Effect Of Wheat Flour On The Quality Of Frozen Dough And Steamed Food

The relationship of wheat flour and frozen dough (steamed products) was studied in thispaper by using the method of separation and reorganization. In order to improve the qualityof frozen dough (bread) and extend the shelf life, we would find out the important flourindicators which affecting the quality of frozen dough (steamed bread); analyze the effect ofprotein on the quality of frozen dough (steamed bread), and explore the mechanism of thedecline in quality of frozen dough during frozen storage by scanning electron microscopy andDSC. The main conclusions were as follows：（1）In wheat flour physical and chemical indexes, the crude protein content, wet glutencontent, gluten index, glutenin content of protein and other protein feature index had closedcorrelation with the quality of frozen dough (steamed bread).Higher content and good qualityof protein in flour, higher quality of frozen dough (steamed bread). Amylopectin content alsohad positive effect on the frozen dough.（2）The effect of rheological properties on the frozen dough (steamed bread) was the sameto proteins characterization. Long stability time, high extension and maximum resistancewere good for frozen dough (steamed bread).（3）Gliadin content and dough extensibility had significant positive correlation with theproofing height of frozen dough within2h.（4）In flour gelatinization property, breakdown was most closely related to the frozen dough.It had significantly negative correlation with the total sensory score, specific volume andsoftness, had a very significantly positive correlation with hardness and TPA gumminess andchewiness, a very significantly negative correlation with TPA cohesion and adhesion（5）When the adding gluten protein was2%, both the quality of frozen dough (steamedbread)and shelf-life time had improved. However, when the addition was excessive thequality decreased obviously. The steamed bread skin appeared popping, the interior wrinkled（6）When the adding glutenin was0.4%, the comprehensive quality of frozen dough(steamed bread) and shelf-life time had improved. When the adding glutenin was over0.8%, frozen dough steamed bread quality decreased obviously.（7）DSC results showed that, when gluten protein or glutenin was added, the frozenenthalpy and melting enthalpy decreased. This showed that gluten protein or glutenin canreduced the freeze water content. And then reduced the number and undermine ability of icecrystals. SEM results showed that when the frozen dough had been hided4w, gluten networkof3groups were broken in different degree. Blank group almost cannot watch glutenmembrane. Starch particles are mostly bare outer. Gluten protein group and glutenin groupcan be still observed broken gluten network in the starch surface and surrounding.