Drying characteristics and quality evaluation of dehydrated catfish (Clarias gariepinus)

Abstract

Purpose

Fresh catfish (Clarias gariepinus) is highly perishable. This paper aims to investigate the drying characteristics and quality of body-mass dehydrated catfish to determine the effective dehydration parameters for preservation.

Design/methodology/approach

Brine concentration (3-9 per cent), brining time (30-90 min) and drying temperature (90-130°C) interacted using the response surface methodology. Preliminary experiments were conducted to select treatments. Moisture content and ratio and drying rate were determined and fitted into five thin-layer drying models; the goodness of fit was evaluated by average grade ranking of the regression parameters. Proximate compositions and microbial load of dehydrated catfish were determined using standard methods.

Findings

Treatments with 110°C gave initial higher drying rate (0.034-0.043 kg H₂O/kg solid/h) and shorter drying time (20-21 h). Drying occurred at two falling rate periods. Midilli model ranked first in fitting the drying data. It explained up to 99.6-99.7 per cent of the total variations in the independent variables with low values of error terms; RMSE was 0.02131-0.01794 and χ² was 0.00037-0.00043, indicating good predictive quality. Processing parameters positively and significantly (p < 0.05) influenced the proximate compositions of dehydrated catfish. Treatment: 6 per cent brine, 90 min and 110°C presented the most effective dehydration parameters for quality preservation of body-mass catfish.

Practical implications

The dehydration technique used in this study could enhance nutritive quality and storage stability of body-mass dehydrated catfish that could serve as a useful and convenient tool for commercial application.

Social implications

Hygienically processed dehydrated catfish of good quality could be used as a source of nutrients to ameliorate malnutrition and reduce post-harvest losses of catfish.

Originality/value

The effective processing parameters established is an important step to harness the high nutrients and economic values embedded in catfish.

Citation

Otolowo, D.T., Olapade, A.A., Oladele, S.O. and Egbuna, F. (2017), "Drying characteristics and quality evaluation of dehydrated catfish (Clarias gariepinus)", Nutrition & Food Science, Vol. 47 No. 6, pp. 765-779. https://doi.org/10.1108/NFS-12-2016-0192