Drying of Mentha piperita leaves on a fixed bed at different temperatures and air velocities

Abstract

RESUMO -A espécie Mentha piperita, conhecida popularmente como hortelã pimenta além de ser uma planta medicinal, é utilizada nas indústrias farmacêutica, alimentícia e cosmética. Desta forma, o processo de secagem se faz necessário para aumentar o tempo de conservação e vida útil do produto facilitando seu transporte, manuseio e armazenamento. Para que os derivados do hortelã tenham qualidade, é necessário estudos sobre a pré e a pós-colheita. Objetivou-se neste estudo a avaliação de secagem, e para a obtenção das curvas foram utilizadas as temperaturas no ABSTRACT -The species Mentha piperita, popularly known as peppermint, is not only a medicinal plant but is also used in the pharmaceutical, food and cosmetic industries. Consequently, the drying process is necessary to increase shelf and product life, facilitating transport, handling and storage. For mint derivatives of quality, work into pre-and post-harvest is necessary. The aim of this study was to evaluate drying. To obtain the curves, temperatures in the range of 30 o C to 70 o C were used, with drying air velocity varying between 0.3 and 0.5 m.s -1. For drying the leaves, a laboratory-scale, fixed bed dryer was used, having a fan to move the air and a heating system. The results showed that the Midili model best fit the experimental data. The relationship of the diffusion coefficient to the drying temperature can be described by the Arrhenius equation, giving an activation energy of 68.42 KJ mol

Mathematical Modelling of Muña Leaf Drying (Minthostachys mollis) for Determination of the Diffusion Coefficient, Enthalpy, and Gibbs Free Energy

“…This phenomenon was confirmed by other researchers who studied the drying kinetics in other medicinal plants, for example, Martins et al [18] in timbo leaves; this was also performed by Silva et al [19] in genipapo, as well as Gasparin et al [20] in Mentha piperita leaves. The effect of the temperature of the drying air on the reduction of the drying time of muña leaves can be attributed to the fact that the main cause of the drying process is the difference in vapor pressure between the product and the drying air.…”

METABÓLITOS SECUNDÁRIOS E COR DE FOLHAS DE Bauhinia forficata Link e Piper aduncum L. SUBMETIDAS À SECAGEM EM LEITO FIXO E FLUIDIZADO

“…Note that the drying time was reduced in the fluidised bed system, since it has higher drying air speed (Figure 1A). These behaviours have been observed by Gasparin et al (2017) when drying Mentha piperita leaves, Silva et al (2017) when studying the drying of B. forficata leaves and Sousa et al (2015) in leaves of Ziziphus joazeiro.…”

Comparación de métodos sensoriales descriptivos: perfil flash y preguntas CATA para caracterizar infusiones de muña (Minthostachys mollis)

“…El aumento de la temperatura del aire de secado reduce considerablemente el tiempo necesario para que las hojas de muña alcancen un menor contenido de humedad, este fenómeno fue observado por Martins et al (2018) y Gasparin et al (2017) quienes estudiaron el secado hojas de timbó y menta, respectivamente. El efecto de la temperatura del aire de secado sobre la reducción del tiempo de secado de las hojas de muña, puede atribuirse al hecho de que la causa principal del proceso de secado es la diferencia de presión de vapor entre el producto y el aire de secado.…”