Características físico-químicas e atividade antioxidante de vinhos tinto seco bordô gama irradiados

Abstract

The moderate consumption of wine can offer several health benefits. The characteristics of this product are due to numerous factors, such as soil, climate, biological, agronomics and oenological aspects. The interaction between these causes of variation is called Terroir. The south part of Minas Gerais and the Serra Gaúcha are famous regions for making this beverage. The Bordô grape (Vitis labrusca) is very important in the Brazil’s economy, because many wineries utilize it as base in their products. The gamma irradiation can be utilized on wines, but it can bring improper changes on physical-chemical and antioxidants characteristics of the beverage. Given these facts, the objective of this investigation was to ascertain whether or not the gamma irradiation and the place of origin (Terroir) significantly influence on physical-chemical and antioxidants characteristics of four dry red wines types made with Bordô’s grape, pointing out that two of them are from Flores da Cunha and São Marcos cities, both located in Serra Gaúcha (RS) region and bought in local commerce, and two others from south of Minas Gerais, from the cities of Andradas, acquired commercially, and Caldas, homemade wine. After being bottled and stowed, the beverages underwent through irradiation with the following doses: 0; 1.0; 3.0 and 6.0 kGy, the cobalt 60 was the source used. Finished the irradiation, the following analysis were done: pH, titratable, fixed and volatile acidity; water activity (aW); soluble solids, total sugars and soluble solids/titratable acidity relation (ratio); color; ethanol content; relative density; minerals (potassium, calcium and sodium), dry extract, reduced dry extract and alcohol by weight/reduced dry extract relation determinations; antioxidant activity by DPPH and beta-carotene/linoleic acid methods; total phenolics and anthocyanins. The Scott-Knott’s test was used to make the statistical analysis of the obtained data. The irradiation doses promoted the reduction of titratable acidity and increased the antioxidant activity in the handmade wine, differences in detection of mineral content, more detection of total phenolics in the samples from the city of Andradas and less anthocyanins content detected in the wines from the cities of Flores da Cunha and São Marcos. The values the Brazilian Legislation and other authors establish as criterion of identity and quality of wines were not substantially altered by the irradiation.