ANTIOXIDANT BEVERAGES AS A METHOD OF THE FIGHT AGAINST OXIDATIVE STRESS
The article presents a characterization of endogenous and exogenous sources of free radicals, and also shows the classification of antioxidants according to the mechanism of action. In addition, the antioxidant activity and other indicators of quality, such as acidity, reducing sugars and solids content, in natural and reduced juice and fruit syrups were analyzed. The study of antioxidant activity of various kinds of tea and other tea drinks prescription components, such as syrups and juices was recovered. Measurement of the antioxidant activity was carried out by stripping voltammetry, which is a relatively simple method of electrochemical analysis with low detection limits (10<sup>-9</sup>-10<sup>-10</sup> mol / dm<sup>3</sup>). The antioxidant activity was found to range from 4.128 to 3.869 mmol/l·eq in green tea and from 2.279 to 0.737 mmol/l·eq in black tea depending on the grade. The antioxidant activity of natural cherry, apple and grapefruit juices is equal to 9.740, 2.045 and 2.752 mmol/l·eq, respectively. The value of this indicator determined in «Rich» juices and nectars of the same names are respectively 7.231, 1.134 and 1.542 mmol/l·eq. The antioxidant activity of «Monin» fruit and berry syrups named cherry, apple and grapefruit, are equal to 7.321, 0.027 and 0.043 mmol/l·eq respectively. To improve the antioxidant activity of the diet the green tea should be used both crumbly and packaged. Furthermore, the efficiency of natural juice consumption in comparison with the reduced ones is proved experimentally, due to their increased antioxidant activity. The results indicate that it is necessary to revise the formulation and preparation technology of syrups with fruit raw material, since the values obtained for their antioxidant activity are practically zero. Cherry fruits and their products are the most interest so far as the natural and reconstituted juice, syrups and other products made from it possesses the highest values of the antioxidant activity.