Study On The Mechanism Of The Change Of Processing Properties And Its Effect The On The Bread Quality During The Process Of Frozen Dough

With the popularity of household oven,bread has become a necessity for every family every day,because the amount of bread produced by the small family,the fermentation process is complex,bread making is not only time consuming,but also can not reach the quality standard of bread,introduction of frozen dough bread can make the family convenient,with delicious taste and appearance.Based on the frozen dough and process optimization,basing on the research of the mechanism of changes of starch and protein processing properties of frozen dough,and by the end of the frozen dough bread specific volume,texture and sensory quality indexes were analyzed,the effects of no-frozen and frozen bread quality.The results show:(1)The best and surface conditions of frozen dough are:water temperature of 40 ?,the amount of water added by 50%,the freezing time is about 2 days and the freezing temperature is-20 ?.By using the analysis of variance can get and surface conditions on frozen dough effect;analysis of physicochemical properties of frozen dough paste after texture in elastic lower than outside,other properties were increased,visco elastic modulus of frozen behind the mission were higher than the viscoelastic modulus of dough is not frozen,while the loss tangent delta is less than Tan not frozen dough Tan value;Determination of thermodynamic dough before and after frozen dough flour began melting temperature and melting temperature is not completely change,but the value of enthalpy is higher than that of non frozen flour flour was frozen after the observation value;non frozen and frozen dough solid powder in the 500 and 1000 fold microscope can be.Solid powder in non frozen dough and gluten more closely connected,there are few starch granules exposed after freezing,the starch and protein occurred on the connection part of the separation,more starch granules exposed On the outside,the shape becomes irregular,and the protein becomes a flaky surface;(2)The dough free determination of starch content compared with non frozen frozen,frozen dough free starch content decreased;Determination of dough amylose content compared with non frozen frozen,frozen dough after reduce the starch content of amylose;analysis by Starch Physicochemical Properties:thermodynamic properties not frozen starch started melting temperature,melting temperature and enthalpy of complete melting temperature,complete melting temperature and enthalpy value was significantly higher than that of starch of frozen dough;numerical starch pasting properties after freezing in each index were lower than the starch gelatinization starch not frozen;Fourier transform infrared spectroscopy analysis showed that the absorption peak at 3600-3300cm-1 offset right in the frozen starch significantly,1241cm-1 characteristic peaks of starch by freezing the wavelength shift to the left,in the 1081cm-1 of the peak of starch cold Right shift after freezing,little change in other locations;500 times under the objectives of starch pictures can be seen after the frozen dough size of starch granules than non freezing conditions is more uniform,but the starch granules appear obvious deformation by the original circular elliptical shape and rod shape;(3)The content of soluble protein in non frozen and frozen dough,its content decreased after freezing;the two level structure of glutenin and gliadin of wheat flour do not contain random coil,for gliadin,decreased after the frozen beta sheet content than non frozen content,and the content of alpha the spiral and p-turns than content in frozen dough increased;for glutenin content increased after freezing,betafolding and p-turns,and alpha helix content than those after the frozen frozen condition decreased,frozen disordered protein increased,reduced stability;(4)The determination of protein electrophoresis can mainly in flour:non frozen and frozen dough gliadine Lane color difference is obvious,and the emergence of missing band is not frozen dough gliadine Lane color should be deep in frozen dough gliadine lane,and with the number of frozen dough after gliadin in a small molecular weight about 17kDa and no bands;the difference was not frozen and frozen dough glutenin Lane staining degree is no band loss,but the color of frozen dough glutenin lane should be deep,the molecular weight of 20kDa is not frozen dough glutenin bands on the main color is shallow;protein flour in subunit composition analyzed:non frozen and frozen dough in gliadins are a total of 6 bands,the molecular weight distribution between 35-180kDa in 100kDa molecules The amount of near band,and after freezing no band has two bands in the vicinity of the molecular weight of 90kDa,two bands in 60-80kDa between the non frozen and frozen gliadin,gliadin appears only one strip;non frozen and frozen dough gluten are a total of 8.With the molecular weight distribution between 10-135kDa.Slightly lower in molecular 130kDa near the frozen dough glutenin content,but its content was significantly higher than that in non frozen dough molecular weight glutenin content,not frozen dough glutenin content was the highest molecular weight appeared at 37.16kDa the content is 32.1%,and the frozen dough molecular weight glutenin content was highest at 58.73kDa the content is 32.57%;morphological observation available:for gliadin,not frozen dough gliadine is sheet structure of different size and thickness of the surface,there are a lot of convex and irregular,and frozen behind the mission gliadin structure disorder,lamellar structure is relatively small,mostly irregular blocky structure dispersed;for glutenin,not frozen dough glutenin into blocky structure of different sizes,most of the surface is smooth,there is little clutter like structure,and glutenin of frozen dough The structure of the protein is messy,the structure is small,and most of them are uneven;(5)The determination of specific volume of bread:The frozen dough bread volume and quality than non frozen volume and the overall quality of bread decreased,before and after frozen bread is basically the same;bread texture determination:frozen bread dough skin texture properties are higher than in the non frozen dough bread texture among them,the increase of hardness is the quality defects of bread,but other textural properties that make the frozen bread texture characteristics were improved;the bread core texture,frozen dough bread behind the core recovery,poly,springiness,gumminess and chewiness were better than non frozen these characteristics,but not less than the hardness of frozen dough bread core hardness,look at all the indicators are better than the non frozen dough bread internal index from the internal structure of bread;sensory evaluation of bread available Non frozen dough bread sensory score was lower than that of frozen dough bread sensory score,but from the two state bread sensory score evaluation indexes of color,appearance,softness,chewiness and odor by score indicates that the two basic difference,while the internal structure region of bread dough don't obvious after the frozen bread pores is more uniform not frozen bread dough,stomatal rough and uneven;the bread,observed from the surface non frozen and frozen dough bread have no obvious difference,appearance and color are basically the same;but from the cross section,cross section of frozen dough bread behind the small aperture and uniform,but not frozen dough bread in cross section large aperture,uneven and rough.