In the process of circulation of commodities, not only the types, specifications, and quantities, but also many links. There is an opportunity for contamination with moldy and tainted microorganisms at all stages of commodity circulation. If there are suitable environmental conditions around the product, the product will develop mildew. Therefore, in order to protect the goods safely through storage, distribution, sales and other links, it is necessary to carry out mold-repellent packaging for products susceptible to mildew. Anti-mold packaging technology currently has the following main types.
First, chemical agents anti-mold rot packaging technology Chemicals anti-mold rot packaging technology is mainly the use of anti-mold and anti-corrosion chemical agents to be packaged items, packaging materials for proper treatment of packaging technology. Some add the anti-mholeosal agent directly to a certain process; some spray or smear it on the surface of the product, and some need to soak the packaging material and then pack it. However, these treatments will affect the quality and appearance of some products to varying degrees. The use of anti-mildew preservatives for the sterilization mechanism is mainly to coagulate, precipitate, and denature bacterial proteins; some use antifungal and antiseptic agents in combination with the microbial enzyme system to affect bacterial metabolism; some use anti-mildew antiseptics to reduce the surface tension of bacterial cells. Increases the permeability of the cell membrane and breaks or dissolves the cells.
When using anti-mold antiseptics, anti-mildew antiseptics that are highly efficient, low-toxic, easy to use, cheap, and easy to purchase should be selected. At the same time, it is also required that the anti-mildew antiseptic does not affect the performance and quality of the commodity, has no corrosion effect on the metal, and requires the anti-mold antiseptic itself to have good stability, heat resistance and durability. Phenolics (such as phenol), chlorophenols (such as pentachlorophenol), organic mercury salts (such as phenyl mercury oleate), and organic coppers (such as copper naphthenate soap) are commonly used as anti-mushroom agents. Organic tin salts (such as triethyltin chloride) and inorganic salts (such as copper sulfate, mercuric chloride, sodium fluoride). Anti-mold and antiseptic agents have two major categories. One is anti-mold agents for industrial products, such as carbendazim, chlorothalonil, and sterilized Dan. The other type is a mildew-repellent agent for foods, such as benzoic acid and its sodium salt, dehydrogenated wax acid, thiophanate, and the like.
Second, gas phase anti-mold rot packaging technology gas phase anti-mold rot packaging technology is the use of volatile anti-mold antiseptic, the use of its volatile gases directly contact with moldy microorganisms, killing these microorganisms or inhibit their growth to achieve the goods Anti-mold rot purpose. Moreover, since the gas phase anti-mold rot is a gas phase molecule directly acting on the commodity, it does not have an adverse effect on its appearance and quality. However, packaging materials and packaging containers are required to have characteristics of low gas rate and good sealing performance.
Vapor-phase anti-mould rot has paraformaldehyde anti-mould agent. Paraformaldehyde is a polymer of formaldehyde that slowly sublimes to depolymerize at room temperature into a gas with a stimulating odor of formaldehyde, which can cause the bacterial protein to coagulate to kill or suppress the moldy rot microbes. When used, it is packaged into small packets or compressed into tablets. The agent, together with the product, is placed in a packaging container and sealed to allow it to sublimate and diffuse naturally. However, the formaldehyde gas sublimated from paraformaldehyde may combine with the water vapor of air to form formic acid under the condition of high temperature and high humidity, and it has corrosive effect on the metal. Therefore, products with metal accessories cannot be used. In addition, formaldehyde gas has a stimulating effect on human eye mucous membranes, so operators should do a good job of protection.
There is also an ethylene oxide anti-male agent. Ethylene oxide can bind to free hydrogen atoms in the carboxyl, amino, and hydroxyl groups of bacterial proteins, phenolic molecules, and generate hydroxyethyl groups, which can cause bacterial metabolism to die and die. Ethylene oxide molecular penetration greater than formaldehyde. Therefore, the bactericidal power is also stronger than that of formaldehyde, and it can also exert bactericidal action under low temperature and low humidity. Therefore, it is preferable to apply bactericidal and mildewproof rot to a product that cannot be heated and fear moisture. However, ethylene oxide can liquefy proteins, and can destroy vitamins and amino acids in foods, and it also leaves toxic chlorohydrins. Therefore, ethylene oxide can only be used for the anti-mold rot of daily-use industrial products, and should not be used as anti-mold rot for food and food.
Third, the modified atmosphere anti-mold rot packaging technology is one of the forms of ecological anti-mold rot. The three factors of air, moisture, and temperature are all related to the respiratory metabolism of moldy rot microbes and biological products. As long as one of the factors is effectively controlled, the purpose of preventing the occurrence of mildew in the commodity can be achieved. For example, as long as the concentration of oxygen in the air is controlled and regulated, artificially creating a low-oxygen environment, the growth and reproduction of moldy and rot microbes and the breathing of biological products themselves. Will be controlled.
Air-conditioned mildew-repellent packaging is to reduce the concentration of oxygen in the package under the conditions of sealed packaging, to reduce the concentration of oxygen, resulting in a low-oxygen environment to inhibit the life activity of microbial humic microorganisms and the respiratory intensity of biological products, so as to achieve The purpose of preventing moldy rot on packaged goods. This is also the principle of the modified tone mold.
Air-conditioning anti-mold and rot-proof packaging is a gas that is non-toxic to human body and has an inhibitory effect on moldy rot microbes. At present, carbon dioxide and nitrogen are mainly charged. The normal content of carbon dioxide in the air is 0.03%. Trace amounts of carbon dioxide have a stimulating effect on the growth of microorganisms; when the concentration of carbon dioxide in the air reaches 10% to 14%, it has an inhibitory effect on microorganisms, and if the concentration of carbon dioxide in the air exceeds 40%, the microorganisms are significantly suppressed and killed. effect. The packaging material must use gas-tight materials that have a certain resistance to gas or water vapor in order to maintain the gas concentration in the package.
The key to the air-conditioning, mold-repellent and rot-proof packaging technology is sealing and oxygen reduction, and the sealing of the packaging container is the key to ensure the air-conditioning and mold-removal protection. Oxygen reduction is an important part of the air conditioning and anti-mold rot. At present, the methods of artificial oxygen reduction mainly include mechanical oxygen reduction and chemical oxygen reduction. Mechanical oxygen reduction is mainly vacuum nitrogen filling method and carbon dioxide method. Chemical oxygen reduction uses a deoxidizer to reduce the concentration of oxygen in the package. (To be continued)