Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 - 5902]
Volume 13: 703 - 706. Published January 5, 2009.
Evaluation of physicochemical and rheological characteristics of soybean fortified yam flour
Jimoh KO.* and Olatidoye OP.**
*Department of Food Science and Technology, The Polytechnic Ibadan, Nigeria; ** Department of Food Science and Technology, Igbinedion University, Okada, Nigeria.
ABSTRACT
Objectives: To evaluate the effect of soy flour fortification on the physicochemical and rheological characteristics and acceptability of yam flour paste (local name: amala).
Methodology and results: Yam flour was fortified with soybean flour at 10, 20 and 30% (w/w) with the aim of producing a more nutritionally balanced product (amala). The protein content of the resulting flour increased significantly from 3.16 to 18.21%, with a corresponding decrease in the carbohydrate content from 80.6 to 64.2%, swelling power (9.6 to 6.8%) and brown index (73.1 to 65.6), as proportion of soy flour in the mix increases. Pasting characteristic (peak viscosity, final viscosity and holding strength) also decreased significantly as proportion of soy flour increases above 10%. The set back value and breakdown viscosity of yam flour containing zero or 10% soy flour were significantly lower than those containing 20 and 30% soy flour. Apart from producing a nutritionally balanced amala meal, 10% fortification was more stable against retrogradation and was assessed to be more acceptable in terms of key quality index (texture and colour).
Conclusion and application of findings: Apart from adding value and varieties to amala meal due to its colour and textural improvement, fortifying yam flour with soy bean flour at 10% level would also reduce the problem of food security especially among children in the sub Sahara region of Africa where malnutrition due to protein deficiency is common.
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