Modeling of microbial growth in refrigerated doughs for "empanadas" with potassium sorbate and whey protein concentrate

Abstract

Dough for "empanadas", a traditional meal in Argentina, are sold refrigerated with the addition of preservatives. The replacement of a small percentage of flour by whey protein concentrate (WPC) improves the color and acceptability of the "empanadas", but can decrease the shelf-life due to the microorganisms incorporated with the WPC. In this work the effect of the addition of two selected concentrations of potassium sorbate (0.067 - 0.134%) to dough for "empanadas" prepared with and without WPC on yeast growth (predominant microorganisms in this product) during refrigeration storage was investigated. Gompertz equation and kinetic parameters as specific growth rate (μ), lag phase duration (LPD), maximum population density (MPD) and activation energies from an Arrhenius-type expression, were estimated. The addition of potassium sorbate increased the storage-life of the dough for "empanadas", prepared with and without WPC, three-four times. The effect of potassium sorbate was more important at the higher concentration assayed. Results allow to predict the growth of yeast in different samples of dough stored between 0 and 10C.