Lactobacillus reuteri 1214,6-α-葡萄糖基转移酶GtfBdN改性薯类淀粉产物结构及理化特性研究  

Structure and physicochemical properties of tuber starches modified by Lactobacillus reuteri 1214,6-α-glucanotransferase GtfBdN

作　　者：蒋彤 纪杭燕 柏玉香[1,2,3,4] JIANG Tong;JI Hangyan;BAI Yuxiang(State Key Laboratory of Food Science and Technology,Jiangnan University,Wuxi 214122,China;School of Food Science and Technology,Jiangnan University,Wuxi 214122,China;Synergetic Innovation Center of Food Safety and Nutrition,Jiangnan University,Wuxi 214122,China;International Joint Laboratory on Food Safety,Jiangnan University,Wuxi 214122,China)

机构地区：[1]食品科学与技术国家重点实验室(江南大学),江苏无锡214122 [2]江南大学食品学院,江苏无锡214122 [3]江南大学食品安全与营养协同创新中心,江苏无锡214122 [4]食品安全国际联合实验室(江南大学),江苏无锡214122

出　　处：《食品与发酵工业》2021年第9期42-48,共7页Food and Fermentation Industries

基　　金：国家自然科学基金青年科学基金项目(31701644);江苏省农业科技自主创新项目(CX(17)2022);食品科学与技术国家重点实验室自主研究课题项目(SKLF-ZZB-202007)。

摘　　要：经过Lactobacillus reuteri 1214,6-α-葡萄糖基转移酶(4,6-α-glucanotransferase,4,6-α-GTase)GtfB改性淀粉可以得到一种具有益生潜力的水溶性膳食纤维。利用截断N端但高表达的全活性GtfBdN改性薯类淀粉,包括红薯淀粉、木薯淀粉和马铃薯淀粉,对产物进行结构和性质测定。通过核磁共振光谱、高效尺寸排阻色谱和高效阴离子交换色谱分析表明,GtfBdN改性分别使红薯淀粉、木薯淀粉和马铃薯淀粉中(α1→6)键比例提升至20.7%、19.5%和26.6%;产物相对分子质量减小,分子质量分布变广;聚合度>24的链段比例降低,聚合度6~12的链段比例大大增加。采用快速黏度分析仪、流变仪和差示扫描量热仪等测试发现,产物黏度大幅下降,表现出更多的流体行为,短期回生和长期回生减慢。该研究为4,6-α-GTase改性薯类淀粉在食品体系中的应用提供了理论和应用依据。After the modification by Lactobacillus reuteri 1214,6-α-glucanotransferase(4,6-α-GTase)GtfB,a water-soluble dietary fiber with probiotic potential can be obtained from starch.At present,the research has focused on the correlation between the structure of the product and its functional properties such as digestibility and probiotics.However,the research on the correlation between the structure and the physicochemical properties which are crucial for food processing has not yet been carried out.In this study,overexpressed GtfBdN with truncated N-terminal but full activity was used to modify tuber starches,including sweet potato starch,tapioca starch and potato starch.The structures and properties of the products were determined.The analysis results of nuclear magnetic resonance(NMR)spectroscopy,high performance size exclusion chromatography(HPSEC)and high performance anion exchange chromatography(HPAEC)showed that GtfBdN modification increased the ratio of(α1→6)bond in sweet potato starch,tapioca starch and potato starch to 20.7%,19.5%and 26.6%,respectively;the relative molecular weight of the product was reduced,and the peak of molecular weight distribution was broader,the proportion of segments with DP>24 decreased,and the proportion of segments with DP 6-12 greatly increased.Tests such as rapid visco-analyzer(RVA),rheometer and differential scanning calorimetry(DSC)showed that the viscosity of the product dropped significantly,showing more fluid behavior,and the short-term and long-term retrogradation slowed down.This research provides theoretical and application basis for the application of 4,6-α-GTase modified tuber starch in food systems.

关 键 词：4 6-α-葡萄糖基转移酶 薯类淀粉 结构分析 糊化特性 黏弹特性 回生特性 

分 类 号：TS235.2[轻工技术与工程—粮食、油脂及植物蛋白工程]