Development of functional resins with kafirin obtained with a food-compatible method for application in the baking industry

Abstract

The evaluation of different methods for kafirin extraction was made to obtain techno-functional concentrates from two sorghum cultivars. The concentrates were rheologically evaluated in a “dough-like” resin system to assess their potential as a gluten substitute. Under acidic extractions (ethanol 70%, pH 2.5), yields of 56.98% and 46.31% for white (WS) and red sorghum (RS) were obtained, with the highest purity for WS (74.54%). A characteristic electrophoretic pattern was obtained for kafirins, including fractions α1, α2, β and γ. The WS protein was used to prepare resins with lactic acid (LA) as a plasticizing agent, showing similar extensibility to zein (11.37 vs. 11.89 mm respectively) but below wheat gluten (42.61 mm). The microstructure of kafirin resins showed air encapsulation and alignment as fibers. This study allowed to explore new food-compatible extractions for kafirin and evaluate how they will perform rheologically at the kneading stage using a simple resin method.