Effect of laboratory milling on properties of starches isolated from different flour millstreams of hard and soft wheat

The properties of starch from different flour millstreams are very important for the production of specific flours used in different wheat-based food products. The present study aimed at characterising starches from different flour millstreams by Buhler laboratory mill and flour from Brabender senior mill. Damaged starch content increased from 3.4% to 15.7% and from 1.8% to 6.0% for flour from B1 to R3 millstream of Beijing 0045 and Zhongmai 175, respectively. Milling resulted in the fragmentation of starch granules, but did not induce significant changes in the relative crystallinity. Starches from different flour millstreams presented similar swelling power values. Except onset temperature of starches from Beijing 0045, no significant differences were observed in thermal transition parameters of starches from Beijing 0045 or Zhongmai 175. Pasting and in vitro digestion profiles of starches from different flour millstreams showed significant differences. This study showed that laboratory milling induces variable differences in functional properties without changing starch crystalline structure.