RESPONSE SURFACE METHODOLOGY FOR EVALUATION THE EFFECTS OF CARBONATION ON THE MICROORGANISM AND VISCOSITY OF RAW MILK

Abstract

The aim of this study was to investigate the effect of carbonation on the growth of microorganism and viscosity of raw milk during refrigerated storage. A Full Factorial Design 2³ was applied to evaluate the effect of pH (between 5,8 to 6,4), time (between 0 to 10 days) and temperature (between 5 to 10°C) storage of carbonated raw milk face of responses psychrotrophic, proteolytic psychrotrophic, mesophilic and viscosity. The results showed that after 10 days the carbonation at pH 5,8 inhibited the growth of all microorganism examined independent of storage temperature. The viscosity was not changed after the carbonation, but during cold storage an increase was observed in the values of this property. The response surface models were adequate to predict the mesophilic and psychrotrophic couts and viscosity measurement, because the lack of fit was not significant and the coefficient of determination (R²) was greater than 0,95.