Guangdong nongye kexue (Jun 2022)
Analysis on the Nutritional Components of Different Varieties of Longan Flowers
Abstract
【Objective】Exploring the nutritional components of longan flowers and comparing the nutritional components of different varieties of longan flowers will provide basis for further processing and comprehensive utilization of longan flowers.【Method】The contents of soluble protein, soluble sugar and vitamin C in female and male flowers of 21 different longan varieties were determined by coomassie brilliant blue staining, anthrone-sulfuric acid method and 2, 4-dinitrophenylhydrazine colorimetric method respectively. The nutritional components in female and male flowers of 21 different longan varieties were evaluated comprehensively by principal component analysis and classified by clustering methodology.【Result】The contents of soluble protein, soluble sugar and vitamin C in male flowers were higher than those in female flowers. The average values of the three nutrients in male flowers were 14.02 mg/g, 191.23 mg/g and 5.29 mg/g respectively, while those in female flowers were 12.54 mg/g, 167.25 mg/g and 5.21 mg/g respectively. Among the 21 tested varieties, Shixia, Hongke, Shuangmamu, Shuiyan, Conghuadageyuan, Jiluanyan and Honghe showed higher level in all three nutrients. Three principal components were extracted, and their cumulative contribution rate reached 78.56%, reflecting the comprehensive nutritional quality of 21 longan varieties. Different results were obtained by clustering with different nutritional components and the 21 varieties could be divided into 3 categories when the threshold value was 5.【Conclusion】Longan flowers have high soluble sugar content, mainly concentrated in 100-250 mg/g, while soluble protein and vitamin C content mainly concentrated in 10-20 mg/g and 2-10 mg/g, respectively. Longan flowers are rich in nutritional components, which can be used as functional food or raw materials for medicinal development.
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