Studies On Antioxidant Extract Of Pepper And Antioxidative Activity Of Pepper Extract

The technology was studied to extract antioxidative components from white pepper. Three extraction methods, including organic solvent, ultrasonic wave and supercritical fluid CO2, were compared, and extraction by ultrasonic wave showed the best results. The optimum condition was as follows: using ethanol to extract the 60-mesh pepper for 12h with the ratio of 20 ml ethanol to 1 g ground pepper.The free radical scavenging ability of the pepper extract was investigated. It indicated that the pepper extract showed stronger ability to scavenge hydrogen peroxide, and 81.5% of hydrogen peroxide was scavenged for 0.6% of the pepper extract. It also indicated that the pepper extract showed stronger ability to scavenge DPPH; 0.08% of the pepper extract had the same effect as 0.02% of BHT, and 0.1% of the pepper extract had a bettereffect than 0.02% of BHT.The antioxidative activity of the pepper extract was investigated for edible oils, andthe pepper extract was found to help to inhibit the oxidation of peanut oil and lard. Though the antioxidative synergist alone, such as vitamin C or citric acid, didn't show any antioxidative effect, the mixture of 0.04% of pepper extract (0.04%) and 0.02%~0.06% of vitamin C showed better effect for peanut oil than 0.02% of BHT, and the mixture of 0.04% of pepper extract and 0.04% of vitamin C showed remarkable antioxidative effect for lard with PF being 2.13.The pepper extract also showed excellent antioxidative effect for lard and palm oil at as high temperature as 60-240°C for 2h, with better effect at 140°C~180°C. The antioxidative effect to lard of pepper extract (0.12%) is the best. Pepper extract has stronger stability, too. Pepper extract (0.08%) has better antioxidative effect to palm oil and lard when it heats long time (200°C, 25 h). Pepper extract (0.08%) has remarkable antioxidative effect to soy salad oil even if it is fried at 190°C.The pepper extract was analyzed using GC-MS, and the main components were identified as piperine, tetrahydro-piperine, and some aldehydes and ketones.