Studies On Antioxidant Activity Of Spices Extracts

Edible oils are prone to be oxidated during the preservation and supplementary, antioxidants can slow down the oxidation process. The synthetic antioxidants such as butylated hydroxyltoluene(BHT) and butylated hydroxyanisole (BHA)have antioxidant activities. However, the synthetic antioxidants have the problem with their biosafety. The development of effective and safe natural antioxidants becomes one of the main topics in the field of food chemistry. There are many Chinese spices available in China and it has been verified that many spices are full of antioxidative components. In the present study, DPPH·spectrophotometeric analysis was used to evaluate the antioxidant activities of 24 Chinese spices,ultrasonic-assist extracts of three spices were systematic studied, extracts with free radical scavenging and antioxidant activity in edible oils. The results showed as fellows:Pericarpium Citri Reticulatae, Geranium, Illicium verum Hook. F, Folium Et Cacumen Murrayae, Flos Albiziae, Jackfruit have higher extract yield than others, among these spices, Pericarpium Citri Reticulatae extract yiled is 29.4%, whose extract yield is 6.7 times of Herba Schizonepetae. Extract yield of Cassia Bark, Clove, Pepper, Cuminum cyminum l, Nutmeg, Cumin are above 10% too. The results indicated that all spices extracts by ethanol showed certain antioxidant activities and their activities varied from each other. Cassia, Prickyash Pee and Clove extracts have higher antioxidant activities than others(α=0.01).The same optimum technology conditions have been attained by RSM as follows: soaked time is 10 h, the ratio solid to liquid is 1:15 and time of ultrasonic treatment is 60 minute.At 60 min, Clove extract(0.04%) showed stronger ability to scavenge DPPH·than (0.02%) BHT (α=0.05); Cassia extract(0.04%), Prickyash Pee extract(0.06%) showed no significant difference with antioxidant activities(0.02%)BHT(alpha=0.01).Reducing power increased with the extracts concentrations gradually increasing; It shows Clove extrac(t0.08%), Cassia extrac(t0.06%) and Prickyash Pee extrac(t0.06%)showed no significant difference with antioxidant activities (0.02%)BHT and (0.02%) VC(α=0.01).Concentrations measured in the laboratory, three spices extracts, VC and Fe2+ triggered by the spread of the oxidation of lecithin were found to help to inhibit the oxidation with the concentrations gradually increasing, in the concentrations >0.06%, extracts have higher antioxidant activities than BHT(alpha =0.01).Under simulated gastric juice, Clove extract(0.2%), Prickyash Pee extract(0.2%) showed significant difference with BHT (α=0.05) by scavenging hydrogen peroxide. In the concentrations >0.2%, Clove extract, Prickyash Pee extract and Cassia extract have better than BHT (α=0.05) by scavenging hydrogen peroxide.According to Arrehenius equation and the connection of reaction velocity constant and shelf lives, the shelf life could be increased from 68 days for peanut oil to 100 days and from 152 days for lard to 213 days at 20℃when Prickyash Pee extract was used.