Low temperature meat products are packaged meat products whose sterilization temperature does not exceed 100 ℃ during processing. To a large extent, the destruction of nutrients is reduced. The product is rich in fat and protein, high in water activity, and has a good taste. It is popular with consumers. However, due to the low processing temperature, the microorganisms in the product cannot be completely killed. Improper operation in the process of production, storage and sales will cause microbial pollution and lead to deterioration of products. Especially in the summer when the temperature is relatively high, it is more likely to happen. A large area of product quality problems will bring irreparable economic losses to enterprises, affect the reputation of manufacturers, and dampen the confidence of consumers. In order to ensure the quality and safety of low-temperature meat products, every year in late spring and early summer, as the temperature rises, meat products enterprises should formulate and implement a series of measures such as strict health management, raw and auxiliary materials receiving, formula anti-corrosion scheme optimization, etc. The author has worked in the meat product industry for many years, and combined with his accumulated practical work experience, he talks about the safe passage of meat products in summer and its countermeasures.

Low temperature meat products are packaged meat products whose sterilization temperature does not exceed 100 ℃ during processing. To a large extent, the destruction of nutrients is reduced. The product is rich in fat and protein, high in water activity, and has a good taste. It is popular with consumers. However, due to the low processing temperature, the microorganisms in the product cannot be completely killed. Improper operation in the process of production, storage and sales will cause microbial pollution and lead to deterioration of products. Especially in the summer when the temperature is relatively high, it is more likely to happen. A large area of product quality problems will bring irreparable economic losses to enterprises, affect the reputation of manufacturers, and dampen the confidence of consumers. In order to ensure the quality and safety of low-temperature meat products, every year in late spring and early summer, as the temperature rises, meat products enterprises should formulate and implement a series of measures such as strict health management, raw and auxiliary materials receiving, formula anti-corrosion scheme optimization, etc. The author has worked in the meat product industry for many years, and combined with his accumulated practical work experience, he talks about the safe passage of meat products in summer and its countermeasures.

I. Microbial indicators of raw and auxiliary materials

Raw meat is the most important ingredient in meat product processing. Raw meat is the most important factor that directly affects the shelf life. If the raw meat is in a good sanitary condition, the shelf life of the product is guaranteed. Otherwise, the product has a great risk. Therefore, when selecting suppliers, we must select qualified manufacturers with good sanitary conditions and ISO9000 and HACCP certification as qualified suppliers. When receiving raw meat, the microbial index shall be strictly controlled to be ≤ 100000 pieces/g. It is strictly prohibited to use raw materials that are green, deteriorated and have peculiar smell. The author suggests that chicken mash or chicken bone paste should not be used in summer unless the enterprise has a strong sanitary inspection level. In terms of excipients, although the proportion of excipients added in the formula is small, its impact on the product shelf life is often ignored. The quality problems of products added with chili powder are often caused by chili powder. At the same time, attention should be paid to the storage temperature when storing auxiliary materials, and measures such as dust prevention, moisture-proof and rat prevention should be taken to ensure ventilation, shade and dryness.

II Workshop Management

(1) When employees enter the workshop, they should strictly follow the disinfection procedures for hand washing and foot disinfection. After entering the workshop, the staff shall flush their hands with clean water, then wash them with hand sanitizer, clean them with clean water, dry them with hand dryer, and sterilize them with 75% alcohol.

(2) The raw meat should be thawed naturally as much as possible, and the ambient temperature should be controlled below 18 ℃ to avoid high temperature thawing. After thawing, the center temperature of raw meat shall be controlled within - 2~4 ℃ (raw meat for injection shall be controlled within 0~4 ℃) to prevent excessive thawing.

(3) Sanitation of tools and equipment. The dressing table, cutter, hopper car and production equipment meat grinder, saline injection machine, filling machine, fumigation furnace and secondary sterilization equipment shall be brushed and disinfected at least twice per shift, and the defrosting rack shall be brushed and disinfected once per cycle. Rinse with clean water (if not, use 82 ℃ hot water for washing), then disinfect with 2 ‰~5 ‰ chlorine dioxide for 5min, and finally rinse off the residual chlorine dioxide with clean water.

(4) The raw material defrosting room, filling room, and curing room are hot processing workshops. The sewage is thoroughly cleaned every day, and 2 ‰~5 ‰ chlorine dioxide is used for disinfection to keep the waterway unblocked and avoid bacterial growth and reproduction. Disinfect the defrosting room, filling room and curing room every 2h. Personnel entering and leaving the sterile room should be hand washed and foot sterilized. Before operation, they must wear disposable gloves and masks that have been disinfected. During the production process, personnel, cases, knives, etc. should be disinfected with alcohol every 20 minutes; Disinfect the floor and wall once every 1h. At the end of production, tools and personal appliances shall be thoroughly cleaned and disinfected, and non packaging personnel are not allowed to touch the products. Work clothes are washed and disinfected once a day.

