Relationships Among Grain Hardness, Pentosan Fractions, and End‐Use Quality of Wheat

Abstract

Cereal Chem. 77(2):241-247Grain texture (hardness) in wheat (Triticum aestivum L.) is a major determinant of end-usage. Variation in grain texture can be conceptually assigned to the two major hardness classes that result from the action of one major gene (Hardness) or to as-yet undetermined factors contributing to residual variation within hardness classes. Identifying the physicochemical basis of both sources of texture variation could provide a means of better controlling or manipulating this quality trait. Pursuant to this objective, the role of pentosans was examined. Pentosan fractions (membrane-associated, total, and soluble) were isolated from 13 hard and 13 soft wheat samples and their flours. Among the hard wheat samples, pentosans had a minimal role in modifying grain hardness. However, among the soft wheat samples, pentosans appeared to have a significant hardness-modifying effect that carried over into end-use quality. Among the soft wheat samples, pentosan fractions, along with wheat protein, accounted for 53-76% of the variation in grain texture, depending on the method used to quantify texture. Membrane-associated pentosans were the most influential single parameter in modeling grain texture for the soft wheat samples. Membrane-associated pentosans were most influential in accounting for variation (69%) in alkaline water retention capacity. Total pentosans, together with flour protein, accounted for 87% of the variation in cookie diameter for soft wheat samples, with the total pentosan fraction being the more influential.

Influence of puroindoline genotypes on grain characteristics, physico-chemical properties of flour and end-use quality of Korean wheats

“…Cookie diameter was influenced by hardness index, milling performances and physico-chemical properties, and especially by the particle size of flour, damaged starch content and SDS-sedimentation volume. Pina-D1a/Pinb-D1a had larger cookie diameter than other genotypes, which is in agreement with the report of Bettge and Morris (2000).…”

“…Hardness index was significantly correlated with flour yield and the proportion of break flour in Korean wheats with all puroindoline genotypes, but no significant relationships were found in Korean hard wheats. However, hardness index was negatively correlated with flour yield in hard wheats (Ohm et al 1998, Martin et al 2001 and Chinese winter wheats (Zhang et al 2005) and also negatively correlated with break flour yield in US wheats with various puroindoline genotypes (Bettge and Morris 2000).…”

Phenolic acid content of sorghum and maize cultivars varying in hardness

“…The presence of DFAs in bran could enhance cross linking with arabinoxylan chains (Gallardo et al, 2006) hence affecting grain mechanical properties (Renger & Steinhart, 2000). Arabinoxylans were shown to have a greater effect in modifying grain hardness in soft wheat than in hard wheat (Bettge & Morris 2000). High levels of polymer similar to water soluble arabinoxylans characterized the peripheral endosperm of soft wheat cultivars (Barron, Parker, Mills, Rouau & Wilson 2005).…”

Quantitative trait loci associated with soft wheat quality in a cross of good by moderate quality parents

“…A negative correlation of -0.45 between these traits was also observed in hard wheat (Gross et al, 2004) and others have reported a negative correlation between these traits in soft wheat (Smith et al, 2011;Cabrera et al, 2015;Hoffstetter et al, 2016). Genetic studies of kernel hardness in bread wheat indicated that phenotypic expression of kernel hardness was tightly linked with FP (Galande et al, 2001), but additional related traits such as arabinoxylan content also played an important role in kernel hardness (Bettge & Morris, 2000).…”