摘要:Globally wheat is main cereal grain in terms of production, consumptions and trade. Milling is a mechanical gradual reduction process with different sets of break and reduction rolls to ensure maximum removal of bran and germ. Roller mills produce different flours from same grain stock. Chemical constituents are not evenly distributed in wheat kernel resulting variation in chemical composition of flour streams. Protein concentration, composition and fraction s vary in distribution both in wheat kernel and flour streams. Salt-soluble proteins are concentrated in sub aleurone cells while endosperm contains mainly salt-insoluble proteins. Stream splitting is useful technique for production of quality flours where desired quality wheat is not available. Mill streams with similar quality and functional properties are blended to produce a variety of flour grades. Blending fulfills economic, qualitative and nutritional constraints and to get standardized flours. Difference in content and chemistry of proteins in different break and red uction flour streams is of immense importance for their characterization and selection for defined end uses. Milled fractions with higher arabinoxylan and protein polymers have a high oxidative potential. Thiol groups and oxidative cross links affect rheological and processing parameters of mill streams. Higher albumins and globulins quantity and lower degree crosslinkings results difference in rheological characters among break and reduction flour. Mill streams vary in dough rheology, baking performance and suitability for baked products. Different flour streams has diverse characteristics making these to suit bread or biscuit process. Selected mill stream blends result in different flour grades and diversified end products.
关键词:mill streams; quality; protein fractions; protein composition; thiol groups; oxidative cross links