Principal Component Analysis and Cluster Analysis for Evaluating Amino Acid of Different Table Grapes (Vitis vinifera L.) Varieties

Objective: In order to find out the differences in the content, composition characteristics and nutritional value of amino acid in different fresh grape varieties. Method: The amino acid type and content were detected by amino acid automatic analyzer. Based on these, their amino acid nutrition were compared to each other using principal component analysis and cluster analysis. Results: 31 table grapes contained more than 18 kinds of amino acid. Among these, the contents of essential amino acid, child essential amino acid, medical amino acid, branch amino acid, flavoring and coloring amino acid, antibacterial amino acid, and primary amino acid were 51.03~111.78, 33.29~138.66, 113.75~341.64, 21.89~49.19, 95.91~316.24, 15.23~31.39 and 113.82~468.34 mg/100 g, respectively. Three principal components were constructed by factor loading. The corresponding contribution ratio was 80.644%. Listed by the amino acid nutrition, the top 3 table grapes were ‘Zaozhongzao’, ‘Yubo No.2’, and ‘Gold Finger’. The last 3 table grapes were ‘Beauty Woodcutter’, ‘Purple Jade’, and ‘Miguang’. The results of cluster analysis and principal component analysis were consistent, indicating that there were significant differences in amino acid nutrition of different fresh grapes. Conclusion: The table grape with good amino acid nutrition in these 31 varieties were ‘Zaozhongzao’, ‘Yubo No.2’, ‘Gold Finger’, ‘Summer black’, ‘Hutai No.8’ and ‘Jasmine’.