Differentiation of black raspberry fruits according to species and geographic origins by genomic analysis and 1H-NMR-based metabolic profiling

Random amplification of polymorphic DNA (RAPD) and NMR techniques were used to differentiate and identify species of black raspberry (BR) of different geographic origins. BR leaf samples from five geographic origins were identified as Rubus japonicus and R. coreanus by RAPD. 1H-NMR analysis was also performed for BR fruit extracts from different geographic origins. Major compounds assigned in 1H-NMR spectra of BR fruits were amino acids, organic acids, sugars, phenolic acids, and purine derivatives. In addition, relative levels of total phenolic compounds, flavanols, flavonoids, and anthocyanins in the BR fruits were further analyzed. Hierarchical cluster analyses (HCA) based on the genetic (RAPD of leaf samples) and metabolic (1HNMR, total phenolic compounds, flavanols, flavonoids and anthocyanins of fruit samples) datasets were independently performed. The HCA dendrogram pattern derived from RAPD genetic fingerprinting of BR leaf samples matched that from the 1H-NMR data of BR fruit samples. This research demonstrates that metabolic profiling of BR fruit based on 1H-NMR is a promising method for differentiating BR fruits of various species and geographic origins.