Why can low temperature preserve food? How much is the low temperature storage?

Low temperatures can preserve food and prevent it from spoiling easily, so there are cellars and refrigerators, because some microorganisms find it difficult to reproduce or even survive at low temperatures. So why can low temperatures preserve food? What is the general temperature for low temperature storage?

Why low temperature can keep fresh

Low temperatures can preserve food mainly because they can reduce the reproduction rate of microorganisms in food. Below 10°C, the reproduction capacity of most microorganisms and spoilage bacteria is greatly weakened. When the temperature drops below 0°C, microorganisms have basically stopped decomposing food, and when the temperature drops below -10°C, most microorganisms will not survive. Low temperatures can also reduce the activity of enzymes in food and microorganisms.

How many degrees is the low temperature storage of food

Low-temperature food storage includes refrigeration and freezing.

Storing food at -1~10℃ is called refrigeration, while freezing food means storing food at -18℃. Due to different temperatures, the types and duration of food storage are also different. For example, refrigeration can only store food for a short period of time (usually a few days or weeks), and is mostly used to store vegetables and fruits. The lower the temperature, the better the storage of animal foods such as meat. Therefore, the effect of freezing animal foods is better.

When freezing food, the microorganisms in the food will be directly frozen, inhibiting the activity of microorganisms or even directly killing the microorganisms. Therefore, food can be preserved for a longer period of time. However, freezing the microorganisms will also affect the taste, flavor and nutritional value of the food itself.

Although it is convenient to store food at low temperatures, the effectiveness of low-temperature preservation is not only affected by temperature, but also by the number of bacteria, type of microorganisms, refrigeration time, and the composition characteristics of the food itself, so it is not all right if you just keep it at low temperatures!

Why some dry foods don't spoil easily

First, let’s look at what can cause food to spoil.

Food spoilage is mostly caused by microorganisms, which need temperature, water, pH, and nutrition for reproduction and secretion. Lowering the temperature, reducing the air content, and increasing the osmotic pressure can all cause food spoilage. The main reason is microorganisms.

Microorganisms exist everywhere in the environment. Food is easily contaminated by microorganisms during production, processing, transportation, storage and sales. As long as the temperature is suitable, microorganisms will grow and multiply, decomposing the nutrients in food to meet their own needs.

Therefore, dry food does not spoil easily, oily food does not spoil easily, and cold food does not spoil easily.