[China Packaging Network News] Today, people's requirements for food health and safety continue to increase, food preservation and preservation has become a key development direction of the modern food industry. Driven by this demand, antibacterial packaging technology has been rapidly developed, and it has achieved remarkable results in extending the shelf life of foods and ensuring food quality and sensory quality. Antibacterial packaging As an important branch of active packaging, antibacterial packaging is a new packaging system formed by adding antibacterial substances to packaging. The combination of the two methods is flexible, such as adding the antibacterial agent directly into the packaging material, or coating or adsorbing the antibacterial agent on the packaging surface, or using a packaging material with an antibacterial effect, or using an ionic bond/covalent bond to make the antibacterial agent Curing on the surface of the packaging material, or using an independent antibacterial packet, can achieve the antibacterial and antiseptic effects of prolonging the period of microbial stagnation, slowing the growth rate of microorganisms, and reducing the number of microorganisms to survive. The development of antibacterial packaging has provided new methods for food preservation, and to a certain extent has reduced the dependence on food preservatives. Antibacterial agents are the core of the antibacterial packaging system. According to the nature of the species, it can be divided into three kinds of inorganic antibacterial agents, organic antibacterial agents and natural antibacterial agents. In practical applications, the mechanism of action of antibacterial packaging is also different due to different antibacterial agents: absorption type antibacterial packaging uses oxygen absorbers to inhibit microbial growth; solidification type antibacterial packaging cures antibacterial agents on the surface of packaging materials through food knots. Contact sterilization; release type antibacterial packaging using antibacterial gas antiseptic. In contrast, the third type of antibacterial packaging achieved sterilization of all corners of the package by virtue of the volatilization of gas, and its antibacterial effect was significantly better than the former two forms. Antibacterial principle and effect analysis of three kinds of gaseous antibacterial agents Release-type antibacterial packaging is an antibacterial packaging form in which the antibacterial gas generating agent is added into the packaging material or is made into an independent sachet/gasket and placed inside the sealed package. Ethanol, sulfur dioxide, and chlorine dioxide are commonly used gaseous antibacterial agents. As early as the 1970s, Japan has begun to use ethanol as a food antiseptic for soy sauce, spices, pickles, etc. Since its development, ethanol has become a very ideal food antibacterial agent with its strong penetration and bactericidal power. Its antibacterial mechanism is mainly manifested in three aspects: (1) The ethanol molecule interacts with the cell membrane of the cell, weakening its permeability to the cytoplasm, resulting in imbalance of cytoplasmic infiltration and leakage, causing the metabolic disorder of the bacteria; (2) The ethanol molecule reacts with the peptide chain of the bacterial protein molecule to denature it; (3) The higher the concentration, the higher the toxicity of ethanol. SO2 is an acidic oxide that reacts with water to produce sulfurous acid. This strong acid in the binary molecule enters the microbial cells, changing the pH of the microbial protoplasm, causing decomposition of the protoplasm and nucleic acids and killing microorganisms. SO2 is therefore also a strong The fungicide. When SO2 is used as an antiseptic agent for antibacterial packaging, SO2 generator (such as sodium metabisulfite, etc.) can be added to the packaging material to make a controlled-release antibacterial package, or it can be made into a separate package and put into a sealed package. It should be noted that sulfur dioxide gas has a stimulating chemical odor. Chlorine dioxide is considered to be a high-efficiency spectrum sterilizer. In the antibacterial packaging system, the main use of synthetic resin, water-absorptive resin polyacrylic acid and other materials adsorbed chlorine dioxide aqueous solution made of solid chlorine dioxide generating agent, packaged as an independent pouch In the sealed package, the sterilization effect is achieved during the slow release of low-concentration chlorine dioxide gas. Its sterilizing effect comes from its strong oxidizing ability, which can rapidly oxidize and destroy the tyrosine in the viral protein capsid, make the partial amino acid of bacterial microbial protein redox and decompose, control the synthesis of its protein, and promote its accelerated death. The chlorine dioxide sterilization packaging has many unique advantages over other traditional sterilization methods. The solid chlorine dioxide generator is specially prepared, its release rate is controllable, and the chlorine dioxide gas diffusion ability is strong, and at least one can be realized. More than a month's packaging is seamlessly sterilized. And chlorine