Drying Kinetics of Onion (Allium cepa L.) Slices using Low-humidity Air-assisted Hybrid Solar Dryer


  • Arun Kumar Attkan Department of Processing and Food Engineering, CCS Haryana Agricultural University, Hisar, Haryana-125004 Author
  • M. S. Alam Senior Research Engineer, Punjab Agricultural University, Ludhiana, Punjab-141004 Author
  • Angam Raleng Assistant Professor, College of Food Technology, Central Agricultural University, Iroishemba, Imphal, Manipur – 795004 Author
  • Y. K. Yadav Professor, Department of Processing and Food Engineering, CCS Haryana Agricultural University, Hisar, Haryana-125004 Author




Moisture diffusivity, mathematical model, onion slice, solar drying, thin-layer drying, low humidity air


Onion slices were dried in a low-humidity air-assisted hybrid solar dryer. Drying occurred in the falling rate period, and the drying rate was attenuated with the initial moisture content of the samples. The effects of different drying air temperatures (50, 60, 70°C) and KMS pre-treatments (0.1, 0.3, 0.5%) on drying characteristics of onion slices were also studied. Eight thin layer drying mathematical models viz. Newton, Page, Modified Page, Exponential, Asymptotic, Logistic, Wang and Singh, and two-term exponential were investigated and the results were compared to their goodness of fit in terms of coefficient of correlation (r), standard error (es), and the mean square of the deviation χ2. Drying characteristics of onion slices were better delineated by Page’s regression model for hybrid solar drying with values for the coefficient of correlation (0.9962–0.9999), standard error (0.0048–0.0431), and χ² (5.98E-05 to 2.16E-03). Effective moisture diffusivity values of onion slices ranged between 1.33E-08 m2.s-1 to 2.49E-08 m2.s-1 for the drying conditions under investigation.


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Arun Kumar Attkan, M. S. Alam, Angam Raleng, & Y. K. Yadav. (2023). Drying Kinetics of Onion (Allium cepa L.) Slices using Low-humidity Air-assisted Hybrid Solar Dryer. Journal of Agricultural Engineering (India), 58(3), 262-273. https://doi.org/10.52151/jae2021581.1750