<正> 1 INTRODUCTIONFenugreek,i.e.trigonella foenum-graecum,is an an-nual herbaceous plant of leguminosae,which arewidely planted in China.Fenugreek seed consists oftesta,endosperm and plumula cotyledon.Fenugreek...<正> 1 INTRODUCTIONFenugreek,i.e.trigonella foenum-graecum,is an an-nual herbaceous plant of leguminosae,which arewidely planted in China.Fenugreek seed consists oftesta,endosperm and plumula cotyledon.Fenugreekgum is taken from endosperm,which contains morethan 60% galactomannans with the ratio of galac-tose to mannose 1:1.2.It is soluble in water,aque-ous acid and alkali,respectively,and insoluble in or-ganic solvents.It is a natural polysaccharide whichis composed of a linear backbone of 1-4 β linkedD-mannose units with 1-6 αlinked D-galactoseunits attached as side chains.Its molecular formulais (C_6H_(10)O_5)_n.H_2O.Its structure can be showed asFig.1.Its molecular weight is about 2.5 x 10~5to l.3 x 10~5 that is determined by measuring theviscosity.In practice,due to possessing the advan-tages of low friction resistance,low damage to展开更多
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...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。展开更多
基金Supported by the National Natural Science Foundation of China(No.29576238).
文摘<正> 1 INTRODUCTIONFenugreek,i.e.trigonella foenum-graecum,is an an-nual herbaceous plant of leguminosae,which arewidely planted in China.Fenugreek seed consists oftesta,endosperm and plumula cotyledon.Fenugreekgum is taken from endosperm,which contains morethan 60% galactomannans with the ratio of galac-tose to mannose 1:1.2.It is soluble in water,aque-ous acid and alkali,respectively,and insoluble in or-ganic solvents.It is a natural polysaccharide whichis composed of a linear backbone of 1-4 β linkedD-mannose units with 1-6 αlinked D-galactoseunits attached as side chains.Its molecular formulais (C_6H_(10)O_5)_n.H_2O.Its structure can be showed asFig.1.Its molecular weight is about 2.5 x 10~5to l.3 x 10~5 that is determined by measuring theviscosity.In practice,due to possessing the advan-tages of low friction resistance,low damage to
文摘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。
