Novel Methods to Manipulate Autolysis in Sparkling Wine: Effects on Yeast

Sparkling wine made by the traditional method (Méthode Traditionelle) develops a distinct and desirable flavour aroma profile attributed to proteolytic processes during prolonged ageing on lees. Microwave, ultrasound addition of ?-glucanase enzymes were applied accelerate disruption Saccharomyces cerevisiae, added tirage solution for secondary fermentation in sparkling winemaking. Scanning electron microscopy flow cytometry analyses used observe describe yeast whole-cell anatomy, cell integrity structure via propidium iodide (PI) permeability after 6-, 12- 18-months post-tirage. Treatments produced features lees that from untreated control yeast. Whilst displayed budding cells (growth features) with smooth, cavitated flat external appearances; microwave treated exhibited modifications like ‘doughnut’ shapes immediately treatment (time 0). Similar ‘doughnut’-shaped ‘pitted/porous’ observed progressively older control. Flow was discriminate populations; consistent microwave, enzyme treatments, as evidenced up 4-fold increase PI signal treatment. Forward side scatter signals reflected changes size cells, all treatments applied. When interpreted alongside scanning images, bimodal populations low high intensities revealed distinctive association only at tirage, not until 12 months This work offers both rapid approach visualise alterations surfaces better understanding mechanisms lysis. or are tools could potentially initiate release compounds into wine. Further investigation impact such profiles wines through sensory evaluation is warranted.