|Tilley, Michael - Mike|
|Graybosch, Robert - Bob|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/9/2009
Publication Date: 6/19/2009
Citation: Pierucci, V.R., Tilley, M., Graybosch, R.A., Blechl, A.E., Bean, S., Tilley, K.A. 2009. Effects of Overexpression of High Molecular Weight Glutenen Subunit 1Dy10 on Wheat Tortilla Properties. Journal of Agricultural and Food Chemistry. 57:6318-6326. 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. The high molecular weight glutenin subunit (HMW-GS) proteins are important in the formation of the gluten matrix. Flour that had a higher level of one HMW-GS was used to make tortillas. The tortillas had different quality in several parameters such as diameter, shelf stability and overall quality. 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: Wheat (Triticum aestivum L.) flour properties necessary for optimal tortilla production have not been identified. Transgenic wheats (Triticum aestivum L.) over-expressing high molecular weight glutenin subunit (HMW-GS) 1Dy10 were used to produce tortillas and their quality evaluated. The level of HMW-GS 1Dy10 in transgenic flours was 2.5 to 5.8 fold greater than controls. Polymeric proteins in the transgenic samples appeared to have their molecular weight distribution shifted towards larger polymers as indicated by increased levels of polymeric proteins present and greater Mw averages of the largest fractions in the insoluble polymeric proteins. Dough derived from transgenic flours had greater resistance to extension and lower extensibility than controls. Tortilla quality evaluation revealed that transgenic tortillas had decreased diameter, greater thickness and rupture force, lower rollability scores and stretchability than controls. The presence of 1RS chromosomal translocations from rye (Secale cereale L.) in transgenic wheat decreased the negative effects of over-expression of HMW-GS 1Dy10, as tortillas made with this flour mostly resembled those made from control flour. Results suggested that the negative effects of over-expression of HMW-GS 1Dy10 on tortilla properties were derived from a non-ideal gluten matrix formation.