engleski

Application of Biosensor for Determination of Glucose in Croatian Wines

Biosensors are analytical tools characterized by sensitivity, selectivity, fast response and good dynamic range. For all these analytical characteristics, they are often preferred to less accurate or time-consuming conventional techniques. The biocatalyst (enzyme) makes the biosensor selective and the modifications that take place in the system, as a result of the enzymatic reaction, are converted in a measurable signal. A wide range of analytes (sugars, organic acids, amino acids, amines, pesticides, etc.) could be determined using biosensors, especially enzyme-electrodes. Sweetness is one of the most important characteristics of wines. It is mainly given by the concentration of fructose. However, monitoring of glucose, whose concentration should be low due to the fermentation processes, is also necessary providing information on the completion of the fermentation and for final quality control of the wine. A batch and flow-injection system for the determination of glucose in various sorts of red and white Croatian wines using a glucose biosensor based on electrochemically modified carbon paste electrode with glucose oxidase (GOD) immobilized in several ways (via cross-linking with glutaraldehyde and bovine serum albumine, or bonding/entrapment in photocurable membranes) is described. Beside determination of basic characteristics of biosensor, the influence of organic solvents on amperometric response of the biosensor was studied, too. The results obtained for real samples of high and standard-quality red and white wines were compared with spectrophotometric method based on two enzymatic reactions. The fast and easy preparation of the biosensor, high activity and long life, if glucose oxidase was immobilised in mixed polymeric photocurable membrane, as well as reasonably accurate glucose determination, make the proposed procedure appropriate for quality control of the alcoholic beverages in water or in water/organic solvents.

biosensor; glucose determination in wine; polymeric photocurable membrane

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