Physicochemical and microstructure analysis of flour mill streams and milled products

Quality of mill streams is very important for obtaining specialty flour for specific application. In order to have clear picture of distribution of major constituents in the flour mill streams during milling of wheat, the physicochemical and microstructure characteristics of flour mill streams and milled products were studied from the pilot roller flour mill. The result showed wide variation in moisture content, ash (0.42 % to 7.12 %), dry gluten (7.95 % to 9.62 %), damaged starch (4.42 % to 8.10 %), falling number (258 to 372), and sodium dodecyl sulphate (SDS) sedimentation values (41 ml to 61 ml) in different flour mill streams and milled products. Variation in the farinograph water absorption (FWA) was also observed in the flour mill streams ranging from 53.07 % to 62.0 %. Scanning electron microscopic (SEM) images showed that straight run flour (SRF) preserved some characteristics of intact endosperm and consisted of aggregates of broken protein matrix and starch granules embedded in it. In break streams, higher aggregates of starch and protein matrix than the single unaggregated granules were seen and starch granules showed less degree of structural deformation when compared to reduction streams.