Comparative Impact of Saccharomycodes ludwigii Inactivation Techniques on the Physicochemical and Sensory Characteristics of Two Spanish White Wines

Despite the widespread use of yeast derivatives (YDs) in winemaking, comparative studies on the impact of different inactivation technologies remain limited, especially when applied to non-conventional yeast species. To address this, the present study evaluated the impact of Saccharomycodes ludwigii (SL#64) derivatives, a non-conventional species characterized by a high cell wall polysaccharide content, produced via Thermal Inactivation (TI), High-Pressure Processing (HPP), and Partial Lysis combined with HPP (PL + HPP), on the polysaccharide content, colloidal stability, and sensory profiles of Garnacha Blanca and Tempranillo Blanco wines. A commercial Saccharomyces cerevisiae derivative was used as a reference yeast derivative. Polysaccharide concentration and colloidal stability were monitored at 2 and 15 days post-addition. All YDs significantly increased polysaccharide levels (3–21%), primarily within the first 48 h. HPP-treated SL#64-YDs proved the most effective in enhancing protein stability, reducing heat-induced turbidity by 21% after 15 days. SDS-PAGE analysis suggested that YD-derived polysaccharides acted as protective colloids, partially maintaining pathogenesis-related (PR) proteins in solution. In contrast, no significant improvement in tartaric stability was observed across treatments. Overall sensory evaluation, including quality, balance, aroma intensity, and Flash Profile characterization, revealed that YD treatments more clearly modified the sensory profile of the aromatically neutral Garnacha Blanca wines, whereas the greater aromatic complexity of the Tempranillo Blanco matrix partially masked these effects, although prolonged contact with TI and HPP reduced aroma intensity and perceived quality. These results suggest that HPP-derived yeast derivatives could be especially suitable for short contact applications, representing a promising non-thermal strategy for tailoring functional YDs to specific wine matrices.