FORMATION OF THE QUALITY OF UNFORTIFIED WINE MATERIALS OBTAINED FROM BLACK ELDERBERRIES

Abstract

The use of local non-conventional raw materials will allow significantly enriching unfortified fruit wines with ascorbic acid and phenolic substances and make it possible to obtain products with increased biological value. The paper considers black elderberries grown in the forest steppe zone of Ukraine. It has been determined that they contain 12–13% of soluble solids, 6.9–8.1 of sugars, 0.93–1.2% of titratable acids, 33.4–53.1 mg/100 g of ascorbic acid, and 2331–3888 mg/100 g of phenolic substances. The pressing process and its dependence on the method of treating berries have been studied. It has been proved that juice extraction from black elderberries is the highest when they are pretreated with heat at 98±2°C for 3–5 minutes, with 15% of water added. Depending on the treatment method, juices retain ascorbic acid (15.8–33.4 mg/100 g) and phenolic substances (2538–3888 mg/100 g), which indicates their high biological value. Juices like these can be used to improve the biological composition of blended juices and wines. To ferment high-sugar black elderberry must, active dry yeast was used, namely the yeast races EC-1118 of the genus Saccharomyces bayanus (France) and ENSIS LE-1 or ENSIS LE-5 of the genus Saccharomyces cerevisiae (Spain). The musts were fermented for 36–62 days. The period of vigorous fermentation coincides with the period of initial fermentation and ends in 9–10 days, with accumulation of 12–14% of ethanol by volume. Unfortified wine materials obtained from black elderberries contain 22–38.3 mg/100 g of ascorbic acid (its content in wine materials is by 7.8–49.55% lower than in fresh berries) and 1750–3510 mg/100 g of phenolic substances (which is lower by 9.7–39.6%, as compared with fresh elderberries). The active acidity of black elderberry wine materials is 3.90–4.09 pH units, depending on the yeast race. A similar difference has been found for the redox potential (160–176 mV), which indicates that the wine materials from black elderberries are low-oxidised. The intensity of colour of the wine materials obtained from black elderberries (D420 + D520) varied from 3.08 to 3.20, and the colour shade from 0.88 to 0.92, which is typical of young red wines. These wine materials can be used to increase the quality and biological value of blended wines.