Foaming of commercial grade food products in a continuous stirred column

A Narrow Annular Gap Unit (NAGU) was used to produce food foams under steady-state conditions. Raw materials consisted of three kinds of emulsions, corresponding to commercial grade food products. The composition of these materials was defined to be representative of a fresh cheese, an ice cream mix and a model emulsion based on meat. Interfacial and theological properties of these emulsions were determined and related to their composition. The respective influence of formulation and operating conditions on foaming operation was analysed and compared for the three products in the light of foam properties, such as texture, bubble size and foam stability with time. An attempt was made to correlate the combined effects of process parameters and raw material properties on mean bubble size in foams using a dimensionless Weber number. Rotation speed of the impeller was shown to affect only bubble size for the meat model, while it affects mainly texture for ice cream and also overrun for fresh cheese.