An arabinoxylan oxidative gelation method and its potential to explain variation in soft wheat flour quality

Authors: Bettge, Arthur; Morris, Craig

Submitted to: Proceedings of the International Cereal Chemists Conference
Publication Type: Proceedings
Publication Acceptance Date: 9/26/2005
Publication Date: 10/1/2005
Citation: Bettge, A.D., Morris, C.F. 2005. An arabinoxylan oxidative gelation method and its potential to explain variation in soft wheat flour quality. Proceedings of the Intern. Cereal Conference, Gosford, NSW, Australia. pp45-59.

Interpretive Summary: Within soft wheat flour products, factors other than gluten strength are considered more important in end-use quality. One factor that is critical in batter-based applications is viscosity. In batter coatings, cake or pancake production, viscosity is a crucial quality parameter. Batters for coating must be thick enough to cling to the product, but without clumping (as in tempura). Pancake or donut batter must be thick enough to retain leavening gasses and prevent settling and to retain leavening gas, but without being so thick as to inhibit flow and spread. There exists a substantial amount of unexplained variation in batter viscosity. Better understanding and control of the biochemical components contributing to viscosity would translate into cost savings in processing as well as increased consumer acceptance of a product.

Technical Abstract: Within soft wheat flour products, factors other than gluten strength are considered more important in end-use quality. One factor that is critical in batter-based applications is viscosity. In batter coatings, cake or pancake production, viscosity is a crucial quality parameter. Batters for coating must be thick enough to cling to the product, but without clumping (as in tempura). Pancake or donut batter must be thick enough to retain leavening gasses and prevent settling and to retain leavening gas, but without being so thick as to inhibit flow and spread. There exists a substantial amount of unexplained variation in batter viscosity. Better understanding and control of the biochemical components contributing to viscosity would translate into cost savings in processing as well as increased consumer acceptance of a product. The elucidation of the biochemical underpinnings of viscosity variation has the potential to guide breeding programs to produce wheat that will perform in end-use applications without additional additives, leading to “shorter” labels, concomitant consumer acceptance and decreasing the need for expenditures on remedial, modifying ingredients. Variation in batter viscosity has traditionally been attributed to two sources: HMW glutenins and arabinoxylans (also known as pentosans, hemicellulose or non-starch carbohydrate). A test to measure the oxidative gelation potential, manifested as viscosity, was developed that measures the combined impact of arabinoxylan and/or protein polymerization on viscosity. Indications are that oxidative gels were formed and measured in this method; oxidative gelation occurred among arabinoxylan polymers, likely through di-ferulic acid bridges; among proteins, likely via di-tyrosine bridges and possibly among arabinoxylans and proteins through ferulic acid – tyrosine bridges. Oxidative gels appeared to affect cookie diameter (a major quality factor), but are more likely to have a much larger influence on the quality of batter-based products.