Antioxidant and antimicrobial properties of chitosan-sugar complex

Antioxidant and antimicrobial properties of chitosan-sugar complex from six types of sugar (glucose, fructose, lactose, arabinose, maltose, and galactose) were investigated. Antioxidant properties were measured by the DPPH test and a measurement of reducing power. These two methods showed the same profile of antioxidant activity. All chitosan-sugar complexes demonstrated better antioxidant activity than chitosan. Chitosan-arabinose complex and chitosan-galactose complex seemed the most effective antioxidant activity. The IC50 values of chitosan-arabinose complex and chitosan-galactose complex were 26.38 g/ml and 28.50 g/ml, respectively. While antiradical efficiencies were 0.03791 and 0.03509, respectively. The reducing power of chitosan-galactose complex was similar to reducing power of BHA (Butylated hydroxyanisole) (p > 0.5). High correlation between antioxidant activity and browning product (A420) was observed (r=0.959 for antiradical efficiency). It is indicated that browning product exhibited antioxidant activity. For antimicrobial activity, most chitosan-sugar complexes were more effective than chitosan. Chitosan-sugar complex could be potential alternative natural product for synthetic food additive replacement and also meet consumer safety requirement.