体外模拟胃肠道消化和结肠发酵对长黑青稞多酚生物有效性和抗氧化活性的影响

Effects of in Vitro Gastrointestinal Digestion and Colonic Fermentation on Bioavailability and Antioxidant Activity of Phenolic Compounds in Changhei Hulless Barley

青稞中含有丰富的酚类化合物,具有多种生物活性,其吸收和利用有助于人体健康。为探究青稞经体外模拟胃肠道消化和结肠发酵对其多酚生物有效性和抗氧化活性的影响,本实验以长黑青稞为原料,利用体外模拟胃肠道消化和结肠发酵,分别测定青稞酚类化合物在不同消化阶段和发酵时间的总酚、类黄酮含量及抗氧化活性,进一步分析其生物有效性,同时利用高效液相色谱法测定酚类化合物组成。结果表明,青稞经体外模拟胃肠道消化后,总酚、类黄酮含量和抗氧化活性均升高,生物有效性增强;与未消化样品相比,总酚和类黄酮含量分别提高92.87%和13.89%,同时生物有效性也分别提高93.17%和14.97%。在结肠发酵前30 h,总酚、类黄酮含量和抗氧化活性显著提高(P<0.05),在30 h时总酚和类黄酮含量达到最高值,分别为(20.25±2.07)μmol/g md和(0.72±0.11)μmol/g md,与0 h相比,生物有效性分别提高了110.14%和58.70%;在发酵30 h后,总酚、类黄酮和抗氧化活性的生物有效性逐渐降低。高效液相色谱共鉴定出18种酚类化合物,分为羟基苯甲酸、羟基肉桂酸和类黄酮3类。综上,体外模拟胃肠道消化和结肠发酵能够改善青稞中酚类化合物的生物有效性,同时结肠发酵可以促进青稞中键合多酚的释放。

Hulless barley is rich in phenolic compounds with a variety of biological activities,whose absorption and utilization are helpful for human health.In order to explore the biological effectiveness and antioxidant activity of hulless barley polyphenols,the total phenolic and flavonoid contents,as well as antioxidant activity of Changhei hulless barley at different digestive stages and different fermentation times were measured by simulated in vitro gastrointestinal digestion and colon fermentation,and their bioavailabilities were further analyzed.Meanwhile,the composition of phenolic compounds was determined by high performance liquid chromatography.The results showed that the total phenolic and flavonoid contents,and antioxidant activity were increased,and the bioavailability of hulless barley phenolics was enhanced after in vitro gastrointestinal digestion.Compared with undigested samples,the contents of total phenolics and flavonoids were increased by 92.87%and 13.89%and their bioavailabilities by 93.17%and 14.97%,respectively.The total phenolic and flavonoid contents,as well as antioxidant activity were significantly increased during colonic fermentation from 0 to 30 h(P<0.05).The highest total phenolic and flavonoid contents of(20.25±2.07)μmol/g md and(0.72±0.11)μmol/g md,respectively were attained at 30 h.Moreover,at this time,the bioavailability of phenolics and flavonoids were improved by 110.14%and 58.70%in comparison to those at 0 h,respectively.However,the bioavailabilities of total phenolics,flavonoids and antioxidant activity were decreased in comparison to those after 30 h.Eighteen phenolic compounds were identified,belonging to the hydroxybenzoic acid,hydroxycinnamic acid and flavonoid classes.The bioavailability of phenolics compounds in hulless barley can be improved by in vitro gastrointestinal digestion and colon fermentation,and colon fermentation can also promote the release of bound polyphenols from hulless barley.