Title: Moisture-sorption isotherms of Bambara nut and Tiger nut

Authors: Ogbonnaya Chukwu, Emmanuel Sunday Akin Ajisegiri

Addresses: Department of Agricultural Engineering, Federal University of Technology, PMB 65 Minna, Niger State, Nigeria. ' Department of Agricultural Engineering, Federal University of Technology, PMB 65 Minna, Niger State, Nigeria

Abstract: Moisture sorption characteristics of Bambara nut [Voandzeia subcerranea (L.) thouars] and Tiger nut (Cyperus esculentus L.) were investigated at 34°C and 0.10-0.98 water activity. Both the adsorption and desorption modes for the nuts followed the Brunauer-Emmet-Teller (BET) Type 2 model. Five moisture sorption models, namely Bradley, Smith, Henderson, BET and GAB (Guggerhein-Anderson-de Boer) were tested for their predictive capability on the data. The coefficients of determination varied from 0.7825-0.9949. The Henderson and Bradley models gave the closest moisture content estimates to the experimental data under the adsorptive and desorptive modes. The monolayer moisture contents were calculated using both the GAB and BET models, providing useful data for assessing the storage stability of the nuts.

Keywords: moisture sorption; Bambara nuts; Tiger nuts; water activity; modelling; storage stability; monolayer; adsorption; desorption; moisture content; postharvest storage.

DOI: 10.1504/IJPTI.2011.041042

International Journal of Postharvest Technology and Innovation, 2011 Vol.2 No.2, pp.211 - 219

Published online: 18 Feb 2015 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article