Rheological and water binding properties of xanthan, guar and ultra-finely milled oatmeal in white birch sap: Influence of sap minor constituents.

Abstract White Birch Sap (WBS) contains appreciable amounts of mineral ions and phenolic compounds and can be used as alternate solvent for food applications. In this study, the effect of the mineral and phenolic composition of WBS was evaluated on the physical properties of xanthan gum, guar gum, ultra-finely milled oatmeal and their combinations in solution. Solutions were formulated with WBS and with solvents mimicking WBS without phenolic compounds and WBS without phenolics nor mineral ions. The influence of solvent composition was evaluated on flow properties and water mobility of the solutions. From WBS without mineral ions nor phenolics, the addition of mineral ions led to increased pseudo-plasticity and decreased flow consistency, and decreased water mobility. Addition of phenolic compounds through WBS led to opposite effects possibly due to phenolic-driven aggregation of the hydrocolloids which also seemed to inhibit guar/xanthan interactions.