Research Article | OPEN ACCESS
Convective and Microwave Dryings of Raffia Fruit: Modeling and Effects on Color and Hardness
1Raymond G. Elenga, 2Daniel Massamba, 3Romain R. Niece, 1Jean Goma Maniongui and 4Guy Dirras
1Laboratoire des Matériaux et Energie, Faculty of Sciences,
2Equipe Pluridisciplinaire de Recherche en Alimentation et Nutrition,
3Ecole Nationale Supérieure Polytechnique, Marien Ngouabi University, B.P. 69 Brazzaville, Congo
4Laboratoire des Sciences des Procédés et Matériaux, CNRS, Université Paris 13, Sorbonne Paris Cité, 99 av. Jean-Baptiste Clement, 93430 Villetaneuse, France
Research Journal of Applied Sciences, Engineering and Technology 2013 15:2715-2723
Received: November 08, 2012 | Accepted: January 01, 2013 | Published: August 20, 2013
Abstract
Biodiversity conservation with the improvement of living conditions requires the efficiency in use of all resources. For instance, A better exploitation of the endemic oleaginous plants of the tropical forests should mitigate the extension of the palm plantations which is one of the greatest threats of the biodiversity in this area. The raffia palm fruit contains edible oil richer in nutrients than oil palm. However, oil raffia production remains weak because entirely based on empirical methods. This study compares the effect of convective and microwave dryings on the drying kinetics, color and hardness of the raffia pulp. Moreover, four drying kinetics models and the concept of characteristic drying curve have been tested for this pulp. To this end, six drying temperatures and four power levels have been used. The results show that the drying time passes from 10 h at 40°C to 3 h at 90°C and from 30 min at 140 W to 5 min at 560 W. The results could be represented by one characteristic drying curve. Among the four models used, the Modified Khazaei model is the best. The coefficient of effective diffusivity varies from $0.63×10^{-10}$ to $3.8×10^{-10} m^2/s$ for convective drying and from $10.05×10^{-10}$ to $88.5×10^{-10} m^2/s$ for microwave. The activation energy is 34±2 KJ/mol. It is found that convective drying degrades the color and increases the hardness of the pulp more than microwave drying.
Keywords:
Color, convective drying, microwave drying, modeling, raffia fruit, hardness,
Competing interests
The authors have no competing interests.
Open Access Policy
This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Copyright
The authors have no competing interests.
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ISSN (Online): 2040-7467
ISSN (Print): 2040-7459 |
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