Processamento de plantas medicinais para obtenção de extratos secos e líquidos.

Abstract

In this study, the processing of the medicinal plants of mint (Menta x villosa Hudson) and milona (Cissampelos sympodialis EICHL) was researched for the obtaining of dry and liquid extracts, by means of convective drying. In the Northeast of Brazil, mint is largely used in folk remedies for stomach problems, anxiety, menstrual and diarrhea cramps. It is also used in the treatment of parasites, such as amoeba, giardia and trichomonas. The Cissampelos sympodialis EICHL plant, known popularly as milona, grows abundantly in humid areas of the Northeast, being considered na endemic species of Brazil. From the therapeutic point of view, the leaves are used in the treatment of hypertension, asthma, bronchitis, among other inflammatory diseases. Desorption isotherms were investigated in the study, using Novasina equipment and the drying kinetics of the fresh mint and milona leaves, as well as the quantification of flavonoids, before and after the processing, in the expectancy of the development of plant therapy products. The solid pharmaceutical forms are adequate for storage and conservation of active ingredients. However, few data are found in literature which include temperature and moisture content effects in the physical properties of these materials. In this research, desorption isotherms were studied at temperatures 30, 40 and 50 oC, adjusted by the GAD model, having demonstrated a good adjustment. The influence of temperature and drying time and type of leaf over the percentage of flavonoids, moisture content, and the content of the solids extracted from the fresh mint and milona leaves during convective drying in thin layers on a convective dryer at 1,5 m/s of air velocity and temperatures of 40, 50 and 60 oC were analyzed. The curves of the drying kinetics were adjusted by the model of Fick, considering five terms of the series, with a good adjustment of the model to the experimental data. By means of experimental planning, using a 23 matrix with duplicates and two 22 + 3 repetitions at the central point, the effect of the drying variables over the yielding of the extractible solids on the liquid extract and over the percentage of flavonoids was analyzed. The results demonstrate that convective drying of mint and milona leaves is a viable technique for future conservation of the product, aiming at its utilization in the processing of plant medicines, as well as in the improvement of the extraction of active ingredients.