Use of Near-Isogenic Wheat Lines to Determine the Glutenin Composition and Functionality Requirements for Flour Tortillas

Abstract

In wheat ( Triticum aestivum L), the synthesis of high molecular weight (HMW) glutenins (GS) is controlled by three heterologous genetic loci present on the long arms of group 1 wheat chromosomes. The loci Glu-A1, Glu-B1, and Glu-D1 and their allelic variants play important roles in the functional properties of wheat flour. This study focused on understanding the functionality of these protein subunits on tortilla quality. Near-isogenic wheat lines in which one or more of these loci were absent or deleted were used. Tortillas were prepared from each deletion line and the parent lines. The elimination of certain HMW-GS alleles alter distinct but critical aspects of tortilla quality such as diameter, shelf stability, and overall quality. Two deletion lines possessing HMW-GS 17 + 18 at Glu-B1 and deletions in Glu-A1 and Glu-D1 had significantly larger tortilla diameters, yet tortilla shelf life was compromised or unchanged from the parent lines used to develop the deletion lines or the commercial tortilla flour used as a control. Alternatively, a deletion line possessing Glu-A1 and Glu-D1 (HMW-GS 1, 5 + 10) and a deletion in Glu-B1 also significantly improved tortilla diameters. Whereas the increase in diameter was less than the line possessing only HMW-GS 17 + 18 at Glu-B1, the stability of the tortillas were, however, maintained and improved as compared to the parent lines containing a full compliment of HMW-GS. Thus, the presence of subunits 5 + 10 at Glu-D1 alone or in combination with subunit 1 at Glu-A1 appears to provide a compromise of improvement in dough extensibility for improved tortilla diameters while also providing sufficient gluten strength to maintain ideal shelf stability.

Effect of high molecular weight glutenin subunit composition in common wheat on dough properties and steamed bread quality

“…HMW‐GS composition of experimental genotypes was identified by the Lab‐on‐a‐Chip method in an Agilent 2100 bioanalyzer following the Protein 230 chip kit protocol (Agilent Technologies, Palo Alto, CA, USA) as described previously . The standards used were Chinese Spring (null, 7+8, 2+12) and Jagger (1, 17+18, 5+10).…”

Relationship Between Objective and Subjective Wheat Flour Tortilla Quality Evaluation Methods

“…Tortilla extensibility is believed to be influenced to a large extent by gliadin proteins (Mondal et al 2008), whereas glutenin is believed to primarily influence tortilla resistance to extension (force to extend). Tortilla extensibility is believed to be influenced to a large extent by gliadin proteins (Mondal et al 2008), whereas glutenin is believed to primarily influence tortilla resistance to extension (force to extend).…”

Evaluation of the genetic diversity of an Afghan wheat collection based on morphological variation, HMW glutenin subunit polymorphisms, and AFLP

“…Regardless of topography, tribes and dietary culture, semi-fermented flat bread is traditionally preferred in Afghanistan. However, according to Mondal et al (2008), the major composition of HMW glutenin subunit in Afghanistan is not very good for making of flour tortillas, a kind of non-fermented flat bread preferred in Mexico. This indicates that the Afghan major composition is not suitable for making of flat bread.…”