Secagem da Mentha piperita em leito fixo utilizando diferentes temperaturas e velocidades de ar.

Abstract

The species Mentha piperita, popularly known as peppermint as well as being a medicinal plant, can be used to obtain flavoring, tea infusions and spices for pharmaceutical, food and cosmetics use. Thus, drying process is necessary to increase the shelf life of the product and facilitate its transport, handling and storage. Due to the aimed good mint quality, it is necessary to study the pre-and post-harvest. The objective of this study was the evaluation of drying the curves of drying mint, by mathematical modeling, in the range of 30 to 70 °C with temperature variation of the drying air velocity of 0.3 and 0.5 m.s-1 and quality analysis of the obtained product. To carry out the drying of leaves, we used a fixed bed dryer at a laboratory scale, which has a fan for air movement and a heating system. There were two analysis regarding the quality, essential oil yield and analysis of color. The results showed that the model Midilli is the one that best fits to the experimental data. The temperature has some influence on the drying process, but the speed had no effect on the analysis of essential oil yield nor on the color of the leaves. The temperature at 50 °C proved to be most suitable for drying of the species, because it presented the highest yield of essential oil and preservation of the green color.