New Materials and Technology of Food Packaging

    The application of food packaging technology will become the development trend in the future. The concept of "active packaging" originates from the "inert" packaging materials, which are usually selected by law or custom. It refers in particular to the packaging materials with "shielding" function, which are applied to food packaging and approved by current European regulations. Active technology packaging includes the interaction between packaging and gases in packaging and food. Active packaging can effectively maintain the nutrition and flavor of food. Due to the progress of material science, biology science and gas packaging, the technology of active packaging has developed rapidly in recent years. For example, the oxygen in the remaining space of packaging will accelerate the oxidation of food, and the deoxygenated active packaging system emerges as the times require. Deoxidizers have been used in food packaging since the 1970s. Among them, iron-based deoxidizer is a kind of deoxidizer with rapid development, and then nitrite, enzymatic catalytic system, organic deoxidizer, photosensitive deoxidizer and so on have been developed. If the active packaging system which can produce sterilizers, including ethanol and other sterilization systems, is to absorb food-grade ethanol onto a carrier and put it into food bags, food can be sterilized for a long time. The combination system of active sterilizing substances and packaging materials is to add sorbitol, sorbate, sodium benzoate, silver zeolite and other substances into the materials of packaging containers, and then manufacture and process them into containers to release the active ingredients slowly. When we study the fresh-keeping packaging of fresh fruits and vegetables, we find that ethylene is released from fruits and vegetables in the fresh-keeping packaging. When ethylene reaches a certain concentration, fruits and vegetables will rot faster. Therefore, ethylene absorbent should be added to the fresh-keeping packaging to accelerate the oxidation of ethylene released from fruits and vegetables, so as to achieve good fresh-keeping effect, reduce the ethylene content in the packaging and improve the fresh-keeping effect and prolong shelf life. The main nanoparticles used as oxidation catalysts are Fe3O4, Fe2O3, Co3O4, NiO, Pt, Rh, Ag and Pd.