1. Introduction
Many countries have embarked on conducting research to
clearly identify their own flora and medicinal plants from other
countries [1]. An important medicinal plant indigenous to Iran
is the Roman chamomile (Chamaemelum nobile). This plant is
antipyretic, analgesic, energizer, anti-insomnia, anti-anorexia,
and anti-enteritis, as well as a medicine for anemia, gastrointestinal
helminthes and so forth [2]. Energy consumption and dryer
efficiency are among the most important criteria for the drying
of agricultural crops and food products as well as medicinal plants
[3,4]. Therefore, it is essential to apply economical and high-quality
drying practices for such materials, especially medicinal plants
which are sensitive products.
Challenges to the direct use of sunlight for drying purposes have
forced practitioners to replace traditional methods with industrial
dryers. However, industrial dryers are characterized as highly
energy-consuming [3,4]. Alternative methods need to be evaluated
for drying agriculture material in an efficient manner. Before
describing the experimental procedure using various drying
methods, an overview of the previous applications of these
methods is presented below.