Preservation characteristics of the hottest vacuum

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The preservation characteristics of vacuum fried food and vacuum nitrogen filled packaging

 vacuum frying technology organically combines frying and dehydration, making it widely adaptable to processing raw materials. Therefore, in the 1980s, this technology had a great development in the United States and Japan. The vacuum nitrogen filled packaging matched with vacuum frying is to fill the packaging container with inert gas nitrogen after removing the air, so as to effectively prevent the oxidation, mildew and moth eaten of the product, and achieve the purpose of moisture-proof, quality assurance, fresh preservation and extending the storage life of the product. Nitrogen filled food packaging is widely popular in Japan, the United States and other advanced countries, and has attracted great attention of the international community

 the vacuum fried foods that have been sold internationally include fruit apples, kiwi intelligent energy (600869) announcement, persimmons, strawberries, grapes, bananas, etc; Carrots, pumpkins, tomatoes, green beans, sweet potatoes, potatoes, garlic, green peppers, onions, etc. of vegetables; Beef jerky, fish fillet, shrimp, etc. for meat and aquatic products. In order to improve the added value of local products in rural areas, China has been active in the research and development of vacuum frying technology in recent years, and has successively developed vacuum frying products of fruits and vegetables such as bananas and apples

 the circulation and sales of vacuum fried foods are different from those of ordinary fried foods. Generally, fried foods are sold immediately after they are prepared without storage. However, because of their low moisture content, vacuum fried foods generally require a long retention period for circulation and storage at room temperature

preservation characteristics of vacuum fried food

 1 Hygroscopicity of vacuum fried food

the crispness of food is the characteristic of vacuum fried food. To maintain the crispness of fried food, its moisture content should be controlled within 5%. Therefore, the problem of moisture absorption (moisture resistance) during storage should be seriously considered. The strong hygroscopicity of vacuum fried food is mainly due to the expansion of vacuum fried food, and its product structure presents porous structure, so it has strong hygroscopicity. Different vacuum fried food has different hygroscopic capacity. The hygroscopicity of vacuum fried food of agricultural products is stronger than that of meat aquatic products

 in a word, vacuum fried food should be packed with nitrogen filled moisture-proof packaging to keep it crisp and still fail to reach a consensus and ensure a long shelf life. The packaging can select the nitrogen filling purity according to the different varieties of packaging, and directly vacuumize and fill nitrogen to create an anoxic environment for the packaged items, so that they can not only maintain their activity, but also inhibit their respiration and mold breeding, so as to keep the stored items dry and prevent mildew caused by moisture

 2 Oxidation of oil during preservation

vacuum fried foods have a porous structure, and a layer of oil is adsorbed on the surface of the pores. This layer of oil cannot be removed by centrifugation. Therefore, vacuum fried foods have a certain oil content. During the storage process of the machine, if the oil contacts with oxygen, the oxidation reaction of the oil will occur. The oxidation degree of the oil is measured by the price of peroxide

the food hygiene law has strict provisions on the peroxide price of products, and the products cannot exceed these standards when they reach consumers. Light, oxygen and temperature are the promotion factors of oil oxidation, i.e. peroxide price. The influence of these main factors is discussed below

(1) storage temperature

(1) the oxidation rate of grease is significantly accelerated with the increase of temperature, and the oxidation rate is increased by 2 times when the temperature increases by 10 ℃. When the vacuum fried food is packed with nitrogen, the effect of temperature on the shelf life of the food will be significantly reduced. The peroxide price of the product will exceed the standard when it is stored for 12 months at room temperature and 2 months at 50 ℃

(2) oxidation concentration

the test results of the effect of oxygen concentration on the peroxide value of vacuum fried food made in Japan show that the higher the oxygen concentration, the faster the oxidation reaction speed, and the faster the peroxide value rises. The oxygen concentration should be lower than 2% to make the shelf life of the product reach half a year; In order to make the shelf life of the product reach one year, the oxidation concentration should be less than 1%

vacuum nitrogen filled packaging of vacuum fried food

 1 Beautiful and generous packaging

vacuum fried food can not be satisfied with pure broken vacuum packaging, because there is a pressure difference (-600~ - 700mmhg) inside and outside the vacuum packaging, and the air will gradually penetrate into the packaging bag through the micropores of the packaging bag, making the fresh-keeping products prematurely corrupt and deteriorate. The vacuum nitrogen filled packaging can balance the internal and external pressure difference, isolate oxygen and moisture, which can not only ensure the quality of materials, but also make the appearance of goods beautiful and generous

2. Lightproofness of materials and packaging lightproofness of contents is an important consideration in the storage of vacuum fried products. Ultraviolet has a great impact on the quality of fried food. It is necessary for packaging to block the light with 550mm wavelength. However, from the sales point of view, consumers want to see the contents through the packaging. Therefore, a reasonable packaging is: when packaging with aluminum foil, print a picture of the product on the packaging box or punch a small hole so that consumers can observe the contents

3. Moisture proof and oxidation proof

vacuum fried food should be packed with nitrogen to avoid the rise of prices in contact with peroxide, but at the same time, gas retention should be considered. Vacuum fried food has good storage performance, but it is still necessary to master the storage conditions and use reasonable packaging. The product can be stored at room temperature for 12 months, but the quality can still meet the requirements

reprinted from: China Packaging News

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