Estudo cinético da produção de vinho do fruto da palma forrageira (Opuntia ficus-indica Mill).

Abstract

Due to the fact that the food demand in Brazil is growing mainly in the areas of Northeast, where there is a shortage and the malnutrition, it is very important to make a search of alternatives, which can minimize this serious regional and socioeconomic problem. The use of such studies has fundamental importance for the developing countries. The use of renewable raw materials and their products of larger shelf time are needed to be found out. The Pear Cactus (palma forrageira ou ficus-lndian Opuntia Mill) and its fruit (Indian Fig) are practically used in the bovine feeding in Brazil. The Indian Fig fruit is rich in vitamins A and C, calcium and phosphorous. It possesses high nutrition values and a calorific power. The total amount of free amino acids is greater than the average found in other fruits. In fact, this value is only found in the citric fruits and in the grape. Therefore in this research a study of the best form of using a raw material which is least used in Brazil but is abundant in the semiarid area of the Brazilian North-east (Caatinga) has been made. In this study the kinetics of the alcoholic fermentation for the production of two types of wine was performed. The methodology used consisted of the initial elaboration of a 22 factorial planning. The two types of wine production studied were the wine of the integral fruit and the wine of the pulp of the fruit. In the first case seven experiments where three being at the central point and in the second case eleven experiments with eight being different and three at the central point were made. In the case of fruit pulp wine, a star configuration factorial planning was also needed to be performed. In both types of wine, effects of the initial °Brix concentration and of the yeast concentration were verified. A batch polythene bioreactor of 10L capacity with magnetic agitation was used. First the juice of the clarified fruit and the inoculums (bakery yeast), at the temperature of 30 °C, were added to the bioreactor. The initial concentrations of °Brix and yeast concentrations were determined in agreement with the factorial planning for the integral fruit and of the pulp wines respectively. Afterwards, as the alcoholic fermentation process started, the decline of the limiting substratum sucrose, the production of cells, the product ethanol, the pH and the total acidity were analyzed at regular time intervals. At the end of the process the solution was filtered, bottled, pasteurized and stored. In the production of the wine of the fruit of the Pear Cactus, the juice presented a variation of alcoholic concentration from 3.3 to 5.3 °GL; the total acidity from 0.25 to 1.02g/1Q0mL and the pH from 3.1 to 4.65 for the wine of the integral fruit. For the wine of Pear Cactus fruit pulp the variations were: alcoholic concentration from 3.62 to 5,32°GL; the total acidity from 0.23 to 0.91g/1Q0ml_ and the pH from 2.86 to 4.8 for. The production of alcohol was satisfactory according to the standards required by the Brazilian legislation. The maximum yield and productivity were of 88% and 5.9 g/L.h for the wine of the integral fruit and 95% and 3.6 g/L.h for the pulp wine. This study showed that the production of the wine under the two aspects has technical viability.