[The effect of natural polyphenol complex of red grape wine on L-arginine/NO system in peripheral blood of rats under low doses of ionizing radiation].

The total activity of NO-synthase and content of stable metabolitic products of nitric oxide in the peripheral blood of rats under low doses of ionizing radiation and administration of natural polyphenol complex of grape was investigated. It was found that natural polyphenol compounds of grapes have the ability to correct radioinduced changes in L-arginine/NO system. It was noted that the action of X-radiation increased activity of NO-synthase in the peripheral blood of rats. However, the consumption of natural polyphenol complex of grape led to a decrease of this index to control values. An increase in NOS activity under irradiation leads to the increase of NO stable metabolites content, which is reflected in the accumulation of nitrite- and nitrate-anions in the peripheral blood of rats. The consumption of preparation of polyphenol complex this index decreased in the early period of the experiment, and on the third day after exposure, the total content of NO stable metabolites is slightly higher compared to the indices of control animals. Thus, the ability of natural polyphenol complex to cause attenuation of oxidative-nitrative stress caused by ionizing radiation was investigated experimentally.

[Amperometric biosensor for ethanol analysis in wines and grape must during wine fermentation].

The amperometric biosensor for ethanol determination based on alcohol oxidase immobilised by the method of electrochemical polymerization has been developed. The industrial screen-printed platinum electrodes were used as transducers for creation of amperometric alcohol biosensor. Optimal conditions for electrochemical deposition of an active membrane with alcohol oxidase has been determined. Biosensors are characterised by good reproducibility and operational stability with minimal detection limit of ethanol 8 x 10(-5) M. The good correlation of results for ethanol detection in wine and during wine fermentation by using the developed amperometric biosensor with the data obtained by the standard methods was shown (r = 0.995).

[Amperometric biosensor for lactate analysis in wines and grape must during fermentation].

The amperometric biosensor based on lactate oxidase for determination of lactate has been developed, and two methods of immobilization of lactate oxidase on the surface of industrial screen-printed platinum electrodes SensLab were compared. A sensor with immobilized in the Resydrol polymer lactate oxidase by the method of physical adsorption is characterized of narrow dynamic range and greater response value in comparison with a biosensor based on immobilised in poly(3,4-ethylenedioxythiophene) lactate oxidase by the method of electrochemical polymerization. Operational stability of the biosensor developed was studied and it was shown, that the immobilization method does not influence their stability. The analysis of the lactate in wine and during wine fermentation has been conducted. High correlation of the data obtained by means of amperometric lactate biosensor and a standard method of an ionic chromatography has been shown. The developed biosensor could be applied in the food industry for the control and optimization of the wine fermentation process, and quality control of wine.