Three highly reproducible food models have been developed to evaluate rheological and functional properties of starches. The food models are dutch vla, dressing, and white sauce, and they vary in pH, serving temperature, oil content, and content of other functional ingredients than starch (milk proteins, whole egg, carrageenan). The viscous properties were calculated in a controlled stress rheometer, and the power law index, n, and the consistency index, K, was calculated. The viscoelastic properties at small deformations were measured by oscillating viscometry. Also a spreadability analysis was performed. The rheological data for the three food models were analysed by use of a principal component analysis (PCA), which enabled an evaluation of the functionality of the models and visualisation of the correlation to the concentration of starch. The rheological parameters all varied significantly with starch concentration in dutch vla. In dressing and white sauce most of the rheological parameters depended on the starch concentration. In addition, it was found that results from the empirical rheological method (USDA consistometer) correlate well with fundamental rheological parameters. Syneresis was measured for a period of time up to 15 days. The degree of syneresis of dressing was highly dependent on starch concentration, while the syneresis of the white sauce was dependent on time but not on starch concentration. The dutch vla showed no syneresis at all.
|Status||Udgivet - 2002|