A Comparative Study On Whole Wheat Flour Produced By Stone Mill And Roller Mill

This paper is based on a research which takes middle gluten wheat and strong gluten wheat, the two most typical wheat variety in China, as raw materials, and after tempering in different moisture content, the whole wheat were ground into flour with stone mill and roller mill respectively. Then the wheat bran were being ultrafine ground, so as to make two different particle size of the whole wheat flour. It analysis the effect of different grinding methods, moisture content of wheat, grain sizes and wheat varieties on the physic-chemical quality, processing characteristics and nutritional quality of the produced whole wheat flour as well as the quality of the whole wheat steamed bread.The experiment result indicates that the whole wheat flour which was made by stone mill loss more fluid than that by roller mill, and ash content unchanged. The grain size and milling mode had a significant impact on the sand content of the whole wheat flour, the sand content of the whole wheat flour that was made by stone mill is higher than that by roller mill. However, the falling number of the whole wheat flour that was made by roller mill is higher than that by stone mill. And the grinding methods had significantly impact on the damaged starch content of whole wheat flour, which was made by stone mill is much higher than the one made by roller mill. The moisture content of tempered wheat and grinding methods had significantly impact on the peak viscosity of whole wheat flour, The whole wheat flour’s peak viscosity increased sharply while improving the moisture content. Water absorption of whole wheat flour was highly significant negative correlation with moisture content of tempered wheat, and positive correlation with grain sizes, the formation time of whole wheat flour dough and moisture content of tempered wheat showed a significant positive correlation. For strong gluten wheat, as tempering water increases, the dough stability time shortened, as grain size reduces, the stabilization time extended, and this is contrary to the variation law of the middle gluten wheat. Stone mill produced wheat wheat flour and roller mill produced flour had different dough extensograph properties.The fatty acid value of whole wheat flour made by stone mill is higher than roller made flour during storage. Stone mill made whole wheat flour, which rich in Mn,Fe,Ca than roller made flour, provided less zinc. Comparing to roller mill made whole wheat flour, there were no obvious advantages in vitamin reservation for stone made flour, and as the particle size decreasing, vitamin loss increase.The volume, height/diameter ratio and specific volume of stone mill made whole wheat steamed bread was superior to the roller made one’s. The moisture and particle size variations did not show regular changing trends on the whole wheat steamed bread’s volume and specific volume. Compared to the roller mill made whole wheat flour, stone mill made one’s whiteness and brightness was better. The moisture and particle size had no discernible impact on the color of the whole wheat steamed bread. Besides, the whole wheat steamed bread, which was made of middle gluten wheat flour, was harder and more elastic than the one made of high gluten wheat flour, as well as its gumminess and chewiness. Under the condition of 13% moisture content and grain size 80 mesh, the streamed bread of strong gluten wheat made by stone mill owned the best comprehensive quality of sensory evaluation. The principal element that influences the sensory quality of the whole wheat steamed bread, which was not significantly associated with the moisture content of wheat, was the milling mode and its particle size.