THIN LAYER DRYING OF NILE TILAPIA FINGERLINGS USING MECHANICAL DRYER

Basiouny, Mohamed A.

doi:10.21608/mjae.2014.99631

THIN LAYER DRYING OF NILE TILAPIA FINGERLINGS USING MECHANICAL DRYER

Document Type : Original Article

Author

Mohamed A. Basiouny

Senior researcher in Agric. Eng. Res. Inst. (AEnRI), ARC, Giza, Egypt.

10.21608/mjae.2014.99631

Abstract

In this study, the drying experiments were conducted on fresh fingerlings of Nile tilapia, which does not benefit the consumers (non-marketed and juvenile fish), for production of the fishmeal to be used as an ingredient in feedstuffs in the aquaculture, dairy, and poultry industries. The thin layer drying behaviour of Nile tilapia fingerlings was experimentally investigated in a mechanical dryer and the mathematical modeling by using two thin layer drying models (simple and modified simple exponential models). The butane-gas was used as heat energy source for the dryer. The impact of the drying air temperature (50, 60, 70 and 80^oC) and hot air velocity (0.5, 1.0 and 1.5m/s) on the fish moisture losses against drying time has been studied. Drying rate, moisture ratio, cost estimation and microbial assays of the drying process were also considered. The obtained data showed that, the shortest drying time of the fish was recorded at 140min with 80^oC drying air temperature and 1.5m/s air velocity. While, the longest drying time was recorded at 280min with 50^oC and 0.5m/s treatments. Tilapia moisture content decreased from an initial level of about 84.56%(d.b.) to range between 9.18 and 11.86%(d.b.) at the end drying process depending on the drying conditions. Moreover, drying rate was increased with the increase of drying air temperature and air velocity. Between the two tested models, the modified simple exponential model was found to be the most suitable for describing the drying behavior of the fish. The effects of drying air temperature and velocity on the drying constant and coefficient were also shown. On the other hands, the calculated operation cost of the dryer approaches about 2.88LE/kg of dried whole fish. Also, the final product had a microbial count below allowed level.

References

Abila, R. O. (2003). Food Safety in Food Security and Food Trade: Case Study: Kenyan Fish Exports. 2020 Vision for Food, Agriculture and Environment. International Food Policy Research Institute, Washington, DC, USA.

Akpinar, E.; Y. Bicer and F. Cetinkaya (2006). Modeling of thin layer drying of parsley leaves in convection drier and under open sun. J. of food Eng., 75: 308-315.

AOAC (2005). Official Methods of Analysis. AOAC., International, Maryland, USA.

APHA, American public health association (2001). Compendium of methods for the microbiological examination of foods. Washington DC., 4: 1219.

Bala, B. K. and M. R. A. Mondol (2001). Experimental investigation on solar drying of fish using solar tunnel dryer. Drying Technol., 19(2): 1-10.

Bellagha, S.; A. Sahli; A. Glenza and N. Kechaou (2005). Isohalic sorption isotherm of Sardine (Sardinella aurita): experimental determination and modeling. J. of Food Eng., 68: 105-111.

Bellagha, S.; E. Amami; A. Farhat and N. Kechaou (2002). Drying kinetics and characteristic drying curve of lightly salted Sardine (Sardinella aurita). Drying Technol., 20(7): 1527-1538.

Doungporn, S.; N. Poomsa-ad and L. Wiset (2012). Drying equations of Thai Hom Mali paddy by using hot air, carbon dioxide and nitrogen gases as drying media. Food Bioprod. Process., 90:187-198.

Duan, Z. H.; L. N. Jiang; J. L. Wang; X. Y. Yu and T. Wang (2011). Drying and quality characteristics of tilapia fish fillets dried with hot air-microwave heating. Food and Bioprod. processing. 89: 472-476.

Duan, Z. H.; M. H. Yi and Z. G. Wang (2005). Processing technique of tilapia. Fish Sci Technol. Infor., 32(6): 250-252.

Duan, Z. H.; M. Zhang and J. Tang (2004). Thin layer hot-air drying of bighead carp. Fisheries Sci., 23(3): 29-32.

Elmesery, H. S. (2008). Development and evaluation of mechanical dryer for drying figs. Unpublished Ph.D. Thesis, Department of Agric. Eng., Faculty of Agriculture, Kafrelsheikh University, Egypt.

FAO (1986). The production of fish meal and oil. Fisheries and aquaculture department. Food and Agric. organization of the united nations. FAO fisheries technical paper, 142-163.

Fatouh, M; M. Metwally; A. Helali and M. Shedid (2006). Herbs drying using a heat pump dryer. Energy Conversion and Management. 47: 26-29, 43.

Henderson, S and S. Pabis (1961). Grain drying theory. Temperature effect on drying coefficient. J. Agric. Eng. Res., 6(3): 169-174.

Hunt, D. (1983). Farm power and machinery management. 8^th Ed. Iowa State Univ. Press, Ames., USA, 59-76.

Jain, D. (2006). Determination of convective heat and mass transfer coefficients for solar drying of fish. Biosyst. Eng., 94(3): 429–435.

Jain, D. and P. B. Pathare (2007). Study the drying kinetics of open sun drying of fish, study the drying kinetics of open sun drying of fish. J. Food Eng., 78: 1315–1319.

Lagunas, S. M. C.; N. X. Zeng; T. K. Essert; T. D. Truong; C. Pina; J. S. Cullor; W. L. Smith and R. Larrain (2005). Disinfection of fishmeal with radiofrequency heating for improved quality and energy efficiency. J. of the Sci. of Food and Agric., 85: 2273–2280

Lewis, W. K. (1921). The rate of drying of solid materials. J. of Industrial Eng., 5(13): 427-433.

Li, J.; B. S. Li and W. Li (2009). Study on tilapia pickling technique. Modern Food Sci. Technol. 25 (6): 646–649.

Mary, J. Z.; D. A. Power; S. M. Miller; G. E. Wilson and J. A. Johnson (2009). Manual of Microbiological Culture Media (Difco™ and BBL™ Manual). Second Ed. USA.

Oyelese, O. A. (2006). Shelf life of tilapia fishmeal, paste and cake. J. Fish. Int., 1: 98-101.

Sobukola, O. P. and S. O. Olatunde (2011). Effect of salting techniques on salt uptake and drying kinetics of African catfish (Clarias gariepinus). Food and Bioproduct Processing, 89: 170-177.

Togrul, I. T. and D. Pehlivan (2004). Modeling of thin layer drying kinetics of some fruits under open-air sun drying process. J. of Food Eng., 65(3): 413-425.

USFDA, US Food Drug Adminstration (1998). Bacteriological Analytical Manuals. 8^th Edition, Revision A, AOAC International, Valsan AP, Gaithersburg MD, Nambiar,VN, Damle SD, Garg DK, Iyer SS (1985). In: Harvest and Post-harvest Technology of fish. Quality of dry nonpenarid of Bombay markets. 661-664.

Watanabe, W. O.; T. M. Losordo, and K. Fitzsimmons (2002). Tilapia production systems in the Americas, Technological advances, trends, and challenges. Rev Fish Sci., 10(3): 465-498.