IMMERSION CHILLING AND FREEZING - PHASE-CHANGE AND MASS-TRANSFER IN MODEL FOOD

The influence of immersion chilling and freezing process variables (te mperature, concentration, agitation) on phase change and salt gain, wa s studied on a gelatin gel dipped into a NaCl solution, with particula r emphasis on unsteady state (first hour). Under freezing conditions, water loss was (2 g/100g initial gel and salt gain remained low (< 1 g /100g initial gel). Salt penetration was hindered by formation of an i ce barrier, which was favored by high concentration and low temperatur e. Under chilling conditions, salt gain was higher (up to 2 g/100g ini tial gel), and was enhanced when temperature or concentration increase d.