Determination of Quantitative Sodium Mass Transfer Coefficient During Osmotic Processing of Potatoes

Abstract

Identifying sodium reduction strategies in processed foods remains a critical need toward improving public health. In this work, sodium absorption in potatoes was studied using sodium chloride osmotic solutions. The specific aims of this study were to quantify the diffusion of sodium into a potato sample and change process variables to determine how to alter sodium concentration in the samples. Sodium adsorption was quantified using linear correlation equations, derived from simplifications of Fick's second law. A sodium mass transfer coefficient (ks) was calculated from linear regression analysis. The parameter changes investigated were temperature, concentration and presence of anion species. Among these parameters, changes in temperature ranging above and below the starch gelatinization temperature resulted in the largest effect on sodium diffusion, followed closely by introduction of anion species larger than chloride. This research indicates that simple changes in cooking conditions can lead to significant mitigating strategies to reduce the sodium content in a model food system. Practical Applications The trends presented in this work represent a reliable way to predict the quantity of sodium that will diffuse into the potato matrix under the specified processing conditions. With careful control of these process variables, a meaningful reduction in final sodium content of processed potatoes can be reproducibly accomplished.