The Maillard reaction of chitosan oligosaccharide and the antioxidative activities of its derivatives
低聚壳聚糖的美拉德反应及其衍生物的抗氧化性能研究

Three kinds of chitosan oligosaccharide derivatives prepared through Maillard reaction by heating chitosan oligosaccharide for 8, 16 and 24 hours were named CC-8, CC-16 and CC-24, respectively. The pH, absorbance and fluorescence were determined during the reaction. Chitosan oligosaccharide derivatives were characterized by Fourier transform infrared (FTIR) spectroscopy and their molecular weights were determined by Gel permeation chromatograph (GPC). Their antioxidative activity was investigated by employing various established in vitro systems, such as superoxide anion, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals scavenging, and their reducing capacity was also studied. The results showed that the pH value of the reaction system decreased during Maillard reaction. The UV-Vis absorbance increased significantly at 280 nm and this increase slowed down after 16 hr. The fluorescence intensity significantly increased with Ex at 343 nm and Em at 420 nm and also slowed down after 16 hr. All the three derivatives kept the characteristic absorption peak of chitosan oligosaccharide. Their antioxidative and reducing capacities were both much stronger than those of the chitosan oligosaccharide and CC-16 has the strongest antioxidative activity.