Optimization of additive content and their combination to improve the quality of pure barley bread

The objective of this study was to model the influence of pregelatinized OSA starch (OSA), wheat gluten (Gl) and xylanase (Xyl) on breadmaking potential of barley flour by using response surface methodology. Addition of these ingredients had significant effect on specific bread volume, crust and crumb lightness, crumb texture, average cell size and crumb density. OSA showed the most pronounced effect on specific bread volume, average cell size, crumb density and hardness. Interaction between OSA and Gl, as well as Gl and Xyl, respectively, increased and decreased the specific bread volume and crumb chewiness, while the interaction between OSA and Xyl decreased the specific volume decrease and increased crumb chewiness. An optimal barley bread formulation appeared to be the one containing 9.68% OSA, 2.0% Gl and 4.51 g/100 kg Xyl. This optimal barley bread formulation predicted an increment of 14–28% in volume and a decrease of 105–217% in crumb chewiness in comparison to formulations containing medium amounts of improvers (1% Gl, 5% OSA, 2.5 g/100 kg Xyl).