The evaluation and laboratory screening of selected commercially available orotein supplement products

Abstract

Protein supplements have grown in popularity in recent years since they are utilised by both physically active people and athletes. However, the regulation of supplement products by the relevant authorities within the sector has been inadequate. As a result, unscrupulous manufacturers of these products take advantage of this by mislabelling, adding inadequate protein, and incorporating adulterants to enhance the apparent protein content. This is a widespread practice throughout the world, including South Africa. Unsuspecting customers may be misled by incorrectly labelled products. According to research, adding adulterants such as melamine to these products may cause kidney disease. The purpose of this study was to evaluate the label information of selected protein supplements sold in South Africa, quantify the protein content, and determine the prevalence of melamine, cyanuric acid, and uric acid in these products. Predetermined labelling information categories for protein supplement products (n = 21) were assessed, including claims, warnings, disclaimers, and product pricing. Label claims were typically observed to be vague and unsupported by scientific literature/evidence. The actual protein content of the selected protein supplements was determined using a multi-protein assay approach. In this study BCA, Bradford, and Lowry assays were used for the protein assessment. There was a statistically significant difference (p<0.05) between analysed protein values and the label reported values, in 86% products analysed by BCA, and 67% by Lowry assay. A simple and rapid reverse phase high performance liquid chromatography (HPLC-UV) method was developed and validated to determine presence of adulterants simultaneously in protein supplements. All of the supplements tested positive for one or more adulterants using this approach. The mean concentrations estimate for the adulterants were 12.5 μg.ml1 for melamine, 120 μg.ml1 for cyanuric acid and 57.8 μg.ml1 for uric acid. The findings of this study demonstrate that protein supplement manufacturers take advantage of the lack of effective governance through unethical practices. This research is significant as it supports the need for an improved regulatory framework within the supplement sector.