大叶紫薇叶提取物抗氧化性能的研究

采用不同溶剂对大叶紫薇叶进行浸泡提取,计算提取率,并用FolinCiocalteu方法测定总酚含量;采用DPPH分析法和FRAP分析法评估了不同溶剂提取物的抗氧化活性,选出抗氧化活性最高的提取物添加到猪肉中,于4℃光照下贮存12d,通过测定贮存期间猪肉的TBARS值、pH值和亨特L、a、b值,评估了提取物抗脂质氧化、防腐保鲜和护色作用,并与BHT、VE、茶多酚比较。结果表明,不同溶剂提取物显示出不同的抗氧化活性,其中甲醇提取物抗氧化活性最高(高于BHT),其提取率和总酚含量也最高。大叶紫薇叶甲醇提取物在生猪肉中具有明显的抗脂质氧化和防腐保鲜的作用,且随着提取物含量的增大,抗氧化的效果增强,有明显的量效关系。

Study on the Antioxidant Activity of the Extract of the Leaves of Lagerstroemia specious L.

The leaves of Lagerstroemia specious L. were extracted with petroleum ether, ethyl acetate, methanol, anhydrous ethanol and water. The yield and the total phenolic content of the extracts was measured by Folin-Ciocalteu method. The antioxidant activities of different polar solvent extracts were evaluated by DPPH and FRAP assay and the results were compared with three ‘reference' antioxidants BHT, V_E and tea polyphenols. Pork patties with the highest antioxidant activities extracts or the `reference' antioxidants were stored at 4℃ under fluorescent lights for 12 days. The inhibition effect on lipid oxidation, rancidity and color changes were assessed in pork by determination of 2-thiobarbituric acid reactive substances(TBARS) and pH values. The results showed that different solvent extracts had different antioxidant activities. The methanol extract generally demonstrated stronger antioxidant power and higher extraction yield and total phenolic content than other extracts. As compared with the reference antioxidants, the methanol extract demonstrated stronger antioxidant power than BHT. The methanol extract of the leaves of Lagerstroemia specious L. effectively inhibited lipid oxidation and rancidity in pork patties throughout the storage, and the increase of extract concentration exhibited higher antioxidant activity.