Effect of Altered Solvent Environment on the Pasting Characteristics of Pigeonpea (Cajanus cajan) and Cowpea (Vigna unguiculata) Starches

  • Mwanjala A Mwasaru Department of food Science and Technology, Jomo Kenyatta University of Agriculture and Technology, P O Box 62000, Nairobi, Kenya

Abstract

The (Brabender) pasting characteristics of pigeonpea and cowpea starches as a function of pH, sucrose concentration, added corn oil and legume protein isolates were investigated. Adjusting pH to 2 resulted in complete loss in paste consistency at 97°C for both starches. For pigeonpea starch, incorporation of corn oil and 10% sucrose resulted in significant (p<0.05) increase in the initial pasting temperature. Separate additions of corn oil and protein isolates caused significant reductions (p<0.05) in the paste consistency of pigeonpea starch at 97° and 50°C, respectively. For cowpea starch, adjusting pH to 2, and the addition of protein and sucrose caused significant (p<0.05) increases in the initial pasting temperature. The paste consistency of cowpea starch at 97°C was decreased and increased significantly (p<0.05) by adjusting the pH to 2 and 4, respectively. Incorporation of corn oil caused a significant increase in the consistency of cowpea starch at 50°C whereas adjusting pH to 4 and addition of protein resulted in significant (p<0.05) reductions. It was concluded that the pasting properties of the legume starches were influenced by both the botanical sources of the starches and altered solvent environment.

J. agric. Sci. technol. Vol.5(1) 2003:80-90
Published
2004-11-15
Section
Articles

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eISSN: 1561-7645