Levels of vitamins B12, C. and E in the tested samples were
measured using HPLC with UV (371 nm), electrochemical and UV
(300 nm) detectors according to the methods of Quesada-Chanto
et al. (1998), Albrecht and Schafer (1990) and Nierenberg and
Nann (1992), respectively.
The GABA content was determined by HPLC with a C18 column
according to Kim, Lee, Ji, Lee, and Hwang (2009).