Food safety and food hygiene issues have been raised in China. Although the government is making unremitting efforts for it, food safety issues are still commonplace. Recently, some netizens have released pictures showing that in the Changmao Wal-Mart Supermarket Changfeng Store, A salesman in a white shirt is stepping on the freezer that sells cooked meat, and at the foot is the cooked food being sold. After the posting of the net post, the netizens were highly concerned, and many netizens expressed their concerns about the food safety of the supermarket.
As we all know, cooked meat food is a food that directly enters the mouth of the consumer. Preserving the cooked meat with the cooked meat cabinet can prevent the cooked meat food from being contaminated by bacteria, and the low-temperature cooked meat cabinet can also maximize the preservation of the product. In addition to the deli cabinet, China has made unremitting efforts on how to preserve meat.
The anti-corrosion preservation of cooked meat products has long been a major research topic for researchers in various countries. The factors that cause deterioration of meat products are: microbial contamination and growth and reproduction, fat oxidative rancidity, gas discoloration of myoglobin. These three factors multiply, such as the proliferation of microorganisms will promote oil oxidation and myoglobin discoloration, and oil oxidation will also change the microbial strain and promote the discoloration of myoglobin. The preservative preservation of meat products is mainly based on the above factors causing the spoilage of meat products, and some measures are taken to reduce or inhibit the occurrence of the above factors. At present, traditional preservation techniques and modern preservation techniques are generally combined to achieve better preservation effects.
Low temperature refrigeration technology: general microbial growth and reproduction temperature range is 5 ° C ~ 25 ° C, the appropriate temperature is 20 ° C ~ 40 ° C, 45e above and -18 ° C below the general microbes have no growth potential. Refrigeration is the preservation of meat products at temperatures slightly above their freezing point, usually between 2 ° C and 4 ° C. Most pathogenic bacteria stop breeding in this range, but psychrophilic bacteria can still grow. Effective temperature control, low temperature refrigeration, can effectively inhibit the growth and reproduction of residual microorganisms in meat products, can extend the product storage period without changing the physical and chemical state of meat products. However, this method also has some shortcomings. For example, the freezing and thawing process will cause the quality of the meat to decrease due to the formation of ice crystals and salting out; if the packaging is poor, the surface moisture will sublimate and cause "frozen burning". The transportation cost is high during cold storage. In addition, China's cold chain system is still not perfect.
Heat treatment technology: heat treatment is used to kill spoilage bacteria and pathogenic bacteria present in meat products, which can play a role in inhibiting bacteria and destroying enzymes. If it is heated to 70 ° C in the center of the meat product, the heat-resistant buds remain, and the pathogenic bacteria have basically died. When heated to a central temperature of 120 ° C, the heat-resistant Bacillus licheniformis can be killed in a few minutes. All microorganisms in the body "but heating can not effectively prevent the oxidation of oil and myoglobin, but it has a promoting effect, so the heat-treated meat products must be combined with other preservation techniques.
Fermentation treatment technology: The suitable pH value for microbial growth is 6.5-9.0. When the pH value of meat products is reduced to a certain acidity, it can be more effective in inhibiting the killing of certain microorganisms than in alkaline environment. Fermentation treatment is utilized. The artificial environment control makes the lactic acid bacteria in the meat products become the dominant bacteria, converts the carbohydrates in the meat products into lactic acid, and lowers the pH value of the products, thereby inhibiting the growth of other microorganisms.
Vacuum packaging technology: Oxygen is an important factor affecting the shelf life of meat products. At present, vacuum packaging technology has been widely used in food preservation. The functions of vacuum packaging mainly include: inhibiting the growth of microorganisms; preventing secondary pollution: slowing down the rate of fat oxidation; making meat products clean and improving competitiveness, etc. "China uses vacuum packaging for the preservation of meat products more and more widely.
Modified atmosphere packaging technology: The fresh-keeping mechanism of modified atmosphere packaging is to reduce the biochemical changes of packaged foods and inhibit the growth of microorganisms by filling a certain component of gas into the packaging bag to destroy or change the gas conditions for the microorganisms to survive and reproduce. To achieve the purpose of preservation and preservation. There are three kinds of gas commonly used in modified atmosphere packaging: (1) CO2, which can change the pH value of meat products and inhibit the growth of aerobic bacteria, thereby delaying the occurrence of spoilage, but has no effect on anaerobic bacteria and yeast; (2)02 Maintain oxygenated myoglobin, make meat bright, and inhibit the growth of anaerobic bacteria, but also provide conditions for aerobic bacteria; (3) N2, can prevent mold growth, anti-oxidation without affecting meat products Color, and since N2 is an inert gas, it can be used as a filling gas. At present, high CO2 inflatable packaging is commonly used internationally.
Vacuum freeze-drying technology: Vacuum freeze-drying technology is referred to as freeze-drying technology. The consumption of freeze-dried food in Europe, America and Japan is large, and the consumption of freeze-dried food in China is also increasing year by year. Freeze-drying technology is to quickly freeze the food and then sublimate and dehydrate it. It not only maintains the color, aroma, taste and shape of the food, but also maintains the nutrients in the food to the utmost. The freeze-dried food does not require refrigeration equipment, and only needs to be sealed. It can be stored for a long time and is light in weight, but the disadvantage is that the processing cost is high.
Preservative preservation: Meat is susceptible to microbial contamination in all aspects of production, storage, transportation, packaging, sales and consumption. How to prevent the corruption and deterioration of meat has attracted more and more attention. It is a more effective method to extend the shelf life of food by adding a preservative to the meat. Preservatives used in food production enterprises are mainly classified into chemical synthetic preservatives and natural preservatives. Due to the low cost of chemically synthesized preservatives, the preservatives commonly used in the food industry in the world are mostly chemically synthesized preservatives.
However, long-term research has found that some chemical synthetic preservatives have problems such as carcinogenicity, carcinogenicity, teratogenicity and food poisoning. In addition, chemical synthetic preservatives may have certain side effects if used improperly, and long-term excessive intake. It will cause certain damage to the health of the body. For children, pregnant women and other special people who have special periods of physical development, excessive consumption of certain chemical synthetic preservatives will affect their health. As recently reported, benzoic acid and its sodium salt have a superimposed poisoning phenomenon, which can cause allergic reactions and have certain irritation to the skin, eyes and mucous membranes. Sodium benzoate can cause intestinal discomfort, plus a bad taste (sodium benzoate can taste a minimum of 0.1%), and in recent years, its application has become narrower. These problems with chemically synthesized preservatives force people to pursue broad-spectrum, high-efficiency, low-toxic, safe natural preservatives. Natural antiseptics are increasingly favored by researchers because of their strong antibacterial properties, safe and non-toxic, good water solubility and wide range of effects. In addition, the continuous improvement of natural preservative production process also makes the use of natural preservatives more The more widely it comes.
In addition to the above technology, it is more important to pay attention to the separation of raw and cooked foods during food processing and storage. Because the food is cut by the knife that cuts the raw food, the container of the raw food is filled with the cooked food, and the cooked food may be contaminated by bacteria, parasite eggs, etc. on the raw food, thereby endangering human health. Therefore, raw and cooked foods should be placed and processed separately to avoid direct or indirect contact with raw and cooked foods.