Rapid determination of collagen in meat-based foods by microwave hydrolysis of proteins and HPAEC–PAD analysis of 4-hydroxyproline

A rapid microwave procedure for protein hydrolysis coupled with High Performance Anion Exchange Chromatography and Pulsed Amperometric Detection (HPAEC–PAD) was developed to quantify the amino acid 4-hydroxyproline in meat and meat-based products. This innovative approach was successfully applied to determine collagen content (4-hydroxyproline × 8) as the index quality of meat material employed in the preparation of typical meat sausages (“Mortadella di Bologna PGI” and “Salamini italiani alla cacciatora PDO”) and fresh filled pastas. Microwave hydrolysis showed a precision and accuracy similar to traditional hydrolysis (RSD% from 0.0 to 6.4; relative error 1.4–10.0%) with a reduction in the hydrolysis time from 24 h to 20 min. HPAEC–PAD allowed detection of 4-hydroxyproline without pre or post-column derivatization and the use of non-toxic eluents.