RHEOLOGICAL PROPERTIES OF DATE JUICE CONCENTRATE (DIBS) DURING EVAPORATION PROCESS | ||||
| Misr Journal of Agricultural Engineering | ||||
| Article 18, Volume 34, Issue 1, January 2017, Page 317-330 PDF (771.09 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/mjae.2017.97116 | ||||
 View on SCiNiTO | ||||
| Authors | ||||
| Omnia E. Salama1; Manal A. Sorour1; M. M. Mostafa2; M. A. Elnono2 | ||||
| 1Food Engineering and Packaging, Department, Food Technology Research Institute, Agricultural Research Center, Giza, Egypt. | ||||
| 2Agriculture Engineering Department, Faculty of Agriculture, Ain Shams University., Egypt. | ||||
| Abstract | ||||
| Date concentrate was obtained under vacuum using rotary evaporator by heating the date extract (19%) until it reaches (70%). Samples were collected during process until the end of process The rheological properties of Date juice concentrate were studied using Brookfield Rheometer (DV III ultra) at different temperatures (30, 40, 50 and 60°C),concentrations (30, 40, 50 and 60%) and shear rates (9.3– 93 s-1). Shear rate - shear stress data indicated that all samples exhibited non-Newtonian pseudoplastic behavior.Dependence of apparent viscosity on temperature was related through the Arrhenius law. Effect of concentration on apparent viscosity was also studied and fitted well to power law. | ||||
| Keywords | ||||
| Rheological Properties; Date Juice Concentrate; Flow Behavior; Activation Energy | ||||
| References | ||||
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(1) Ibarz, A., Pagan, J., Gutierrez, J., & Vicente, M., (1989). "Rheological properties of clarified pear juice concentrates, J. of food Eng., Vol. 10, 57-63,. (2) Heldman, D. R., and Singh, R. P. (1981). food process Engineering (2nd ed.). Westport, Conn: AVI Publishing Company. (3) Rizvi, S. S. H., and Mittal, G. S. (1997). Experimental methods in food engineering. New Delhi: CBS Publisher and Distributors, pp. 35. (4) Alvardo, J. D., and Romero, C. H. (1989). Physical properties of fruits I-II. Density and viscosity of juices as functions of soluble solids contentand temperature. Latin American Applied Research, vol. 19, pp. 15-21. (5) Walker, S., and Prescott, J. (2000). The influence of solution viscosity and different viscosifying agents on apple juice flavor. Journal of Sensory Studies, vol. 15, pp. 285-307. (6) Steffe, J. F [ED.] (1996). Rheological Methods in Food Process Engineering. 2ed. Freeman Press. East Lansing, MI. USA. (7) Alpaslan, M. and M. Hayta. (2002). Rheological and sensory properties of pekmez (grape molasses)/tahin (sesame paste) blends. Journal of Food Engineering, 54 (1): 89-93. (8) Altay, F. Lokumcu and M M. AK. (2005). Effects of temperature, shear rate and constituents on rheological properties of tahin (sesame paste). Journal of the Science of Food and Agriculture, 85 (1): 105-111. (9) M.A. Sorour and M.T. Assous, (2008), "Effect of Mixing During Extraction on the Quality of Date Juice" J. of Engineering And Applied Science, Vol. 55, No.1, pp.93-108. (10) Assous, M.T.M. and Sorour, M.A., (2014). "Effect of concentration Methods on Quality of Date", TESCE, The Transactions of the Egyptian Society of Chemical Engineers, 40(3). (11) A.O.A.C. (2000). "Official methods of analysis of the association of official analytical chemists International". Published by the Association of Official Analytical Chemist’s International. Maryland 20877-2417. USA. (12) Lees, R. (1975). "Food analysis: Analytical and quality control methods for the food manufacturerand buyer". Laboratory handbook of methods of analysis, Lenoard Hill Book Publisher, London, England. (13) Ranganna, S. (1977). "Manual of Analysis of fruit and vegetable products".Tata McGraw-HillPublishing Company Limited, New Delhi. (14) Grigelmo- Miguel, et al., (1999). "Rheology of peach dietary fibre suspensions", J. of Food Eng., Vol. 39, pp 91-99. (15) Imeson, (1992). "Thickening and gelling agents to food", Edited by A. Imeson, Research and development manager, London Blackie Academic, 132. | ||||
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