Laccase-mediated crosslinking of gluten-free amadumbe flour improves rheological properties.

ABSTRACT

The absence of gluten in gluten-free flours presents a challenge to their application in baking. Enzymatic modification of the protein and polysaccharides may result in a network that mimics gluten. In the current study, the effects of laccase on the rheological properties of amadumbe dough were investigated. Thiol and total phenolic contents of dough decreased by up to 28% and 93%, respectively, as laccase activity was increased (0-3 U/g flour). Both G' and G″ of laccase-treated dough increased significantly due to laccase-catalysed cross-linking of proteins and polysaccharides esterified with phenolics, as demonstrated by relevant model reactions. Tan δ decreased with increase in laccase activity indicating an increase in the elastic character of the dough. The improvement in dough viscoelasticity may enable the retention of adequate carbon dioxide during proofing and production of more acceptable gluten-free bread.