ANTIOXIDATIVE PROPERTIES OF METHANOLIC EXTRACTS FROM PEANUT HULLS

Antioxidative properties of methanolic extract's from peanut hulls (MEPH) have been investigated. MEPH had good thermal stability and showed an 85.2% inhibition of peroxidation of linoleic acid when heated at 185-degrees-C for 2 h. Only a slight decrease in antioxidative activity of MEPH occurred when the extract was stored at different temperatures (-20, 5 and 30-degrees-C) under air or nitrogen (30-degrees-C) for 70 d. Antioxidative activity of MEPH decreased with an increase of pH from 3 to 9. No synergistic effect of ascorbic acid, citric acid, cysteine or alpha-tocopherol was observed on the inhibitory effect of MEPH. The reducing power of MEPH increased with an increase in concentration and was significantly correlated (r = 0.9793, P < 0.05) to the extent of antioxidative activity. MEPH also showed good inhibitory activity in lard oxidation when compared with butylated hydroxyanisole.