Analysis on the Difference of Quality Characteristics of Different Flour Flow of Wheat Milling System

The purpose of this research was to determine wheat quality characteristics of individual flour flow, to better define their functional characteristics in flour blending, and to develop patent flour with certain quality specifications. In this study, flour whiteness, wet gluten content, protein content, starch pasting properties, farinograms parameters, and extensograms parameters were investigated among the 39 individual flour flows. The quality differences were assayed by principal component analysis, factor analysis and cluster analysis. The results showed that the whiteness and starch pasting properties of the former streams of core flour were generally higher than those of other flour flow; The starch pasting properties, stabilization time and farinograph quality index of the latter break streams of core flour were generally lower than those of other mill streams; The dough development time, stabilization time, farinograph quality index, extensibility area and extensibility of the flour from break system were higher than those of other mill streams; The content of protein and gluten in the flour from break system and re-sieve flour was generally higher than that in core flour. Principal component analysis showed that the first four principal components contributed 87.6321% of cumulative variance, and basically synthesize most information of flour quality characteristics. According to the quality characteristics of flour, the flour sample in 39 individual flour flows can be divided into four categories by cluster analysis. The first category comprises 18 flour flows, the second category comprises 12 flour flows, the third category comprises 5 flour flows and the fourth category comprises 4 flour flows. The results can be used as a reference and basis for developing patent flour with certain quality specifications in the commercial mills.