To make it possible to simple evaluate the foaming amount at the time of shaking a milk beverage by measuring the dynamic surface tension of the beverage containing milk ingredient.
A PTFE tube 2 is so inserted into solution 1 that the end becomes perpendicular to the surface level of the solution 1 to e measured. Air or an inert gas is fed from a compressor into the tube 2 to generate bubble in the solution 1. The maximum value Pmax of the pressure in the bubble to be detected by a pressure sensor 3 is proportional to the dynamic surface tension σ, and is obtained by a Laplace's formula σ=(Pmax-P0) r/2, where P0, r are the water pressure and inner diameter of the end of the tube 2 respectively. It is recognized by experiments that the dynamic surface tension of the milk beverage has correlation with the injection amount and bubbling amount. Accordingly, if the dynamic surface tension of the beverage is measured, the foaming amount of the beverage and the injection amount when it is filled in a positive pressure can and the can is opened after shaking can be evaluated.
MIYAMA SUSUMU
NISHIYAMA SADAO
