Potential of sweet cherry (Prunus avium L.) by-products: bioactive compounds and antioxidant activity of leaves and petioles

In recent years many researchers have taken into account other parts of plants than commonly edible ones because of their beneficial chemical composition. The objective of the study was to determine the content of bioactive compounds, including HPLC analysis of polyphenols, and antioxidant activity of leaves, petioles, and fruit of selected cultivars of the sweet cherry. Cultivars Kordia, Regina, Vega, Hedelfińska and Vanda from Sandomierz (Poland), Kordia, Regina, and Summit from Szczodrkowice (Poland) as well as sweet cherries imported from Spain and Hungary (only petioles and fruit) were analyzed. Statistically significant effect of cultivar and part of the plant on the bioactive compounds content and antioxidant activity was found. The leaves and petioles had a higher concentration of dietary fiber, vitamin C, carotenoids and polyphenols as well as an antioxidant activity than the fruit. The fruit was characterized by the presence of total anthocyanins. In the studied samples, the following polyphenols were identified: coffee acid, chlorogenic acid, p-coumaric acid, and myricetin. Additionally, the ferulic acid was detected in leaves. Due to the high antioxidants level, the leaves and petioles can be a potential source to produce functional food. Further studies are needed to prove processability and usefulness of this plant material in the food industry.