Phenolic compounds and ascorbic acid in black currant (Ribes nigrum L.)

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

Black currant (Ribes nigrum L.) - an insight into the crop

There is an increasing interest in the inclusion of berries, especially the black currant in the human diet mainly for the health benefits associated with their consumption. Black currant (Ribes nigrum L.) belonging to the genus Ribes is widely cultivated across temperate Europe, Russia, New Zealand, parts of Asia and to a lesser extent North America. Besides high content of tasty juice, black currant is a valuable source of bioactive compounds like vitamin C and polyphenols, acting as antioxidants, with a potential to protect against disorders such as cardiovascular events, cancer and other degenerative symptoms. Industrially, black currant fruits are considered to be of importance; however other anatomical parts like buds and leaves are also excellent sources of phenolic compounds. The leaf and bud extracts are of relevance as raw material for the food and health industry thereby making black currant a lucrative product for use as functional food ingredient. Research until now has investigated the content of different polyphenolic fractions of the fruits and to lesser extent on content of these fractions on plant parts like buds and leaves. The breeding of black currant is mainly focussed on national and international requirements, as related to specific quality desired from the processing sector alongside with important agronomic characters. Black currant cultivation is in different areas limited by a lack of climate adaptation in the existing cultivars as well as susceptibility of these cultivars to different pests and diseases. Also, the levels of bioactive compounds in black currant like content of ascorbic acid and polyphenols are influenced by genotype, environment and genotype x environment interactions. Durable resistance towards damaging pest and diseases together with an increase in content of health promoting compounds and adaptability to local climates remain to be of high priority for breeders. Additionally flavour, mouth feel, aroma and after taste are important primary quality factors for the fresh fruit market and juice industry. This introductory paper focuses on the history of development and biology of black currant; their ecology and environmental adaptability; crop utilisation; bioactive compounds, genetic, biochemical and phenotypic diversity. The breeding objectives and important pest and diseases are also presented. This paper is an attempt to review important work that has been done so far and the background literature, whilst providing the scope for the current PhD study