dioxide gas itself is colorless and odorless, avoiding changes in food odors. Functional and Safety Issues for Released Antimicrobial Packaging Applications According to the above introduction, the release of anti-bacterial packaging according to the different antibacterial agents of its sterilization principles are also different, but its thorough and long-term antibacterial antibacterial methods have unparalleled advantages. Judging from the current status of application, this type of antibacterial packaging is still in its infancy. How to balance the relationship between its sterilization rate and sterilization effect, and how to ensure its safety, etc., need to be further discussed. The effect of gaseous antimicrobial agents on the physical properties of packaging materials. A part of the release type antibacterial package is prepared by adding the antibacterial agent itself or the antibacterial gas generating agent to the packaging material. During the process, the antibacterial agent fills the pores inside the material, so this method will generally cause the tensile strength of the packaging material, Mechanical processing properties such as burst strength and toughness, as well as gas permeability, water vapor permeability, moisture absorption, oil resistance, gloss, and the like, bring about subtle changes. It is recommended to increase the monitoring of the physical properties of the packaging materials during the development of such packaging to achieve a balance between antibacterial and packaging effects. Antibacterial gas production rate and permeability rate. For another part of the release type antibacterial package, the gas generating agent is encapsulated in a separate pouch and then put into a food package to form an antibacterial package, and the antibacterial agent is released by self-evaporation of the gas generating agent or slow reaction with water vapor. Gas, to achieve the purpose of sterilization. In this process, the “slow release†of the antibacterial gas at an appropriate rate is a key point in determining the sustainability of the antibacterial effect, which is rooted in the rate of penetration of the water vapor into the antibacterial agent packaging material and the rate at which the gas permeates the antibacterial agent packaging material. Taking ethanol gas as an example, the author tested the ethanol, gas, PC, AL, PET, and PE materials using the OR2/410 organic gas transmission rate test system and the W3/060 water vapor transmission rate test system of the Languang Packaging Safety Center. And the water vapor transmission rate. It is not difficult to find through the test data that the water vapor transmission rate and the ethanol transmission rate of each kind of material are quite different, and thus it can be used as a data basis for studying the changing rules of the generation, penetration, and diffusion rates of antibacterial gases. In addition, the data in the table comprehensively reflect the difference in the barrier properties between the two, which is basically the same. Therefore, the material's water vapor barrier property can be used to roughly estimate the organic gas barrier property of the material. However, the type of organic gas and the characteristics of the material will have an impact on the final data. Therefore, the error caused by this estimation method will become an important factor in the failure of the antibacterial packaging system and needs to be treated with caution. Antibacterial gas concentration control. The control of the gas concentration is mainly related to the generation rate and the permeation rate of the gas generating agent, and different kinds of antibacterial gases require different concentrations in the sterilization process. For example, with ethanol sterilization, foods with low water activity require 2% to 4% by mass of lower concentrations of ethanol for bacteriostasis, while high water activity foods require ethanol dosages of 0.002 to 0.004 mL/cm2. Should try to avoid using a high concentration of ethanol gas antibacterial, so as not to affect the natural flavor of food. For chlorine dioxide gas, if the concentration is less than 50mg/m3, there is basically no significant bactericidal effect, if the concentration is higher than 10% there is a danger of explosion. Therefore, effective control of the amount of antibacterial gas generated and the amount of penetration can both ensure the bactericidal effect and ensure the safety of the food and the surrounding environment. Antibacterial gas to the environment safety issues. Although the antibacterial gases used in the antibacterial packaging system, such as ethanol, chlorine dioxide, etc. are mostly of low concentration, their own flammability and explosive risk cannot be ignored. Therefore, regardless of the combination of antibacterial agent and outer packaging material, the permeability of the antibacterial gas to the outer packaging material needs to be considered to avoid the safety risk caused by the penetration of the antibacterial gas out of the packaging system and at the same time reduce the failure of the antibacterial packaging system. Chance. Puyang Degren Medical Equipment Co., Ltd. , https://www.degrenyuwei.com