M.Tech. / Sorghum (Sorghum bicolour (L) Moench) and millets are drought resistant cereals (Kent and Evers, 1994) that can grow in areas with poor soils and inconsistent rainfall (Dendy, 1995) where other crops fail. They serve as staple food for many people in tropical sub- Saharan Africa and Asia (Klopfenstein and Hoseney, 1995). Traditionally, bread is made from wheat, which is a temperate cereal not able to grow well in these tropical regions. Leavened bread is seldom made from anything other than wheat (Alais and Linden, 1991) and this is because of the unique visco-elastic property of wheat flour (Hoseney, 1994). Unfortunately in tropical regions such as South Africa wheat is imported at a premium price. The aim of this study was to produce a wheat-finger millet composite flour which is suitable for bread making. Finger millet grain (FMV6) was milled with a laboratory hammer mill fitted with a 0.8 mm screen. The following wheat-finger millet composite doughs were made using standard bread making methods, 0:100 (Control); 90:10; 80:20; 70:30, respectively. Selected quality attributes of the composite dough and the bread thereof were analysed using standard methods. The formulation with 10% finger millet showed better results than other formulations. One formulation (80:20) was selected for improvement which included mixing ingredients at elevated temperatures (50°C and 93°C) and addition of 0.002% of a lipase enzyme, lipopan F; 0.3% vital wheat gluten and a combination of 0.002% lipopan F and 0.3% gluten. All formulations (including the basic formulation) contained Fungamyl Super MA (enzyme combination which contained fungal a-amylase and a xylanase). As the mixing temperatures were elevated, loaf volume decreased but when the industrial baking enzymes were introduced there was an improvement in peak time, dough stability and loaf volume. Image analysis showed that there was an improvement in crumb structure and bubble size distribution after the application of enzyme lipopan F. The crumb colour was lighter and softer when a combination of enzyme lipopan F and vital wheat gluten was applied. The bread made from formulation 80:20 with addition of a combination of enzyme lipopan F and vital wheat gluten (WFM2GL) was more acceptable than other formulations except the control bread. The bread had a high score in taste, crust appearance and mouth feel. The results suggest that there is a potential for producing a composite bread by substituting wheat flour with finger millet flour (up to 20%); mixing at 25°C with application of a combination of a lipase and vital wheat gluten. However, more work is needed to improve the quality of the bread to a greater extent.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:9085 |
| Date | 13 August 2012 |
| Creators | Beswa, Daniso |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
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