Journal of Agricultural Engineering

  • Year: 2021
  • Volume: 58
  • Issue: 3

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

  • Author:
  • Arun Kumar Attkan1, M. S. Alam2, Angam Raleng3, Y. K. Yadav4
  • Total Page Count: 12
  • Page Number: 262 to 273

1Assistant Professor, Department of Processing and Food Engineering, CCS Haryana Agricultural University, Hisar, Haryana-125004

2Senior Research Engineer, Punjab Agricultural University, Ludhiana, Punjab-141004

3Assistant Professor, College of Food Technology, Central Agricultural University, Iroishemba, Imphal, Manipur-795004.

4Professor, Department of Processing and Food Engineering, CCS Haryana Agricultural University, Hisar, Haryana-125004

*Corresponding author email address: arun.pfe@hau.ernet.in

Online published on 27 January, 2022.

Abstract

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.

Keywords

Moisture diffusivity, Mathematical model, Onion slice, Solar drying, Thin-layer drying, Low humidity air