Location: Grain Quality and Structure ResearchTitle: Combination of null alleles with 7+9 allelic pair at Glu-B1 locus on the long arm of group 1 chromosome improves wheat dough functionality for tortillas
|TUNCIL, Y - Texas A&M University|
|JONDIKO, T - Texas A&M University|
|Tilley, Michael - Mike|
|HAYS, DIRK - Texas A&M University|
|AWIKA, J - Texas A&M University|
Submitted to: LWT - Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/29/2015
Publication Date: 1/1/2016
Citation: Tuncil, Y.E., Jondiko, T., Tilley, M., Hays, D.B., Awika, J.M. 2016. Combination of null alleles with 7+9 allelic pair at Glu-B1 locus on the long arm of group 1 chromosome improves wheat dough functionality for tortillas. LWT - Food Science and Technology. 65:683-688.
Interpretive Summary: Tortillas are the second most consumed bread type in the United States after white bread and are offered on two-thirds of restaurants menus nationwide. Good quality tortillas must be soft without sticking together, flexible without cracking and tearing when folded, have large diameters (17- 18 cm), and good shelf stability, because most of them are not consumed on the day of production. To provide these desirable properties of tortilla, functionality of gluten is important, because both diameter and flexibility are mainly controlled by wheat storage proteins (glutenins and gliadins) rather than other endosperm sub-fractions. Therefore, it is possible to select right glutenin and gliadin composition in wheat cultivars to produce good quality. However, no wheat cultivars have been developed to produce optimum quality tortillas. Tortillas made from bread flour often give smaller diameter due to the strong gluten network, thus require use of additives, such as reducing agents, to obtain extensible dough which is suitable for production of large diameter tortillas. This study showed that combining glutenin subunits 7+9 with deletions at Glu-A1, Glu-D1 loci have potential for the production of wheat tortillas with optimum quality.
Technical Abstract: Deletion of one or more high molecular weight glutenin subunit (HMW-GS) alleles reduces gluten strength in a way that may be beneficial for tortilla quality. Wheat lines in which one or more of the HMW-GS alleles were absent from Glu-A1, Glu-B1 or Glu-D1 locus (deletion lines) were compared with non-deletion lines for dough and tortilla making properties. Flours were evaluated for insoluble polymeric protein (IPP) content and mixing properties. Tortillas were produced by hot-press method and evaluated during 16 days of storage. Compared to non-deletion lines, deletion line generally had lower IPP (362 vs 414 mg/g); produced more extensible dough (44.9 vs 33.4 mm), which required lower equilibrium force to compress (4.12 vs 7.55 N); and produced larger diameter tortillas (180 vs 165 mm). In general, deletion lines produced large diameter tortillas, but with poor flexibility (score <3.0) during 16 days of storage. However, combination of 7+9 allelic pair at Glu-B1 locus with deletions at Glu-A1 or Glu-D1 or 2+12 at Glu-D1 produced tortillas that had large diameter and retained good flexibility during 16 days of storage. The 7+9 allelic pair at Glu-B1 may play a crucial role in wheat development for tortilla making.