Development of a new method for the determination of 4-hydroxyproline as a measurement of collagen content in meat products and dietary supplements by cyclodextrin-assisted electrokinetic chromatography

Abstract

The rise in consumption of ultra-processed meat and dietary collagen supplements challenges food quality control. 4-hydroxyproline stands out as collagen signature amino acid, and its determination is a well-known way to estimate collagen content, although for this measurement, the majority of the methods require a mandatory derivatization step. Therefore, this study aimed to develop an innovative method using cyclodextrin-assisted electrokinetic chromatography with indirect UV detection to determine 4-hydroxyproline for collagen monitoring in dietary supplements and meat products. Separations were performed in fused silica capillaries, at 12.5 °C, detection at 220 nm, 30 kV voltage, and hydrodynamic injection. Background electrolyte consisted of histidine 25 mmol L-1, butylamine 180 mmol L-1, and β-cyclodextrin 10 mmol L-1 at pH 11.4. Samples were hydrolyzed with sulfuric acid, and their removal was accomplished by simultaneous neutralization/precipitation reactions using strontium carbonate. Validation assured method detectability, accuracy (recoveries 88% - 102%), and precision (CV < 7%). Dietary supplements and meat products were successfully evaluated, indicating that this method is a feasible quality control alternative.