CONCEPT OF SHELF-LIFE EXTENSION:
Chitosan is a polymer which is extracted from chitin. It is natural, and thusly biodegradable and biocompatible. As a novel food preservative, chitosan offers the possibility to form edible film coatings on fresh or processed perishable foods in order to extend their shelf life. The chitosan film has antimicrobiological properties which allow it to protect the food it is coating. In most foods, microbial contaminations occur predominantly at the surface, meaning using edible films such as chitosan allows minimal space between the foods’ surface and its’ environment. However, the coating has weak mechanical properties, and is permeable for gas and water vapour. Blending chitosan with starch improves its mechanical properties and allows a better novel food preservative.
ADVANTAGES:
- As chitosan is the second most abundant carbohydrate after cellulose, it’s not unusual that its waste exceeds 25bn tonnes per year. Using chitosan as a food preservative allows for reuse of this waste, making its use environmentally beneficial; while also reasonably cheap and cost-effective in production and usage.
- Its biodegradability also allows chitosan biofilms to be beneficial to the environment.
- The chitosan film has antibacterial and antifungal properties, meaning that it ultimately prolongs shelf-lives of the foods which it coats.
- As chitosan film is a polysaccharide which physically coats the food product, it offers the advantage of being edible,