Antioxidant activity of polyphenol compounds extracted from Nypa fruticans Wurmb. (Nipa palm) fruit husk with different ethanol concentration

Oxidative stress is a condition characterized by a higher content of free radicals than the potential antioxidants in the body. Exogenous antioxidants are needed to resolve this condition. The Nypa fruticans (Nipa palm) fruit husk is a source of polyphenol potential and can be used as a natural antioxidant agent. Therefore, this study aimed to determine the effect of ethanol concentration on polyphenol and tannin contents and their antioxidant activities. The polyphenol substances were extracted using several ethanol concentrations, whereas the antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl method. The results show that the ethanol concentration has no effect on the yield of extraction. However, it affects the total polyphenol and tannin contents with high levels in the 50% and 70% ethanol concentrations. Fifty percent ethanol exhibits more effective antioxidant activity when compared to other ethanol concentrations. Therefore, a 50% ethanol concentration is a suitable solvent to extract polyphenol and tannin substances from nipa palm fruit husk and can be used as an alternative natural antioxidant.