The role of modified atmosphere packaging for chilled meat

The editor of Mingwei Machinery will analyze the effect of modified atmosphere packaging on chilled fresh meat for you.

The packaging of chilled meat has several forms, such as vacuum packaging, nitrogen-filled packaging and modified atmosphere fresh-keeping packaging. Because the color of cold meat after vacuum packaging and nitrogen-filled packaging is darkened, the original fresh color of fresh meat is lost. Safe, shelf life three to five times longer than general packaging (2-3 days), the modified atmosphere packaging method (MAP)

In order to maintain the bright red color of fresh meat, oxygen should be filled in the sales packaging of fresh meat to maintain the color of the meat. The required oxygen content is related to the amount of myoglobin on the surface of the meat, usually It can be estimated according to the average requirement of 70~100 ml of oxygen per 100 grams of fresh meat. And introduce CO2 for anti-corrosion and fresh-keeping, the mixed gas can be composed of O2, CO2, N23 kinds of gas, N2 can prevent the collapse of the package caused by the loss of CO2 escape. Modified atmosphere packaging of red meat requires that the packaging material has good oxygen barrier properties to maintain the required oxygen partial pressure. In fact, after packaging, oxygen should penetrate into the atmosphere through the packaging film or penetrate into the packaging from the atmosphere, and its atmosphere environment is a dynamic balance. The CO2 concentration in the mixed gas should not be too high, because too high will reduce the formation of oxymyoglobin, generally not more than 30%. The Atmospak fresh meat modified atmosphere packaging system adopted by European countries has a mixed gas ratio of 70% O2 (volume fraction, the same below), 10% N2, 20% CO2 or 65%~80%O2, 20%~35%CO2, When the storage temperature is 1.6C, the sales period of pork is 10 days, and the sales period of ground beef is 10~12 days.

Since fresh poultry meat is not "red meat", it does not need to be filled with oxygen, but only needs to be filled with N2 and CO2. The commonly used ratio is 40% CO2 and 60% N2. When the storage temperature is 1.6C, the sales period is 10 days. Studies have shown that adding a small amount of CO to replace high oxygen in the modified atmosphere packaging of fresh meat can greatly extend the shelf life of fresh meat, and the shelf life of cooled pork can be extended to 2l days, and it can maintain a longer-lasting bright red color. CO can bind firmly to myoglobin to form carboxymyoglobin, giving meat a stable cherry red color. With the increase of CO concentration in the gas, the redness of the cooled meat increases and the color is more stable, but CO is a toxic gas, so the concentration of CO should be reduced as much as possible under the premise of ensuring a stable red color. Low-concentration CO gas mixtures (0.5% to 1.0%) do not have any harmful effects on consumers.