Exploring the impact of processing temperatures on cod protein modifications by α, β-unsaturated aldehydes using a clickable probe

To investigate the effects of processing temperatures on α, β-unsaturated aldehyde-mediated modifications of cod protein, a clickable probe, 4-(2-Propyn-1-yloxy)-2-butenal (yne-ACR), was developed to simulate α, β-unsaturated aldehyde modifications on cod protein in simulated processing systems (25 °C, 90 °C, and 180 °C). Processing at 180 °C resulted in a 3-fold increase in the hydrophobicity, while modifications under thermal processing had limited effects on the content of free nucleophilic amino acids. However, modification at 180 °C significantly increased the content of carbonylated proteins to 14.7 nmol/mg protein. Cod protein modified during thermal processing (90 °C and 180 °C) exhibited superior emulsifying and foaming properties than those subjected to heating alone. Cod protein processed at 90 °C exhibited 757 identified modified components, representing the highest number among the three processing temperatures, and thermally induced structural changes in cod protein facilitated multiple modifications on a single peptide. These findings provide new tools and insights for the study of food protein modification.