BIOCHEMICAL AND PHYSICAL CHARACTERIZATION OF HARD WINTER WHEAT QUALITY FOR END-USE QUALITY
Location: Grain Quality and Structure Research Unit
Title: Effects of transglutaminase on the rheological and noodle-making characteristics of oat dough containing vital wheat gluten or egg albumin
Submitted to: Journal of Cereal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 25, 2011
Publication Date: July 1, 2011
Citation: Wang, F., Huang, W., Kim, Y., Liu, R., Tilley, M. 2011. Effects of transglutaminase on the rheological and noodle-making characteristics of oat dough containing vital wheat gluten or egg albumin. Journal of Cereal Science. 54:53-59.
Interpretive Summary: The use of oats (Avena sativa L.) in foods has received increased interest due to their nutritional value (e.g. high in soluble dietary fiber, proteins, unsaturated fatty acids, vitamins, minerals and other nutrients). A substantial amount of the dietary fiber of oats comes from ß-glucan (mixed linkage (1-3)(1-4)-ß-D-glucan), a cell wall polysaccharide that can reduce the concentration of serum cholesterol, attenuate blood glucose level, slow insulin response in the blood, and maintain the balance of intestinal flora . Furthermore, the FDA reports the positive role of soluble dietary fiber from oats in reducing the risk for coronary heart diseases. Utilization of oats in baked products is limited due to the inability of oat flour to form cohesive, viscoelastic dough, such as the gluten network of wheat dough. The addition of proteins from other food sources and/or enzymes to food ingredients is often used to improve the quality, texture, and storage stability of products. Addition of the enzyme transglutaminase (TGase) to dough systems results in an increase in the elasticity, water-holding capability, and other functional properties of end-products. In this study, oat dough containing 15% vital wheat gluten (VWG) and oat dough containing 15% egg albumin (EA) were used to produce oat noodles with or without gluten (gluten-free), respectively. TGase was added to examine the effects on the noodle-making characteristics and overall quality of the oat noodles. Adding 1.0% TGase to oat dough with or without the addition of VWG or EA improved the cooking quality, reduced the cooking loss, and enhanced the hardness and springiness of the noodles. This research has shown that it is possible to produce oat noodles both with and without gluten (gluten-free) and has provided an essential foundation for development of other oat products.
Incorporating exogenous proteins into food production is a common practice for improving processing characteristics. In the present study, oat dough containing 15% (w/w, blends of protein-oat flour basis [POB]) vital wheat gluten (VWG) or 15% (w/w, POB) egg albumin (EA) were used to produce noodles with or without gluten (i.e., gluten-free). The rheological and noodle-making characteristics of oat dough containing exogenous proteins and the effects of added transglutaminase (TGase) were examined. The results indicate that the extent of TGase’s modification of the thermomechanical and dynamic rheological characteristics (G’ and G”) are dependent on the source of exogenous proteins in the oat dough. By adding 1.0% (w/w, POB) TGase, the cooking qualities of the resulting noodles (i.e., those containing VWG and EA) were significantly elevated with lower cooking loss; the elasticity of both types of noodles increased. The effects of TGase in different dough systems were analyzed by SDS-PAGE. In oat dough prepared with VWG, TGase was shown to catalyse the cross-linking of both oat protein and gluten protein; however, oat protein acted as the only substrate of TGase in the noodles that had been prepared with EA.