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Factors Affecting the Quality of Vacuum Packing Preservation
Food is in the atmospheric environment and will be affected by temperature, moisture, oxygen and sunlight. At the same time, it will also be attacked by microorganisms, insects and mice. The oxygen content in the atmosphere is about 21% . Oxygen can oxidize the fats and oils in foods, make them discolor or discolor, reduce vitamin components, and produce a large number of harmful substances, changing the taste. Foods that are often in the atmosphere for a long time can cause spoilage and reduce freshness. The reason for this is mostly caused by the proliferation of microorganisms, including bacteria, molds and yeasts.
Under the influence of the given temperature and in the presence of oxygen, the growth and reproduction will be rapid and the food will be quickly corrupted. The water vapor in the atmosphere also has a great influence on food storage. Apart from promoting the growth and reproduction of emblems, its presence can also cause food deliquescence and loss of fragrance. In addition, high temperatures can accelerate the aging of fruits and vegetables, causing them to lose their value. The sun's ultraviolet rays can cause cracking of organic molecules, damaging commodities, and reducing their practical value. With the development of commodity economy, the scope of food circulation has been continuously expanding, and it is imperative to extend the shelf life of food.
The reasons for the above food deterioration can be caused by a single factor or by a variety of factors. For different factors, physical or chemical methods can be used to prevent it. Such as low-temperature refrigeration, high-temperature sterilization, dry food, or salted with sugar, salt, organic acids, add preservatives, drying, ultraviolet sterilization, radiation sterilization, functional film storage. Vacuum packed food is a simple and easy method. It removes the air from the bag and seals it again, isolating the food from the atmosphere. This prevents food oxygen
, mildew and spoilage, reduce discoloration and discoloration, keep vitamins A and C from depleting, and prevent color and flavor from changing.
The quality of vacuum package preservation depends on the following factors :
1 The better the degassing is, the less oxygen in the bag should be reduced to prevent the oxidation of foods and reproduction of the oxygenophilus and prolong the food.
Storage time.
The number of contaminated bacteria at the beginning of the second day is as small as possible. It is necessary to control the bacterial infection before food packaging, and also to prevent the food bags from being
Contaminated by microorganisms and insects.
3 The material of the packaging bag is selected to have low air permeability. The lower the air permeability, the better the retention after degassing, ie, the vacuum degree in the bag is maintained.
The better. For different packaging objects, selecting different performance materials will work. In addition, the sealing of the bag is also very important. If the sealing is not good, it will also lose its freshness.
4 The lower the gas content, the longer the shelf life of the package. Some foods have a high gas content. At that time, they looked good, but after a while, they found that there was swelling, which was caused by degassing.
5 material soft film, good adhesion after packaging.
6 After vacuum encapsulation, the food is kept at a low temperature and the shelf life will increase accordingly.
If vacuum-packed foods are stored at room temperature, the moisture content of foods must be below the limit of bacterial proliferation. Otherwise, vacuum-packaged foods need to use salt, sugar, organic acids, and preservatives as an aid to achieve a long-term preservation purpose.
In the past food industry, foods with poor preservation were generally treated with heat sterilization or refrigerated. The use of vacuum-packed foods can also be combined with heat sterilization, and the effect is better. However, it is better to refrigerate after vacuum packaging and have excellent results.
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