Title: Water-extractable nonstarch polysaccharide distribution in pilot milling analysis of soft winter wheat Authors
Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 1, 2011
Publication Date: September 1, 2011
Repository URL: http://handle.nal.usda.gov/10113/53883
Citation: Souza, E.J., Guttieri, M.J., Sneller, C. 2011. Water-extractable nonstarch polysaccharide distribution in pilot milling analysis of soft winter wheat. Cereal Chemistry. 88(5):525-532. Interpretive Summary: Profitability in soft wheat flour milling depends on maximize the total extraction of flour while minimizing the total water absorption of the final flour produced. We found that total extraction and the main components contributing to water absorption, follow relatively simple models. Based on this behavior, cultivar selection should favor cultivars that produce the maximum amount of flour in very simple flour mills. If additional complexity is added to the mill to recover the target levels of flour, it typically results in elevation of damage starch and arabinoxylans contributing to increased water absorption.
Technical Abstract: Commercial wheat (Triticum aestivum em. Thell) flour milling produces flour streams that differ for water absorption due to variability in protein concentration, starch damaged by milling, and non-starch polysaccharides. This study characterized the distribution of water-extractable non-starch polysaccharides in long-flow pilot milling streams of soft wheat to model flour quality and genetic differences among cultivars. Existing reports of mill stream analysis focus on hard wheat, which breaks and reduces differently from soft wheat. Seven soft winter wheat genotypes were milled on a Miag Multomat Flour Mill, which yields 3 break flour streams, 5 reduction streams, and two re-sifted streams. Protein concentration increased linearly through the break streams. Water-extractable non-starch polysaccharide (WE-NSP) concentration was small and similar in the first two break streams, which are the largest break streams. Flour recovery decreased exponentially through the reductions streams; flour ash and water-extractable (WE) glucose and galactose polymers increased exponentially through the reduction streams. Protein concentration and WE-xylan concentration increased linearly through the reduction streams. The ratio of arabinose to xylose in WE-arabinoxylan (WE-AX) decreased through the reduction steams, and response varied among the genotypes. Flour ash was not predictive of stream composition among genotypes. Although within genotypes, ash and other flour components were correlated when measured across streams. The second reduction flour stream was the largest contributor to straight grade flour WE-AX, due both to the size of the stream and the concentration of WE-AX in the stream.