抄録
The processes used by a French chef and a non-professional to prepare white sauce were compared to identify those factors which would give desirable physical properties to the resulting sauce.
The main difference lay in the process of mixing the roux and milk. It was found that the professional stirred the mixture at twice the speed of the non-professional. Oil and starch were finely dispersed in the chef-made sauce which was lower in the yield stress, thixotropic paremeter and consistency index, and higher in the flow behavior index than the other. In the sauce made by the nonprofessional, oil was dispersed in larger grains, and the starch particles cohered. The sensory test results showed that the chef-made sauce was more favored than that of the non-professional because of its lower viscosity and smoother and softer texture.
Several sauces prepared with different stirring speeds were examined. As the stirring speed was increased, the dispersion and physical properties of the sauce contributed to the better evaluation of taste. Smoothness, which greatly contributed to the evaluation of taste, was well correlated with the consistency index and with the size of the starch and protein particles.
The higher speed by the professional in stirring the mixture of roux and milk therefore resulted in preferable physical properties of the white sauce-in which starch and oil were finely dispersed.
