Protein contents in different peanut varieties and their relationship to gel property

Abstract

The objective of this work was to study the contribution of different peanut varieties with regard to their arachin and conarachin fractions, and their respective subunits to protein gel properties. It was found that the proteins of various cultivars could be classified into two groups according to the lack of the 35.5 kDa acidic subunit of the arachin. Two peanut cultivars, Yueyou7 and Qinglan8, had the highest content of arachin (62.3%) and conarachin (53.5%), respectively. Three indexes, namely, hardness, springiness, and cohesiveness, were used to describe the protein gel properties. An efficient approach was developed to characterize the three gel properties into one index. The correlation coefficients between the newly depicted index and the original ones were 0.87, 0.41, and 0.47, which corresponded to hardness, springiness, and cohesiveness, respectively. Principal component analysis, linear discriminant analysis, and cluster analysis were used as classification techniques. About 40 varieties were classified into three groups by principal component analysis and all group members determined by principal component analysis are in the predicted group that 100.0% of original grouped cases correctly classified by linear discriminant analysis. The result of cluster analysis had some similarities with the principal component analysis. Copyright © Institute of Agro-Products Processing Science and Technology, Chinese Academy of Agricultural Sciences.