THE STUDY OF SELECTED COMPONENTS OF GRAPE AND FRUIT WINES

This study aimed to compare chemical properties, in terms of the content of volatile substances, antioxidant compounds, and antioxidant activity (AOA), in samples of fruit and grape wines. For this purpose, the following types of wine were selected, namely fruit wines (apple, strawberry, and elderberry) and grape wines (Müller-Thurgau, St. Lawrence Rosé, and Blue Portugal). Basic analyses of fruit and grape wines were conducted by using the ALPHA method and volatile substances in wines were determined by the GS/MC method. The antioxidant content and AOA were estimated by spectrophotometry, using two types of DPPH method. The results of the experiment showed that the highest values of antioxidant compounds (anthocyanins and flavanols) were found in the samples of Blue Portugal wine and elderberry wine. Significant differences were determined among the wines in antioxidant content, which may have been influenced by the production technology. The results showed that the alcohol content of the wines ranged from 10.99% to 19.49% vol. The highest alcohol content was measured in the elderberry wine samples and the lowest in those of the apple wine. The strawberry wine had the highest titratable acid content, which corresponded to a pH of 3.38. The lowest content was measured in the apple wine samples. Due to the higher acid content of the strawberry wine, a higher residual sugar level of 46.9 g.L-1 was obtained. We noted that the red fruit wines contained a higher proportion of valuable bioactive substances than white grape wines. Wines with superior sensory properties did not contain higher levels of antioxidants or higher AOA. The research results can provide a helpful reference for the widespread use of grape and fruit wines in medical, nutritional, and other fields.