|Tilley, Michael - Mike|
|Alviola, J. Novi|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/14/2007
Publication Date: 1/1/2008
Citation: Mondal, S., Tilley, M., Alviola, J., Waniska, R.D., Bean, S., Glover, K.D. and Hays, D.B. 2008. Use of Near-Isogenic Wheat Lines to Determine the Glutenin Composition and Functionality in Flour. Journal of Agricultural and Food Chemistry. 56:179-184. Interpretive Summary: The tortilla industry is one of the fastest growing segments of the U.S. baking industry with annual sales surpassing $6 billion. Flour used in tortilla production has been typically optimized for bread making and thus the flour properties that determine good quality bread do not necessarily provide good quality tortillas. Wheat lines in which one or more of the high molecular weight glutenin subunit proteins were absent were used to make tortillas. The tortillas missing certain proteins had different quality in several parameters such as diameter, shelf stability and overall quality. The results indicated better tortillas with a longer shelf-life were obtained with higher protein content flours containing HMW-GS 5+10. This data will allow wheat breeders to target the characteristics for development of tortilla or multi-use wheat lines and decrease the addition of additives to adjust flour quality in the tortilla industry.
Technical 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, 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. While 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 compared to the parent lines containing a full compliment of HMW-GS. Thus, 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.