Rheological properties of a commercial food glaze material and their effect on the film thickness obtained by dip coating

MEZA, BARBARA ERICA; PERALTA, JUAN MANUEL; ZORRILLA, SUSANA ELIZABETH

Florianópolis

Congreso; XX Congresso Brasileiro de Engenharia Química; 2014

Glazing refers to the application of a coating material onto the surface of foods to enhance their shine and appearance. The objective of this work was to analyze the rheological properties of a commercial food glaze material and to study their effect on the film thickness obtained by dip coating. Glazing suspension (83.33% solid content) was obtained using a commercial powder product. Apparent viscosity was determined (shear rate 0.6-50 s-1) and yield stress was estimated with a creep test (1-10 Pa during 5 s). Experimental data were analyzed applying the generalized Herschel-Bulkley model. A comparison between average thickness values obtained by dip coating and using a phenomenological mathematical model was carried out. All determinations were done at 20, 30, 40, and 50C. Rheological parameters were obtained with satisfactory root mean squared errors. Good agreement between experimental and theoretical film thickness, as affected by temperature, was obtained.