Simultaneous Determination of S-Methylmethionine, Vitamin U and Free Amino Acids in Extracts of Green Tea with an HPLC-Amino Acid Analyzer

Abstract

Free amino acids and S-methylmethionine (MMS, an anti-ulcer factor, Vitamin U) in green tea extracts were simultaneously determined with an HPLC-amino acid analyzer using lithium citrate buffers. Rapid analysis of MMS and free amino acids was achieved with a high resolution column, MCI Gel CK-10U 0.46cfx 15cm, within 180min. MMS in the column eluates was identified as dimethyl sulfide by a gas-chromatographic method with a flame photometric detector. The contents of MMS and free amino acids in various green teas were determined and compared with respect to the quality of commercial teas, blended teas and non-blended teas, and the place of cultivation of the tea. The described method is rapid and useful for checking the quality of green tea. © 1987, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.