【作者】 李娟；

【导师】 陈正行；

【作者基本信息】 江南大学 ， 食品科学， 2013， 博士

【摘要】 全麦粉富含蛋白质、膳食纤维、维生素、矿物质、酚类和植物化学素等功能性营养成分。近几年，随着全麦食品逐渐深入人心，全麦苏打饼干作为一种营养、健康、方便的新型食品，正受到越来越多消费者的认可与喜爱。本论文对全麦苏打饼干和大麦苏打饼干的制作配方及加工工艺条件分别进行了优化确定，并对终产品的堆垛重量、堆积高度、比容和断裂力等指标进行测定。全麦苏打饼干的品质评价结果表明，全麦粉对饼干的烘焙品质特征造成了严重破坏（尤其降低了苏打饼干的烘焙体积）。因此，本论文采用内切木聚糖酶、活性小麦面筋和阿拉伯胶对全麦苏打饼干的品质进行改良；分别采用阿拉伯胶、瓜尔胶和黄原胶对大麦苏打饼干进行品质改良，并研究了这些品质改良剂对全麦饼干粉理化特性及流变学特性的影响。最后，利用低场核磁技术对全麦面团体系中的水分迁移现象进行了研究，证明了影响全麦苏打饼干烘焙品质差的内在机理原因是全麦面团中的阿拉伯木聚糖与面筋蛋白网状结构之间存在竞争性吸水，使得面筋蛋白无法吸水形成网状结构，使之持气性降低，导致全麦苏打饼干烘焙体积减小。具体实验结果如下：全麦苏打饼干的堆垛重量、堆积高度、比容和断裂力值都随着全麦粉添加量的增加而减小；大麦苏打饼干的堆垛重量和断裂力值随大麦粉添加量的增加而增大，堆积高度和比容值随着大麦粉添加量的增加而减小。随着全麦粉添加量的增加，全麦饼干粉的吸水率SRC值、面团的P和P/L值、G′′模量和蛋白质弱化度升高，而L和W值、G′模量则随之减小，且全麦粉抑制了淀粉的糊化和回生速率。内切木聚糖酶的加入可降低全麦粉的W-SRC和Suc-SRC值、P和P/L值；提高了全麦面团的L值。随着阿拉伯胶添加量的增加，降低了全麦粉的SRC值、P、W和P/L值；提高了全麦面团的L值。活性小麦面筋可提高全麦粉的P、L、W值和全麦苏打饼干的堆积高度、堆垛重量、比容和断裂力值。全麦面团的G′和G′′模量都随着内切木聚糖酶、活性小麦面筋和阿拉伯胶添加量的增加而增大。全麦苏打饼干的堆积高度和比容值随内切木聚糖酶和阿拉伯胶添加量的增加而升高；全麦苏打饼干改良剂最优复配比为：0.035%的内切木聚糖酶、1.5%的活性小麦面筋和1.5%的阿拉伯胶。阿拉伯胶降低了大麦饼干粉的SRC值和蛋白质弱化度，提高了大麦苏打饼干的堆积高度和比容值；降低了大麦饼干粉的P和W值，提高了L和P/L值。瓜尔胶和黄原胶增加了大麦饼干粉的SRC值，降低了大麦苏打饼干的堆积高度和比容值；提高了大麦饼干粉的P和P/L值，而降低了L和W值。阿拉伯胶、瓜尔胶和黄原胶降低了大麦粉中淀粉的糊化和回生速率。随着小麦麸皮颗粒度的增加，对小麦面筋蛋白网状结构的剪切稀释作用越强，使得小麦面筋蛋白中α-螺旋，β-折叠，β-转角和β-反平行的含量减小，无规则卷曲的含量增加。在全麦面团的T2弛豫时间曲线中，T21代表AX凝胶的吸水峰，T22代表面筋蛋白-淀粉复合物的吸水峰，T23为自由水峰。内切木聚糖酶和阿拉伯胶降低了全麦面团的RT21，增加了RT22，RT23变化不显著。全麦面团醒发后，内切木聚糖酶和阿拉伯胶使T21和T22峰左移；T23峰位置没有显著位移。LF-NMR实验结果表明，内切木聚糖酶和阿拉伯胶可使全麦面团体系中的水分从AX凝胶迁移至面筋蛋白-淀粉的网状结构中去。更多还原

