Chitosan in sparkling wines produced by the traditional method: influence of its presence during the \u201cPrise de Mousse\u201d.

Chitosan, a natural polysaccharide prepared from fungal origin, has been quite recently admitted in winemaking as clarifying, antimicrobic and contaminant reducing agent [1]. However, other features, such as antiradical and antibrowning activity have been recognized to this polymer [2]. Due to these latter characteristics, chitosan has been proposed as potential sulphite substitute. In the production of sparkling wines obtained following the traditional method, the second fermentation (Prise de Mousse) is a crucial step that needs to be carried out avoiding oxidation and/or sluggish or unwanted fermentations. Chitosan could have the potential to fulfils both the functions but, information about the impact of its presence during the fermentation are still notably scarce. In this work we tried to deepen such a subject by comparing the chemical and sensory characteristics of sparkling wines obtained with i) the presence of chitosan (20 g/HL) or ii) sulfure dioxide (60 mg/L), during the \u201cprise de mousse\u201d. Fixed, phenolic and volatile compounds demonstrated significant differences due to the presence of the two preservatives. Chitosan reduced the browning of wines without significantly modifying the fermentation kinetic. Sensory analysis further confirmed the differences emerged from volatile composition, highlighting that chitosan may positively impact on the final products while permitting to reduce the amount of sulfur dioxide used during winemaking