Conservação da polpa de mangaba (Harconia speciosa Gomes) por métodos combinados

Abstract

This work aimed to evaluate the physico-chemical, microbiological and sensorial aspects of the mangaba (Hancornia speciosa) pulp preserved by combined methods during 90 days. The research was divided into three experiments: "Assessment of physico-chemical characteristics of mangaba pulp preserved by combined methods", "Evaluation of the growth of filamentous fungi and yeasts in mangaba pulp preserved by combined methods" and "Sensorial evaluation of juice produced from mangaba pulp preserved by combined methods". All experiments combined the preservation techniques of pasteurization, preservatives (potassium metabisulfite and sodium benzoate) and different storage temperatures, forming a factorial arrangement of 2 x 4 x 2 (two forms of processing, four forms of preservatives and two storage temperatures) totaling 16 treatments. In the first experiment, the pulps were evaluated for soluble solids, pH, titratable acidity, ascorbic acid, reducing sugars, non-reducing sugars and tannins. Periodic evaluations revealed that the heat treated pulps reduced vitamin C by approximately 14% during processing. By contrast, freezing stabilizes the amount of ascorbic acid of the pulps. All treatments used resembled the requirements of the Brazilian technical regulations, except those involving pulp unpasteurized and refrigerated. When examining the quantitative changes of CFU (Colony Forming Units) of filamentous fungi and yeasts, in the second experiment, it was notice that the pulps treated thermally reduced 99.35% of CFU g-1, 24 hours after fabrication and allow the retention of the pulp mangaba under refrigerated conditions (at +8 ° C) throughout their shelf life. There was no significant effect of potassium metabisulphite or sodium benzoate in the conservation. It was also found that the way of manufacturing pulp by the conventional process (without pasteurization, without additives and storage at - 18 ° C) provides quality consistent to Brazilian regulations. In the third experiment, there were evaluated sensorial parameters: appearance, aroma, color, viscosity and flavor. Mangaba juices were prepared maintaining about 13 ° Brix and served at a temperature of 10 ° C (± 2 ° C). The results of the sensorial trial were highly satisfactory and encouraging as the tasters recorded mostly notes corresponding to "like very much" according to the hedonic scale used for acceptance testing.