发酵法提取梨渣、姜渣和豆渣膳食纤维的分离纯化及表征

采用发酵法提取果蔬渣膳食纤维，并对分离纯化后的膳食纤维进行结构表征。方法 利用红曲霉发酵梨渣、姜渣和豆渣制备可溶性膳食纤维，采用离子交换层析柱和凝胶层析柱对制备的可溶性膳食纤维进行分离纯化，通过扫描电镜、气相色谱质谱联用和红外光谱等方法进行微观结构、单糖组成和官能团分析，并测定其热特性和抗氧化活性。结果 红曲霉发酵后梨渣可溶性膳食纤维、姜渣可溶性膳食纤维和豆渣可溶性膳食纤维产量分别为6.28%、4.50%和7.69%；这些纤维的结构呈疏松多孔状态；主要的组成成分包括鼠李糖、阿拉伯糖、木糖、葡萄糖醛酸、葡萄糖和半乳糖；所有纤维样品在红外光谱图中4000~500 cm-1范围内均具有多糖的特征吸收峰。此外，这3种果蔬渣可溶性膳食纤维表现出一定的热稳定性和抗氧化能力，其中姜渣可溶性膳食纤维的2,2’-联氮-二(3-乙基-苯并噻唑啉-6-磺酸)二铵盐[2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) ammonium salt, ABTS]阳离子自由基清除率和1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl, DPPH)自由基清除率分别达到了86.65%和51.61%。结论 红曲霉发酵制备的果蔬渣可溶性膳食纤维的各方面理化性质较为优异，在功能性食品领域具有应用潜力。

Separation, Purification and Characterization of Dietary Fiber from Three Kinds of Fruit and Vegetable Residues

Objective To extract the dietary fiber from fruit and vegetable residues by fermentation, and characterize the structure of the purified dietary fiber. Methods In this study, the soluble dietary fiber was prepared by the fermentation of pear residue, ginger residue and okara residue by Monascus. The soluble dietary fiber was separated and purified by DEAE-Sepharose CL-6B and Sepharose CL-6B. Then, the microstructure, types of monosaccharides, and functional groups were analyzed through methods such as scanning electron microscopy, gas chromatography-mass spectrometry, and infrared spectroscopy. The thermal properties and antioxidant activities were also measured. Results After Monascus fermentation, the yields of pear residue soluble dietary fiber, ginger residue soluble dietary fiber, and okara residue soluble dietary fiber were 6.28%, 4.50% and 7.69%, respectively. The results of the scanning electron microscope showed that the purified components were looser and more porous in structure. These soluble dietary fibers were mainly composed of rhamnose, arabinose, xylose, glucuronic acid, glucose and galactose. In the infrared spectra within the range of 4000-500 cm-1, all fiber samples exhibit characteristic absorption peaks of polysaccharides. Additionally, 3 kinds of soluble dietary fibers all had certain thermal stability and antioxidant capacity. The 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) ammonium salt (ABTS) cation free radical scavenging rate and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging rate of the purified ginger residues soluble dietary fiber reached 86.65% and 51.61%, respectively. Conclusion The soluble dietary fibers from fruit and vegetable residues fermented by Monascus have excellent properties, and they have considerable potential for application in the field of functional foods.