Scientific Research and Essays Vol. 2 (10), 458-461, October 2007          
ISSN 1992-2248 © 2007 Academic Journals

Full Length Research Paper

Rheological properties of aqueous cashew tree gum solutions

E. Gyedu- Akoto¹, I. Oduro², F. M. Amoah¹, J. H.  Oldham², W.O. Ellis² and K. Opoku-Ameyaw¹

¹Cocoa Research Institute of Ghana Akim-Tafo, Ghana.

²Department of Biochemistry, Kwame Nkrumah University of Science and Technology, Kumasi

*Corresponding author. E-mail: akua_akoto2004@yahoo.co.uk, Tel. (+233)243329587. 

Accepted 3 October, 2007

Abstract

The rheological properties (gel and flow properties) of cashew gum (CG) collected from four cashew growing districts (Sampa, Wenchi, Bole and Jirapa) in Ghana were studied to help promote the utilization of cashew gum in the food industry. The gum was collected from trees of two age groups, those that are 10 years and below and those above 10 years. Gelation properties of CG showed that the gum gelled at a high concentration of 80% and rapidly dissolved at 80°C. Viscosities of aqueous gum solutions at concentrations of 1.0, 2.5, 5.0 and 10% were studied with measurements adopted at 25 and 70°C. Viscosity increased with concentration while an increase in temperature reduced the viscosity. The CG from mature cashew trees (above 10 years) was found to be more viscous than that from younger trees (10 years and below). However, CG from different cashew growing districts did not differ significantly. Gum produced during the rainy season was less viscous than that produced in the dry season. Viscosities of gum reduced slightly after 6 and 12 months storage. The study showed that location, maturity and storage has no significant effects on the viscosity of cashew gum.

Key words: Rheological properties, gelation properties, cashew gum, viscosities.