Using the Chopin Mixolab to model the effects of arabinoxylan ingredients on breadmaking. Part 1: Modelling combined effects of AX and water adjustment on Mixolab parameters

Abstract

A novel approach is presented to use the Chopin Mixolab 2 to quantify the effects of arabinoxylans (AXs) on the required water absorption of a dough formulation and on other parts of the Mixolab torque profile relevant to bread quality. The Mixolab is operated with removal of flour and substitution with AX over a range of water additions. Linear models are fitted that allow defining an Arabinoxylan Multiplication Factor (AXMF) that quantifies the effects of AX relative to the effect of flour, and an Arabinoxylan Water Absorption Factor (AXWAF) that quantifies the amount of water absorbed by the AX. The modelling allows the effects of flour substitution with AX and the associated water adjustment to be distinguished, and their combined effects to be predicted. The approach is illustrated with an AX sample extracted from wheat, which gave AXWAF = 1.19, which indicates the AX absorbed 119% of its own weight of water, and AXMF = 0.89, which indicates this particular AX was 89% as effective as flour at absorbing water, requiring a small reduction in the water absorption to give the same dough consistency based on a Mixolab C1 value of 1.1 N m. The effects of the substituted AX and water adjustment were quantified in relation to other key measures of the Mixolab profile (development time, stability and torque measures related to gluten softening and starch gelatinisation, hydrolysis and retrogradation), illustrating how the removed flour, added AX and adjusted water affected different elements relevant to bread quality. The approach (patent pending, GB2415536.8) allows the separate effects of flour removal, AX addition and water adjustment on the Mixolab profile to be distinguished, and their combined effect modelled, giving greater precision to scientific interpretation of phenomena, and aiding translation to identify AX and other fibre and hydrocolloid ingredients suited to enhancing specific aspects of bread quality.