摘要
为提高茭白多糖抗氧化活性,对茭白多糖进行硫酸化修饰,并探索其最佳修饰条件。以茭白为原料,利用水提醇沉法提取并纯化一种新型水溶性多糖,采用三氧化硫-吡啶法,以甲酰胺为溶剂,对多糖进行硫酸改性,以硫酸根取代度(DS)为指标,利用响应面法对茭白多糖进行硫酸改性条件优化,同时通过体外自由基清除率实验对比改性前后体外抗氧化活性。结果表明:采用响应面法辅助茭白多糖硫酸化修饰条件优化得到最佳反应条件为多糖样品100 mg,酯化时间4 h,酯化温度70℃,三氧化硫-吡啶复合物添加量2.6 g,得到最佳DS为1.79;热重分析显示茭白多糖在46.38℃时失重最快,失重率为16.48%;硫酸化茭白多糖在65.04℃时失重最快,失重率为2.92%。在体外抗氧化实验中,茭白多糖对于DPPH·、·OH以及ABTS^(+)·清除能力的IC_(50)值分别为3.49、3.28和12.70 mg/mL;硫酸化茭白多糖为0.39、1.00和1.82 mg/mL;阳性对照(V_(C))为0.069、0.17和0.077 mg/mL。综上表明,硫酸化修饰能提高茭白多糖的热稳定性;同时一定程度上增强其自由基清除能力。
In order to improve the antioxidant activity of Zizania latifolia polysaccharides,sulfate it and explore the optimum modification conditions.Polysaccharides was extracted by water extraction and alcohol precipitation method from Zizania latifolia,then it was separated and purified to obtain a new type of water-soluble polysaccharide.Using formamide as solvent,polysaccharides were sulfated by sulfur trioxide-pyridine method.The degree of substitution(DS)was set as the examination index,the optimal sulfonation conditions were selected by response surface method.Through the free radical scavenging rate trial in vitro,compared with natural polysaccharides,to explore the changes of antioxidant activity of sulfated polysaccharides in vitro.The results showed that the optimum reaction conditions obtained as polysaccharide 100 mg,time 4 h,temperature 70℃,sulfur trioxide-pyridine complex 2.6 g.The optimum DS was 1.79.Thermogravimetric analysis showed that the fastest weight loss rate of Zizania latifolia polysaccharides was 16.48%at 46.38℃,and the sulfated polysaccharides was 2.92%at 65.04℃.In the antioxidant test in vitro,the IC_(50) of free radical scavenging ability of Zizania latifolia polysaccharides to DPPH·,·OH and ABTS^(+)·were 3.49,3.28 and 12.70 mg/mL respectively.The sulfated polysaccharides of Zizania latifolia polysaccharides were 0.39,1.00 and 1.82 mg/mL respectively,and the positive control(V_(C))was 0.069,0.17 and 0.077 mg/mL respectively.In summary,sulfation modification can enhance the thermal stability of Zizania latifolia polysaccharides and enhance its free radical scavenging ability to some extent.
作者
马笑笑
王兵
刘会平
张欣
张慧慧
李灿
刘盈
MA Xiaoxiao;WANG Bing;LIU Huiping;ZHANG Xin;ZHANG Huihui;LI Can;LIU Ying(College of Food Science and Engineering,Tianjin University of Science&Technology,Tianjin 300457,China)
出处
《食品工业科技》
CAS
北大核心
2024年第7期25-34,共10页
Science and Technology of Food Industry
基金
国家自然科学基金(31801568)
天津市自然科学基金(21YDTPJC00060)。
关键词
茭白
多糖
硫酸化
响应面优化
抗氧化活性
Zizania latifolia
polysaccharide
sulfated
response surface methodology
antioxidant activity
