Secagem em camada de espuma (foam-mat drying) das folhas de arruda (Ruta graveolens L.)

Abstract

With the high prices of industrialized medicines, the use of medicinal plant-based products for the cure and prevention of diseases by the population reaches approximately 82% in Brazil and the demand for medicinal properties of plants has been growing progressively every day. Ruta Graveolens L. which is popularly known as Arruda, is an aromatic medicinal plant that has several active groups and has been studied all over the world for having numerous proven herbal and medicinal activities. However, the useful life of leaves is very short after harvesting, and one of the ways of conservation is drying, and using one of the drying methods foam-mat drying (drying in foam layer), the harvested leaves are obtained. in powder form, being a simple and low cost alternative. Preliminary tests were carried out to determine the sparkling wine used and the number of leaves necessary for the formation of foam, physical characteristics of the foam obtained from the rue leaf: stability, density, capacity for incorporating air, percentage of expansion and moisture content; in addition to the study of drying kinetics and physical characterizations of the obtained powder: determination of theoretical yield, water activity, hydrogen potential, total titratable acidity, moisture content, ascorbic acid, total lipids and total chlorophylls and carotenoids . The drying was carried out according to the levels defined in a complete factorial experimental design 2³ + 3 central points, in which the input variables were: temperature (50, 60 and 70 ° C), concentration of emulsifier (2, 4 and 6 %) and stirring time (3, 5 and 7 min). With results obtained where the concentration of sparkling wine and the stirring time were the variables that most significantly affected the foam characteristics and temperature was the only variable that influenced the drying time. All experiments presented a typical drying curve, represented by a period of constant rate and a decreasing rate. In the physico-chemical characterizations of the rue powder, mean pH values of 6.42, water activity (aw) of 0.3815, theoretical yield of 6.4236%, total titratable acidity of 0.2505g of citric acid were observed / 100g, moisture content of 16.39%, lipids of 13.56%, chlorophyll at 0.95645 g / mg, chlorophyll b 0.54805 g / mg, total chlorophylls at 1.4025 g / mg and total carotenoids of 0.13855 g / mg. The drying process of the foam of the rue leaves by the foam layer method was satisfactory in terms of the parameters evaluated.