Impact of Lipid Oxidation Products on the Digestibility and Structural Integrity of Myofibrillar Proteins During Thermal Processing

This study explores the effects of lipid oxidation products (LOPs), specifically CHP, t,t-DDE, and MDA, on the digestibility and structural integrity of myofibrillar proteins (MP) during processing. LOPs were first assessed by heating at 180 °C for 15 min, showing a significant reduction in digestibility in MDA-treated samples (65.40 %), followed by t,t-DDE (45.10 %) and CHP (13.07 %). MALDI-TOF MS analysis revealed decreased peptide abundance and lower average molecular weight in t,t-DDE- and MDA-treated samples. Notably, substantial decreases in α-helix content and increases in random coil structures were detected, particularly in MDA-treated samples. Assessments of surface hydrophobicity and thiol content underscored the detrimental impact of secondary LOPs on MP structure. Higher MDA concentrations led to a substantial reduction in intrinsic fluorescence intensity, along with an increase in Schiff base content. A PLS regression model demonstrated strong predictive capabilities for MP digestibility, highlighting the importance of optimizing meat processing parameters to minimize nutritional degradation.