Section 1 Solar Drying

**Chapter 1**

**Abstract**

**1. Introduction**

**3**

Technologies

*and Gerardo A. Mejia Pérez*

colorimetric study, computational analysis

successfully to cure or relieve diseases [2].

recognized as safe and effective [3].

Kinetics of Drying Medicinal

*Margarita Castillo Téllez, Beatriz Castillo Téllez,*

Plants by Hybridization of Solar

*José Andrés Alanís Navarro, Juan Carlos Ovando Sierra*

**Keywords:** medicinal plants, indirect solar drying, mathematical model,

The knowledge of medicinal plants extends to any part of the world where man has traditionally needed them to cure his illnesses. Thus, a mixture of magic and religion, combined with necessity and chance, trial and error, the passage of different cultures has created a whole knowledge of plant remedies that has been the basis of modern medicine [1]. However, many studies have been performed to test if they are truly effective and, as a result of these studies, the therapeutic use of many medicinal plants as substitutes for pharmaceutical medicines has been applied

According to the WHO, herbal medicines include herbs, herbal material, preparations, and herbal products, which contain as active ingredients parts of plants or other plant materials, and their use is well established and widely

It has been shown in studies and reviews that medicinal plants have various

properties that cure, for example, anticancer and antiviral activities [4],

Historically, medicinal plants have always had an important place in medicine. Medicinal plants processing represents a great challenge, due to their compounds sensitive to the environmental conditions that surround and degrade them. Mostly of these plants require to be dry to preserve its safety and medicinal properties; therefore, for proper drying, it is necessary to use sustainable devices that protect the desirable characteristics of plants from direct radiation. In this work, the kinetics of dehydration of three medicinal plants are presented in an indirect solar dryer. In addition, the experimental results were adjusted to nine mostly used models, to estimate the drying conditions required to achieve a desired final moisture content. Modified Page and Page were the models with better fit to experimental results. Furthermore, a computational simulation of temperature evolution and distribution inside the dryer is presented. These results agree with those obtained experimentally.

#### **Chapter 1**
