Studies On The Effect Of Wheat Germ On Dough Formation And The Quality Of Flour Products

Wheat germ is the most nutritious part of the grain, added to the flour canimprove the quality of flour and flour products, but flour industry needs to make itsresources is not fully used. Wheat germ added to wheat flour is a kind of practical andsafe method. It can make full use of rich nutrition of wheat germ and strengthen thenutritional of flour products. This topic mainly adopts the three varieties of wheatgerm, and defatted processing, and gets six types of wheat germ powder. Then thewheat germ powder added to flour in nine different proportion respectively,determination of physical and chemical indicators of the mixed powder, the change ofrheological properties and changes in the quality of steamed bread, and the effect ofwheat germ on the changes of the amount of sulfhydryl/disulfide bond and doughmicrostructure in unfermented and fermented dough. The paper compared wheat germsteamed bread flavors with flavor of bran bread, and then discusses the flavor ofsteamed bread. This topic research results were as follows:1. With the increase of the content of wheat germ in flour, the ash and sedimentationvalue had grown gradually; and falling number changed little; Wet gluten and glutenindex decrease after rising first; The results of mixed powder color showed that avalue and b value increased, while the brightness (L value) and whiteness (H value) ofall type of mixed powers showed a downward trend, showed the color of mixedpowder were worse and worse. And adding the defatted wheat germ of powder colorwas better. The various indexes of gelatinization characteristics of mixed power haddeclined in varying degrees, but the changes of the gelatinization characteristics ofwhole wheat germ mixed power had a small rang; A small amount of wheat germ (<3%) could improve the properties of the dough to make dough water absorptionincreased, the ductility good, disulfide bond content, gluten structure reinforcement;With wheat germ content (>3%) to further increased, free sulfhydryl content increased,reduced disulfide bond content, gluten structure, dough holders of gas is reduced, thedough structure damaged, draw ratio (R/E) reduced obviously, the processingcharacteristics of the dough showed deteriorate. Small amounts of adding full-fatwheat germ (2-3%) were more advantageous to improve the structure properties of thedough than the defatted wheat germ.2. Before wheat germ content reached3%, the indicators of the quality of steamed bread were better. When high addition amount of wheat germ, the specific volume ofsteamed bread had a degradation quality. TPA indicators decreased rapidly, the flavorof steamed bread would deterioration, and the color showed yellowish, and theinternal structure of steamed bread varied rough, volume reduced and the hardnessincreased. Adding the defatted wheat germ and whole wheat germ in the steamedbread, the change trend of quality were basically identical, but the influence ofdefatted wheat germ on steamed bread reduced a lot.3. A total of50kinds of flavor compounds in steamed bread were detected, mainlyalcohols and hydrocarbons. Add different ratio of wheat germ, the total kinds ofvolatile substances of steamed bread were not changed substantially, the number ofspecies in all kinds of compounds also hadn’t changed much; But there a lot ofisomers compounds, these compounds were not in the raw steamed bread, and thecontent of wheat germ was higher, the more volatile components occurred. Comparethe flavor of bran steamed bread and wheat germ steamed bread were visible: wheatgerm provided the flavor of steamed bread was compounds with fragrant smell,although bran could also increased the content of flavoring substances, but theirritating odor had increased.