Comparison of Depolymerization of Chitosan into Chitooligosaccharides from the Shrimp Shell Waste of Parapeneopsis Stylifera by Non-Specific Enzymes
Abstract Two different non-specific proteolytic enzymes (papain and pepsin) and two carbohydrase enzymes (α-amylase and β-amylase) were used for the depolymerization of chitosan to produce chitooligosaccharides (COS). The COS produced using papain, pepsin, α-amylase and β-amylase were characterized for physico-chemical, structural, thermal and antioxidant activities. Chitooligosaccharides produced using pepsin enzyme had higher solubility compared to other three COS. Structural variation of chitosan and their oligosaccharides were studied by FTIR analysis and it revealed the existence of various structural difference among the oligosaccharides and chitosan. Thermal behavior of chitosan and oligosaccharides were examined using DSC analysis, and it exhibits difference in the glass transition temperature among the four oligosaccharides and native chitosan. Anti-oxidant analysis such as DPPH radical scavenging activity and reducing power revealed the antioxidant ability of chitooligosaccharides. Among the four COS, pepsin-COS had the highest DPPH radical scavenging and reducing power activity. According to the patterns of molecular weight reduction, antioxidant properties, thermal behavior properties, four enzymes α- amylase, β-amylase, pepsin and papain found suitable for hydrolyzing chitosan into chitooligosaccharide. As it is superior to chitosan, chitooligosaccharide can be utilized in food industry as bio-preservatives to enhance the quality, safety and shelf life of the products.