Abstract:
To explore the metabolic differences of flavonoids among three varieties of
Actinidia arguta ('Longcheng 2', 'L133' and '909'), and identify the core differential metabolites and key metabolic pathways, this study employed a widely targeted metabolomics approach to conduct qualitative and quantitative analysis of flavonoids in the mature fruits of the three varieties. Principal component analysis (PCA), hierarchical cluster analysis (HCA), and orthogonal partial least squares-discriminant analysis (OPLS-DA) were combined to screen differential metabolites, and pathway enrichment analysis was performed using the KEGG database. The results showed that a total of 286 flavonoids belonging to 11 categories were detected, among which flavonols were the most abundant (118 species, accounting for 41%). PCA and HCA results indicated significant differences in flavonoid composition among the three varieties, each containing characteristic and highly enriched flavonoid components. Specifically, 'Longcheng 2' exhibited the highest contents of quercetin-5,4'-di-O-glucoside, delphinidin-3-O-(6-caffeoyl-
β-D-glucoside), and tricin-7-O-glucuronide, which possess strong antioxidant and anti-inflammatory activities, highlighting its potential for developing functional products. 'L133' had the highest levels of luteolin and its derivatives, contributing to its unique flavor profile and suitability for processed flavor products. '909' showed the highest anthocyanin content, which imparts vivid coloration to the fruit, making it advantageous for developing functional dried fruits or dietary supplements. These characteristic metabolites may serve as key markers for variety differentiation. KEGG enrichment analysis revealed that the differential flavonoids were mainly enriched in the isorhamnetin-O-glycoside biosynthesis pathway, flavonoid biosynthesis pathway, and kaempferol aglycone biosynthesis II pathway. This study provides theoretical support and data references for the variety breeding of
A. arguta, the precise development of flavonoids, and the research and development of functional foods.