Investigation of Wheat Milling Yield Based on Grain Hardness Parameters

Abstract

The objectives of this study were to investigate the relationship between milling yield and grain hardness. A preliminary study was carried out with 20 samples (both hard and soft wheats) using the Brabender hardness tester (BHT) with two grind settings: one‐step grind (0‐10) and two‐step grind (2‐12: coarse; 0‐8: fine). The two‐step grind was correlated with particle size index, single‐kernel characterization system (SKCS) hardness, break yield, and reduction yield (P < 0.05), whereas there was no correlation with the one‐step grind method. An additional 64 samples were ground with the two‐step grind setting to further validate this method. In terms of the BHT crush profile, no discernible differences were observed between varieties for the coarse grind, whereas for the fine grind, hard wheat gave a higher BHT maximum peak height and shorter grinding time compared with soft wheat. The break and reduction yields were significantly correlated with both BHT and SKCS hardness (P < 0.05). The findings indicated that the BHT method could be used to differentiate for milling yield among the different varieties. Based on the results, two milling yield models were developed, and both gave highly significant correlations between the predicted and Buhler mill break (R2 = 0.791, P < 0.05) and reduction yield (R2 = 0.896, P < 0.05).