Effect of foaming agents on the stability, rheological properties, drying kinetics and flavour retention of tamarind foam-mats

Abstract

Tamarind foam-mats were prepared using as foaming agents ovalbumin, mesquite gum and a low molecular weight surface active blend, by themselves or in combination, in accordance to a 2 3 factorial experimental design. The stability, rheological properties (flow and viscoelasticity) and drying kinetics of the different foam treatments were evaluated. Sensory evaluation of the dried powders was performed. Response surface analysis yielded polynomial models that explain the influence of the foaming agents treatments on the selected foams response variables: drainage mean time, yield stress, apparent plastic viscosity, critical drying time, instantaneous elastic modulus, and mean retardation time. In general terms, the use of binary combinations of the foaming agents at their high usage level yielded foams that exhibited longer drainage mean times; higher yield stress, apparent plastic viscosity, instantaneous elastic modulus and mean retardation times; and a shorter onset of the critical drying time, that yielded dried tamarind powders with better sensory flavour perception. A close interrelationship existed between the drainage mean time and the apparent plastic viscosity, and between the critical drying time and the mean retardation time of the foams.