Identification of a salt-enhancing compound in thyme using sensory-guided preparative-LC fractionation

Excessive salt intake is recognized as a leading dietary risk factor, necessitating the development of new strategies to reduce sodium consumption without compromising flavor. In this study, salt-enhancing compounds were investigated in Thymus vulgaris L. (thyme) using a sensory-guided, multi-dimensional preparative liquid chromatography fractionation approach. Among the isolated constituents, (9S,12S,13S)-trihydroxy-octadeca-10E,15Z-dienoic acid was identified and confirmed by mass spectrometry, nuclear magnetic resonance, and optical rotation analysis. Sensory evaluation revealed that this compound significantly enhanced salt perception at concentrations as low as 0.2 mg/L in both sodium chloride solutions and low-sodium chicken broth. This is the first report to describe this molecule as a natural salt enhancer, offering an approach to reduce sodium content in foods while preserving flavor.