Determination and comparison of total polyphenol and vitamin C contents of natural fresh and commercial fruit juices

Abstract

Owing to interest in the role of antioxidants in human health which has prompted research to assess fruit and their products antioxidants, such as vitamin C and phenolics and also because of increment in commercial fruit juices consumption, the objectives of present study were to determine and compare the total polyphenol and vitamin C contents of natural fresh and commercial fruit juices. Folin-Ciocalteu assay and Spectrophotometric method were used to measure the total polyphenol and vitamin C. The concentrations of total polyphenol were ranging from 23.75آ±1.6 to 420.69آ±4.9 mg/100 ml for fresh and 18.57آ±3 to 381.9آ±3.4 mg/100 ml for commercial juices with lowest amount in apricot and the highest amount in pomegranate juices in both sources. Significant differences (p<0.05) were observed in the polyphenol contents of peach, pomegranate, grapefruit and orange between fresh and commercial juices. The vitamin C levels of fresh juices were ranging from 14.31 for apricot to 24.51 mg/100 ml for orange juices and those of commercial were from 13 for mango to 17.29 mg/100 ml for pomegranate juices. The mean vitamin C contents of fresh juices were higher than those of commercial but these differences were not significant. Although various juices differed markedly in the quantity of polyphenol and vitamin C, they can be considered as a good source of these components. é Asian Network for Scientific Information, 2010.