Variation in flavonol content among blackcurrant cultivars

Increased consumption of fruits and vegetables has been associated with decreased mortality rate and incidence of cancer and heart diseases in many epidemiological studies. Besides containing large amounts of vitamin C and fibre, fruits also contain a variety of different phytochemicals possessing antioxidant and free radical scavenging activities. An HPLC-based quantitative method, with improved extraction and hydrolysis of flavonols, was used to analyse the content of the flavonols quercetin, myricetin, and kaempferol in ten blackcurrant cultivars from organic farms and in five cultivars from conventional farms. Myricetin was the most abundant flavonol, and its amount varied significantly among cultivars, from 8.9 to 24.5 mg 100g(-1) (fresh weight). The quercetin levels also varied widely among the cultivars, from 5.2 to 12.2 mg 100 g(-1). The kaempferol level in blackcurrant was low, ranging from 0.9 to 2.3 mg 100 g(-1). No consistent differences in the contents of flavonols were found between the same blackcurrant cultivars grown in organic and conventional ways. The high variability in the levels of flavonols in different cultivars offers possible avenues for identifying and selecting cultivars rich in certain flavonols for the special production of berries for industrial use.