甘薯叶提取物中酚类物质测定及在冷却肉保鲜中的应用

Determination of Phenolic Composition of Active in Sweet Potato Leaves Extracts and Their Application in the Preservation of Chilled Pork

摘要:

本文研究了甘薯叶粗提物中酚类物质含量、组成、抗氧化活性、抑菌活性及其处理冷却肉后对保鲜效果的影响。采用体外抗氧化法（DPPH、ABTS自由基清除率和总还原力）及抑菌圈直径法评价各萃取（余）相的抗氧化活性和抑菌活性，筛选出抗氧化及抑菌活性强的萃取（余）相；同时通过测定pH值、硫代巴比妥酸反应物值（TBARS）、肌红蛋白含量（MetMb%）、挥发性盐基氮（TVB-N）及菌落总数等指标评价活性强的萃取（余）相对冷却肉的保鲜效果，并利用UPLC-DAD/ESI-TOF-MS鉴定其主要酚类成分。结果表明：乙酸乙酯相的总酚含量、抗氧化活性及抑菌活性均强于其它萃取（余）相，与对照组相比，1%乙酸乙酯相能有效减缓冷却肉的pH、TBARS值、MetMb%含量、TVB-N和菌落总数的增加，延长冷却肉的保鲜期，乙酸乙酯相中主要含有9种酚类化合物。

Abstract:

The total content, composition, antioxidant activity, antibacterial activity of phenolics in sweet potato leaves crude extracts, and their effects on the preservation of chilled pork were investigated in this study. The antioxidant activity and antibacterial activity of crude extracts were evaluated using the method of in vitro antioxidant (DPPH and ABTS clearance rate and total reducing power) and inhibition-zone diameter to screen out the more strong activity extract phase. Simultaneously, the effects of the active extraction on the preservation effect of chilled pork was evaluated by determing pH, TBARS, MetMb %, TVB-N and colony count. In addition, the main composition of phenols in crude extracts were identified by UPLC-DAD/ESI-TOF-MS. The results showed that ethyl acetate fraction exhibited the higest phenols content as well as the strongest antioxidant and antibacterial activity than other fractions. Compared with the control group, ethyl acetate fraction with the concentration of 1% could effectively reduce the total plate counts, TVB-N, pH, and TBARS values of pork stored at 4 ℃, and then could extend their shelf life. The ethyl acetate fraction mainly contained 9 kinds of phenolic compounds.