Antioxidant and free radical scavenging activities of pigments extracted from molasses alcohol wastewater

The pigments from molasses alcohol wastewater were extracted by the macroporous resin adsorption method. The antioxidant and free radical scavenging activities of these pigments were also investigated. The adsorptive characteristics of five macroporous resins including HPD-600, HPD-500, D301-R, NKA-II and D296-R were studied and the results showed that the macroporous resin HPD-600 was most appropriate for extracting the pigments from molasses alcohol wastewater. The antioxidant and free radical scavenging activities of pigments extracted from alcohol wastewater were evaluated using nitrate, hydroxyl radical, superoxide anion radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) in vitro model systems. The pigment extract exhibited a concentration-dependent radical scavenging activity in all the systems. Meanwhile, scavenging activity of pigment extract in the DPPH system was found to be significantly (P < 0.05) higher than that in other systems and the 50% inhibitory concentration (IC₅₀ value) was about 0.07 mg/ml. The scavenging effect of pigment extract on superoxide anion radical was very weak with IC₅₀ value greater than 10 mg/ml.