Temperature Dependence of Bulk Viscosity in Edible Oils using Acoustic Spectroscopy
Sunandita Ghosh*, Melvin Holmes and Malcolm Povey
epartment of Food Science and Nutrition, University of Leeds, Leeds, UK
- *Corresponding Author:
- Sunandita Ghosh
Department of Food Science
and Nutrition, University of Leeds
E-mail: [email protected]
Received Date: May 09, 2017 Accepted Date: May 26, 2017 Published Date: June 02, 2017
Citation: Ghosh S, Holmes M, Povey M (2017) Temperature Dependence of Bulk Viscosity in Edible Oils using Acoustic Spectroscopy. J Food Process Technol 8: 676. doi: 10.4172/2157-7110.1000676
Copyright: © 2017 Ghosh S, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
When ultrasound waves are applied to a compressible Newtonian fluid, bulk viscosity plays an important parameter to cause attenuation. Ultrasound spectroscopy is an important technique to characterise and determine the physico-chemical properties of many food components because it is a non-invasive, non-destructive, easy and accurate technique. The aim of this study was to find the bulk viscosity of three brands of sunflower and extra-virgin olive oil by using the Navier’s-Stoke equation across a temperature range of 5°C to 40°C and to test the hypothesis that there is a significant difference in the value of bulk viscosity between the different brands of sunflower and olive oil used. The value of bulk viscosity was not found to be constant over the operating frequency range of 12-100 MHz, which suggested edible oils are non-Newtonian fluids. Also, no significant statistical difference of bulk viscosity values was found between different brands of the same oil (p ≥ 0.05). This shows bulk viscosity is not affected by small compositional variations. Acoustic spectroscopy is increasingly being used to characterise food materials. More studies on bulk viscosity must be employed in order to be able to utilise this technology to its full strength.