胡萝卜膳食纤维与结合多酚之间肠道酵解特性及抗氧化性的相互影响研究

For a long period, researchers have focused on the carbohydrates component in the dietary fiber definition that can't be digested by human, such as cellulose, hemicellulose, resin, pectin and lignin. However, less attention has been paid to polyphenols associated with dietary fiber. The by-products from processing of fruit and vegetables are rich in dietary fiber, and there are a large amount of polyphenols associated with dietary fiber, their functional characteristics will interact with each other in the process of intestinal fermentation. This study intends to prepare carrot dietary fiber(CDF) by enzymic method from carrot processing by-products (carrot peel, carrots pomace) as the raw material, using polyphenols content as indexes, and optimize the extraction process via the single factor experiment and response surface experiment. Then separate and extract polyphenols components (CDF-PP) from the CDF, the rest of component are dietary fiber (CDF-DF) after extracting polyphenols components. Through in vitro simulating human intestinal fermentation and gavaging the mice, this study will measure the amount and type of polyphenols and metabolites, short chain fatty acid production, pH, bacteria growth in the in vitro fermentation products or the mice feces, respectively, as well as in vitro chemical and cell antioxidant capacity of in vitro fermentation products and in vivo antioxidant capacity in the colon of mice, thus investigate the interrelationship of intestinal fermentation and antioxidation properties between carrot dietary fiber and associated polyphenols.

长期以来研究人员都关注于膳食纤维定义中的不能被人体消化的碳水化合物组分，然而对与膳食纤维结合的多酚关注较少。果蔬加工副产物中含有丰富的膳食纤维，而且膳食纤维结合着大量多酚，两者在肠道发酵过程中会发生功能特性的相互影响。本研究拟以多酚含量为指标，以胡萝卜加工副产物（胡萝卜皮、胡萝卜渣）为原料，通过单因素实验和响应面实验优化提取工艺，用酶法制备胡萝卜膳食纤维CDF，进一步从CDF中分离提取多酚组分CDF-PP和膳食纤维组分CDF-DF。通过体外模拟人体肠道发酵和体内小鼠灌胃胡萝卜膳食纤维CDF及其膳食纤维组分CDF-DF和多酚组分CDF-PP，分析体外酵解产物和小鼠粪便中多酚及代谢物的种类与数量，短链脂肪酸产量，pH值和菌群生长情况；检测体外酵解产物的体外化学抗氧化能力和细胞内抗氧化能力，以及小鼠体内结肠的抗氧化能力；从而探讨胡萝卜膳食纤维与结合多酚之间肠道酵解特征及抗氧化性的相互影响。

胡萝卜是一种常见的食用蔬菜，非常受到人们的欢迎，是天然抗氧化剂的良好来源。但是，许多富含膳食纤维和多酚的胡萝卜副产品，例如胡萝卜皮和残渣，并未得到充分利用，通常被丢弃。本实验室前期研究了大量农副产品来源膳食纤维的理化性质和功能特性，但对膳食纤维中结合的化合物，特别是多酚发挥的作用仍不清楚。基于此，本实验以胡萝卜加工副产物为研究对象，研究了胡萝卜加工副产物中胡萝卜膳食纤维和膳食纤维中的结合多酚的酵解特性和抗氧化特性，及胡萝卜膳食纤维体外消化酵解释放结合多酚的规律及其营养功能特性。主要内容如下：. 第一，优化提取了富含结合多酚的胡萝卜膳食纤维并分离制备脱酚胡萝卜膳食纤维（CDF-DF）组分和胡萝卜膳食纤维结合多酚（CDF-PP）组分及其体内体外抗氧化特性；. 第二，通过建立小鼠体内灌胃实验，研究了结合多酚对CDF和CDF-DF体内酵解特性和结肠抗氧化性的影响；. 第三，通过模拟体外结肠酵解，研究了结合多酚对CDF和CDF-DF酵解特性和抗氧化性的影响。. 第四，研究了胡萝卜膳食纤维体外消化酵解释放结合多酚的规律及其营养功能特性。. 本项目研究已经达到预期目标，通过本研究阐明了结合多酚作为一种膳食纤维中的一部分，对膳食纤维的酵解特性和抗氧化特性均有显著性的影响，胡萝卜膳食纤维结合多酚粗提物中鉴定出了42种结合态多酚类化合物，且表现出较高的体内体外抗氧化能力，结合多酚可能在膳食纤维的胃肠道和结肠健康中发挥潜在的作用。这为揭示胡萝卜膳食纤维的营养功能机制提供了科学依据，为开发胡萝卜膳食纤维的高附加值产品奠定了理论基础，且助于进一步了解结合多酚在胃肠道和结肠健康中发挥潜在的益处，促进了结合多酚作为功能性食品成分的开发潜力。