High-quality protein, vitamin A, vitamin B2 and calcium. The protein in milk accounts for about 3%.

Milk refers to the general term for fresh milk and all products made with milk as the main raw material, including raw milk, pasteurized milk, ultra-high temperature sterilized milk, yogurt, milk powder, condensed milk, butter, Ice cream, ice cream, cheese and other products.

The fresh milk that people drink mainly comes from cows, buffaloes, sheep, and horses. According to the traditional production method, after fresh milk is squeezed out, it is transported from the pasture to the processing plant. It goes through several links: that is, small tanks from the milk producer are poured into large tanks (barrels) from the purchaser, and then transported to the milk processing plant. In a stainless steel refrigeration tank, the milk is cooled to below 10°C in about an hour.

This decentralized collection method is prone to quality problems. If a can of spoiled milk is poured into a large can, it will affect the quality of the entire can. Therefore, it is very important to strengthen quality inspection and fully clean and disinfect large and small tanks and barrels in a timely manner. The deterioration of fresh milk is mostly caused by the proliferation of bacteria.

Spoilage may also occur due to the breakdown of proteins or the oxidation of fats. Raw milk already contains a lot of bacteria. According to statistics, the milk in cows contains more than 500 bacteria per milliliter. When the number of bacteria per milliliter of milk increases to 107, the milk will show obvious spoilage. Therefore, the key to controlling the quality of fresh milk lies in timely cooling and sterilization, strengthening the disinfection of containers and preventing secondary contamination.

Fresh milk is a good culture medium for microorganisms. It has a large moisture content, a pH value close to neutral, a high content of fat, protein and lactose, and is rich in nutritional value.