APPLICATION OF GLUTAMATE-SENSITIVE BIOSENSOR FOR ANALYSIS OF FOODSTUFF

The aim of the work were the optimization of an amperometric glutamate-sensitive biosensor and its utilization for the determination of the glutamate concentrations in food samples. Amperometric method of measurements was used. The biosensor was based on immobilized glutamate oxidase and platinum disc electrode. The biosensor was connected to the working cell with auxiliary (platinum wire) and reference (Ag/AgCl) electrodes. The biosensor exhibited high sensitivity to glutamate, duration of one analysis was about 5 min. An influence of the ionic strength, pH, and buffer capacity on the biosensor operation was investigated. The sensitivity of biosensor to various possible interfering substances, including amino acids, was studied; high selectivity to glutamate was shown. The reproducibility of analysis of food samples and an impact of sample dilution was evaluated. Glutamate concentrations in different sauces and seasonings were measured by the developed biosensor; the results correlated well with those obtained by the spectrophotometric method (R2 = 0,988). Thus, the amperometric biosensor for glutamate determination was successfully optimized and used for measurement of glutamate concentrations in sauces and seasonings.