There are three main reasons for food deterioration:
1, microorganism. There are microorganisms everywhere in the environment, and food is easily contaminated by microorganisms in the process of production, processing, transportation, storage and sales. As long as the temperature is appropriate, microorganisms will grow and reproduce, decompose nutrients in food and meet their own needs. At this time, the protein in food will be destroyed, the food will become smelly and sour, lose its original toughness and elasticity, and the color will also change.
2, the role of enzymes. There are many kinds of enzymes in animal food. Under the action of enzymes, the nutrients in food are broken down into a variety of low-grade products. Usually rice turns sour and fruit rots, that is, carbohydrates are decomposed and fermented by enzymes.
3. Chemical reaction of food. Oils and fats are easily oxidized, resulting in a series of chemical reactions. Oil has a strange smell after oxidation, such as fat turning from white to yellow.
Deteriorated food not only changes in appearance, but also loses the color, fragrance and taste quality of the original food, and its nutritional value will also decrease, and it will also contain corresponding toxins harmful to human health.