Storage Effect on Phenolic Compounds and Antioxidant Activity of Nephelium lappaceum L. Extract

Preparation of potential antioxidant extracts with less process for storing in a long period is preferable. N. lappaceum rind, well known as a promising source of phenolic antioxidants agricultural residue, was employed to prepare crude extracts by different solvents. The phenolic content, flavonoid content, antioxidant, and anti-tyrosinase activities of the extracts were evaluated. The stability of the potential extract was then assessed for phenolic content and antioxidant activity under various storage conditions. The extractive yields of crude phenolic extract ranged from 16.61 to 28.78%. The ethanolic extract of N. lappaceum rind exhibited potential antioxidant activities and contained a high amount of phenolics and flavonoid contents. The extract remained with a high amount of the phenolic content (up to 88.79%) and retained its antioxidant property under various temperatures (4, 25, and 45 degrees C) after the first week of the storage period. The results suggest that phenolic content and antioxidant activity of N. lappaceum rind extract, as a nutraceutical or anti-aging ingredients in cosmetics, could be stored at a temperature from 4 degrees C to 45 degrees C with or without oxygen exposure at least for 16 weeks.