The physicochemical and sensory properties of milk supplemented with ascorbic acid-soluble nano-chitosan during storage

This study was carried out to assess the feasibility of adding the ascorbic acid-soluble nano-chitosan (AANC) into the milk for improving the functionality of milk and to determine the effects of such addition on the physicochemical and sensory properties of the product during storage. The pH and titratable acidity of the AANC milks were not changed significantly when stored at 4°C for 15days. The addition of the nano-chitosan solution (1∼9%, v/v) into the milk samples led to an increase in the amounts of L-ascorbic acid, thereby indicating an enhancement in health benefits. The sensory test revealed that astringency scores increased and colour scores decreased when the highest concentration of the nano-chitosan solution (9%, w/w) was added into the milk samples The colour values, L- and a-, in the milks were not significantly influenced by adding the nano-chitosan solution (1∼9%, v/v); whereas the b-values significantly increased with the addition of the nano-chitosan solution (5∼9%, v/v). Based on the data obtained from this study, it is concluded that the low concentrations (1∼3%, v/v) of the nano-chitosan solution could be used to produce a nanopowdered chitosan-added milk without the significantly adverse effects on the physicochemical and sensory properties.