Rapid detection of pork meat freshness by using L-cysteine-modified gold electrode

In this research, a simple and rapid glucose sensor was developed and applied in the detection of meat glucose. The gold electrode was modified using L-cysteine and nanogold solution, and a polyglutamate–glucose oxidase (GOx) complex was prepared and dropped on the modified electrode; the electrostatic binding between the L-cysteine on the electrode surface and the polyglutamate moiety of the complex resulted in the formation of a GOx-attached electrode. Glucose in meat was detected, and the enzyme electrode showed a quick response. The optimum operating conditions for this sensor were determined as follows: 0.1 M citrate buffer pH 5.0 was found to be suitable for this experiment, and the temperature was kept between 25 and 30 °C which is the suitable range for the GOx activity. A linear relationship was found between 0.1 and 0.9 mM/mL. High pressure liquid chromatography (HPLC) was also used to detect pork meat glucose, and total volatile basic nitrogen (TVBN) production was as well detected as a quality index of pork meat freshness. The results showed that the developed sensor was fast and reliable method for the detection of glucose in meat.