Mathematical Modeling of Thin-Layer Solar Drying for Yarrow, Coriander and Hollyhock

Abstract

The objective of this study is to investigate the drying kinetics of Yarrow, Coriander and Hollyhock flowers. These three medicinal products were dried using a solar hybrid photovoltaic-thermal dryer. The drying process was examined at the air temperatures of 40°C, 50°C and 60°C and air velocities of 0.5, 1 and 1.5 m/s. The experimental drying data were fitted to different theoretical models to predict the drying kinetics. Nonlinear regression analysis was performed to relate the parameters of the model with the drying conditions. The performance of these models was evaluated by comparing the correlation coefficient (R 2 ), root mean square error (RMSE) and the chi-square (χ 2 ) between the observed and the predicted moisture ratios. Among all the models, the exponential two-term was found to have the best fit in this study. Also the influence of plant type, air temperature and velocity was investigated.

Convective and microwave drying of coriander leaves: Kinetics characteristics and modeling, phenolic contents, antioxidant activity, and principal component analysis

“…Previous studies on the drying processes modeling of coriander leaves have been reported, namely on the microwave (Sarimeseli, 2011), solar (Amanlou, Tavakoli Hashjin, Ghobadian, & Najafi, 2015), and convective one (Olabinjo, Asamu, & Filani, 2020). Sarimeseli (2011) investigated microwave drying by providing results on D eff , color, rehydration capacity, and modeling using six models.…”

“…On the other hand, Amanlou et al (2015) have studied solar drying, so the modeling of the kinetics obtained under various conditions of temperature and speed of the air using 13 models indicate that the exponential two-term was found to have the best fit. Olabinjo et al (2020) studied convective drying and provided results on D eff and activation energy and modeled the kinetics using 13 models.…”

Secagem solar de coentro: efeito de pré-tratamentos e do processo sobre, os aspectos físicos-químicos

“…Estas observações encontram suporte nos estudos conduzidos por Amanlou et al (2015), os estudaram a secagem solar de coentro, milefólio e malva rosa. Com relação aos pré-tratamentos utilizados, verificou-se que estes não alteraram significativamente o processo cinético de secagem, entretanto, foi constatado que o coentro sem branqueamento apresentou-se ligeiramente mais rápido, o que pode ser observado pelo maior valor na constante de secagem (k) na Tabela 1.…”

“…Diante disso, o uso da radiação para a desidratação ou secagem de alimentos é bastante viável, tendo em vista o baixo custo em termos de equipamentos e energia e por ser uma tecnologia simples de implantar em comunidade rurais e cooperativas A radiação solar foi empregada na desidratação de tomate por Latapi e Barret (2006), os quais avaliaram o emprego de pré-tratamentos sobre a qualidade do tomate desidratado, e por Amanlou et al (2015), na secagem solar de coentro, milefólio e malva-rosa.…”