Journal of Food Processing & Technology

Abstract

Comparison of Ascorbic Acid, Total Phenolic Content and Antioxidant Activities of Fresh Juices of Six Fruits Grown in Oman

Nafja Khalfan Al-Musharfi, Hamed Suliman Al-Wahaibi and Shah Alam Khan

Background: Regular consumption of fruits and their juices play a beneficial role in the prevention of many diseases owing to the presence of dietary antioxidants such as ascorbic acid, flavonoids and polyphenols.

Aim: The aim of the study was to analyze and estimate total phenolics, ascorbic acid content and to investigate free radical scavenging activity of six locally grown and commonly eaten fruits in Oman.

Methods: The fruits were thoroughly washed and mechanically squeezed to obtain the juices. The fruit juices after filtration were analyzed for total acidity, ascorbic acid, total phenolic content and in- vitro antioxidant activity by alkalimetery, iodimetric (volumetric), Folin Ciocalteu reagent (colorimetric) and 1,1, diphenyl picrylhyrazyl (DPPH) assay methods respectively.

Key findings: Lime juice was found to be the most acidic while grapefruit juice had the maximum ascorbic acid content. Total phenolic content of the juices were observed in the following order of decreasing levels; pomegranate>grapefruit>lemon>lime>s weet melon>watermelon. The result of in- vitro antioxidant activity of all juices, barring watermelon and sweet melon, were quite significant, but the highest scavenging activity of DPPH radicals was exhibited by pomegranate juice closely followed by grapefruit and lemon juices respectively.

Conclusion: The Results of this study indicated that these fruits are important to the consumer’s health and a potential source of dietary antioxidants due to their high phenolic and ascorbic acid contents.