体外消化对不同极性植物多酚的抗氧化能力及生物利用度的影响

Effects of in vitro digestion on antioxidant activity and bioavailability of plant polyphenols with different polarities

研究鼠尾草酸、芦丁、绿原酸、表没食子儿茶素没食子酸酯(epigallo-catechingallate,EGCG)、槲皮素在不同pH值条件下的亲水亲油性,经过体外模拟消化后多酚含量和抗氧化活性,生物可接受率和生物利用度的变化。采用超声-摇瓶法,高效液相色谱法(high performance liquid chromatography,HPLC)测定5种多酚的表观油水分配系数,采用体外模拟消化模型测定多酚含量和抗氧化活性。结果表明,在pH 1.5、pH 5.8时,鼠尾草酸、芦丁、槲皮素和绿原酸的lgP均在[0,3]内,具有良好的亲水亲油性,可以跨膜转运并被吸收,而EGCG的lgP <0,亲水性较强,很难跨膜转运;在pH 7.8,EGCG、芦丁和绿原酸的lgP在[-3,-1]内,水溶性较强,不能跨膜,而槲皮素和鼠尾草酸亲油性较强,可以跨膜转运。EGCG和绿原酸具有较高的1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除能力和亚铁离子还原能力。经过体外模拟消化后,芦丁的多酚生物接受率指数最高,其余4种多酚生物接受率指数均<1,多酚生物利用度指数也均<1,而EGCG和绿原酸的抗氧化性生物可接受率指数最高,但槲皮素的抗氧化性生物利用度指数最高。可见,5种多酚因其结构、极性不同,经体外模拟消化后,槲皮素的抗氧化性生物利用度最高,鼠尾草酸最低,芦丁、绿原酸和EGCG无显著差异(P <0.05)。该研究可为利用富含槲皮素、绿原酸、EGCG等多酚的食品原料开发功能食品提供理论依据。

Effects of in vitro digestion on partition behavior,bioaccessibility and bioavailability of five polyphenolics were evaluated,which included carnosic acid,rutin,chlorogenic acid,EGCG and quercetin. The partition coefficients,contents and antioxidant activity of the five polyphenols after in vitro digestion were determined using ultrasonic-shaking bottle and high performance liquid chromatography (HPLC). The results showed that when lgP value of carnosic acid,rutin,chlorogenic acid and quercetin between 0 and 3 and pH value were 1. 5 and 5. 8,the four phenolic compounds could cross the gut membranes and be absorbed in intestine with better hydrophilic and hydrophobic properties.However,EGCG was difficult to cross the gut membranes if lgP was less than 0. Likewise,at pH 7. 8,EGCG,rutin and chlorogenic acid were not able to cross the gut membranes with their lgP values within the range from-3 to-1. On the contrary,both quercetin and carnosic acid could transport across membranes showing stronger hydrophilic ability. Besides,EGCG and chlorogenic acid showed higher DPPH radical scavenging and ferrous reduction ability. After in vitro digestion,the phenolic bioacceptability index (PAC) of rutin was highest,while PACs of the other four polyphenols were smaller than1,and the phenolic bioavailability index (PAV) of the five polyphenols were also small than 1. Furthermore,the antioxidant bioacceptability indexes (BAC) of EGCG and chlorogenic acid were high,but the antioxidant bioavailability index (BAV) of quercetin was the highest. Moreover,quercetin showed the highest BAV value,while carnosic acid’s BAV value was lowest which relation to its different polarity and structure. And there were no significant differences in BAV value of rutin,chlorogenic acid and EGCG after in vitro digestion (P < 0. 05). The present study provided a theoretical basis for the development of functional foods rich in quercetin,chlorogenic acid,EGCG and other polyphenols.