基于主成分分析和聚类分析研究改性小麦蛋白的结构和功能特性  

Studies on Structural and Functional Characteristics of Wheat Gluten Based on PCA and HCA

作　　者：廖兰 陈林萍 倪莉 Liao Lan;Chen Linping;Ni Li(Institute of Food Science and Technology,College of Bioscience and Biotechnology,Fuzhou University,Fujian Center of Excellence for Food Biotechnology,Fuzhou 350108)

机构地区：[1]福州大学生物科学与工程学院食品科学技术研究所福建省食品生物技术创新技术研究中心,福州350108

出　　处：《中国食品学报》2018年第7期263-271,共9页Journal of Chinese Institute Of Food Science and Technology

基　　金：国家自然科学基金项目(31201287);福建省自然科学基金项目(2015J05067)

摘　　要：研究3种处理条件,相同脱酰胺程度下(25%,40%和55%)的9个小麦蛋白的结构和功能特性的变化。测定9个样品的水解程度、表面疏水性、Zeta电位、分子粒径、乳化性、乳化稳定性和起泡性等19个指标,采用主成分分析和聚类分析对这19个指标进行比较分析。结果显示,依据主成分的累计贡献率和碎石图提取8个主成分反映原变量,得到相同脱酰胺程度的样品。其彼此间的距离比较近(在同一区域)并且指标变化也比较一致,说明同一脱酰胺程度下,处理条件的变化对小麦蛋白的结构、功能特性指标的影响不大。在聚类分析谱系图中将9个样品分成同样组成的3类:第一类主要聚集了脱酰胺程度为55%,第二、三类样品分别是脱酰胺程度为25%的样品和脱酰胺程度为40%的样品。聚类结果与主成分得分图结果一致,结果表明相同脱酰胺程度的改性小麦蛋白的结构和功能变化与处理条件的改变无相关关系。The work is to investigate wheat gluten＇s structural and functional properties under the same degree of deamidation but obtained different treating conditions. 9 modified wheat gluten samples with the 25%, 40%, and 55%degree of deamidation were compared based on principal component analysis（PCA） and hierarchical cluster analysis（HCA） by total 19 indexes of the degree of hydrolysis, surface hydrophobicity, Zeta potential, dynamic light scattering,emulsification activity index（EAI）, emulsion stability index（ESI）, foaming property and FTIR. According to the cumulative contribution ratios and screen plot, 8 principal components that reflect original variables are extracted in PCA. The first principle component mainly combines the surface hydrophobicity, ESI, α-helix, β-turn, and α-helix/β-sheet. The second is the combination of dynamic light scattering and others. From the PCA scores, it＇s visually to find that the distance of the three samples of 55% degree of deamidation are close to one another and their indexes varies consistently, so they can be divided into the same zone. Similarly, samples of 2, 5 and 8 belong to the same zone, and samples of 1, 4 and 7 another one. These results demonstrate that the variation of treating condition makes a little difference to wheat gluten＇s structural and functional characteristics under the same degree of deamidation. In addition, the same thing happens to the dendrogram of HCA, leading to the similar separated 3 groups with 9 samples. Thus, the results of clustering（dendrogram of HCA） agrees with the PCA scores. It provides a further theoretical proof that structural and functional properties of wheat gluten have no correlation with the variations of treating conditions under the same degree of deamidation.

关 键 词：主成分分析 聚类分析 小麦蛋白 脱酰胺改性 

分 类 号：TS210.1[轻工技术与工程—粮食、油脂及植物蛋白工程]