Nutritional Attributes and Phenolic Composition of Flower and Bud of Sophora japonica L. and Robinia pseudoacacia L.

Abstract

Sophora japonica L. (SJL) and Robinia pseudoacacia L. (RPL) are widely cultivated in China. However, the utilization of their main by-products are limited due to a lack of comprehensive nutritional attributes. Herein, the proximate composition, mineral elements, fatty acids, amino acids, monosaccharides, and phenolics were analyzed to investigate the nutritional attributes of SJL and RPL. Dietary fiber was the main ingredient in SJL and RPL, followed by protein and lipids. The content of Fe in SJL and RPL was highest, especially in flowers of SJL, reaching about 1179.51 mg/kg. The total unsaturated fatty acids accounted for 89.67% of the bud of SJL. Meanwhile, the essential amino acids contents of the flower and bud of SJL and RPL accounted for 35.95–40.59% of total amino acids. The flower of SJL (373.75 mg/g) exhibited the most abundant monosaccharides. Meanwhile, the total phenolics and flavonoid contents in the buds of SJL and RPL were significantly higher than that of the flower, implying the buds possessed better biological activity. Moreover, the bud of SJL possessed the most abundant phenolics. The results provided a reference for the development of functional food derived from SJL and RPL.