Antioxidative properties of methanolic extracts from peanut hulls

Antioxidative properties of methanolic extracts 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°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°C) under air or nitrogen (30°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 α‐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.