Non-heat-treated or lightly processed food packaging

Currently, packaging technologies for non-heat-treated or lightly processed foods are constantly evolving and innovating. At the IFT annual meeting and the food exhibition, countries demonstrated their advanced technologies, and through the application of these technologies, the quality and safety of non-heat-treated or lightly processed foods were further guaranteed.

Ion-Ray Sealed AirCryovac's Charles Bar-more is an American expert in applying ionizing radiation to packaging. He believes that US regulatory authorities have not accepted new packaging materials for food radiation for many years. This is a 60-year history. A major obstacle to the further development of the technology. Only three companies in the United States use radiation for pasteurization to process raw beef. As with many traditional methods of operation, the beef is cut into pieces and placed in a stretch-formed polystyrene tray. This container has oxygen barrier properties and does not seal above; the dish is transported through a nitrogen spout. The (lower oxygen content) channels are exposed to electron beams or X-rays to reduce the pathogenic microorganisms they contain. Then, in a very clean environment, the plates are quickly heat-sealed and their packages filled with 80% oxygen and 20% carbon dioxide. This modified atmosphere packaging can promote the production of oxidized muscle cell red pigment and prolong its cooling. Shelf life in the chain.

Microwave killing was inspired by the microwave sterilization technology of Classica in the 1980s and Classica in the 1980s. Currently, the relevant industry associations, governments, and universities in the United States are developing this technology, which is to use microwave energy in a stressful environment. The sterilization of the packaged food takes only 2.5 minutes throughout the sterilization process.

Microwave sterilization generates a certain amount of heat, strictly speaking, it is not completely heat-free, but it can bring a long shelf life to foods placed at room temperature. However, foods are susceptible to oxidative deterioration even if they are affected by oxygen remaining in the package or impregnated in the barrier package.

Pulsed electric field sterilization In this technology, a rapidly circulating electric field is used to sterilize liquid foods, and the electric field can break microbial cell walls in foods to achieve sterilization. Howard Zhang, now in the US Department of Agriculture, said that the sterilized product can be transported to filling machines under sterile conditions for filling.

Ultra High Pressure Treatment (HPP)

George Sadler of the University of Technology, Illinois, hinted that the bag packaging materials used today should be replaced by special packaging materials for ultra-high pressure processing. Experiments have shown that the effects of temperature and pressure on ultra-high pressure processed food packaging lead to blistering and delamination of multilayer packaging materials. This effect may be due to gas molecules that remain between the material layer and the layer during the coating and lamination process, resulting in an expansion bubbling phenomenon during pressurization and decompression. The difference in the compressibility of plastics and metals in lamination can change the gas permeability. In addition, gas migration or immersion and heat seal strength are also responsible for this phenomenon.

U.S. regulatory agencies have not yet established relevant laws. Experts claim that ultra-high pressure treatment is an effective method for food sterilization and control such as Listeria. The technology is continuously improving and the pressure has been increased to 800 MPa, supplemented with high temperature or low temperature treatment to achieve the goal of stable shelf life of microorganisms at room temperature.

There are already many foods processed using HPP in the U.S. market. Fresh Foods introduced Gua-camole products, which are the front runners of Salsas products. The company’s products include jams, juices, and some refrigerated side dishes and meats. Menu Fresh supplies six HPP sterilized products, including pre-cooked fajita meat and chicken steak. Hormel supplies deli meat products such as sliced ​​ham, which are also processed using the HPP method. Despite problems with processing costs, packaging, and processing cycles, the current results of this method tell people that HPP is an effective method for ensuring food safety.

Active Packaging Active packaging can sense changes in the environment and change the packaging to accommodate this change. At present, most of active packaging mainly focuses on moisture control, oxygen removal, odor elimination, and incorporation of antimicrobial agents into packaging materials. Relevant smart packaging can sense and record changes such as temperature, location, and value, and finally control the production and circulation of products through signal modification. People in the food processing and packaging industry are working hard to combine non-heat treatment with active packaging to make active packaging an effective non-heating technology for wider application in food processing.

The Role of Antimicrobial Agents John Krochfa of the University of California summarized many cases of edible packaging and its combination with active substances, particularly antibacterial agents. At present, the main antibacterial agents used are neomycin, natamycin, ethylenediaminetetraacetic acid, p-aminobenzoic acid, lysozyme, benzoate and sorbic acid, lactic acid, oxalic acid, etc. The agent is coated or bonded on the surface or inside of the packaging material. This active packaging has a bactericidal effect in the use of non-heat treated foods. But at the same time, the bactericide can be precipitated from the packaging material into the food. Therefore, whether this new material can be widely used still requires further extensive research.

Air Liquide's BioMAP is the perfect combination of bioactive substances and modified atmosphere packaging. It should be clear that the application of any packaging material cannot be the final step in food safety control. To be precise, food packaging is one of the lines of defense in food safety protection systems. In theory, bioactive substances can always have the role of removing pathogens, producing antibacterial chemicals, controlling the growth of spoilage microorganisms. The use of biologically active substances in combination with other technologies can have unexpected effects, such as its combination with HPP and modified atmosphere packaging, oxygen attacks that kill pathogens, liquid carbon dioxide, and irradiation.

Surface Activation Joe Horhkhks of the University of Cornell proposed a method that could change the surface structure of the packaging material and enhance the activity of the active agent. The surface of the material that is "activated" promotes the formation of covalent species of the active agent, allowing controlled release of the active agent. For example, the release of methylcyclopropylene blocks the production of ethylene in fresh fruit, thereby prolonging the shelf life of fresh fruit. At present, this technology is continuously improving. Enzyme preparations have been implanted into the structure of packaging materials. Enzyme preparations can react with the contents of the packaging to change their properties.

Aseptic packaging of peracetic acid and hydrogen peroxide, which have the function of killing microbial spores, has been put into commercial applications. Anand Mohan of Pennsylvania State University and Charles Sizer of the International Federation for Processing and Development pointed out that surface active peroxyacids can inactivate bacteria such as Bacillus subtilis. When 2% of peracetic acid is used in combination with octanoic acid, spores of Bacillus can be killed within 50 seconds at 50°C-70°C. This method has a significant bactericidal effect on packaging materials. The researchers believe that its bactericidal effect comes from hydroxide, hydrogen peroxide and peroxide.

Source: China Food News