Antioxidant potential and antimicrobial activity of chitosan-inulin conjugates obtained through the Maillard reaction

Chitosan (1%) was glycated with inulin (0.5, 1, and 2%) via the Maillard reaction at various initial pH values (5, 5.5, and 6). Higher pHs led to a greater pH drop and increase in the intermediate products and browning intensity (BI). The chitosan-inulin conjugates were then classified into three levels of low, medium, and high BI through K-means clustering in order to investigate the effect of BI development on the antioxidant and antimicrobial attributes of the conjugates. Covalent linkage between chitosan and inulin was confirmed by fourier transform infrared spectroscopy. High BI chitosan-inulin conjugate had significantly higher antioxidant property compared to chitosan and other conjugate fractions. In addition, the conjugates obtained at low pH values mainly presented greater antimicrobial activities than those prepared at high pHs. It can be concluded that chitosan-inulin Maillard-born conjugates can be used as novel antioxidant and antimicrobial prebiotic-based ingredients for food applications.