Carefully controlled batch experiments were performed to determine the amounts of the total soluble vitamin C and antioxidant from various citrus fruit peels such as grapefruit, lime, lemon, orange, and tangerine. The citrus fruits' skins were air-dried for two weeks and then were ground using a commercial coffee grinder. An appropriate amount of peel sample was mixed with distilled water followed by filtration. The filtrate was used to determine the total soluble antioxidant capacity and vitamin C using Trolox Equivalent Antioxidant Capacity and 1, 10-phenanthroline-iron(III) indicator assays, respectively. Experimental results showed that all citrus fruit peels adopted in this research could be reliable antioxidant capacity sources. The grapefruit peels displayed the highest soluble antioxidant capacity, while the least antioxidant capacity was observed from the lime peels. For vitamin C, similar amounts of vitamin C were easily extracted in water from lemon and tangerine than those from lime, orange, and grapefruit peels which showed no significant differences; approximately two-third of the vitamin C quantities extracted from the lemon and tangerine peels. In conclusion, while vitamin C is one of the primary sources for the total antioxidant capacity, there is no clear proportional relationship between the amount of vitamin C and the total available soluble antioxidant capacity in the citrus fruit peels studied in this research.

Total available water-soluble vitamin C and antioxidant capacity from five common citrus fruit peels

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.