Secagem da folha de guajiru (Chrysobalanus icaco L) pelo método de camada deespuma (foam-mat drying)

Abstract

The Chrysobalanus icaco L. popularly called in Brazil by guajiru, abajerú, guajuru, among others, is a plant that has been used in traditional medicine for some years. The plant uses its different parts, from the leaves, as well as the fruit and its peel. The use of leaves is traditional in some regions of Brazil and Mexico due to its use in the form of teas. Once the leaves are collected, their useful life is short. In this way, the foam-mat drying method can be used in order to improve their conservation. Therefore, this work aimed to produce the powder of the guajiru leaf by the method of drying in a foam layer. A complete factorial experimental design 2³ + 3 central points was elaborated in order to analyze the influences of the independent variables: emulsifier concentration (3, 4 and 5%), drying temperature (50, 60 and 70 ºC) and drying time. agitation (3, 5 and 7 min) with dependent variable drying time during the process and in the characterization of the obtained powder, by means of statistical analysis. The physical and physical-chemical characterizations of the formed foam were carried out: capacity to incorporate air (over run), percentage of expansion, density, stability and humidity on a wet basis. Through the kinetics data, drying curves and curves for drying rates were presented. The results showed a typical drying curve in two periods, a long period of constant rate followed by a short period of decreasing rate. It was also found that as the drying temperature increased, there was a reduction in drying time. The variable that most influenced the drying process was temperature. A shorter drying time of 40 minutes and a maximum time of 140 minutes were observed. It was found that the highest drying rates were presented in the experiments at 70 ° C, while the lowest rates were at 50 ° C. The mathematical models that best fit the kinetics data were those of Modified Page and Page for all temperatures (50, 60 and 70 ° C). The powder samples showed water activity on average of 0.290 within the parameters required by law. In the 11 tests, the powder produced showed an average pH of 5.49. For physical-chemical characteristics (macronutrients) the powder of the guajiru leaf showed an ash content with an average of 7.20%. and presented high values of bioactive compounds. Foam layer drying is considered an effective technique for obtaining the powder from the guajiru leaf as it is able to preserve the properties present in the leaf.