Evaluation of the heat treatment effect on yoghurt water holding capacity by response surface methodology

Abstract

Good quality yoghurts must have appropriate firmness and little or no syneresis. The milk thermal treatment is one of the most important known factors to improve the consistency of the yoghurt. Surface Response Methodology (SRM) allows optimizing products or processes through the modeling of the focused variable. The objective of this work was to use the SRM to verify the effect of the thermal treatment on the water holding capacity of set yoghurts. Eleven combinations of time (12.95; 15; 20; 25 and 27.05 min) and temperature (82.1; 83; 85; 87 and 87.82 °C) of initial thermal treatment of the milk for the yoghurts manufacture were tested. The yoghurts had the water holding capacity measured in triplicate. The thermal treatments 85 °C for 20 min and 87 °C for 25 min presented the highest water holding capacity value, what is related to lower syneresis and, probably, to better features in the product consistency.