Submitted to: Journal of Zhengzhou Institute of Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/2001
Publication Date: 12/20/2001
Citation: Shi, Y., Hareland, G.A. 2001. The effects of milling variables on physicochemical components of semolina and flour in the first break system. Journal of Zhengzhou Institute of Technology. 22(4):1-7. Interpretive Summary: The configurations of the first break rolls in pilot durum mill trials affected the physicochemical components of the products of durum wheat. By increasing the number of corrugations in the first break rolls, semolina and flour yields and starch damage levels increased, semolina contained higher ash and lower starch contents, and flour contained lower ash and higher starch contents. Dull-to-dull roll orientation resulted in higher flour yields and lower starch damage levels in the semolina and flour. Sharp-to-sharp roll orientation resulted in higher flour yields. Greater speed differential resulted in higher semolina and flour yields and higher ash and protein contents. Higher tempered wheat moisture content resulted in lower semolina and flour yields and lower protein and damaged starch levels. The intensity of the yellow amber color in semolina was negatively correlated with tempered wheat moisture content and positively correlated with semolina protein content. The intensity of the yellow amber color in flour was greater when flour yields and flour particle size increased.
Technical Abstract: The effects of corrugation, orientation, speed differential, and wheat moisture content on the physicochemical components of a durum wheat variety (Renville) in the first break system was investigated. The yields, ash, protein (N x 5.7), total starch, and damaged starch contents of both semolina and flour, resulting from the first break system, were examined. The quality differences between semolina and flour and the relationship between the intensity of the amber to other components were analyzed. The increase in the number of corrugations resulted in a significantly higher yield and higher level of damaged starch both in semolina and flour, higher ash and lower starch contents in semolina, and lower ash and higher starch contents in flour. Dull-to-dull roll orientation resulted in a significantly higher semolina yield and lower level of damaged starch in semolina and flour. All quality parameters between semolina and flour were significantly (P <0.001) different. The intensity of amber in semolina was negatively correlated to tempered wheat moisture content and positively correlated to semolina protein content. The intensity of amber in flour was greater when flour yields or flour particle size increased.