Determining Monosodium Glutamate in Cafeteria Foods at the Eastern Mediterranean University

Monosodium Glutamate (MSG) is a flavor enhancer that is used widely around the world. In this thesis, MSG was extracted from samples of cooked foods purchased from four different cafeterias in EMU; and from packaged foodstuffs such as chicken bouillon and four different powdered soups (Brand II) bought locally. The identification as well as relative concentrations of MSG in these samples were determined by TLC and their actual concentrations were estimated by HPLC using a 50:50 water-acetonitrile mobile phase. Peaks were monitored at 210, 220, 230, 240 and 250 nm but highest sensitivity was obtained with 210 nm radiation. Although good results were obtained with pure MSG standard solutions, there were, however, problems with the food extracts when analyzed with HPLC. There were overlapping unresolved peaks for some of the food extracts that could not be conclusively identified. These peaks, we suspect, are due to water soluble amino acids extracted for the cooked foods. Due to their great solubility, they tend to have low retention times and thus exit the column almost simultaneously. For the samples that could be identified and quantified, relatively high amounts of MSG ranging between 0.94 % and 6.5 % were found. These amounts of MSG may be added or naturally present in the food. More accurate measurement of the MSG concentration by HPLC can be done by derivatizing the MSG to make it more hydrophobic. This would increase the retention times of the components thereby providing greater degree of separation and resolution. Keywords: MSG, analysis, food, TLC, HPLC, Derivatization.