Depolymerization of Chitosan from Shrimp Shell Using Papain Enzyme and Ultraviolet Light Irradiation

Abstract

Chitosan is a natural polymer with a positive charge that is good for the pharmaceutical field as a drug carrier. However, commercial chitosan has a large molecular weight and a low degree of deacetylation, so the application is limited due to its low solubility in water. This study aims to determine the effect of the depolymerization method of two classes of chitosan on the market. The types of chitosan used to produce chitooligosaccharides were pharmaceutical and food grade. The treatments were depolymerization using UV-C light irradiation (75 minutes), papain enzyme hydrolysis (15 g/L for 16 hours, 40oC and pH 5), and the combination of UV and enzymes. The results showed that the grade of chitosan and the depolymerization method affected the product characteristics. The three methods used in pharmaceutical grade chitosan produce chitooligosaccharide that dissolved directly in water with a neutral pH. Chitooligosaccharide yields were >62%, whiteness degree of 99.33%, molecular weight <5.5 KDa, and degree of deacetylation >85%. Food grade chitosan depolymerized using different methods was not dissolved in water with a neutral pH.