Phenolic compounds and ascorbic acid in black currant (Ribes nigrum L.) : variation due to genotype, ontogenetic stage, harvest date and location

Abstract: Black currant is an edible soft fruit crop that is now attracting increased scientific attention due to its high content of potentially beneficial phenolic compounds and ascorbic acid. Using HPLC and spectrophotometry, this thesis examined the content of phenolic compounds in buds, leaves and fruits of black currant plants grown in southern and northern Sweden. In addition, the content of ascorbic acid, soluble solids, titratable acidity and total anthocyanins were studied in the fruits. Differences due to genotype, ontogenetic stage, harvest date and location were determined. The genotypes 'Ben Finlay', 'Poesia' and 'JHI 8944-13' had the highest content of several compounds in both buds and fruits. Among the different bud ontogenetic stages, dormant buds had the highest content of total phenols. In the leaves, the content of phenolic compounds generally varied depending on the position of the leaf on the shoot and on harvest date. A higher content of total phenols was recorded late in the season, except in the basal leaves. Black currant fruits grown in the south had higher contents of most phenolic compounds, ascorbic acid and soluble solids than those grown in northern Sweden. Buds picked from plants grown in the north had higher content of flavan-3-ols, phenolic acids and several flavonols than buds from the south. In conclusion, proper selection of genotype and location for cultivation is essential for promoting the food and health attributes of black currant. Moreover, knowledge related to influence of ontogenetic stage and harvest time on content of specific bioactive compounds in black currant could help tailor functional foods or pharmaceutical products. Black currant production could thereby be carefully planned to enhance the content of specific compounds for product optimisation.

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