How processing affects marker peptide quantification - A comprehensive estimation on bovine material relevant for...

Area of Science:

• Food Science
• Analytical Chemistry
• Proteomics

Background:

• Food and feed processing induces protein modifications, complicating accurate quantification.
• Existing methods may underestimate protein levels due to these modifications.
• Understanding processing effects is crucial for reliable official controls.

Purpose of the Study:

• To investigate the impact of processing-induced protein modifications on quantification accuracy.
• To identify specific modified peptides in bovine food and feed matrices.
• To develop strategies for improving targeted mass spectrometry (MS)-based protein quantification.

Main Methods:

• Bottom-up proteomic analysis of 37 bovine food and feed samples.
• Identification of 335 post-translational modifications (e.g., oxidation, deamidation).
• Comparison of peak areas between modified and unmodified peptides to assess recovery.

Main Results:

• Peptide-specific recoveries and variances were observed across raw, spray-dried, and pressure-sterilized samples.
• Processing significantly altered protein sequences, impacting quantification.
• Modified peptide versions showed varying recovery rates compared to unmodified counterparts.

Conclusions:

• Protein modifications significantly affect targeted MS-based quantification in processed food and feed.
• Incorporating modified peptide versions alongside unmodified markers can enhance quantification accuracy.
• This approach offers improved reliability for official food and feed control.