Predictive Models for Available Chlorine Depletion and Total Microbial Count Reduction During Washing of Fresh-Cut Spinach

ABSTRACT: Washing of fresh-cut spinach with aqueous chlorine solutions eliminates foreign matter, removes cellular fluids produced by cutting and reduces the initial microbial contamination. Response Surface Methodology was used to evaluate the effect of initial chlorine concentration (25 to 125 ppm), water-to-produce ratio (10 to 26 L/kg) and washing time (2 to 8 min) on the total and available chlorine depletion and the total microbial count reduction after washing. All variables affect the chlorine depletion but the microbial count reduction was only influenced by initial chlorine concentration and washing time. Different combinations of the variables were determined by the predictive models to reduce microbial contamination assuring residual levels of chlorine in the washing solution.