How can modified atmosphere packaging technology improve the fresh-keeping value of food II
▲ modified atmosphere packaging of fresh meat of poultry and livestock
the modified atmosphere fresh-keeping packaging of fresh pork, sheep and cattle should not only keep the original red of fresh meat, but also be antiseptic and fresh-keeping. The gas of modified atmosphere packaging is composed of O2 and CO2. According to different types of meat, the gas composition is different. The gas composition of modified atmosphere packaging of pork is 60% - 70% O2 and 30% - 40% CO2. The shelf life at 0 ℃ - 4 ℃ is generally 7-10 days (including chilled pork that is cooled at 0 ℃ - 4 ℃ for 24h after slaughter to lose ATP active substances and become soft, fragrant and palatable). The modified atmosphere packaging of poultry meat is mainly anti-corrosion and fresh-keeping, and the fresh-keeping gas is composed of CO2 and N2. The poultry meat is packaged with 50% - 70% CO2/50% - 30% O2 at 0 ℃ - 4 ℃ for 14 days
in the modified atmosphere fresh-keeping packaging of meat, the use of high concentration of O2 can make the fresh meat keep bright red and bright. In the anoxic environment, the meat is light purple. For example, with CO2, N2 and other fresh-keeping gases, the meat color is light purple. If you need to implement a more accurate calculation, the fresh period can reach about 30 days. Fresh meat packaging materials also require the use of composite plastic packaging materials with high barrier to gas
▲ modified atmosphere fresh-keeping packaging of baked goods and cooked food products
baked goods include cakes, cakes, cookies, bread, etc., and the main component is starch. Spoilage caused by bacteria and mold, rancidity and deterioration caused by fat oxidation, aging and hardening of starch molecular structure, etc. cause food deterioration. The gas used in the modified atmosphere packaging of this kind of food is composed of CO2 and N2. Cakes without cream can be kept fresh for 20-30 days at room temperature. Moon cakes and pudding cakes can be kept fresh for 60-90 days at room temperature with high barrier composite film
filling CO2 and N2 into microwave dishes, bean products and cooked meat products of livestock and poultry can effectively inhibit the reproduction of coliform bacteria. Keep fresh at 20 ℃ - 25 ℃ at room temperature for 5-12 days, which can easily realize the exchange of accessories. After conditioning and sterilization at 85 ℃ - 90 ℃, keep fresh at room temperature for about 30 days, and keep fresh at 0 ℃ - 4 ℃ for 60-90 days
▲ modified atmosphere fresh-keeping packaging of fresh fruits and vegetables. After harvest, fruits and vegetables can still maintain the metabolism of absorbing oxygen and discharging CO2, while consuming nutrition. Fresh keeping of fruits and vegetables is to reduce the content of O2 in the environment and low temperature storage, reduce the respiratory progress, eliminate the CO2 produced by respiration, and delay the maturity and aging of fruits and vegetables, so as to achieve the fresh-keeping effect. The modified atmosphere packaging gas of fruits and vegetables is composed of O2, CO2 and N2. The fruits and vegetables are packed with breathable film, filled with low O2, high CO2 and mixed gas for replacement. Generally, the mineral oil with medium viscosity is adopted and sealed, so that the O2 content in the package is lower than the air and the accumulated CO2 is higher than the air. The gas exchange is carried out through the film, so as to achieve the modified atmosphere balance conducive to the fresh-keeping environment of fruits and vegetables and maintain weak aerobic respiration
most fruits and vegetables are packed in a mixed proportion of 5%o2, 5%co2 and 90%n2, and have a long fresh-keeping period at a low temperature of 6 ℃ - 8 ℃. Modified atmosphere packaging is used for litchi preservation and fresh-keeping. Treating litchi fruit with 10% CO2 + 90% N2 and 20% CO2 + 80% N2 for 24hr can not only achieve the purpose of fresh-keeping, but also improve the good fruit rate of the fruit, keep the peel red, and do not affect the nutritional components. With high CO2 and low oxygen conditions combined with ozone treatment (4.3mg/m3 concentration) and edible thin coating, the shelf life of strawberries can be extended by 8-10 days
the environmental protection benefit of Kochi in the United States is 10 points significant. The scientists used the modified atmosphere packaging test on mango, skinning and cutting the mango, using oxygen packaging, mixed gas (n286%, co210%, o24%) packaging and vacuum packaging respectively. The results showed that the mango packaged with mixed gas has the longest shelf life. During storage, the mango's color, texture and other appearance effects are good, and the damage caused by microorganisms is the least
modified atmosphere packaging is also suitable for fresh-keeping of clean vegetables. Clean vegetables, also known as cut fruits and vegetables and semi processed fruits and vegetables, are new food processing products for office workers. They are safe, fresh, nutritious and convenient, but they are prone to browning after cutting. Using modified atmosphere packaging to reduce oxygen content can maximize the shelf life. For example, cut lettuce in the United States prevents browning with 1% - 3% O2, 5% - 6% CO2 and 90% N2. Modified atmosphere fresh-keeping packaging is also suitable for the fresh-keeping of peeled and sliced apples, potatoes, leafy vegetables and other fruits and vegetables. Developing the packaging film suitable for the fresh-keeping effect of modified atmosphere packaging of fruits and vegetables is the key to broaden the way of fresh-keeping of fruits and vegetables
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