【Abstract】 Whole wheat flour is riched in protein, dietary fiber, vitamin, minerals, polyphenol, andphytochemicas. In recent years, with the whole wheat food go into the customers’ heartsdeeply, the whole wheat crackers becoming a novel products as nutrient, health, convenientare accepted by more and more people. In this study, the formula and processing craft ofproducing whole wheat saltine crackers and barley saltine crackers were optimized,respectively. Also, the stack weight, stack height, specific volume, and breaking strength weremeasured to evaluate the baking quality of end products. The results of quality evaluation ofwhole wheat saltine crackers showed that the whole wheat flour had a detrimental effect onthe baking quality attributes of whole wheat saltine crackers, especially in reducing the ovenspring of the end products. Therefore, the endoxylanases, vital wheat gluten, and arabic gumwere utilized to improve the baking quality of whole wheat saltine crackers; arabic gum, guargum, and xanthan gum were employed to modify the baking quality of barley saltine crackers.In addition, the effects of these modifiers on the physicochemical characteristics andrheological properties of whole wheat flour were observed. Finally, the low-field nuclearmagnetic resonance was performed to determine the water migration in whole wheat doughsystem. The LF-NMR data proved that the mechanism of resulting in inferior baking qualityof whole wheat saltine crackers was the water competition between arabinoxylans matrix andgluten-starch network in whole wheat dough system. The gluten network was unable to formdue to lack of water, which led to reduce the puffiness of whole wheat saltine crackers sincethe weak gas retention ability of dough.The stack weight, stack height, specific volume, and breaking strength of whole wheatsaltine crackers were all reduced with increased the addition levels of whole wheat flour. Thestack weight and breaking strength were increased, and the stack height and specific volumeof barley saltine crackers were reduced with increased the addition levels of whole barleyflour. With increasing the addition levels of whole wheat flour, the water absorption of wholewheat cracker flour, the P and P/Lvalues, G′′modulus of whole wheat dough, and proteinweakening were all increased, and L and W values, G′modulus were reduced. Besides, thegeltinization rate and retrogradation rate of starch were reduced by the whole wheat flour.The W-SRC, Suc-SRC, P, and P/L values were reduced, and L value of whole wheatflour was increased with the presence of endoxylanases. With increased addition levels ofarabic gum, the SRC values, P, W and P/L values were reduced, and L value of whole wheatflour was enhanced. The P, L, W values of whole wheat dough and the stack weight, stackheight, specific volume, and breaking strength of whole wheat saltine crackers were allincreased with the presence of vital wheat gluten. The G′and G′′moduli of whole wheatdough were increased with increased addition levels of endoxylanases, vital wheat gluten, andarabic gum. The stack height and specific volume of whole wheat saltine crackers wereincreased with increased addition levels of endoxylanases and arabic gum. The optimum of combined modifiers of whole wheat saltine crackers is:0.035%endoxylanased,1.5%vitalwheat gluten, and1.5%arabic gum.Arabic gum reduced the SRC, P, W values, and protein weakening of barley cracker flour,and increased the L and P/L values of barley cracker flour and stack height and specificvolume of barley saltine crackers. The SRC, P, P/L values of barley cracker flour wereincreased, L and W values of barley cracker dough and stack height and specific volume ofbarley saltine crackers were reduced with the presence of guar gum and xanthan gum. Thegeltinization rate and retrogradation rate of starch in barley cracker flour were all reduced bythe arabic gum, guar gum, and xanthan gum.With increased the particle size of whole wheat flour, the dilute and shearing effects onwheat gluten network were enhanced. The content of α-helix， β-sheet， β-turn, andβ-anti-parallel of whole wheat dough were reduced, and the content of random coil wasincreased. In T2relaxation time distribution curve, peak T21represents the water absorption ofAX matrix, T22represents the water absorption by gluten-starch network, and T23is free water.The RT21of whole wheat dough was reduced, and RT22was increased by the endoxylanasesand arabic gum. RT23changed insignificantly. After dough resting, the peak T21and T22wereshifed left with the presence of endoxylanases and arabic gum. Resultes of Low field-NMRshowed that the water was migrated from arabinoxylanas matrix into gluten-starch networkunder the action of endoxylanases and arabic gum.更多还原