Quantification of bio- and techno-functional peptides in tryptic bovine micellar casein and β-casein hydrolysates

The quantification was based on calibration curves drawn using synthesised purified peptides. The regression analysis comparing >30 standard measurements of each peptide standard showed a regression coefficient R2 > 0.9958. The inter-day repeatability of the quantification method was always within a relative error of 0.2-6.5%, while the relative error of the accuracy for reproducibility was in the range of 0.1-2.4%. The established method was successfully applied for the quantitative analysis of the eleven functional peptides in different dairy fractions generated by cross-flow ultrafiltration.