Introduction to Modified Atmosphere Packaging Operation Method
Modified atmosphere packaging is a relatively new technology in current food packaging, including deoxygenated packaging and air-filled packaging. There are many kinds of air conditioning methods, which are different due to different equipment conditions and gas concentration index requirements. In general, they can be divided into these types: natural oxygen reduction, nitrogen filling and oxygen reduction, optimal concentration index gas replacement, and decompression gas Modified atmosphere packaging.
(1) Deoxygenated packaging
① Mechanism: Deoxygenated packaging is the use of continuous nitrogen filling and then vacuuming to remove oxygen in the packaging container and then sealed packaging.
②Characteristics: Generally, 2%-3% of oxygen remains after treatment with this method, so it is often necessary to add small deoxidizer packages or deoxidizer flakes in the packaging bag. Commonly used deoxidizers include: reduced iron powder, ferrous salts, platinum membrane, glucose oxidase, ascorbic acid, oleic acid, etc.
③Application: This method is not suitable for the packaging of fresh fruits and vegetables due to the lack of oxygen in the packaging container.
(2) Inflatable packaging
① Mechanism: Inflatable packaging is to fill the packaging container with one or more gases and then seal the packaging. Commonly used filling gases are oxygen, nitrogen, and carbon dioxide.
②Characteristics: It is very important to choose the right gas and gas composition according to the packaged object. For fresh fruits and vegetables, it is necessary to reduce oxygen and inhibit respiration strength, but also to consider their tolerance to low oxygen and high carbon dioxide. It is generally believed that the composition of O22%-5% and CO23%-8% in the gas is for most Fruits and vegetables are suitable. At the same time, fresh fruit and vegetable products in inflatable packaging must be stored at an appropriate low temperature to prevent excessive breathing caused by high temperature, resulting in hypoxia and respiratory disorders.
③Application: For fresh meat and meat products, 60% CO2 and 40% N2 inflatable packaging are better. Hypoxia can prevent the formation of oxygenated hemoglobin and help maintain the bright red color of raw meat. It can also prevent the growth of aerobic microorganisms and the oxidative deterioration of unsaturated fatty acids in meat products. According to verification, the ham that has passed 60% CO2 and 40% N2 inflatable packaging has better performance than simple vacuum packaging in terms of oil leakage, degree of oxidation and storage time. However, there are also studies that believe that trace amounts of oxygen should be retained to inhibit the reproduction of anaerobic microorganisms.