Metabolomics as a critical tool for deeper understanding of pickled foods: From biomarker discovery to nutrition function

Pickling, as an ancient culinary technique (predate to 2400 BCE), protected food in brine and/or sugar, which caused metabolites to undergo a series of chemical changes and slowly changing raw materials' structure to bring beneficial or harmful influences. Metabolomics was a systematic analysis of small metabolites in pickles, which provided opportunities to comprehensively investigate quality, safety, process research of pickled food and interactions between metabolism and immunity in disease. This review presents classic workflow of MS based metabolomics of pickled foods investigation, especially focusing on the mass spectrum-oriented computational method, data handing strategies and bioinformatics tools. Selected examples of international studies about hypertension and diabetes associated with pickled foods that implement MS-based metabolomics will be reviewed. Combined with MS-based metabolomics, pickled foods metabolites fingerprinting and pathogenesis of hypertension and diabetes from directly or indirectly can be characterized comprehensively. Hypertension was regulated by adjusting extracellular fluid volume under the control of RAAS. PI3K/Akt pathway and MAPK pathway were applied to alleviate diabetes by regulating metabolism of insulin receptors. Advanced and effective methods of MS-based metabolomics promote in-depth study of hypertension and diabetes associated with pickled foods and provide tangible solutions for further research.