## 3 Results and Discussion
### Oenological Parameters  
Table 1 shows the values of the parameters quantified in all the wines obtained. Only the absorbances at 280 nm and 420 nm, total SO\({}_{2}\), residual sugars, and YAN showed three homogeneous groups at the \(p\leq\) 0.05 significance level. In addition, this last parameter was the only one dependent on the additive tested at the \(p\leq\) 0.01 level, according to the ANOVA performed. The values of pH, titratable acid, volatile acid, ethanol, and lactic acid did not show statistically significant differences among all four wines, which had a pH of 3.25, a titratable and volatile acidity of 6 and 0.45 g L\({}^{-1}\) respectively, and an ethanol content of 13.7% (\(v/v\)).  
The malic acid content of the wines showed two HGs, the differences being due to the action of the yeast. Fermentations carried out with AGGLO and AGGLO + Act resulted in higher contents of this acid, reaching contents 260 mg L\({}^{-1}\) higher than those of WY wines. The malic acid content in white wines is an interesting feature in order to control and preserve their acidity, especially in the context of climate change [32]. However, its excessive accumulation can lead to an overly sour taste, especially in red wines, so a reduction in its content through malolactic fermentation is always recommended, which helps to produce softer, less aggressive red wines from a sensory point of view [33]. The absorbance values at 420 and 520 nm were significantly dependent only on the yeast, while the absorbance at 280 nm (TPI) decreased significantly in the wines obtained with the addition of the ONC-rich additive tested. Thus, wines obtained with the use of additives containing mannoproteins may have a lower color intensity than those obtained without the use of additives containing mannoproteins [31]. One of the proposed reasons is an increase in polyphenol precipitation due to the formation of additional mannoprotein-polyphenol colloidal complexes [34; 35]. It has also been shown that yeast cells and yeast walls can adsorb browning and phenolic compounds in white wines [31]. Furthermore, the ascorbic acid content of the additive studied also contributes to this effect due to its antioxidant activity. This results in a lower tendency of wines to browning compared to those not treated with these additives [35]. By contrast, total SO\({}_{2}\) was affected by both factors studied. Thus, AGGLO wines show lower levels of this compound than WY. This decrease is of great interest because the need to diminish its use has become increasingly relevant due to growing concerns of consumer overexposure to sulfites and the health issues this raises [36]. In this context, the low amount of SO\({}_{2}\) added in our experiments does not compromise the normal evolution of yeast development, in agreement with the results of other authors [37]. YAN is influenced only by the tested additive and shows a significant difference with a \(p\)-value \(\leq 0.001\). In both WY + Act and AGGLO + Act, the final YAN levels are the highest. This is consistent with the results obtained in the fermentation kinetics of AGGLO yeast, which shows the low levels of YAN, which are associated with sluggish or stuck fermentations [31]. This behavior is not observed in spontaneous fermentation and highlights the synergistic effect between the AGGLO yeast and the ONC-rich additive.