Simple and inexpensive flow L-glutamate determination using pumpkin tissue

• Type: Article in International Scientific Journal
• Date: 2003

Authors

Arruda, NJM (Author) Other; Filho, JLL (Author) Other; Montenegro, MCBSM (Author) FFUP; Araujo, AN (Author) FFUP; Silva, VL (Author) Other

Journal

Title: Journal of Agricultural and Food Chemistry

Vol. 51

Pages: 6945-6948

ISSN: 0021-8561

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 6 Citations

ISI Web of Science

Scopus - 6 Citations

Scientific classification

FOS: Agrarian Sciences > Other Agrarian Sciences

CORDIS: Health sciences

Other information

Authenticus ID: P-000-EEE

DOI: 10.1021/jf0344791

Resumo (PT): This work refers to a very easy to implementate flow injection system with potentiometric detection for l-glutamate determination in food samples. The proposed procedure is based on measurement of carbon dioxide produced by decarboxylation of l-glutamate catalyzed by l-glutamate decarboxylase (E.C. 4.1.1.1.5) from Cucurbita maxima (pumpkin). The FI potentiometric system includes an enzymatic reactor with a length of 8 cm and thickness of 5 mm packed with 200 mg of a C. maxima outer layer cut in to small pieces. The proposed procedure allowed l-glutamate determinations in the concentration interval of 10−100 mmol L-1 for an injected sample volume of 50 μL. A phosphate buffer (0.1 mol L-1, pH 5.5) solution flowing at 1.4 mL min-1 was used as the carrier solution in the system. The results obtained in the analysis of food samples revealed a relative error lower than 5% when compared with those provided by the spectrophometric reference procedure. The immobilized reactor retained its initial activity for 21 days. It was possible to measure 40 samples/h with the flow system proposed. <br> <br> Keywords: l-Glutamate; glutamate decarboxylase; potentiometry; flow analysis; pumpkin; Cucurbita maxima <br> <a target="_blank" href="http://pubs.acs.org/doi/abs/10.1021/jf0344791 "> Texto integral </a> <br> <br>

Abstract (EN): This work refers to a very easy to implementate flow injection system with potentiometric detection for L-glutamate determination in food samples. The proposed procedure is based on measurement of carbon dioxide produced by decarboxylation Of L-glutamate catalyzed by L-glutamate decarboxylase (E.C. 4.1.1.1.5) from Cucurbita maxima (pumpkin). The FI potentiometric system includes an enzymatic reactor with a length of 8 cm and thickness of 5 mm packed with 200 mg of a C. maxima outer layer cut in to small pieces. The proposed procedure allowed L-glutamate determinations in the concentration interval of 10-100 mmol L-1 for an injected sample volume of 50 muL. A phosphate buffer (0.1 mol L-1, pH 5.5) solution flowing at 1.4 mL min(-1) was used as the carrier solution in the system. The results obtained in the analysis of food samples revealed a relative error lower than 5% when compared with those provided by the spectrophometric reference procedure. The immobilized reactor retained its initial activity for 21 days. It was possible to measure 40 samples/h with the flow system proposed.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 4