Large Deformation Stress Relaxation And Bi-Axial Compression Recovery Of Gluten Representing Different Wheat Classes
Despite the great variety of physicochemical and rheological tests available for measuring wheat flour, dough and gluten quality, the US wheat classification system still relies primarily on wheat kernel hardness and growing season to differentiate between cultivars. To better understand and differentiate wheat cultivars of the same class, the tensile strength, and stress-relaxation behavior of gluten from 36 wheat cultivars was measured and compared to other available physicochemical parameters, including but not limited to protein content, glutenin macropolymer content (GMP) and bread loaf volume . In addition a novel compression-recovery (CORE) instrument was used to measure the degree of recovery of gluten from 15 common US wheat cultivars. Gluten tensile strength ranged from 0.04 to 0.43 N at 500% extension, while the degree of recovery ranged from 5 to 78 %. Measuring gluten strength clearly differentiates cultivars within a wheat class; nonetheless it is not a good predictor of baking quality on its own in terms of bread volume. Gluten strength is highly correlated with mixograph mixing times (r=0.879) and degree of recovery (r=0.855), suggesting that dough development time is influenced by gluten strength and that the CORE instrument is a suitable alternative to tensile testing, since it is less time intensive and laborious to use.
Mulvaney, Steven J
Moraru, Carmen I
Food Science and Technology
M.S., Food Science and Technology
Master of Science
dissertation or thesis