麸皮预处理对全麦面团及面包的影响

本实验分别采用微波、烘烤、常压蒸汽、高压蒸汽对小麦麸皮进行预处理,研究比较了不同预处理方法对全麦面团和面包品质的影响。结果表明：和未处理全麦粉相比,烘烤、常压蒸汽和高压蒸汽处理均使全麦粉的稳定时间提高,其中常压蒸汽效果最显著,提高了4.2 min；同时,这三种处理方式分别使全麦面包的比容增加了6.92%、9.34%、5.19%,硬度分别降低11.81%、21.79%、19.57%,弹性分别提高2.59%、3.06%、1.65%。推测原因是这三种处理方式均显著降低了麸皮中的还原型谷胱甘肽含量,使全麦面团的游离巯基显著减少,二硫键显著增加,其中常压蒸汽和高压蒸汽效果最显著,分别使还原型谷胱甘肽减少了66.77%、69.30%,使游离巯基减少了40.43%、42.77%,使二硫键增加了51.35%、38.63%。综上,采用烘烤、常压蒸汽、高压蒸汽对麸皮预处理,可以通过降低还原型谷胱甘肽含量、提高二硫键含量来提高面团的稳定性,进而改善面包品质,且常压蒸汽处理的改善效果最好。

Effects of bran pretreatments on the quality of whole wheat dough and bread

In this research, the four pretreatments, microwave, roasting, atmospheric steaming and high-pressure steaming, were used to pretreat wheat bran. Meanwhile, their effects on the quality of whole wheat dough and bread were investigated. Compared with untreated whole wheat flour, roasting, atmospheric steaming and high-pressure steaming increased the stability time, of which atmospheric steaming has the significant effect, increasing by 4.2 min. At the same time, the three pretreatments increased the specific volume of whole wheat bread by 6.92%, 9.34% and 5.19%, decreased the hardness by 11.81%, 21.79% and 19.57% and increased the springiness by 2.59%, 3.06% and 1.65%, respectively. It was speculated that all the three pretreatments significantly decreased the content of glutathione in the bran, decreased the content of free sulfhydryl and increased the content of disulfide bond in the whole wheat dough. Atmospheric steaming and high-pressure steaming decreased glutathione by 66.77% and 69.30%, decreased the content of free sulfhydryl by 40.43% and 42.77% and increased the content of disulfide bond by 51.35% and 38.63% respectively. In summary, roasting, atmospheric steaming and high-pressure steaming could improve the stability of the dough and the quality of bread by decreasing the content of glutathione and increasing the content of disulfide bond.