Sodium and potassium content in sports supplements based on whey protein

Abstract

Different brands of three sports supplement types containing whey protein were evaluated: 15 whey protein supplements, 4 hypercaloric supplements and 7 protein bars. A sample preparation procedure was studied employing microwave-assisted wet digestion in order to determine the sodium and potassium contents using Flame Atomic Emission Spectrometry (Flame Photometry). The sodium concentrations obtained were in the ranges of 0.30 to 5.9 mg/g, 0.52 to 2.8 mg/g and 2.3 to 5.0 mg/g for whey protein supplements, hypercaloric supplements and protein bars respectively. The potassium concentrations varied from 1.3 to 13 mg/g, 0.47 to 5.4 mg/g and 1.7 to 12 mg/g for the same samples, respectively. The ratio between sodium and potassium levels, a parameter associated with incident hypertension, was calculated, showing that for some samples the values exceeded the World Health Organization recommendation. The developed method has presented high analytical frequency, with good accuracy and precision, making it suitable for application in quality control routines.

Keywords

• minerals
• micronutrients
• hypercaloric supplements
• protein bar supplements
• flame photometry.