Desenvolvimento da uva passa da cultivar Sweet sapphire proveniente do Vale do São Francisco - PE

Abstract

The grape cv. Sweet Sapphire® is a new hybrid variety which has as its main characteristics the black color, seedless and a larger shape than the common grape, is described as elongated tubular with a dimpled end. This new variety, cultivated in the city of Petrolina-PE, was submitted to the connective drying to obtain raisins, and this study had as objective to evaluate the potential of grape cv. Sweet Sapphire® for the production of raisins, to define the influence of drying temperature and chemical immersion pretreatment (K2CO3 and extra virgin olive oil solutions) on the final quality of the raisins, as well as determining the effects of the convective drying on the physicochemical characteristics, the content of phenolic compounds, antioxidant properties and sensorial evaluation of the obtained product. In order to define the optimal drying conditions, factorial design 24-1 was applied, having as independent variables the concentration of K2CO3 (2 to 6%), concentration of extra virgin olive oil (0.5 to 2.5%), time immersion (0.5 to 5 min) and drying temperature (45 to 60). The drying temperature was the variable that influenced significantly the moisture, water activity, soluble solids and weight of the samples, while the immersion time influenced the phenolic content. In this way, the optimal drying condition for obtaining raisins cv. Sweet Sapphire® was a temperature of 55°C, immersion time of 2.5 minutes, concentration of K2CO3 of 2% and of extra virgin olive oil of 0.5%, showing significant efficiency in reducing the total drying time. The grapes in nature and raisins were submitted to chemical composition and physico-chemical analyzes and the difference between the evaluated parameters was significant, with concentration in the content of compounds due to loss of moisture. The raisin presented low firmness; high content of phenolic compounds and total anthocyanins and, consequently, exhibited antioxidant potential, since it demonstrated efficiency in the capture of the radicals DPPH● and ABTS+• and ferric reduction (FRAP). The obtained raisins presented satisfactory sensorial quality (percentage of acceptability greater than 70%) and suitable intention of purchase by the consumers, being able to be considered a food with functional characteristics, with potential for the diversification of the commercial production, making it possible to obtain of a new competitive product on the commerce.