Preparation and antioxidant potential of maillard reaction products from (MRPs) chitooligomer

Maillard reaction products (MRPs) were prepared from a chitooligomer solution by heating at 80 °C for different times. A time-dependent increase in UV absorbance, browning, and fluorescence was observed upon heating, indicating formation of MRPs with heating of the chitooligomer solution. The formation was also evidenced by Fourier transform infrared and molecular weight distribution, using gel permeation chromatography. 2,2-Diphenyl-1-picrylhydrazyl (DPPH), and 2,2-azino-bis(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS(+))-scavenging activities, and MRPs, reducing power increased significantly (p<0.05) with an increase in heating time of the chitooligomer solution. MRPs240 was formed after 240 min of heating and showed an inhibitory concentration required for 50% scavenging (IC50) value of 118 μg/ml (against DPPH), 266 μM ascorbic acid equivalent (AE)/mg MRPs240 (against ABTS(+)), and 521 μM AE/mg MRPs240 (against reducing power). MRPs240 exhibited lipid peroxidation inhibition activity in a linoleic acid emulsion, and the malondialdehyde concentration decreased from 29.6 to 8.4 μM. In addition, MRPs showed protection ability against the oxidative stress induced by H2O2 in Chang liver cells.