Saskatoon (Amelanchier alnifolia Nutt.) as a source of bioactive phytochemicals

Bioactive polyphenols are found in high amounts in berries, fruits and in other plant parts. The polyphenols of saskatoon berries grown in Canada has been studied to some extent, while there are no studies concerning Finnish varieties. Although the potential importance for nutraceutical and other food/non-food applications, limited information is available on the phytochemicals in different plant parts of useful crops.

Polyphenols in leaves, stems and berries of four saskatoon cultivars grown at agricultural farms in Finland were identified and quantified with HPLC and LC/MSD systems. Proanthocyanidins (condensed tannins) were determined with butanol-HCl test.

HPLC-analysis revealed over 30 individual phytochemicals in a saskatoon plant. The polyphenolic composition varied among plant parts and the concentrations of compounds varied among cultivars. The most significant cultivar differences were detected in the accumulation of polyphenols in berries. The main berry components were cyanidin-based anthocyanins, quercetin-derived flavonol glycosides and chlorogenic acid derivatives. The leaves consisted of quercetin and kaempferol derived flavonol glycosides, catechins, neolignans and hydroxycinnamic acids. In stems, the main components were flavanones/flavonols, catechins and benzoic acid derivatives. Saskatoon cultivars were also rich in proanthocyanidins: 3 % of dry berry biomass and 10-14 % of dry biomass of stems and leaves. Cultivars were observed similar in their proanthocyanidin contents.

Due to the high concentrations of phytochemicals, cultivation of saskatoon plants may have a great potential in the production of functional raw material to a wide range of food products.

Keywords: Flavonoids, phenolic acids, proanthocyanidins, saskatoon, cultivars

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