Determination of the antioxidant and mineral contents of raspberry varieties

Humans maintain their health by consuming a variety of vegetables and fruits that contain antioxidants, both enzymatic and no enzymatic. Raspberry is one of the most diverse genus of true dicotyledonous plants, which includes 12 subspecies and about 429 species. Raspberry fruit is rich in antioxidant compounds, especially polyphenols. Two species of raspberry were studied to determine the amount of antioxidants and phenolic and flavonoid compounds in their fruits at three different stages of fruit ripening immature, semi-ripe and mature. Natural samples of Rubus idaeus and Rubus strigosus were collected. In this study, the fruit extracts of two species were stored at-23 °C for about six months. Free radical cleansing and Ferric reducing antioxidant power methods were used to determine the antioxidant activities of the extracts. The antioxidant activity of both methods revealed a higher mean value in extracts from fully matured fruits compared with immature and semi-ripe fruits. The results showed that the antioxidant activity of Rubus strigosus is 9%, 10%, and 8% higher than Rubus idaeus in the stages of immature, semi-ripe, and full maturity, respectively.