The color difference of rubus fruits is closely related to the composition of flavonoids including anthocyanins

Abstract

Blackberry and raspberry flavonoid compounds, including anthocyanins, are known for their nutritional and health benefits. Five representative Rubus fruits (blackberry, red raspberry, yellow raspberry, black raspberry, Rubus hybrid ‘Young’ fruit) were examined. The yellow raspberry ‘Colde Summit’ had the brightest color. The Rubus hybrid ‘Young’ had the highest brix and ‘Colde Summit’ the lowest solidity-acid ratio. In total, 2118 and 1089 known metabolites were identified from five representative Rubus fruits by LC-MS in positive and negative ion modes. Isoquinoline alkaloid biosynthesis was the most enriched pathway in the biosynthesis of other secondary metabolites, followed by flavonoid and anthocyanin biosynthesis. Fewer pathways differed between red raspberry and yellow raspberry than among other Rubus fruits. Significant differences among groups occurred in cyanidin-3-sambubioside content in the anthocyanin pathway, which may be predominantly responsible for color differences. This study provides a theoretical basis for the comprehensive utilization and quality improvement of Rubus.