Avaliação da secagem de frutos do juazeiro (ziziphus joazeiro) em estufa e secador solar.

Abstract

Caatinga is a Brazilian biome that shelters a large part of the country's biological heritage and a rich biodiversity with high potential, especially in plant products that can be used for various purposes. The fruits of juazeiro (Ziziphus joazeiro), a native tree from caatinga, are an example of that. The fruits produced are almost totally wasted, being necessary studies for the adoption of conservation methods and the nutritional characterization that may contribute to the development of one more food source, as well as add value, thus reducing the waste of this fruit. The city of Sumé, in the state of Paraíba, is a municipality that has great potential for capturing solar energy, making it possible to perform the natural drying of fruits. The objective of this work was to perform the drying of juá fruits in greenhouse and solar dryer and characterize in natura and dehydrated samples. Characterizations consisted of determination of moisture, total reducing sugars, acidity and vitamin C. In each drying, about 250 grams of juá pulp with bark were used. The initial moisture of the samples was 71%, on wet basis. The oven drying was carried out at 60° C for 20.5 hours, while in the solar dryer the drying lasted 20 hours with maximum temperature of 64ºC, at the times of higher radiation incidence. The dehydrated sample in the solar dryer had a 68% reduction in the water mass, with final humidity of 9%, on wet basis, while in the greenhouse the water mass was reduced by 60% and final humidity of 25% on a wet basis. The maximum humidity stipulated by ANVISA for dried or dehydrated vegetable products is 12%. All the mathematical models used were adjusted in a satisfactory way to the curves obtained, the model of Page presented the highest values of the coefficient of determination R2 for the two processes, so that it can be used to describe the drying behavior. This way, it is also verified that the solar dryer is a good alternative for drying of fruits and vegetables in a sustainable and more economical way than the conventional methods.