Analysis and correlationship of chemical components of various walnut (Juglans regia L.) cultivars

Abstract

Cultivar is one of the key factors to that influences the nutritional and commercial values of walnuts. However, differences in the comprehensive chemical components among walnut cultivars and their internal formation mechanism are rarely reported. In this study, 49 chemical components of 10 main walnut cultivars from Shanxi Province, China were investigated. Polyphenols, flavonoids and vitamin E were especially rich with the contents of 32.20 mg/g, 16.25 mg/g and 42.37 mg/g, respectively. Highly positive correlations existed among amino acids (r > 0.77, p < 0.01), polyphenols-flavonoids (r = 0.85, p < 0.01) and α-Vitamin E - γ-Vitamin E (r = 0.93, p < 0.01). Some microelements (Tl, Ba and Ni) were negatively correlated with most of the essential amino acids (expect for Cys and Lys), α-Vitamin E and γ-Vitamin E. Based on further analysis of the relationships between chemical component groups, there were 13 canonical variate pairs between microelements and other chemical composition groups was up to 13 pairs (r > 0.8, p < 0.01). Then correspondence analysis indicated 17 chemical compositions were typical phytochemical component of these walnut cultivars. Microelements were the major factor that influenced on the comprehensive qualities of walnuts. Finally, walnut cultivars were classified into various industrial developments based on their chemical components. This research demonstrated that differences and relationships of chemical components in walnuts could be efficiently determined and further applied to the food industry.