Increased level of tetrahydro-beta-carboline derivatives in short-term fermented garlic.

In our previous study [1], we found that relatively short-term spontaneous fermentation (40 days at 60-70 degrees C, 85-95% relative humidity) potentiates anti-oxidative properties of garlic, in which scavenging activity against hydrogen peroxide was included. Since tetrahydro-beta-carboline derivatives (THbetaCs) that possess hydrogen peroxide scavenging activity have recently been identified in aged garlic extract, THbetaCs were quantitatively analyzed with liquid chromatography-mass spectrometry (LC-MS). (1R, 3S)-1-Methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid (MTCC) and (1S, 3S)-MTCC were found in the fermented garlic extract whereas only trace levels of MTCCs were detected in the row garlic extract. Therefore, it is suggested that relatively short-term fermentation potentiates scavenging activity of garlic against hydrogen peroxide by forming THbetaCs, especially MTCCs.