Comparative study on the quality characteristics of filter flours collected from different milling streams in a wheat flour milling system

Abstract

This study investigated filter flours extracted from different milling streams in a flour mill, including filter flour from the first milling stream (QF), the final milling stream (HF), and the flour blending system (PF), as well as finisher flour (DF), with wheat flour (F) used as the control sample. The quality characteristics of the different flours, including their structural and physicochemical properties were analyzed. The values of G′ and G″ for the filter flours were both greater than those of wheat flour. The farinograph and extensograph properties of filter flours vary significantly. None of the filter flours had a whiteness higher than that of wheat flour. The starch content (27.99–75.36 %) of the filter flours was lower than that of wheat flour. The gluten index (68.37–91.06 %) and relative crystallinity (10.39–18.68 %) of the filter flours were higher than those of wheat flour, except in the case of QF, with the highest gluten index observed in PF. The peak viscosities ranged from 43.5 cp (DF) to 1077 cp (PF), while the peak temperatures were all higher than that of wheat flour, varying from 57.65 °C (QF) to 59.74 °C (DF). A total of 28 volatile flavor compounds were detected in the filter flours, with DF showing a relatively large difference from the others. These results indicate significant quality differences among the filter flours from different milling streams. This study provides a theoretical basis for the rational utilization of filter flour to increase economic benefits and to precisely determine the specific applications of filter flour from different milling streams.