Maceração sulfítica em vinificação de 'Alicante Bouschet' na Campanha Gaúcha

Abstract

Sulfitic maceration, a technique used only as a form of storage of must and juice, has been widely used as an alternative in the oenological industry. It is the addition of high doses of sulfur dioxide after the destemming and crushing processes (above 1000 mg.L-1 of SO2). In this way, short pre-fermentation macerations are made, and after pressing the must is stored. For further vinification or juice elaboration, this must passes through a desulphuriser (equipment with a vacuum or steam heat exchanger) by which the sulfur dioxide is withdrawn and the product can then be destined for the desired purposes. The objective of this study is to analyze the effects of sulfur dioxide through the physical-chemical analysis of wine produced with sulfite maceration in comparison to wines that did not undergo this process. The vinifications were elaborated in the experimental winery of the bachelor's degree course in oenology from Federal University of Pampa, Campus Dom Pedrito. The Vitis vinifera 'Alicante Bouschet' variety from the region of Campanha Gaúcha, Rio Grande do Sul, Brazil, was used. Three treatments were performed with 3 replicates, obtaining on average 6 liters of must for each replicate. Treatment 1, called control treatment, went through the same procedures as treatment 2, except for the dosage of 1400 mg.L-1 of sulfur dioxide added. In these two treatments, the grapes were destemmed, crushed and macerated for 2 days and before fermentation started, the must was heated to remove SO2. In the treatment 3 a traditional vinification with 5 days of maceration during the alcoholic fermentation was performed. At the end of the fermentations, the physico-chemical analyzes of the wines were carried out using Fourier transform infrared spectroscopy (FTIR) and, from the results, analyzes of variance (ANOVA) and comparisons by Tukey's test at 5% of probability were made. For the concentrations of malic acid, gluconic acid, ammonia and potassium, significant differences were obtained between treatments. The color intensity of treatment 2 did not show a significant difference in relation to the treatment 3, demonstrating that with 2 days of sulphite maceration occurs the same color extraction as in a traditional 5 day maceration.