Wide-Target Analysis of Yogurt Using Triple Quadrupole LC-MS/MS

Significance of the Topic

Food metabolomics enables deep profiling of primary metabolites in dairy products, informing quality control, nutritional evaluation and functional characterization.

Objectives and Study Overview

The aim was to perform a comprehensive evaluation of primary metabolites in eight commercial yogurts using both ion-pairing and non-ion-pairing LC-MS/MS workflows.

Methodology and Instrumentation

Sample preparation involved freeze-drying, solvent extraction (water:methanol:chloroform 1:2.5:1), ultrafiltration and reconstitution in internal standard solution. Two chromatographic methods were applied on a Shimadzu Nexera X3 UHPLC system coupled to a LCMS-8060NX triple quadrupole mass spectrometer with ESI in positive and negative modes.

• Ion-pairing method: Mastro2 C18 column, dipentylamine/acetate mobile phase
• Non-ion-pairing method: PFPP column, formate/acetonitrile mobile phase

Main Results and Discussion

Combined analysis detected over 110 metabolites per sample. Ion-pairing detected mainly glycolytic and pentose phosphate intermediates while non-ion-pairing captured amino acids, organic acids and nucleotides. Principal component analysis revealed distinct metabolic signatures:

• PC1 positive loadings: UDP-glucose, cytidine, thymidine diphosphate
• PC1 negative loadings: phenyllactic acid, succinic acid, cystathionine
• PC2 positive loadings: tyrosine, glutamic acid, FAD
• PC2 negative loadings: threonine, alanine, glycine

Specific yogurt samples exhibited elevated nucleic acid metabolites (Yogurt2, Yogurt6) or sulfur amino acid derivatives (Yogurt3, Yogurt5, Yogurt7, Yogurt8).

Benefits and Practical Applications

This workflow enables rapid, broad coverage profiling of yogurt metabolites supporting quality assessment, batch differentiation and process optimization. Integration of Shimadzu method packages facilitates streamlined data processing and visualization.

Future Trends and Potential Applications

Advances may include higher throughput screening, multi-omics integration with proteomics and genomics, machine learning driven quality prediction, and tailored functional food development.

Conclusion

The dual LC-MS/MS approach offers a powerful platform for comprehensive primary metabolite analysis in yogurt. PCA highlights sample-specific metabolic variations and the Shimadzu workflow enhances lab efficiency in food metabolomics research.

References

• IIDA J, ITO Y, WATANABE J, Wide-Target Analysis of Yogurt Using Triple Quadrupole LC-MS/MS, Shimadzu Corporation and Osaka University Omics Innovation Research Laboratories, 2023.