The preservation and preservation of meat has been an important subject for human research since ancient times. With the change of lifestyle and rhythm of modern people, traditional meat preservation technology can no longer meet people's needs. Therefore, it is imperative to thoroughly study the preservation and preservation technologies of meat. Row. Domestic and foreign scholars have extensively studied the preservation of meat. At present, it is considered that any kind of preservation measures have their shortcomings, and comprehensive preservation techniques must be used to give full play to the advantages of various preservation methods to achieve the purpose of complementing each other and multiplying the effects. The corruption of meat is mainly caused by three factors: (1) microbial contamination, growth and reproduction; (2) fat oxidation failure; (3) myoglobin gas discoloration. The interaction of these three factors, microbial reproduction will promote the oxidation of lipids and myoglobin discoloration, and oxidation of lipids will also change the microbial flora and promote the discoloration of myoglobin, the author reviewed the current methods of preservation of meat preservation. 1, the traditional meat preservation technology 1.1 low-temperature refrigeration and preservation Freshness is the commonly used technical measures, in view of China's national conditions, the cold chain system is the meat of the most important means of preservation. Refrigeration is the preservation of meat at a temperature slightly above its freezing point, usually between 2 and 4 °C. In this range, most pathogens stop breeding, and chills and spoilage bacteria can still grow. It has recently been discovered that Li Sixing has a single core. Proliferative bacteria and Y. enterocolitica can also be propagated. The growth rate of bacteria in the meat is quite fast. Under appropriate conditions, some bacteria reproduce only for 20 minutes or less. In fact, under normal circumstances, such fast rates cannot be achieved because all the environmental conditions are met simultaneously. Impossible, bacterial growth period depends on the species, nutrient composition and temperature, PH value and water activity, the following disadvantages of low temperature preservation: (1) freezing and thawing process will be due to the formation of ice crystals and salting effect, so that The quality of meat is declining; (2) If the packaging is poor, the surface moisture will sublimate and cause "freeze-burning" phenomenon; (3) The transportation cost is high when the frozen quail. 1.2 Low moisture activity Fresh water activity is not the total moisture content of the food, but the moisture that the microorganism can use. The rate of propagation of microorganisms and the type of microbiota composition depend on the water activity (AW). Most bacteria can only reproduce in the substrate with AW higher than 0.85. Botox water activity requirement is 0.94--0.96, Salmonella is 0.92, general bacteria is 0.90, and Staphylococcus aureus is 0.87--0.88. When water activity is lowered To about 0.7, most of the microorganisms are inhibited and reported by RELSS. 45 kinds of Penicillium can be isolated inside and on the surface of meat products. Only the Aspergillus can grow at the low water activity and high temperature. Low-moisture activity preservation methods include drying and adding salt and sugar. Other additives such as phosphate, starch, etc. can reduce the water activity of meat. 1.3 Heat treatment Heat treatment is a fresh-keeping technique used to kill spoilage bacteria and pathogenic bacteria present in meat and inhibit enzyme activity that can cause spoilage. Although heat treatment can play a role in inhibiting bacteria and inactivating enzymes, it cannot be heated. To prevent the oxidation of lipids and myoglobin, but to promote the role, so heat treated meat products must be used in conjunction with other preservation methods. 1.4 Fermentation Treatment Fermentation meat products have better preservation characteristics. It is controlled by artificial environment. The growth of lactic acid bacteria in meat products is dominant, and the carbohydrates in meat products are converted into lactic acid, and the PH value of the products is reduced, while the others are inhibited. The growth of microorganisms and the processing of meat products for fermentation must also be combined with other preservation techniques.
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