Qualidade físico-química e potencial antioxidante de uvas na região Norte de Mato Grosso

Abstract

There are several factors for the success of viticulture, among them are the climatic conditions associated with the choice of the training system. Due to the growing interest in grape cultivation in tropical regions, the technical evaluation of three cultivars widely cultivated in Brazil and in the region of Itaúba/MT was carried out. The experimental field design was DIC with 3 cultivars ('Bordô', 'Niágara Rosada' and 'Isabel Precoce') and 6 replications. Containing 3 rows, each with 6 plants, of the same cultivar. The following parameters were evaluated: total soluble solids content (TSS, º BRIX), pH, total titratable acidity (TTA), phenolic compounds, antioxidant potential by the free radical scavenging method 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2' azinobis – (3-ethylbenzthiazoline6-sulfonic acid) (ABTS), reducing sugars, anthocyanins and flavonoids. The results showed that in relation to antioxidant potential (by DPPH method), total phenolic compounds, anthocyanin and flavonoid content, the cultivar 'Bordô' had a significant difference in relation to the cultivars 'Niágara Rosada' and 'Isabel Precoce' with averages of 260.17 μmol trolox. G-1; 70.89 mg. 100g-1; 12.83 mg.100g-1; and 7.61 mg.100g-1, respectively. 'Isabel Precoce' was higher than the others in TSS content, with 19.67 ºBRIX. The cultivar 'Niagara Rosada' was superior to the others in the pH range (3.81) and showed a significant difference in the TA variable. For the results of ABTS and reducing sugar, there were no differences between the cultivars, whose values were 9.94 μmol.100g-1 and 5.72mg.100g-1; 8.55 μmol.100g-1 and 5.39mg.100-1; 8.33 μmol.100g1 and 5.06mg.100g-1 for the cultivars 'Bordô', 'Isabel Precoce' and 'Niagara Rosada', respectively. Based on the results found, it is concluded that all the cultivars studied are successful when commercially exploited and that the development of cultivation and management techniques can improve the qualitative characteristics at the regional level.