Wheat (Triticum aestivum L. and T. turgidum L. ssp. durum) Kernel Hardness: II. Implications for End‐Product Quality and Role of Puroindolines Therein

Abstract

Wheat kernel hardness is a major quality characteristic used in classifying wheat cultivars. Differences in endosperm texture among Triticum aestivum L. or between T. aestivum and T. turgidum L. ssp. durum cultivars profoundly affect their milling behavior, the properties of the obtained flour or semolina particles, as well as the quality of products made thereof. It is now widely accepted that the presence, sequence polymorphism, or absence of the basic and cysteinerich puroindolines a and b are responsible for differences in endosperm texture. These proteins show features in vitro, including foaming and lipid-binding properties, which provide them with a potential impact in the production of wheatbased food products, where they may improve gas cell stabilization or modulate interactions between starch, proteins, and/or lipids. We here summarize the impact of wheat hardness on milling properties and bread, cookie, cake, and pasta quality and discuss the role of puroindolines therein.

Effect of glutenin subunits on the baking quality of Brazilian wheat genotypes

“…The hardness of wheat is affected mainly by starch and protein contents and their ordering in the endosperm of the grain (Pomeranz and Williams 1990). According to Pauly et al (2013), the presence and functionality of the puroindoline a (PINA) and b (PINB) proteins together with polar lipids determine the wheat endosperm texture. The level of hardness determines the wheat milling conditions because it indicates the grain resistance to fracturing and reducing to flour (Kaur et al 2013).…”

“…The presence of DS is desirable up to a certain amount (about 8%) for bread making, especially in recipes without added sugar. DS is susceptible to amylolytic enzymes, thus providing fermentable sugars to the yeast in sufficient amounts to maintain the fermentation (Pauly et al 2013). …”

Effects of Different Grinding Methods on Morphological, Textural Properties and Pasting Profiles of Mr220 Rice Flour

“…Flour characteristics as result from grinding process, such as particle size and damaged starch level; determine its suitability for specific end-products [6,7]. When starch is heated continuously in excess water with stirring, starch granules swell irreversibly, accompanied by leaching of amylose and possibly solubilisation of amylopectin, resulting in the formation of paste.…”

Particle Size Analysis of Two Distinct Classes of Wheat Flour by Sieving

“…Milling behavior, flour particle size, flour particle size distribution, and flour functionality are influenced by the hardness of the wheat kernels. Wheat hardness is negatively correlated with flour yield (Martin et al, 2001), and the flour particle size depends on the hardness of the wheat (Pauly et al, 2013). Due to the weaker bonding between starch and protein, milling soft wheat results in smaller particle sizes (Bechtel et al, 1993;Pauly et al, 2013) than hard wheat.…”

“…Wheat hardness is negatively correlated with flour yield (Martin et al, 2001), and the flour particle size depends on the hardness of the wheat (Pauly et al, 2013). Due to the weaker bonding between starch and protein, milling soft wheat results in smaller particle sizes (Bechtel et al, 1993;Pauly et al, 2013) than hard wheat. The difference in hardness values results from hard wheat having starch granules that are deeply embedded within the protein matrix of the kernel's endosperm, while soft wheat contains voids in the endosperm protein matrix in which the starch granules are weakly embedded (Turnbull and Rahman, 2002).…”