Main Article Content
Nipa palm vinegar (NPV) is a local product which is widely consumed in habitual diet and used in traditional medicine in Pak Phanang District, Nakhon Si Thammarat Province. This study aimed to investigate antioxidant activities of the NPV. Determination of antioxidant activities were assessed by inhibition of 2,2-azinobis(3-ethylbenzo thiozoline)-6-sulfornic acids (ABTS) radical, nitric oxide, 2,2–diphenyl–1–picrylhydrazyl (DPPH) radical, hydroxyl radical, and lipid peroxidation formation as well as metal ion chelating activity. The inhibition of ABTS and DPPH radicals were concentration-dependent (r = 0.973 and 0.407, respectively) . Besides, 12.5% (v/v) NPV caused the highest inhibition of hydroxyl radical and lipid peroxidation. However, the inhibitory effect was then declined when concentrations of NPV were increased. Inhibition of nitric oxide and metal chelating activity were not observed. NPV inhibits some types of free radicals which support health benefit of NPV. Further study to identify content of active compounds exerting antioxidant effects in NPV is interesting to generate a supportive data to promote NPV consumption.