The phenolic compounds of red wines are responsible for their color, astringency, and antioxidant properties. The fermentative yeasts might be used to modulate wines in terms of their color, aroma and probably healthy properties. In this study, six non-Saccharomyces species were tested because they might enhance the properties of red Tempranillo wines from Rioja. The results confirmed that the anthocyanins and stilbenes composition of wine can be modulated with the use of a specific fermentation starter. Metschnikowia pulcherrima, Zygosaccharomyces bailii, Candida zeylanoides, and Torulaspora delbrueckii achieved the greatest improvements of the monomeric anthocyanin composition, and the latter three yeast species achieved the best results of stilbene composition when compared to S. cerevisiae and the other non-Saccharomyces yeasts. Overall, results suggested that the use of M. pulcherrima, Z. bailii, C. zeylanoides and T. delbrueckii as fermentation starters could be of great interest to achieve wines with better color and likely healthy properties.

This study was aimed to measure the impact of the application of a bio-fungicide against Botrytis cinerea on the microbiota involved in the alcoholic fermentation (AF) of Tempranillo Rioja wines. For this purpose, a bio-fungicide composed of the biological control bacterium Bacillus subtilis QST713 was applied to the vineyard. The microbial diversity was analyzed from grape biofilm to wine. Impact on microbial diversity was measured employing indexes assessed with the software PAST 3.10 P.D. Results were compared to non-treated samples and to samples treated with a chemical fungicide mainly composed by fenhexamid. Overall, the impact of the biological-fungicide (bio-fungicide) on the microbial diversity assessed for grape biofilm and for musts was not remarkable. Neither of the tested fungicides enhanced the growth of any species or acted against the development of any microbial groups. The bio-fungicide had no significant impact on the wine microbiota whereas the chemical fungicide caused a reduction of microbial community richness and diversity. Although environmental threats might generate a detriment of the microbial species richness, in this study the tested bio-fungicide did not modify the structure of the microbial community. Indeed, some of the Bacillus applied at the grape surface, were detected at the end of the AF showing its resilience to the harsh environment of the winemaking; in contrast, its impact on wine quality during aging is yet unknown.

One of the alternatives to SO₂ as an antimicrobial is the use of bioprotection yeasts, which colonize the medium preventing the proliferation of undesirable microorganisms. In this work, the bioprotective effect of a mixed inoculum formed by Torulaspora delbrueckii/Lachancea thermotolerans during fermentation was evaluated. For this purpose, fermentations were carried out using this mixed inoculum and the populations of yeasts, lactic bacteria and acetic bacteria, and the physical–chemical parameters of the wines obtained were studied. The results were compared with those obtained in spontaneous fermentation with and without SO₂. The different fermentation strategies caused a differentiation in the yeast species present during fermentation. Regarding populations of lactic acid bacteria, results showed that the effect of the addition of the mixed inoculum was comparable to that exerted by SO₂. On the other hand, due to the high sensitivity of acetic acid bacteria to SO₂, the sulfite vinifications showed a lower population of acetic acid bacteria in the early stages of fermentation, followed by the vinifications with the mixed inoculum.

The demand for chemical-free beverages is posing a challenge to the wine industry to provide safe and healthy products with low concentrations of chemical preservatives. The development of new technologies, such as Atmospheric Pressure Cold Plasma (APCP), offers the wine industry the opportunity to contribute to this continuous improvement. The purpose of this research is to evaluate the effect of Argon APCP treatment, applied in both batch and flow systems, on Tempranillo red wine quality. Batch treatments of 100 mL were applied with two powers (60 and 90 W) at four periods (1, 3, 5, and 10 min). For flowing devices, 750 mL of wine with a flow of 1.2 and 2.4 L/min were treated at 60 and 90 W for 25 min and was sampled every 5 min. Treatments in batch resulted in wines with greater color intensity, lower tonality, and higher content in total phenolic compounds and anthocyanins, so that they were favorable for wine quality. Among the batch treatments, the one with the lowest power was the most favorable. Flow continuous treatments, despite being more appropriate to implement in wineries, neither led to significant improvements in the chromatic and phenolic wine properties nor caused wine spoilage.

The current study aims to gather information about the color-related characteristics and the monomeric phenolic composition of carbonic maceration (CM) wines. The study was conducted over two vintages, with two different grape varieties. Color-related general parameters and wine monomeric phenolic composition were determined in both free-run and press CM fractions and were compared to conventional winemaking (CW). Overall, wines made by CM had lower phenolic content and color intensity. The analysis of wine detailed phenolic composition showed that CM wines were characterized by low contents of anthocyanins and flavonols. In contrast, free-run wine obtained by CM had the greatest concentration of flavanols and hydroxycinnamic acids, probably due to the presence of stems during the fermentation. In conclusion, vinification by CM leads to important differences in wine phenolic composition and, as consequence, on wine color properties. These differences could play an important role in wine sensorial properties and wine aging potential.