Developing a high‐throughput micromilling protocol for evaluating durum wheat milling performance and semolina quality

Abstract

Background and objectives:Effective and efficient selection of key quality traits is crucial to develop new durum varieties with improved end-use quality. This study was undertaken to develop a rapid micromilling protocol using a single Brabender Quadrumat Jr. (QJ) semolina mill without purification to predict milling performance and generate semolina for quality analysis. Findings: After grinding 200 g of durum wheat with a QJ mill with the reel sifter removed, the resulting wholemeal was sifted through a laboratory sifter equipped with a bottom screen of 180 µm to remove flour and a top screen of 630 µm to retain bran-rich fraction. Semolina materials between the two screens were collected. A model for predicting semolina yield (R 2 = 0.81) was developed based on the amounts of semolina and bran-rich fraction, thus eliminating the need for additional milling to recover semolina in the bran-rich fraction. There were highly significant correlations (r > 0.86) for semolina ash, yellowness, yellow pigment content, protein content, wet gluten, and gluten index between semolina prepared with this proposed protocol and those generated with a Allis-Chalmers mill. Conclusions: The micromilling protocol developed in this study is rapid and reliable for assessing durum milling performance and for preparing semolina for quality characterization. Significance and novelty: The proposed protocol modified QJ mill and optimized milling conditions. A robust and simplified model was developed for predicting semolina yield with one-step milling. It is a useful tool for breeding programs or genetic mapping studies that are usually large in sample number but very limited in sample size. K E Y W O R D Sash content, durum wheat, milling performance, Quadrumat Junior mill, semolina yield, total milling yield | 803 WANG et Al.

A small‐scale rapid screening protocol for quality traits of durum wheat

“…The predicted values showed a good correlation with the actual Buhler milled data ( r 2 : .74, p < .001), indicating that the multiseason model is robust and could be applied to a new season. This outcome is similar to that reported by Wang et al (2019) who used two seasons with only 12 genotypes. Based on the results in Figure 5b, and location of the check varieties, genotypes with a predicted SO <56.5 could be recommended for discard, a 25% discard rate.…”

“…While the correlation for semolina yield with a standard laboratory milling procedure ( r = .82) was promising, high throughput was still limited because this system uses three break and sizing passages, three sieving steps, and one purification stage. However, recently, Wang, Taylor, Pozniak, and Fu (2019) developed a rapid micro milling protocol using a single Brabender Quadrumat Junior semolina mill without purification to predict milling yields using 200 g durum wheat. This was achieved using sifting of the wholemeal to collect particles in the range 180–630 µm and this fraction weight together with the bran rich fraction >630 µm was used to develop models to predict semolina yield.…”

“…Attempts to improve this regression by adding material retained on the 500‐µm screen (bran‐rich fraction) gave a fractional improvement in r 2 from .52 to .53. This was tested as Wang et al (2019) noted their best prediction of semolina yield was using QJM semolina (180–630 µm fraction) plus bran‐rich fraction obtaining a regression coefficient of r 2 : .81. We were unable to achieve this degree of correlation in our material possibly because ours is a more diverse set of samples representing multiple seasons with a larger range in semolina yield.…”

Inter-Relationships between Test Weight, Thousand Kernel Weight, Kernel Size Distribution and Their Effects on Durum Wheat Milling, Semolina Composition and Pasta Processing Quality

“…In Canada, TW greater than 80.0 and 79.0 kg/hL is required to qualify for No.1 and No.2 grades (export) of Canada Western Amber Durum (CWAD) wheat class, respectively [18]. Millers expect CWAD with high TW to possess superior milling quality and produce high yield of granular semolina with minimum production of fine flour [19]. Due to the overall dry growing conditions in 2017 and 2018, majority of durum wheat produced in the Canadian prairies was high in protein content and met the TW requirements for the top grades of CWAD.…”

Effect of Kernel Size and Its Potential Interaction with Genotype on Key Quality Traits of Durum Wheat

“…Wheat samples of various size fractions were milled to predict semolina and total milling yields following the micro-milling procedure previously developed by Wang et al (2019) [10]. After tempering to a moisture content of 16% overnight, 200 g of wheat sample was ground with a Quadruma Junior (QJ)-II-G mill-semolina version (C.W.…”