Oxidative Gelation Measurement and Influence on Soft Wheat Batter Viscosity and End-Use Quality

Viscosity is an important end-use attribute for some soft wheat flour formulations. Specifically, in formulations with minimal gluten development, such as batters (as in cake, pancake, and doughnut) and coatings (as in tempura), viscosity is important to leavening gas retention and flow characteristics. Current tests for predictors of viscosity leave considerable unexplained variation. The potential for water-extractable arabinoxylans to form oxidative gels through ferulic acid dimerization may represent an important component of viscosity variation. A method was developed to identify variation in viscosity due to oxidative gelation. This method, comparing viscosity of flour slurries made with water, a peroxide-peroxidase system, and a system with xylanase, indicated that two, and likely three, types of oxidative gelation were contributing to viscosity. Predicted viscosity due to inter-arabinoxylan gelation through ferulic acid dimerization, dityrosine formation among proteins, and ferulic acid-tyrosine bond formation varied among wheat cultivars. Oxidative gel formation increased batter viscosity probably due to water sequestration; this effect was correlated with reduction in the sugar snap cookie spread (diameter). Results indicate that oxidative gelation is an important contributor to batter viscosity and also contributes to the quality attributes of dough systems.