African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6576

Full Length Research Paper

Drying kinetics of Aristolochia cymbifera Mart. and Zucc. leaves

  Daniel Emanuel Cabral De Oliveira1*, Osvaldo Resende2, André Luiz Montes1 and Fabiano Guimarães Silva2    
  1Agricultural Sciences, Federal Institute of Education, Science and Technology of Goiás – Rio Verde Câmpus, GO, Rodovia Sul Goiana, Km 01 - Zona Rural - CEP: 75901-97, Brazil. 2Board of Undergraduate Studies, Federal Institute of Education, Science and Technology of Goiás – Rio Verde Câmpus, GO, Rodovia Sul Goiana, Km 01 - Zona Rural - CEP: 75901-970, Brazil.  
Email: [email protected]

  •  Accepted: 13 March 2013
  •  Published: 31 March 2013

Abstract

 

Drying medicinal plant materials ensures the retention of their active ingredients. The aim of this study was to fit different mathematical models to experimental data from Aristolochia cymbifera leaves to determine and evaluate the effective diffusion coefficient and to obtain the drying process activation energy under varying air conditions. The experiment was conducted at the Federal Institute of Education, Science and Technology at the Goiás – Rio Verde Campus. Four drying replicates were performed in a fixed bed dryer with a controlled air speed of 1.0 m s-1 and drying temperatures of 28.8, 36.4 and 44.8°C. Increasing the drying air temperature from 28.8 to 36.4 or 44.8°C reduced the A. cymbifera leaf drying time from 58.13 to 13.10 and 5.00 h, respectively. The diffusion approximation model described the drying phenomenon the best. The effective diffusion coefficient increased with increasing air temperature and was described by the Arrhenius equation with activation energy of 107.29 kJ mol-1.

 

Key words: Medicinal plants, jarrinha, activation energy, effective diffusion.