What causes food spoilage

There are roughly two reasons why food spoils. One is that the ingredients of the food itself cause the food to spoil, and the other is that people forget the expiration date and do not eat it when it is fresh, causing it to spoil and expire. Generally in summer, food spoils because the weather is too hot, and bacteria and mold are easy to breed. Generally, fried dishes or open food will spoil in about a day, and other reasons are also introduced below.

1. The so-called food spoilage refers to the change from quantitative change to qualitative change in the original color, aroma, taste and nutritional components of food after it is contaminated by harmful external factors, resulting in the quality of the food being reduced or completely inedible. This process is called food spoilage. Its essence is the decomposition and change process of nutrients such as protein, carbohydrates, fat, etc. in food.

2. Food spoilage is closely related to factors such as the condition of the food itself, the type and quantity of bacteria, and the environment in which the food is located. Whether the contaminated microorganisms in food can grow depends on environmental conditions such as temperature, humidity, oxygen, sunlight and other factors. In an aerobic environment, microorganisms carry out aerobic respiration, grow and metabolize quickly, and food spoils quickly. 3. Microbial action is an important cause of food spoilage. Bacteria, molds and yeasts; Bacillus, Pseudomonas and Proteus break down proteins; Pseudomonas fluorescens, Achromobacter and Bacillus albagenes break down fats; Bacillus subtilis and Bacillus solanacearum break down carbohydrates.

4. The composition and properties of the food itself, including tissue enzymes, nutrient composition, pH, moisture, osmotic pressure, etc. Environmental factors include temperature, humidity, ultraviolet rays and oxygen, etc.

5. Food spoilage due to the growth of microorganisms; oxidation and deterioration of food ingredients due to the action of oxygen in the air; the action of oxidase, peroxidase, amylase, protease, etc. contained in food promotes food metabolism, generates heat, water vapor and carbon dioxide, causing food spoilage; food spoilage due to the erosion and growth of insects and indirect and direct contamination by harmful substances.

6. The role of enzymes. There are many enzymes in animal food. Under the action of enzymes, the nutrients in food are broken down into a variety of low-level products. The spoiled rice and rotten fruits we often see are the result of carbohydrates being broken down by enzymes and fermented.

7. Chemical reactions of food. Fats are easily oxidized, producing a series of chemical reactions. The oxidized fats have a strange smell, such as fat will turn from white to yellow. Spoiled food not only changes in appearance, loses its original color, aroma and taste, but also has a reduced nutritional value and contains toxins that are harmful to human health.