关键词: 南瓜多糖, 磷酸酯化, 抗氧化活性

Abstract: [Objective] The objective of this experiment was to study preparation of phosphoric acid esterification of pumpkin polysaccharide process and its antioxidant activity.[Method] In this experiment,the method of phosphate esterification was used to decorate pumpkin polysaccharide.Meanwhile,effects of temperature,pH,reaction time and esterification were considered.The best modification conditions was achieved based on orthogonal experimental design.The structure of pumpkin polysaccharide between modified and non-modification was compared by infrared spectroscopy and antioxidant activity was estimated via comparing capacities of scavenging hydroxyl free radical (·OH) and superoxide anion free radical (O₂^-·).[Results] The best modification condition was temperature 90℃,pH 9.0,reaction time 6h,esterification reagent 20%.The phosphate groups was added into modified pumpkin polysaccharide.The ability scavenging·OH and O₂^-·in phosphate esterification of pumpkin polysaccharides were higher than that of nonmodification.[Conclusion] Polysaccharides of phosphate esterification pumpkin was more antioxidant than that of non-modification pumpkin.

Key words: pumpkin polysaccharide, phosphate esterification, antioxidation