两种不同质地的莲藕碱溶性果胶组分热降解规律及流变学差异  

Differences in Thermal Degradation and Rheological Properties of Alkali-Soluble Pectin Fraction in Two Kinds of Lotus Rhizome with Different Textures

作　　者：段瑞冰 李洁[1] 刘纪红[2] 严守雷[1,3,4] DUAN Ruibing;LI Jie;LIU Jihong;YAN Shoulei(College of Food Science and Technology,Huazhong Agricultural University,Wuhan 430070,China;College of Science,Huazhong Agricultural University,Wuhan 430070,China;Aquatic Vegetable Preservation and Processing Technology Engineering Center of Hubei Province,Wuhan 430070,China;Yangtze River Economic Belt Engineering Research Center for Green Development of Bulk Aquatic Bioproducts Industry,Ministry of Education,Wuhan 430070,China)

机构地区：[1]华中农业大学食品科技学院,湖北武汉430070 [2]华中农业大学理学院,湖北武汉430070 [3]湖北省水生蔬菜保鲜加工工程中心,湖北武汉430070 [4]长江经济带大宗水生生物产业绿色发展教育部工程研究中心,湖北武汉430070

出　　处：《食品科学》2022年第24期7-15,共9页Food Science

基　　金：国家自然科学基金面上项目(31972001)。

摘　　要：选择两种不同质地的莲藕作为材料,研究其碱溶性果胶(sodium carbonate-soluble pectin fraction,NSF)的热降解差异及其与流变的关系。对碳酸钠提取的NSF进行不同温度处理,通过一级结构和纳米微观结构观察和分析发现,沔城藕(粉藕)的NSF热降解程度大于芦林湖藕(脆藕);芦林湖藕NSF链呈星型状(长支链)而沔城藕NSF链大多呈短直链,两者经加热后均出现链长变短、链高降低、分支度减小的现象;流变学结果表明两种NSF的黏稠度经热处理后均明显降低,沔城藕的NSF假塑性略有增加而芦林湖藕NSF假塑性减小。结合结构分析与流变学结果分析得到果胶链的长度、高度与黏稠度呈正相关;分支度和不同长度的链长所占百分比(分子质量分布)是导致其假塑性不同的重要原因。因此,NSF的结构与流变学特性密切相关,同时也说明NSF的热降解差异与两种藕质地差异存在关联。本研究为NSF的热降解与果蔬质构(加工、成熟度)之间的关系提供了一定理论依据。In this study,sodium carbonate-soluble pectin fraction(NSF) from two kinds of lotus rhizome with different textures(mealy and crunchy) were evaluated for differences in thermal degradation and its relationship with rheology.After heat treatment at different temperatures,primary structure analysis and nanostructure observation of NSF showed that the thermal degradation degree of NSF from Miancheng lotus rhizome(mealy) was greater than that of NSF from Lulin Lake lotus rhizome(crunchy).The chain of NSF from Lulin Lake lotus rhizome was star-shaped(long branched chain),while the chain of NSF from Miancheng lotus rhizome was mostly short,straight.For both of them,the chain length and height decreased and so did the branching degree after heating.Additionally,the consistency decreased significantly.The pseudoplasticity of NSF from Miancheng lotus rhizome increased slightly,while that of NSF from Lulin Lake lotus rhizome decreased.The chain length,chain height and branching degree of NSF were closely related to the consistency,and the branching degree and the proportion of chains of different lengths(molecular mass distribution) contributed greatly to the difference in pseudoplasticity.Therefore,there was a close relationship between the structure and the rheological properties of NSF,and the difference in thermal degradation of NSF was related to the texture difference between mealy and crunchy lotus rhizome.This study provides a theoretical basis for understanding the relationship between the thermal degradation of NSF and the texture(processing and maturity) of fruits and vegetables.

关 键 词：莲藕 果胶 原子力显微镜 热降解 流变学 

分 类 号：TS255.1[轻工技术与工程—农产品加工及贮藏工程]