Discrimination of overheated pasteurized milk using mass spectrometry-based proteomics

Area of Science:

• Food Science
• Analytical Chemistry
• Proteomics

Background:

• Milk is a globally consumed staple, necessitating methods to ensure its quality.
• Detecting the degree of heat treatment is crucial for consumer protection and product integrity.
• Current methods may lack the specificity to accurately assess subtle overheating in pasteurized milk.

Purpose of the Study:

• To develop and validate a novel analytical method for identifying specific peptide markers indicative of milk overheating.
• To differentiate normal pasteurized milk from overheated pasteurized milk using sensitive peptide biomarkers.
• To establish a reliable method for assessing milk processing conditions below 100 °C.

Main Methods:

• Utilized nano liquid chromatography-orbitrap fusion mass spectrometry (nano LC-Orbitrap MS) for initial screening of thermally sensitive peptides.
• Integrated untargeted proteomics and chemometric analysis of protein quantitation data from milk samples subjected to varying heat treatments.
• Employed isotope-dilution ultra-performance liquid chromatography-tandem triple quadrupole mass spectrometry (ID-UPLC-MS/MS) for precise quantification of selected marker peptides.

Main Results:

• Screened and identified thirteen potential peptide markers, subsequently confirmed with standard substances.
• Selected four highly specific and thermally sensitive peptides (INLFDTPLETQYVR, FELLGCELNGCTEPLGLK, QFQFIQVAGR, GEADALNLDGGYIYTAGK) as reliable indicators.
• Quantified marker concentrations, demonstrating their ability to distinguish between normal and overheated pasteurized milk based on specific concentration ranges.

Conclusions:

• The developed mass spectrometry-based method effectively identifies specific peptide markers for detecting milk overheating.
• The four selected peptides serve as reliable biomarkers for differentiating normal from overheated pasteurized milk.
• This research offers valuable insights and a robust tool for quality control in the dairy industry, safeguarding consumer interests.