麸胚挤压稳定化处理对面团特性的影响

Effects of Extrusion Stabilization of Wheat Bran and Germ on Dough Properties

为提高麸胚在面制品中的加工适宜性,对麸胚粉进行挤压稳定化处理。以未处理麸胚粉为对照,探究挤压处理对麸胚粉晶体构型的影响及不同添加量的挤压麸胚粉对面团热机械学特性、动态流变学特性、微观结构和傅里叶红外谱图的影响。结果表明,经挤压处理,麸胚粉的淀粉结晶度降低。在同一添加量时,挤压麸胚面团较未处理麸胚面团的吸水率增加,蛋白质弱化度、稳定时间、黏度峰值和回生值降低,有助于延缓面团的老化;当全麦粉添加量大于25%时,挤压麸胚面团的弹性模量(G′)和黏性模量(G″)均提高。此外,麸胚粉的加入使面团新增C≡C特征峰;挤压麸胚面团在1650 cm-1处的吸收峰强度较未处理麸胚面团减弱,而在3400 cm^(-1)处吸收峰较强。扫描电镜图显示,挤压麸胚面团形成的网络结构交联程度增强。

In order to improve the processing suitability of bran and germ in flour products,the bran-germ flour was stabilized by extrusion.The effects of extrusion treatment on the crystal configuration of bran and germ flour and extruded bran-germ flour with different additions on the thermo-mechanical,dynamic rheological properties,microstructure and Fourier infrared spectra of dough were investigated and compared with unextruded bran and germ flour.The results revealed that the starch crystallinity decreased of bran and germ flour after extrusion.At the same amount,compared with the unextruded bran-germ dough,the water absorption increased,protein weakening degree,stabilization time,peak viscosity and retrogradation value decreased of dough with extruded bran-germ flour,indicating that the aging rate of dough slowed down.When the addition amount of whole wheat flour was more than 25%,the elastic modulus(G′)and viscosity modulus(G″)of dough with extruded bran-germ flour both increased.In addition,the new C≡C characteristic peak added due to the addition of bran and germ flour,and the intensity of peak at 1650 cm-1 of the extruded bran-germ dough was weaker than that of the unextruded bran-germ dough,while the peak at 3400 cm-1 was stronger.Scanning electron microscopy showed that the degree of cross-linking of the network structure formed by extruded bran-germ dough was enhanced.