Overnight soaking or boiling of "Matooke" to reduce potassium content for patients with chronic kidney disease: does it really work?

BACKGROUND There is an increase in number of patients with chronic kidney disease (CKD) in Uganda's health facilities looking for different options of preparing matooke (bananas), their staple food. OBJECTIVE To establish and evaluate an effective method of removing potassium from bananas (matooke). METHODS Bananas were sampled from 5 markets in Kampala, Uganda. Deionized water was used to soak the bananas and the potassium concentration was determined using an atomic absorption spectrophotometer in both the bananas and water after soaking for varying time intervals. We also determined the potassium concentrations in the bananas and the water after boiling the bananas at 200 degrees Celsius at intervals of 10 minutes (for 60 minutes). RESULTS The potassium concentration did not appear to change on soaking alone without boiling. However, on boiling, the concentration in the bananas decreased from about 1.4 ppm to approx. 1 ppm after 60 min; yet the concentration of potassium released into deionized water increased steadily from 0.0 ppm to about 1.2 ppm after 60 min of boiling. CONCLUSION This study demonstrates that boiling the bananas is a more effective way of removing the potassium from bananas than simply soaking them.