Rheological and Physicochemical Properties of Honeys as a Function of Temperature, Concentration and Moisture Content
محورهای موضوعی : food microbiologyM. Ramzi 1 , M. Kashaninejad 2 , F. Salehi 3 , A. R. Sadeghi Mahoonak 4 , M. A. Razavi 5
1 - M. Sc. Student of the Department of Food Science, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
2 - Professor of the Department of Food Science, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
3 - Assistant Professor of the Department of Food Science and Technology, Bu-Ali Sina University, Hamedan, Iran.
4 - Associate Professor of the Department of Food Science, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
5 - Professor of the Ferdowsi University of Mashad, Mashhad, Iran.
کلید واژه:
چکیده مقاله :
In this study the rheological and physicochemical properties of four types of honeys, two poly floral (Mountain, Forest) and two mono floral (Sunflower, Ivy), were investigated. Rheological characteristics of honeys were evaluated at different temperatures (10, 15, 20, 25 and 30ºC). All the honeys exhibited Newtonian behavior for shear rate in the range of 1.045-41.8 s-1. The viscosity of samples varied between 1.70 and 270.48 Pa.s according to the kind of honey and the temperature of measurement. The temperature dependence of viscosity was described using the Arrhenius and the VogelTaummanFulcher (VTF) equations. The values of flow activation energy varied between 89.716 and 112.189 kJ/mol. Two models (Power Law and Exponential models) were also investigated to describe the concentration dependence of viscosity. The samples were found to be different from each other in moisture content, ºBrix, pH, ash, conductivity, free acidity, diastase activity, hydroxymethylfurfural content and sugar content values. The water content of honey samples was between 15.2519.92 g/100 g.
