受热对小麦粉品质及其面团特性的影响

小麦粉在加工过程中会受到热的影响,导致小麦粉品质发生变化。该文研究不同受热条件下小麦粉品质及其面团特性的变化,以稳定或提高小麦粉品质。采用干热处理方式,在60~90℃分别对小麦粉加热10~50 s,测定小麦粉的水分含量、干面筋含量、面筋指数、蛋白质组分含量等理化特性,以及游离巯基含量、二硫键含量、面筋蛋白二级结构等结构组成和面团质构特性。研究结果表明,受热后小麦粉水分含量显著降低,在较长时间和较高温度时,随着温度升高和时间的延长,干面筋含量总体呈先升高后降低的趋势,当温度较高时,面筋指数均低于原粉,且随时间的延长先升高后降低;随着温度升高和时间延长,清蛋白和球蛋白含量降低,醇溶蛋白和麦谷蛋白含量先升高后降低;游离巯基和二硫键含量有显著变化,蛋白质的二级结构受温度影响显著,时间仅对β-转角含量有影响;面团质构特性在起始醒发时差异不大,但在醒发45 min后差异极显著,在温度高时,面团坚实度和黏弹性的值较大。

Effect of heat on the quality of wheat flour and dough

Heat could change the quality of wheat flour.In this study,the quality of wheat flour and dough character were studied under different heating conditions in order to stabilize or improve flour quality.By dry heat treatment,the wheat flour under the treatment of 60-90°C for 10-50 s.Meanwhile,the moisture content,dry gluten content,gluten index and protein component content,as well as free sulfhydryl content,disulfide bond content,the secondary structure content of gluten protein and the texture of dough were determined.Results showed that the moisture content of wheat flour decreased significantly after dry heat treatment.With temperature and time increasing,the dry gluten content increased first and then decreased under longer time and higher temperature treatment.The gluten index was lower than that of untreated sample under the high temperature.Furthermore,with the treatment time increased,the gluten index also increased and then decreased.Meanwhile,albumin and globulin content decreased,gliadin and glutenin content increased first and then decreased.Moreover,the content of free sulfhydryl and disulfide bonds changed significantly after heat treatment.The secondary structure was also affected by temperature significantly,and only theβ-turn content was affected by the time.While dry heat treatment had little effect on the texture of the dough for origin fermentation.But significant change presented on the dough after 45 minutes fermentation.The firmness and viscoelasticity increased with the increasing of the temperature.