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

Area of Science:

• Food Chemistry
• Protein Science
• Biochemistry

Background:

• Food processing can lead to protein modifications affecting nutritional and functional properties.
• Alpha, beta-unsaturated aldehydes are reactive compounds implicated in food protein modifications.
• Understanding these modifications is crucial for food quality and safety.

Purpose of the Study:

• To investigate the impact of varying processing temperatures on alpha, beta-unsaturated aldehyde-mediated modifications of cod protein.
• To characterize the changes in cod protein hydrophobicity, amino acid reactivity, and carbonylation.
• To evaluate the functional properties (emulsifying and foaming) of modified cod protein.

Main Methods:

• Development of a clickable probe, 4-(2-Propyn-1-yloxy)-2-butenal (yne-ACR), to mimic aldehyde modifications.
• Simulated thermal processing of cod protein at 25°C, 90°C, and 180°C.
• Analysis of protein hydrophobicity, free nucleophilic amino acids, protein carbonylation, and functional properties.

Main Results:

• Processing at 180°C increased cod protein hydrophobicity threefold and significantly elevated protein carbonylation (14.7 nmol/mg).
• Thermal processing (90°C and 180°C) improved emulsifying and foaming capacities compared to heating alone.
• Cod protein processed at 90°C showed the highest number of identified modified components (757), indicating complex modifications facilitated by thermal denaturation.

Conclusions:

• Thermal processing significantly influences alpha, beta-unsaturated aldehyde-mediated modifications in cod protein.
• Higher temperatures induce greater hydrophobicity and carbonylation, while moderate heat (90°C) promotes extensive peptide modifications and enhances functional properties.
• The study provides novel tools and insights into food protein modification mechanisms during thermal processing.