Some Functional Properties Of Selected Ghanaian Cereals And Legumes

ABSTRACT This study was designed to examine'the functional properties of whole flours and starches of sorghum, millet, cowpea and bambara nuts from Ghana as well as Canadian wljeart. Functional properties tested on starches were the gelatinization temperature and range, and swelling and solubility patterns. The basic chemical analysis of flours determined and the functional properties tested were viscosity characteristics, gel strength and retrogradation tendency of flour gels. Gelatinization temperature and range of.starches were determined using a staining technique, and the swelling and solubility patterns were tested using a modified Leach's method. Viscosity of hot and cooled flour pastes were measured with the Brookfield Viscometer..-1 The gel strength of flours were determined with the Precision Penetrometer and retrogradation of flour gels was measured as percentage syneresis over different periods of cold storage. The findings of this study showed that all the Ghanaian starches tested gelatinized at higher temperatures and ranges than wheat starch. The trend observed for the swelling and solubility patterns of cereals were^similar to each other than between the legumes. Legumes exhibited higher Tfegree of swelling and solubility than the starches of cereals. Viscosity of flour pastes indicated that sorghum and bambara nut flours had thicker pastes. In cold storage, all flour gels showed increased strength as well as syneresis. Wheat flour gels, however, did not portray any sign of syneresis. Direct relationships were found between gelatinization characteristics and the swelling and solubility patterns of starches. There was no direct relationship between swelling and solubility of starches, and viscosity characteristics of flours from the same source. Gel strength of flours in cold storage and solubles of starch at 95°C showed a direct relationship. The functional properties of the Ghanaian flours and starches indicated a high potential for their use in the home as well as in industry.