Edible materials for food packaging and their applications

Packaging is very important for the quality of the food and for extending the shelf life. The principle of choosing food packaging materials is mainly to reduce the permeability of food storage. For example, the composite plastic material (PET AL LDPE) can play a role in blocking moisture and gas, but this kind of packaging material cannot be eaten at the same time as food, and the packaging waste cannot be naturally degraded, which will cause environmental pollution.
As human beings pay more attention to the living environment, scientists have been devoted to the research of edible packaging materials since 1990. Edible packaging material can not only be eaten together with food, but also can avoid environmental pollution and meet the needs of the green revolution. It is a welcome new packaging material.
Edible coating technology has been used in food for a long time. As early as 800 years ago, China used wax to coat the outer skin of citrus to prevent dehydration and preservation. In the 19th century, sucrose coating was used abroad to prevent oxidative rancidity in almonds and walnuts, and sucrose was used as an edible protection. Coated film; In the 1930s, wax, oil and water emulsions were sprayed on the surface of fruits to improve their appearance (such as color, hardness and brightness), control the maturity of fruits, and delay the escape of fruit moisture; later they adopted edible properties. Polysaccharides, such as alginate, cellulose ester, pectin and modified starch, are used to improve the quality of frozen and refrigerated meat.
In the 1990s, scientists studied the range of edible packaging materials including aroma components, antioxidants, antimicrobial agents, pigments, browning reaction terminators, and vitamins.
Any film-like, sheet-like, thin-layered packaging or coating that becomes part of a food and is edible is called an edible packaging material. Edible packaging materials should be classified as food ingredients or food additives. If edible packaging material can increase the nutritional value of food, it is a food ingredient; otherwise it is regarded as a food additive.
It can thus be seen that the classification of edible packaging materials is entirely dependent on its own use characteristics. Edible packaging materials should be as tasteless as possible or match the taste of the food. Although edible packaging materials have barrier properties against water vapor, air, and solute penetration, it is also necessary to add a layer of outer packaging in consideration of factors such as ease of carrying and hygiene.
The choice of edible packaging material depends on the characteristics of the food being coated: For storage of fruits and vegetables, selective membranes must be used to facilitate the respiration reaction (exchange of gases such as oxygen, carbon dioxide, and ethylene), and to prevent water loss and solute. Infiltration; For oxygen-sensitive foods such as polyunsaturated lipids, low oxygen permeability membranes must be selected.