Fruit of raspberry Rubus Idaeus L. as a source of functional ingredients (review)

Abstract

The article gives a comparative analysis of the data obtained by Russian and foreign scientists considering the content of vitamins and other valuable substances in raspberry fruit. That determines high antioxidant properties of raspberry. The goal of the study was to generalize information which shows specific nature of that plant in relation to the complex of vitamins and polyphenol compounds which it contains. The author shows that fruit of raspberry R. idaeus L. consists of 5–40 mg/100 g of vitamin C, folic acid - 26-44 mg/100 g. Consumption of only 100 g of raspberries satisfies daily requirement of vitamin C (60 mg) by 8.3 - 66.7%, in folates (200 mg) by 13–22%. Total anthocyanin content in red raspberry varies within wide range (20–100 mg/100 g), in black raspberry – form 200 to 600 mg/100 g. Raspberry accumulates from 38 to 270 mg/100 g of ellagic acid. In small amounts the cultivated red raspberry consists of the following substances: carotenoids (β-carotene – 9.3 mg/100 g, zeaxanthin – 11 mg/100 g, lutein – 320 mg /100 g), vitamin E – 0.15–0.44 mg/100 g tocopherol equivalents, thiamine – 0,020 mg/100 g, riboflavin – 0.034 mg/100 g, niacin – 0.036 mg/100 g, pyridoxin – 0.05 mg/100 g, biotin – 5.7 mg/100 g. Total content of antioxidants in the cultivated raspberry fruit is 1.71 mg/g (standard quercetin). As a result of the analysis of different literary sources the author determined that raspberry antioxidant properties are mainly connected with high polyphenol content. Contribution of vitamin C into total antioxidant activity is relatively low. Though raspberry fruit chemical composition has already been studied quite well it is necessary to perform further more detailed research of different raspberry cultivars considering their total antioxidant activity as well as certain biochemical components which comprise antioxidant complex of raspberry fruit. The obtained results will form the base for further research aimed at investigating phytochemical compounds of fruit crops which have become an essential part of healthy human diet and developing nutraceutical products.