Chitosan–genipin film, a sustainable methodology for wine preservation†
A novel approach is described using chitosan–genipin films as a sustainable method for wine preservation. Films prepared from fungi and from shrimp by-products showed similar mechanical and chemical properties. In addition, shrimp derived films showed no IgE positive reaction against shellfish allergenic compounds. The chitosan–genipin films were used to produce white wines without the addition of sulphur dioxide as a preservative. These wines showed lower susceptibility to browning, with organoleptic characteristics comparable to those prepared using sulphur dioxide. It is shown that the formation of iron-tartrate–chitosan complexes promotes the decrease of iron and other metal availability, minimizing oxidation reactions, as well as inhibiting microbial growth. The overall volatile character of the wines was maintained. However, the presence of chitosan–genipin films promotes the occurrence of Maillard and Strecker reactions, producing volatile compounds with positive wine aroma scents. The use of chitosan–genipin films in winemaking is an innovative, green and environmentally friendly technology that could be easily implemented at an industrial scale with no additional costs.