Development of Isotope Dilution-Liquid Chromatography/Mass Spectrometry for the Accurate Determination of Capsaicinoids in Fermented Cabbage Kimchi

Reliable measurements of flavor compounds in fermented food are key for the characterization and standardization of commercial mass production. Among several important flavor compounds, capsaicinoids provide spiciness, one of the most important tastes in traditional Korean kimchi (seasoned and fermented vegetables). In this study, isotope dilution-liquid chromatography/mass spectrometry (ID-LC/MS/MS) was developed as a higher-order reference method for the accurate measurement of capsaicinoids to provide reference materials for reliable measurements and standardization in the kimchi industry. The developed method was validated by measuring gravimetrically fortified samples, and its performance parameters were evaluated. The method showed excellent repeatability (n ≥ 5) and reproducibility with ˂ 1% relative standard deviation. The overall measurement uncertainty for individual capsaicinoids was < 3% at the level of 0.05 mg/kg or higher. Thus, the developed method exhibited a higher-order metrological quality.