Accumulation rule of main nutrients and isoflavones and their relationships in Pueraria lobata var. thomsonii

In order to determine the optimal harvesting period and the application value of each part of Pueraria lobata var. thomsonii and to explore the correlation between the main nutrients and the isoflavones, P. lobata var. thomsonii of Tengxian, Guangxi was used as the material, the contents of isoflavones in different parts, the contents of main nutrients and isoflavones in different growth periods were determined by test box method, enzyme gravimetric method, Soxhlet extraction method, high performance liquid chromatography and other physiological and biochemical techniques, and the relationship between the accumulation of various nutrients and isoflavones was analyzed to clarify the accumulation rule of main nutrients and isoflavonoids and their relationships in P. lobata var. thomsonii. The results were as follows: (1)At the mature stage, the content of genistein in different parts of P. lobata var. thomsonii was not significantly different, but the content of isoflavoues aglycone in leaf was significantly lower than that in middle vine, and the contents of total isoflavones, puerarin and daidzein in root apex and vine were significantly higher than those in leaf and tuberon, and the contents of puerarin in root apex and vine were more than 1.00%. (2)The accumulation of starch, polysaccharide, crude protein, and soluble protein reached the maximum in November and December, the accumulation of insoluble dietary fiber reached the minimum in December, the accumulation of soluble dietary fiber was the maximum in August and December, and the accumulation of total isoflavones and puerarin reached the maximum in August and September. (3)The correlation analysis results showed that the accumulation of total isoflavones and puerarin was negatively correlated with the accumulation of starch and polysaccharide; the accumulation of total isoflavones and puerarin was positively correlated with the accumulation of insoluble dietary fiber. Therefore, it can be concluded that the root apex and vine of pueraria powder contain rich total isoflavones, puerarin, daidzein, which has good value for medicinal development; the best harvest time for medicinal using are August and September, and the best harvest time for edible using are November and December; the accumulation of total isoflavones and puerarin is related to starch, polysaccharide and insoluble dietary fiber. This study clarify the accumulation rule and correlation of the main nutrients and total isoflavones in P. lobata var. thomsonii, and provides a reference for the comprehensive development and utilization of P. lobata var. thomsonii and the determination of the harvest time.