Development of a Reference Measurement Procedure and Certified Reference Material for the Determination of Hydroxyproline in Meat

The concentration of trans-4-hydroxy-l-proline has been traditionally employed as an estimate of collagen content in meat to assess meat quality. Conventional methods use chemical derivatization followed by UV-visible detection. However, complexity of the matrix may cause interferences due to lack of specificity and consequently bias quantification. On the contrary, liquid chromatography (LC) separation coupled to mass spectrometry (MS) detection overcomes these limitations, giving more accurate results. This study describes the development and validation of an exact matching-isotopic dilution mass spectrometry method for the determination of hydroxyproline in meat hydrolysates in the certification of a candidate meat reference material (CRM LGC7154). The method is not biased by changes in method conditions or by matrix load. Hydroxyproline concentrations and relative uncertainties for quality control samples revealed good agreement with the certified values. A mean hydroxyproline concentration of 1.78 +/- 0.28 g/kg (k = 2) was found for the CRM LGC 7154 material.