非淀粉多糖提高高分支麦芽糊精黏弹特性的研究

Enhancement of viscoelastic properties of high-branched maltodextrin by non-starchy polysaccharides

中文关键词:  非淀粉多糖  香豆胶  高分支糊精  粘弹特性  流变

英文关键词:non-starch polysaccharide  fenugreek gum  high-branched maltodextrin  viscoelastic characteristics  rheology

中文摘要:

      目的 探究非淀粉多糖对酶法制备高分支麦芽糊精黏弹特性的影响。方法 利用α-葡萄糖基转移酶(α-glucanotransferase, α-GT)和马铃薯淀粉制备高分支麦芽糊精, 并对其分子量、分支度和消化性进行测定。采用动态流变仪分别测试黄原胶、桃胶、香豆胶、刺槐豆胶和魔芋胶5种非淀粉多糖对高分支麦芽糊精的增稠效果。选取增稠效果适中、稳定性高的香豆胶按不同质量比与高分支麦芽糊精混合, 进行振荡流变测试。通过傅里叶红外光谱对混合体系的结构进行表征。结果 所得高分支麦芽糊精重均分子量为2.78×106 g/mol, 聚合度(degree of polymerization, DP)≤5的超短链含量为52.09%, 消化率显著降低。测得的剪切流变曲线均符合Herschel-Bulkley模型(决定系数R2>0.99), 增稠效果魔芋胶>刺槐豆胶>香豆胶>黄原胶>桃胶, 体系稳定性香豆胶>桃胶>刺槐豆胶>魔芋胶>黄原胶。振荡流变测定结果表明, 随着香豆胶含量的增加, 储能模量、损耗模量和损耗角正切tanδ均逐渐减小, 混合体系由黏性液体逐渐偏向于弹性固体。傅里叶红外光谱结果表明, 随着香豆胶在体系中的含量增加, 指纹区峰值强度下降。结论 α-GT改性马铃薯淀粉, 可以制备出一种分支度高、分子量低且具有缓慢消化特性的高分支糊精。5种非淀粉多糖均可增加高分支麦芽糊精的黏弹特性, 且当高分支糊精与香豆胶的质量比例为5:1时, 黏度最大, 弹性最小, 混合体系具有更好的协同增稠效果。

英文摘要:

      Objective To investigate the effect of non-starch polysaccharides on viscoelastic properties of high-branched maltodextrin prepared by enzymatic method. Methods High-branched maltodextrin was prepared by using α-glucosyl transferase (α-GT) and potato starch, and its molecular weight, branching degree and digestibility were determined. The thickening effect of 5 kinds of non-starch polysaccharides, including xanthan gum, peach gum, fenugreek gum, locust bean gum and konjac gum, on high-branched maltodextrin was tested by dynamic rheometer. Coumarin gum with moderate thickening effect and high stability was mixed with high-branched maltodextrin according to different mass ratios, and the oscillatory rheological test was carried out. The structure of the hybrid system was characterized by Fourier infrared spectroscopy. Results The weight average molecular weight of the obtained high-branched maltodextrin was 2.78×106 g/mol, the content of ultra-short chains with degree of polymerization (DP)≤5 was 52.09%, and the digestibility was significantly reduced. The measured shear rheological curves were in accordance with Herschel-Bulkley model (coefficient of determination R2>0.99). The thickening effect of konjac gum>locust bean gum>fenugreek gum>xanthan gum>peach gum, system stability of fenugreek gum>peach gum>locust bean gum>konjac gum>xanthan gum. The oscillatory rheological measurement results show that the storage modulus, loss modulus and loss Angle tangent tanδ gradually decrease with the increase of the content of gummy gum, and the mixed system gradually shifts from viscous liquid to elastic solid. The results of Fourier transform infrared spectroscopy showed that the peak intensity of the fingerprint region decreased with the increase of the content of coumarin gum in the system. Conclusion A highly branched dextrin with high branching degree, low molecular weight and slow digestion property can be prepared by modification of potato starch with α-GT. All the 5 kinds of non-starch polysaccharides can increase the viscoelastic properties of high-branched maltodextrin. When the mass ratio of high-branched dextrin to coumarin is 5:1, the viscosity is the maximum and the elasticity was the minimum, and the mixed system has better synergistic thickening effect.