This study was conducted to evaluate the convective heat transfer coefficient between Newtonian and non-Newtonian fluids and food particles inside of a glass vessel and to assess the effect of controlled variables: convection phenomena, heating temperature, immersion fluid, and different food particles. The coefficient was evaluated from the sample temperature as a. function of the heating time by two approaches: a lumped parameter method and an analytical methodology. High values corresponded to heating in Newtonian fluids (70-181, 57-248 W/m(2) K), and lower corresponded in non Newtonian fluids (31-169, 28-167 W/m(2) K). Similarly, major heat transfer coefficient corresponded to the heating of mushrooms (32-110, 28-132 W/m(2) K), followed by tomatoes (30-181, 35-183 W/m(2) K) and potatoes (31-148, 34-248 W/m(2) K), respectively. Fluid properties were more important than the thermal properties of the particles. This coefficient was higher at 85 degrees C in both types of fluids. Both methods generated satisfactory values, but the analytical approach showed more accuracy. (C) 2012 Elsevier Ltd. All rights reserved.