Content of total phenolic compounds, anthocyanins and spectral characteristics of Gamza red wines depending on the alcoholic fermentation conditions

Tatyana Yoncheva, Georgi Kostov and Hristo Spasov

Abstract: The study was focused on the influence of yeast strains, temperature and the inoculum yeast culture amount on the variation of the total phenolic substances and anthocyanins in the course of the alcoholic fermentation. It was also found the impact of these factors on the spectral characteristics of Gamza wines. Collection strains Badachoni and 24-6 of Saccharomyces cerevisiae species were used. The fermentation was carried out at 20°C, 24°C, 28°C and inoculum yeast culture ratio of 2%, 3%, 4%. The change in the concentration of the studied components was similar and reached its peak during the rapid fermentation (day 5th), thereafter started to slowly go down. As the temperature and the amount of yeast culture increased, the total phenolic compounds and anthocyanins rate went up. The optimal temperature for getting of more intensely coloured wines with a higher content of phenolic substances was 28°C. Samples of both strains fermented at 28°C/4% had more quantity of total phenols, flavonoid and non-flavonoid phenolic compounds and anthocyanins. The colour intensity ІС’ and the indicator dA%, determining the red colour brightness, corresponded to the amount of anthocyanins. The red colour involvement was the largest in the variants obtained at 28°C. The mathematical modeling and the presentation of the wines’ organoleptic parameters in the form of surfaces showed that the tasting evaluation results of the samples obtained with Badachoni strain were more homogeneous, with more clearly defined zones of maximum compared to those of 24-6 strain.

Keywords: alcoholic fermentation; anthocyanins; neural networks; organoleptic profile; phenolic compounds; Saccharomyces cerevisiae; spectral characteristics; wine

Date published: 2023-02-24