TY - JOUR
T1 - Drying Kinetics and Quality Analysis of Coriander Leaves Dried in an Indirect, Stand-Alone Solar Dryer
AU - P. W. Jayasuriya, Hemanatha
AU - Pathare, Pankaj
AU - Al-Attabi, zaher
AU - Al-Hamdani, Anfal
N1 - Funding Information:
We would like to thank Sultan Qaboos University for their financial support under the internal grant project with code: IG/AGR/SWAE/20/01.
Publisher Copyright:
© 2023 by the authors.
PY - 2023/6
Y1 - 2023/6
N2 - In this study, coriander leaves were subjected to three different drying techniques; direct sun, shade, and using an indirect solar dryer. In the developed dryer, hot air obtained from a black-body solar collector was pushed by a blower powered by a solar panel, and sent to the drying chamber with multiple trays for thin-layer drying. Experiments were conducted for summer and winter seasons, and temperature and relative humidity variations in the drying chamber were measured using a data acquisition system. Indirect solar dryer performance was evaluated and compared with sun drying and shade drying for drying kinetics, moisture diffusivity, and product quality. The drying rate curves show a linear falling rate throughout the drying process. The drying kinetic models are well-fitted with the Midilli and Kucuk thin-layer drying model. The effective moisture diffusivity of the dried coriander shows a decreasing trend, sun drying (2.63 × 10
−10 m
2/s and 1.05 × 10
−10 m
2/s) followed by solar dryer (1.31 × 10
−10 m
2/s and 6.57 × 10
−10 m
2/s), and shade drying (6.57 × 10
−11 m
2/s and 3.94 × 10
−11 m
2/s) for winter and summer seasons, respectively. Green color changes from −7.22 to −0.056, −7.22 to 3.15, and −7.22 to −0.35 in indirect solar, direct sun, and shade drying, respectively. The hue angle and Chroma are reduced by 12% and 32% in indirect solar drying, respectively. The total phenol content (TPC) value increases with drying, with summer showing the highest values (365 to 852 mg caffeic acid/100 g dry weight) while the antioxidant capacity reaches 3.41 and 3.53 in winter and summer, respectively from 0.22 μmol Trolox/g dry matter of fresh leaves.
AB - In this study, coriander leaves were subjected to three different drying techniques; direct sun, shade, and using an indirect solar dryer. In the developed dryer, hot air obtained from a black-body solar collector was pushed by a blower powered by a solar panel, and sent to the drying chamber with multiple trays for thin-layer drying. Experiments were conducted for summer and winter seasons, and temperature and relative humidity variations in the drying chamber were measured using a data acquisition system. Indirect solar dryer performance was evaluated and compared with sun drying and shade drying for drying kinetics, moisture diffusivity, and product quality. The drying rate curves show a linear falling rate throughout the drying process. The drying kinetic models are well-fitted with the Midilli and Kucuk thin-layer drying model. The effective moisture diffusivity of the dried coriander shows a decreasing trend, sun drying (2.63 × 10
−10 m
2/s and 1.05 × 10
−10 m
2/s) followed by solar dryer (1.31 × 10
−10 m
2/s and 6.57 × 10
−10 m
2/s), and shade drying (6.57 × 10
−11 m
2/s and 3.94 × 10
−11 m
2/s) for winter and summer seasons, respectively. Green color changes from −7.22 to −0.056, −7.22 to 3.15, and −7.22 to −0.35 in indirect solar, direct sun, and shade drying, respectively. The hue angle and Chroma are reduced by 12% and 32% in indirect solar drying, respectively. The total phenol content (TPC) value increases with drying, with summer showing the highest values (365 to 852 mg caffeic acid/100 g dry weight) while the antioxidant capacity reaches 3.41 and 3.53 in winter and summer, respectively from 0.22 μmol Trolox/g dry matter of fresh leaves.
KW - indirect solar drying
KW - moisture diffusivity
KW - physicochemical properties
KW - color retention
KW - drying kinetics
KW - coriander leaves
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UR - https://www.mendeley.com/catalogue/43353129-2dba-383a-9337-97d93f4c9f5a/
U2 - https://doi.org/10.3390/pr11061596
DO - https://doi.org/10.3390/pr11061596
M3 - Article
SN - 2227-9717
VL - 11
JO - Processes
JF - Processes
IS - 6
M1 - 1596
ER -