Effect of oxidation and hydrolysis of porcine myofibrillar protein on Nε‐carboxymethyl‐lysine formation in model systems

Abstract

SummaryThis study investigated the effects of oxidation and hydrolysis of porcine myofibrillar protein (MFP) on Nε‐carboxymethyl‐lysine (CML) formation in model systems. Model systems of MFP/oxidised linoleic acid (MFP/OLA), mildly oxidised MFP/OLA (MO‐MFP/OLA), severely oxidised MFP/OLA (SO‐MFP/OLA), mildly hydrolysed MFP/OLA (MH‐MFP/OLA) and severely hydrolysed MFP/OLA (SH‐MFP/OLA) were incubated, and CML content was determined. Compared with MFP/OLA (39.1 ± 5.7 ng mg−1 protein), there was a significant increase of CML in MO‐MFP/OLA (53.9 ± 2.5 ng mg−1 protein), whereas a marked decrease was observed in SO‐MFP/OLA (25.1 ± 4.4 ng mg−1 protein) during incubation. CML level increased with increasing degree of hydrolysis of MFP after 6 days of incubation. Therefore, mildly oxidised MFP and hydrolysed MFP could promote CML formation, while severely oxidised MFP impeded CML generation. These results suggested that effects of oxidation and hydrolysis of MFP on CML generation were mainly dependent on the degree of structural changes of MFP.