CHARACTERIZATION OF GRAIN BIOCHEMICAL COMPONENTS RESPONSIBLE FOR END-USE QUALITY
Location: Grain Quality and Structure Research Unit
Title: Predicting hot-press wheat tortilla quality using flour, dough and gluten properties
Submitted to: Journal of Cereal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 13, 2010
Publication Date: September 1, 2010
Citation: Barros, F., Alviola, J.N., Tilley, M., Chen, Y.R., Pierucci, V.R., Rooney, L.W. 2010. Predicting hot-press wheat tortilla quality using flour, dough and gluten properties. Journal of Cereal Science. 52:288-294.
Interpretive Summary: Currently, the suitability of wheat lines for tortilla production is done by milling the wheat, evaluating the flour, and processing it into tortillas. Wheat milling to tortilla evaluation takes about 90 h, which is distributed over 4 weeks. Moreover, it requires at least 1 kg of flour to do all the tests. This makes the wheat line screening process time-consuming, labor-intensive and costly. Developing prediction equations is one approach to make this screening process more efficient. For example, from our results, one can predict tortilla diameter from any given flour by having the mixograph mixing time and dough resistance to extension values. Both parameters are determined using tests that are easy and require a small amount of flour sample. Moreover, the mixograph test can be completed in a short time and is already widely used in the academe and the industry. In addition, the dough resistance to extension can also predict (alone or with another parameter) tortilla L* value, specific volume and rupture force at day 0. The extensibility test that is used to determine this parameter is done with a texture analyzer, and has the advantage of good repeatability.
A cost-effective, faster and efficient way of screening wheat samples suitable for tortilla production is needed. This research aimed to develop prediction models for tortilla quality (diameter, specific volume, color and texture parameters) using grain, flour and dough properties of 16 wheat flours. Another set of 18 samples was used to validate the models. The prediction models were developed using stepwise multiple regression. Dough rheological tests had higher correlations with tortilla quality than grain and flour chemical tests. Mixograph mixing time and dough resistance to extension (from extensibility test using a texture analyzer) were correlated best with tortilla quality, particularly tortilla diameter (r= -0.87 and -0.86 respectively, P<0.01). Insoluble polymeric proteins (IPP) and gluten index were significantly correlated with tortilla diameter (r = -0.70 and -0.67 respectively, P<0.01) and specific volume (r = -0.73, P<0.01). Tortilla diameter was the quality parameter best explained (R2 = 0.86) by the prediction models using mixing time and dough resistance to extension. Rheological parameters such as rupture distance and maximum force were also successfully predicted. These prediction models, developed from linear equations, will be an easy and fast tool for breeders to advance or eliminate wheat lines specifically bred for tortilla production.