Wide target analysis of acylglycerols in miso (Japanese fermented soybean paste) by supercritical fluid chromatography coupled with triple quadrupole mass spectrometry and the analysis of the correlation between taste and both acylglycerols and free fatty acids

Rationale: The acylglycerols in miso have not been studied although it is known that they are important to the taste. In order to determine the fatty acid constituents in the acylglycerols and analyze them individually, multiple reaction monitoring (MRM) was performed utilizing a single platform, typically using both gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry. Methods: Acylglycerols and fatty acids (FAs) in miso were extracted using the Bligh-Dyer method. Supercritical fluid chromatography (SFC) with a C30 column was conducted for separation, and mass spectrometric (MS) analysis was performed with electrospray ionization using a triple quadrupole mass spectrometer (QqQMS) in the MRM mode. Results: The detection of FAs from the hydrolysis of acylglycerols and individual acylglycerols was achieved using only an SFC/MS platform. From the quality control (QC) sample of miso, we determined the main FA constituents, and then performed wide target analysis using MRM. In total, 23 triacylglycerols, 10 diacylglycerols, two monoacylglycerols, and five FAs were annotated effectively. Furthermore, the important compounds related to taste were determined through the analysis using both the relative quantitative data of acylglycerols and FAs and the quantitative descriptive analysis data of miso. Conclusions: A method for the determination of the FA constituents in acylglycerols after hydrolysis and the comprehensive analysis of acylglycerols and FAs using MRM with SFC/QqQMS was developed. Using the data from the comprehensive analysis of acylglycerols and quantitative descriptive data, the key compounds related to taste were investigated. This type of research on lipids and the taste of food is expected to progress hereafter.