【作者】 李艳；

【导师】 韩育梅；

【作者基本信息】 内蒙古农业大学 ， 农产品加工及贮藏工程， 2019， 硕士

【摘要】 马铃薯渣是淀粉加工副产物,含有丰富的膳食纤维,但其中可溶性膳食纤维含量较低,为提高膳食纤维品质,需对其进行改性研究,改性方法中酶法改性温和、高效。本文首先研究确定了酶法改性马铃薯渣膳食纤维的工艺条件,在此基础上,对比研究了原马铃薯渣膳食纤维(O-DF)、纤维素酶改性马铃薯渣膳食纤维(C-DF)、木聚糖酶改性马铃薯渣膳食纤维(X-DF)、纤维素-木聚糖复合酶改性马铃薯渣膳食纤维(D-DF)的组成成分、单糖组分、理化性质、结构和吸附特性,研究结果如下:1.以可溶性膳食纤维(SDF)得率为指标,采用单因素试验,分别研究了纤维素酶、木聚糖酶改性马铃薯渣膳食纤维的工艺条件,SDF最高得率分别为21.27%、22.10%。以单因素结果为基础,利用响应面分析法优化纤维素-木聚糖复合酶改性马铃薯渣膳食纤维的工艺条件,最佳条件为:料液比1:15(g/mL),纤维素酶添加量0.41%,木聚糖酶添加量0.40%,pH5,酶解温度50℃,酶解时间1.55h,在此条件下SDF得率从12.45%(马铃薯干渣)提高到23.15%。2.组成成分测定结果表明,3种酶法改性后纤维素和半纤维素含量均有所降低,木质素无明显变化。与O-DF相比较,D-DF变化最显著,纤维素和半纤维素含量分别降低10.95%和16.37%。单糖组分测定结果表明,O-DF、C-DF、X-DF、D-DF中均含有葡萄糖、半乳糖、半乳糖醛酸、阿拉伯糖、木糖5种单糖,但不同酶法改性前后膳食纤维各单糖含量有显著差异(p><0.05)。3.理化性质测定结果表明,C-DF、X-DF、D-DF的持水力、结合水力、溶解性、持油力、阳离子交换力均高于O-DF,其中D-DF变化最显著,比O-DF 分别提高了 115.22%、27.18%、10.06%、16.73%、173.18%。4.傅里叶红外光谱分析结果表明,O-DF、C-DF、X-DF、D-DF均具有糖类特征官能团,在某些波长处出现相似吸收峰,但吸收峰的强度和面积发生了改变,表明可溶性成分含量发生变化。X-射线衍射曲线分析结果表明,C-DF、X-DF、D-DF与O-DF相比较,出峰位置及峰型没有发生明显变化,都属于纤维素Ⅰ型。扫描电镜测定结果表明,C-DF、X-DF、D-DF与O-DF相比较,网络结构被破坏,表面变得凹凸不平,膨松多孔,其中D-DF变化最显著,出现了较为明显的断裂和缺口,组织结构更加疏松。5.胆固醇和葡萄糖吸附测定结果表明,C-DF、X-DF、D-DF吸附胆固醇的能力均比O-DF高,且pH7条件下D-DF吸附胆固醇能力分别高于O-DF、C-DF 和 X-DF1.28、1.10、1.09 倍。葡萄糖浓度为 200mmol/L 时 D-DF吸附葡萄糖能力达到最高11.42mmol/g,分别高于X-DF、C-DF及O-DF0.46%、4.58%及9.84%。更多还原

【Abstract】 Potato residue is a by-product of starch processing,which is rich in dietary fiber,but low in soluble dietary fiber.It needs to be modified to obtain high-quality dietary fiber.The modification method is mild and efficient in enzymatic modification.In this paper,the process conditions of enzymatically modified potato dregs dietary fiber were firstly studied.On the basis of this,to compara the composition,monosaccharide composition,physicochemical properties,structure and adsorption characteristics of the original dietary fiber from potato residue(O-DF),cellulase modified dietary fiber from potato residue(C-DF),xylanase modified dietary fiber from potato residue(X-DF)and cellulose-xylan complex enzyme modified dietary fiber from potato residue(D-DF).The research results are as follows:1.The yield of soluble dietary fiber(SDF)was used as the index.The process conditions of cellulase and xylanase modified potato dregs dietary fiber were studied by single factor test.The highest yields of SDF were 21.27%and 22.10%respectively.Based on the single factor results,the response surface methodology was used to optimize the process conditions of cellulose-xylan complex enzyme modified potato slag dietary fiber.The optimum conditions were:ratio of material to liquid 1:15(g/mL),cellulose.The enzyme addition amount was 0.41%,the xylanase addition amount was 0.40%,the pH was 5,the enzymatic hydrolysis temperature was 50℃,and the enzymatic hydrolysis time was 1.55 h.Under this condition,the SDF yield was increased from 12.45%(dry potato residue)to 23.15%.2.The results of compositional determination showed that the content of cellulose and hemicellulose decreased after three kinds of enzymatic modification,and there was no significant change in lignin.Compared with O-DF,the change of D-DF was the most significant,and the cellulose and hemicellulose content decreased by 37.63%and 45.88%,respectively.The results of monosaccharide component determination showed that O-DF,C-DF,X-DF and D-DF contained five kinds of monosaccharides such as glucose,galactose,galacturonic acid,arabinose and xylose,but the content of monosaccharides in dietary fiber modified by different enzymatic methods was significantly different(p<0.05).3.The results of physicochemical properties showed that the water holding capacity,combined hydraulic power,solubility,oil holding capacity and cation exchange capacity of C-DF,X-DF and D-DF were higher than those of O-DF,and D-DF changed most significantly.Compared with O-DF,it increased by 115.22%,27.18%,45.27%,16.73%,and 173.18%,respectively.4.The results of Fourier transform infrared spectroscopy indicated that O-DF,C-DF,X-DF and D-DF all have saccharide-characteristic functional groups,and similar absorption peaks appeared at some wavelengths,but the intensity and area of absorption peaks has changed that indicating a change in the content of soluble components.X-ray diffraction curve analysis showed that C-DF,X-DF,D-DF and O-DF showed no significant changes in peak position and peak shape,and all belonged to cellulose type I.The results of scanning electron microscopy showed that compared with O-DF,C-DF,X-DF,D-DF and O-DF were destroyed,the surface became rugged,and the surface was loose and porous.The change of D-DF was the most significant.Obvious breaks and gaps,the structure is more loose.5.The results of cholesterol and glucose adsorption measurements showed that the ability of C-DF,X-DF and D-DF to adsorb cholesterol was higher than O-DF,and the ability of D-DF to adsorb cholesterol was higher than that of O-DF,C-DF and X-DF,respectively.1.28,1.10,1.09 times.When the glucose concentration was 200 mmoI/L,the ability of D-DF to adsorb glucose reached the highest 11.42 mmol/g,which was higher than X-DF,C-DF and O-DF by 0.46%,4.58%and 9.84%,respectively.更多还原