Antioxidant Activity of Sun-Dried Tropical Lemon (Citrus Limon) Peel

Abstract

The peels of lemon (Citrus limon) are the major by-products obtained during the processing of lemon and are most of the time discarded as food waste. Lemon peels have been reported to possess many bioactive substances with beneficial properties. These properties may probably have potential applications for use in agriculture, industry, aquaculture, medicine and food processing. This research was conducted to determine the antioxidant activity of lemon peels. The free radical used was 2, 2-diphenyl-1-picrylhydrazyl (DPPH), while ascorbic acid was used as the standard antioxidant for the analysis. The DPPH free radical scavenging activity of the lemon peel extracts increased from 6.29 to 53.32% with a corresponding increase in the concentrations of the peel extract from 0.2 to 1.0 mg/ml. The lemon peel extracts, therefore, exhibited DPPH free radical scavenging activity in a dose-dependent manner. The inhibition of ascorbic acid at the concentration of Img/ml was 98.65% while for the lemon peel at the same concentration the inhibition obtained was 53.32%. Lemon peels which are considered a waste product have been shown to possess some level of antioxidant activity. The half-maximal inhibitory concentration (IC50) is the value of the test sample that can scavenge 50% of DPPH free radical. The IC50 value recorded for the lemon peel was 0.93mg/ml as against the IC50 value of 0.41mg/ml of ascorbic acid. Lemon peels are by-products that may be used as a potential low-cost natural antioxidant source for human food and animal feed.