Surfactant to dye binding degree based approach for the selective determination of l-glutamate in foodstuffs
- 123 Downloads
A selective method for the determination of l-glutamate in foodstuffs has been developed. It was based on the competition established between the analyte and the dye Coomassie brilliant blue G (CBBG) to interact with the surfactant didodecyldimethylammonium bromide (DDABr). The measurement parameter was the amount of DDABr required to reach a given dye-to-surfactant binding degree. It was obtained by photometric titration on the basis of the changes observed in the spectral characteristics of the dye when CBBG–DDABr aggregates were formed. The calibration graph obtained was linear in the l-glutamate concentration interval 0.2–5 mM (detection limit 0.05 mM). The high selectivity of the proposed method (other amino acids and food additives did not interfere at the concentrations present in foodstuffs) permitted the direct analysis of food samples after dissolution of the analyte in hot water. The accuracy of the surfactant to the dye binding degree method was demonstrated by determining l-glutamate in different kinds of foodstuffs (liquid and dried soups, seasonings, pasta sauces and dried mushroom creams) and comparing the results obtained with those provided by the commercial Boehringer Mannheim essay.
KeywordsSurfactant to dye binding degree method l-Glutamate Food analysis Routine quality control
The authors gratefully acknowledge financial support from CICyE (Junta de Andalucía, project no. FQM 166).
- 3.Geha RS, Beiser A, Ren C, Patterson R, Greenberger PA, Grammer LC, Ditto AM, Harris KE, Shaughnessy MA, Yarnold PR, Corren J, Saxon A (2000) J Nutr 130:1058S–1062SGoogle Scholar
- 5.Sixty-third meeting of the Joint FAO/WHO Expert Committee on Food Additives, Geneva, 2004Google Scholar
- 6.Toxicological evaluation of certain food additives. Thirty-first meeting of the Joint FAO/WHO Expert Committee on Food Additives, Geneva, 1988Google Scholar
- 7.European Parliament and Council Directive no 95/2/EC on food additives other than colours and sweeteners, Brussels, 1995Google Scholar
- 13.Hattula MT, Wallin HC (1991) J AOAC 74:921–925Google Scholar
- 23.Daniela DH, Joe FL Jr, Diachenko GW (1995) Food Addit Contam 12:21–29Google Scholar
- 24.Beljaars PR, van Dijk R, Bisschop E, Spiegelenberg WM (1996) J AOAC Int 79:697–702Google Scholar