Aplicação de quitosana em vinho tinto cabernet sauvignon da campanha gaúcha

Abstract

The main objective of this work was to evaluate the potential of chitosan as an alternative product to SO2 in the microbiological stabilization of Cabernet Sauvignon red wine of the Gaucho Campaign and its effect on the physicochemical and sensorial characteristics of the same. Chitosan is a non-toxic polymer that has wide use in the food and beverage industry and is sold commercially as an input to avoid Brettanomyces bruxelensis. In addition, chitosan can also serve as a clarifier, helping to stabilize the wines. SO2, in turn, is a widely popular input, but can pose many health risks. Therefore, it is of general interest to decrease their doses. Due to the lack of research on the potential of microbiological stabilization of chitosan in wines, the present work seeks to evaluate the effects of its use in two stages in the winemaking process, first in destemming and grinding of the grape, and after malolactic fermentation with independent applications or in conjunction with SO2. Five different treatments were tested with three replicates each. They were: Treatment 1 = 75 mg.L-1 of SO₂ in the destemming and crushing of the grape + 75 mg.L-1 of SO₂ after the malolactic fermentation; Treatment 2 = 50 mg.L-1 chitosan in the destemming and crushing of the grape + 50 mg.L-1 chitosan after the malolactic fermentation; Treatment 3 = 75 mg.L-1 of SO₂ in destemming and crushing of the grape + 50 mg.L-1 chitosan after the malolactic fermentation; Treatment 4 = 50 mg.L-1 of chitosan in destemming and crushing of the grape + 75 mg.L-1 of SO₂ after the malolactic fermentation; Treatment 5 = 35 mg.L-1 SO₂ + 20 mg.L-1 chitosan in the destemming and crushing of the grape + 35 mg.L-1 SO₂ + 20 mg.L-1 chitosan after the malolactic fermentation. The respective treatments were submitted to physical-chemical analyzes, to the sensorial analyzes and statistically compared. The results were interesting for the application of chitosan, since the sensorial analyzes of treatments T2 and T3 presented good results. The jelly index was higher for T4 treatments followed by T3, with 63% and 55% respectively. The volatile acidity was lower for the T1, the other treatments had the highest acidity, with the T2 having the highest value. As for the ionization index, T2 presented the highest percentage of anthocyanins contributing to color, with 38%, with T1 being the lowest value, 7.75%, both values still acceptable for a young wine. The use of chitosan presented interesting results, but it was necessary to repeat the experiment in other crops.