African Journal of
Food Science

  • Abbreviation: Afr. J. Food Sci.
  • Language: English
  • ISSN: 1996-0794
  • DOI: 10.5897/AJFS
  • Start Year: 2007
  • Published Articles: 924

Full Length Research Paper

Effects of charcoal kiln and microwave oven drying techniques on the chemical and thermal characteristics of tomato and yam slices

Chibuzo S. Nwankwo
  • Chibuzo S. Nwankwo
  • Department of Food Science and Technology Federal University of Agriculture Makurdi, Benue State, Nigeria.
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James T. Mbachiantim
  • James T. Mbachiantim
  • Department of Nutrition and Dietetics, College of Food Technology and Human Ecology, Federal University of Agriculture, Makurdi, Benue State, Nigeria.
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Victor O. Olanegan
  • Victor O. Olanegan
  • Department of Food Science and Technology Federal University of Agriculture Makurdi, Benue State, Nigeria.
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Okpomor O. Endurance
  • Okpomor O. Endurance
  • International Centre for Biotechnology (ICB) Under the Auspices of UNESCO, at the University of Nigeria, Nsukka, Enugu State, Nigeria.
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Carew E. Irene
  • Carew E. Irene
  • Department of Food Science and Technology Federal University of Agriculture Makurdi, Benue State, Nigeria.
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Chigozie F. Okoyeuzu
  • Chigozie F. Okoyeuzu
  • Department of Food Science and Technology, Faculty of Agriculture, University of Nigeria, Nsukka, Enugu State, Nigeria.
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Belay Dereje
  • Belay Dereje
  • Department Food Process Engineering, College of Engineering and Technology, Wolkite University, Ethiopia.
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Abebe Teshome
  • Abebe Teshome
  • Department of Chemical Engineering, Kombolcha Institute of Technology, Wollo University, Wollo, Ethiopia.
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  •  Received: 01 December 2021
  •  Accepted: 01 February 2022
  •  Published: 31 March 2022

Abstract

Most drying equipment required constant electricity, which is rarely available in Sub-Saharan African countries for local farmers. In order to reduce postharvest loss, it is important to develop and use alternative equipment that is cheap and does not require electricity. The aim of this study was to compare the charcoal kiln oven and microwave oven on the drying characteristics of tomato and yam slices, as well as the effects of these different drying techniques on the chemical parameters of tomato and yam slices. The experiment was laid out based on a completely randomized design. In the charcoal kiln, the final moisture content of dried tomato and yam slices was 16.20 and 5.70%, while in the microwave it was 12.25 and 6.60%. These differences were significant (p<0.05). The ash content was higher in microwave-dried tomatoes (1.35%) and kiln-dried yams (3.15%) slices. The protein and carbohydrate contents of kiln-dried tomato slices were significantly (p<0.05) higher than microwave-dried ones, but microwave-dried yam slices were significantly (p<0.05) higher than kiln-dried yam slices. The potassium and iron contents of kiln-dried yam slices were significantly (p<0.05) higher than microwave-dried samples. The heat transfer in microwave-dried tomato and yam slices was significantly (p<0.05) higher than in kiln-dried ones. The charcoal kiln oven was better at drying yam than tomato. Local farmers could benefit from charcoal kiln dryers for the drying process since they do not require power supply.

 

Key words: Drying, microwave, kiln, tomato, yam.