(5) Workshop temperature control. The ambient temperature should be controlled below l8 ℃, and the temperature of the curing warehouse must be controlled at 0-4 ℃; The temperature of the filling operation room shall be controlled below 15 ℃. If the filling operation is carried out in a sterile room, the ambient temperature shall be controlled below 12 ℃. During production, the ground cannot be cleaned with alkaline water.

(6) Production arrangement. The semi-finished products shall not be overstocked between processes, and the time between each process shall not exceed 30min. As there is no sterilization treatment in the semi-finished products, the growth rate of bacteria and microorganisms is fast, and the production process must be completed as soon as possible. If the production process can not be coordinated, resulting in a backlog of semi-finished products, the semi-finished meat filling should be put into the curing warehouse for cooling to ensure that the temperature of the meat filling is kept below 4 ℃.

(7) Packaging room management. The cutting, sorting and vacuum packaging of products shall be carried out in the sterile room. The ambient temperature shall be controlled below 12 ℃, and the ground shall not be cleaned with alkaline water during production. Personnel entering and leaving the sterile room shall wash their hands and disinfect their feet. Before operation, they must wear disposable gloves and masks that have been disinfected. During the production process, personnel, cases, knives, etc. shall be disinfected by alcohol spraying every 20 minutes: the floor and walls shall be disinfected once every 1h. At the end of production, tools and personal appliances shall be thoroughly cleaned and disinfected, and non packaging personnel are not allowed to touch the products. Work clothes are washed and disinfected once a day. Sterilization of the sterile room shall be conducted with ultraviolet ray for 3 times per shift. The products are placed in sterilized baskets and boxes. The baskets and boxes cannot directly contact the ground to prevent pollution.

(8) Secondary sterilization. The packaged products should be sterilized again as soon as possible. During sterilization, the product must not be stacked to avoid incomplete sterilization. Enterprises with large production can use secondary sterilizer for continuous sterilization. After secondary sterilization, it should be immediately put into 0~4 ℃ cold water. The secondary sterilization and cooling water should be kept clean, free of dirt, and the water should be replaced in a timely manner

III. Use of preservatives

Low temperature meat products cannot kill all bacteria and spores in meat products due to low sterilization temperature. Adding appropriate preservatives can effectively inhibit the growth and propagation of microorganisms in the products, and ensure the quality and safety of meat products within the shelf life. At present, the preservatives that can be used in meat products within the scope of GB2760-2014 Hygienic Standard for the Use of Food Additives include potassium sorbate, sodium dehydroacetate, lactic acid streptococcin, sodium diacetate, etc. Sodium lactate is a water retention agent in the national standard, but because of its role in reducing water activity, and also has a good antiseptic effect, it is basically added in the formula of low-temperature meat products. The higher the amount added, the better the effect will be. However, if the amount added is too high, it will make people feel astringent. Generally, the amount added should be controlled within 3.5%. Other organic preservatives, such as lysine, protamine and other new preservatives, have a certain antiseptic effect. Due to cost constraints, they are not commonly used at present. Sodium dehydroacetate has a good antiseptic effect, but it has a strong pungent smell and is not very popular. The cost is not high, the effect is good, and there is no peculiar smell. The most suitable preservative for meat products is sodium diacetate, lactic acid streptococcin, and potassium sorbate. The experiment proved that, under normal conditions, the product added at low temperature (under the cooking condition of sterilization at 95 ℃ for 30min), NISIN (0.01%), sodium diacetate (0.07%), sodium lactate (3%), potassium sorbate (0.05%). In terms of meat filling, the effect of several preservatives used together is better. However, in summer, in order to ensure that the product does not have quality problems, the dosage of preservatives should be appropriately enlarged, but should not exceed the national standard limit.

IV. Selection of Packaging Materials

The inner packaging materials also have a very important impact on the product shelf life. The inner packaging materials with good barrier performance should be selected. At present, food packaging materials include PA, PVDC, EVOH, aluminum foil bags, etc. The structure, ingredients, additives, storage conditions, sterilization methods and packaging forms of different product contents are different, and packaging materials are also different. PVDC and EVOH are high barrier materials, but EVOH has stable performance at low temperature, but its performance of oxygen and water vapor barrier drops sharply in the environment with high humidity. PVDC is different. Its barrier performance is not affected by ambient temperature and humidity. This material should be used as much as possible in summer. Due to China's vast territory, large north-south span, large temperature difference between the south and the north, and the early summer weather in the south, more than 20 degrees of temperature will appear in April, the summer crossing plan can be implemented in April, and the summer in the north of the Yangtze River is late. It is suggested that the summer crossing plan should be implemented after the May Day holiday.

V. Conclusion

The shelf life of low temperature meat products is related to each link in the production process. Any problem in raw materials, auxiliary materials, production, packaging and sales will have a negative impact on the shelf life of the products. Because the temperature difference between winter and summer is large, and the temperature in summer is high, which is conducive to the growth of microorganisms, leading to product quality problems, Manufacturers of low-temperature meat products should adopt stricter production management measures during production in summer, and appropriately increase the dosage of preservatives to ensure the quality and safety of low-temperature products.