Rapid and sensitive automated method for glucose monitoring in wine processing.

ABSTRACT

A rapid and sensitive automated method for glucose monitoring that might be employed during wine fermentation and processing was developed. A flow injection (FI) system coupled with an automated dilutor and the "redox-versatile" modified electrode were used to directly measure glucose in wine. To avoid interferences during wine analysis, different formulations of enzymatically modified carbon paste electrodes (CPE) were used and evaluated in oxidation and reduction mode. The best selectivity and sensitivity for glucose monitoring in real samples was obtained in cathodic mode at a fixed potential of 0 V versus Ag/AgCl using a CPE modified with glucose oxidase, horseradish peroxidase, and ferrocene as redox mediator. A total linear range of 0.02-50 g/L glucose was covered using this automated system and allowed the measurement of glucose in dry, medium, and sweet white or red wines without any sample pretreatment. The results showed a good correlation with the standard method, and the proposed method is very rapid, simple, and reliable and does not need skilled operators.