Reduction of potassium content of green bean pods and chard by culinary processing. Tools for chronic kidney disease

Introduction: In order to prevent a possible hyperkalemia, chronic renal patients, especially in advanced stages, must follow a low potassium diet. So dietary guidelines for chronic kidney disease recommend limiting the consumption of many vegetables, as well as to apply laborious culinary techniques to maximize the reduction of potassium. Objective: The aim of this work is to analyze potassium content from several vegetable, fresh products, frozen and preserved, as well as check and compare the effectiveness in potassium reduction of different culinary processes, some of them recommended in dietary guidelines such as soaking or double cooking. Methods: Sample potassium content was analyzed by triplicate using flamephotometry. Results: The results showed significant reductions in potassium content in all culinary processes studied. The degree of loss varied depending on the type of vegetable and processing applied. Frozen products achieved greater reductions than the fresh ones, obtaining in some cases losses greater than 90%. In addition, it was observed how in many cases the single application of a normal cooking reached potassium reductions to acceptable levels for its inclusion in renal patient diet. Conclusion: The results shown in this study are very positive because they provide tools for professionals who deal with this kind of patients. They allow them to adapt more easily to the needs and preferences of their patients and increase dietary variety. (C) 2016 Sociedad Espanola de Nefrologia. Published by Elsevier Espana, S.L.U. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).