基于主成分分析不同加工方式鲜食小麦蛋白功能特性及亚基结构

Functional Characteristics and Subunit Structure of Fresh Wheat Protein with Different Processing Methods Based on Principal Component Analysis

摘要:

本实验以炒制和煮制两种热处理后的鲜食小麦为原料，通过碱提酸沉法提取蛋白，并对其结构和功能特性进行测定，同时借助于主成分分析法对不同加工方式鲜食小麦蛋白的功能特性进行综合评价。结果表明：煮制的鲜食小麦蛋白中的分子量为21.20 ku的条带逐渐消失，而炒制中的此条带则逐渐显现；两种处理的鲜食小麦蛋白的持水性随热处理时间的增加均不断提高，而持油性、起泡性、乳化性、溶解性则呈先上升后下降的趋势，最大值分别为4.23 g/g、4.30 m2/g、44.67%和30.31%，乳化稳定性则与之相反。根据主成分分析结果进行综合评价，煮制和炒制综合得分最高分别为29.43%、14.08%，得出煮制的功能特性优于炒制，且煮制15 min时鲜食小麦蛋白的功能特性最好。综上所述，煮制的鲜食小麦蛋白功能特性较炒制的好，适合对鲜食小麦进行加工，为鲜食小麦原料热加工提供一定的理论依据。

Abstract:

Two kinds of heat-treated fresh wheat were used as raw materials, the proteins were extracted by alkaline extraction and acid precipitation in this paper, and their structure and functional properties were determined. At the same time, the functional characteristics of fresh wheat protein with different processing methods were comprehensively evaluated by mean of principal component analysis. The results showed that the subunit band with a molecular weight of 21.2 ku gradually disappeared in the cooked fresh wheat protein, while the same subunit band gradually appeared in the fried fresh wheat protein; the water holding capacity of the two kinds of heat-treated fresh wheat protein continuously increased with the extension of heat treatment time, whereas the changes of oil retention, emulsification, foaming, and solubility for the two kinds of heat-treated fresh wheat protein showed a trend of first increasing and then decreasing, the corresponding maximum values were 4.23 g/g, 4.30 m2/g, 44.67%, and 30.31%, respectively; the changes of emulsion stability showed opposite trend. According to the results of the principal component analysis of functional characteristics, the highest comprehensive scores of cooked and fried fresh wheat protein were 29.43% and 14.08%, respectively. It was concluded that the functional characteristics of cooked fresh wheat protein were better than those of fried fresh wheat protein. Moreover, the functional characteristics of fresh wheat protein were best at cooked time of 15 min. In a word, the functional properties of cooked fresh wheat protein were better than those of fried fresh wheat protein, which was suitable for the processing of fresh wheat. Furthermore, a certain theoretical basis was provided for the thermal processing of fresh wheat raw materials.