氧化魔芋葡甘聚糖对面团特性及面包品质的影响

Effect of oxidized konjac glucomannan on dough properties and bread quality

采用微波协同臭氧氧化法制得了不同取代度的氧化魔芋葡甘聚糖(oxidized konjac glucomannan,OKGM),将其添加至小麦粉中制备面团和面包,以研究不同取代度OKGM(OKGM-20,40,100)对面团粉质、拉伸、动态流变学特性以及面包品质的影响。结果表明,OKGM能在一定程度上改善小麦粉的粉质和拉伸特性。与空白组相比,OKGM显著提高了面粉的吸水率并降低了回生值;添加OKGM-40的面团弱化度最低,OKGM-40有效增大了面团的拉伸能量、拉伸阻力和延伸度。动态流变学特性结果显示,添加OKGM可增大面团的储能模量G′和耗能模量G″,OKGM取代度越小,面团的G′和G″越大。OKGM-40组面团发酵体积最大。从面包品质结果来看,OKGM-40改善面包比容的效果最佳,由空白组的4.05 mL/g增大到4.68 mL/g;OKGM显著延长了面包的保质期;OKGM-40、OKGM-100明显增强了贮藏期间面包的保水性;OKGM-20能有效延缓面包的老化。以上结果表明,OKGM能够较好地改善面团特性和面包品质,以OKGM-40综合效果最佳。

Oxidized konjac glucomannan(OKGM)with different degrees of substitution was prepared by microwave-assisted ozone oxidation method,which was added to wheat flour to prepare dough and bread.Meanwhile,the effects of OKGM(OKGM-20,40,100)on dough quality,stretching,dynamic rheology,and bread quality were investigated.Results showed that OKGM could improve the quality and tensile properties of wheat flour to a certain extent.Compared with the blank group,OKGM significantly increased the water absorption of flour and reduced the setback value.The dough with OKGM-40 had the lowest weakening degree,and OKGM-40 effectively increased the tensile energy,tensile resistance,and extension of the dough.The results of dynamic rheological properties showed that the addition of OKGM could increase the storage modulus G′and energy consumption modulus G″of the dough.The smaller the substitution value of OKGM,the larger the G′and G″of the dough.The dough with OKGM-40 had the largest fermentation volume.From the perspective of bread quality,OKGM-40 had the best effect in increasing the specific volume of bread,from 4.05 mL/g in the blank group to 4.68 mL/g.OKGM significantly extended the shelf life of bread.OKGM-40 and OKGM-100 significantly enhanced the water retention of bread during storage.OKGM-20 could effectively delay the ageing of bread.The above results showed that OKGM could better improve the dough characteristics and bread quality,and OKGM-40 had the best overall effect.