| Autor: |
Hosainpour, A., Yamchi, A. Akhoundzadeh, Feizollahzadeh, M., Moradias, A., Nejhad, F. Khayyati |
| Předmět: |
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| Zdroj: |
Journal of Researches in Mechanics of Agricultural Machinery; Jul2024, Vol. 13 Issue 2, p29-41, 13p |
| Abstrakt: |
Nettle is one of the most important and abundant medicinal plants available seasonally. Increasing the shelf life, along with achieving the quality characteristics expected by the consumer markets, is one of the most important goals of the drying process and is one of the factors influencing processing time and quality characteristics. This research aims to find a suitable mathematical model to describe the experimental drying process, evaluate the diffusion coefficient, and obtain the activation energy to determine the thermodynamic properties during the nettle drying process. Nettle leaves with initial moisture content (2.15 ± 0.05 kg of water/kg of dry matter) in an infrared dryer at three temperatures of 40, 45, and 50 degrees Celsius and with two times of ultrasonic pretreatment with a power of 20 kW were dried for 5 and 10 minutes until reaching a constant weight. The best model to describe the nettle drying process was chosen by Midilli et al. The moisture diffusivity coefficient of nettle increased with increasing drying temperature and duration of ultrasound treatment. The activation energy during the drying of nettle was 11.45 - 40.54 kJ.mol-1. Enthalpy and entropy decreased with increasing drying temperature and duration of ultrasound pretreatment, while Gibbs free energy increased. Enthalpy value changed between 37.8-76.94 kJ.mol-1, entropy value between -178.00 and -73.18 kJ.mol-1 and Gibbs free energy value between 60.85-66.28 kJ.mol-1. These results confirm that using ultrasonic waves to dry the nettle increases the drying rate and reduces energy consumption at low drying temperatures. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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