg), Calcium (104.00 mg), Phosphorus (73.00 mg), Sodium (37.20 mg), Magnesium (11.00 mg), Iron (0.30 mg), Zinc (0.42 mg), selenium (1.94 μg), copper (0.02 mg), manganese (0.03 mg), potassium (109.00 mg), cholesterol (15.00 mg).
The nutritional value of milk is very high, and the types of minerals in milk are also very abundant. In addition to the calcium we know well, the contents of phosphorus, iron, zinc, copper, manganese and molybdenum are all very high. The most difficult thing is that milk is the best source of calcium in the human body, and the calcium and phosphorus ratio is very suitable for the absorption of calcium. Complex species, at least more than 100 kinds, the main ingredients are water, fat, phospholipids, proteins, lactose, inorganic salts.
The general chemical composition of milk is as follows:
Milk (15 photos) Water: 87.5%
Fat: 3.5--4.2%
Protein: 2.8--3.4%
Lactose: 4.6% to 4.8%
Inorganic salt: about 0.7%
There are 20 kinds of amino acids that compose the human body protein, of which 8 kinds of amino acids cannot be synthesized by the human body (9 kinds for infants, and histidine is more than adult). These amino acids are called essential amino acids. If we include all essential amino acids in the protein we eat, this protein is called whole protein. The protein in milk is whole protein.
Inorganic salts in milk are also called minerals. Milk contains Ca2+, Mg2+, K+, Fe3+ cations, and PO43-, SO42-, Cl-, and other anions; in addition, trace elements I, Cu, Zn, Mn, and others. Calcium in nature is present in a compound state. Only passive and plant-assisted calcium bioactive compounds can be better absorbed and utilized by the body. Milk is rich in active calcium, and it is one of the best calcium sources for humans. 1 litre of fresh milk contains about 1,250 mg of active calcium, which is the first of many foods, about 101 times that of rice, 75 times that of lean beef, and thin. 110 times that of pork, it is not only high in content, and lactose in milk can promote human intestinal absorption of calcium, the absorption rate of up to 98%, thereby regulating the body's calcium metabolism, maintain serum calcium concentration, promote bone calcification. Absorption is especially critical for calcium supplementation. Therefore, the statement that "milk can supplement calcium" is scientifically justified.
For the elderly, milk has a big advantage, that is, cholesterol levels in milk are lower than many animal protein cholesterols (milk: 13 mg/100 g; lean: 77 mg/100). g). It is worth mentioning that certain ingredients in milk can also inhibit the amount of cholesterol produced by the liver, making milk also have a cholesterol-lowering effect.
The chemical composition of milk differs depending on the type, age, feeding method, time of milk collection, life and health status, and temperature of cattle. Moisture per 100 g milk approximately 87 g, protein 3.1 g, fat 3.5 g, carbohydrate 6 g, ash 0.7 g, calcium 120 mg, phosphorus 90 mg, iron 0.1 mg, thiamine 0,04 mg, riboflavin, 0,13 mg, niacin, 0,2 mg, ascorbic acid, 1 mg, vitamin A, 140 IU. The protein in milk is mainly phosphorus-containing protein, also contains albumin and globulin. All three proteins contain all essential amino acids. Milk fat is mainly palmitic acid, stearic acid glyceride, also contains a small amount of lower fatty acids such as butyric acid, caproic acid, caprylic acid and so on. In addition, it also contains a small amount of lecithin, cholesterol, pigments and so on.