Chitosan-sugar derivatives demonstrate some useful biology activities (for example antioxidant and anti-microbial activities). In this study, water-soluble chitosan–glucose derivatives
(WSCGDs) were produced from a water-soluble chitosan hydrochloride (WSC) with 12.5 kDa of
molecular weight and 24.05% of degree of acetylation (DA) via Maillard reaction with the heating
temperatures of 100 °C and 121 °C. The Maillard reaction between WSC and glucose was
investigated by measuring the absorbances at 420 nm and 294 nm, indicating that the reaction took
place more effectively at 121 °C. All WSCGDs exhibited higher anti-oxidant activity than WSC, in
which WSCGDs obtained at the treatment 121 °C for 2 h, 3 h, and 4 h expressed the highest ability
(IC50 range from 1.90–1.05 mg/mL). Increased anti-α-amylase and anti-α-glucosidase activities were
also observed in WSCGDs from the treatment at 121 °C. In detail, the highest IC50 values of anti-αamylase activity were 18.02 mg/mL (121 °C, 3 h) and 18.37 mg/mL (121 °C, 4 h), whereas the highest
IC50 values of anti-α-glucosidase activity were in range of 7.09–5.72 mg/mL (121 °C, for 1–4 h).
According to the results, WSCGD obtained from 121 °C for 3 h was selected for further
characterizing by high performance liquid chromatography size exclusion chromatography (HPLC
SEC), colloid titration, FTIR, as well as 1H-NMR, indicating that the derivative of WSC and glucose
was successfully synthesized with a molecular weight of 15.1 kDa and degree of substitution (DS)
of 34.62 ± 2.78%. By expressing the excellent anti-oxidant and anti-diabetes activities, WSCGDs may
have potential use in health food or medicine applications.
