Determination of sotolon, sotolon precursors, and minerals in Okinawan awamori

抄録

Sotolon (3-hydroxy-4,5-dimethyl-2(5H)-furanone) is a volatile aroma compound with various desirable odors, including sweet, honey-like, and caramel-like. In this study, sotolon was quantified in 44 commercial awamori, an Okinawan rice-based distilled alcoholic beverage. Sotolon was detected at concentrations up to 20.5 µg/L, and awamori stored in earthenware jars had a significantly higher sotolon content than that in non-earthenware jars (p < 0.0001). Additionally, sotolon precursors (diacetyl, acetoin, acetaldehyde, and 2-oxobutyric acid) were present at concentrations of 0.13–1.48, 0.24–4.70, 77.50–332.50, and 0.16–0.96 mg/L, respectively, and showed no notable differences between storage vessels or periods. Moreover, Al and Cu were considerably higher in earthenware-jar-stored awamori, whereas Al, Cu, Fe, and Mn were markedly higher in aged awamori. These results suggest the possibility of mineral elution catalyzing the oxidation of sotolon precursors in earthenware jars and provide a foundation for further research on the mechanism of sotolon generation in awamori.