Yield, fruit quality, antioxidant capacity and phenolic composition of advanced raspberry lines from Quebec

Ten red raspberry genotypes selected from the Agriculture and Agri-Food Canada breeding program ('RSK88', 'RSK88-1', 'RSK88-2', 'RSK88-3', 'RSK88-4', 'RSK88-5', 'RSK88-6', 'RSK88-7', 'RSK88-8' and 'SM222') were studied for their yield, fruit weight, soluble solids content, titratable acidity, shelf life, phenolic content and composition (anthocyanins, flavonols, ellagic acid, procyanidins and resveratrol), and total antioxidant capacity (TAC) compared with two commercially grown cultivars ('Festival' and 'Killarney'). The results showed that 'RSK88-7' had higher yield, longer shelf life, higher total phenolic content (TPC; measured by both the Folin-Ciocalteu method and high-performance liquid chromatography), stronger antioxidant capacity, better fruit quality, and higher concentrations of anthocyanins, flavonols, ellagic acid and procyanidins. There was a positive correlation (r = 0.55, p = 0.0006) between TAC and TPC measured by the Folin-Ciocalteu method, and a significant correlation (r = 0.92, p < 0.0001) was found between anthocyanins content and TPC, which was calculated based on the sum of the five classes of phenolic compounds. Anthocyanins were the most predominant phenolic class, accounting for 69.4% of total phenolic, followed by procyanidins. Resveratrol content was lowest among the five classes of phenolic compounds.