Food Science and Technology Department
Date of this Version
Sorghum is an ancient crop grown almost everywhere in the world and used for different purposes. In the U.S, and other developed countries, sorghum is used largely for animal feeding. In developing countries, especially in Africa and Asia, it is used primarily as human food.
Sorghum is a dependable food crop in Tanzania and its production and use ranks second after maize. Different traditional methods including malting and fermentation have been used in addition to decorticating and milling to process sorghum for the purpose of providing diverse materials. However, sorghum has major drawbacks of poor starch and protein digestibilities that undermine its nutritional value. Thus sorghum has been underutilized compared to maize, wheat or rice. Therefore, a study was undertaken to determine if malting and fermentation pretreatments can affect the digestion of starch and protein in sorghum flour. The specific purpose of the study was to investigate effects of malting and fermentation on food-grade Macia and red tannin containing sorghum flour composition and functionality.
Flour samples (regular (Rg), malted (mal), fermented (fe), and malted and fermented (malfe)) from both varieties were prepared using malting, milling and fermenting procedures.
Levels of reducing sugars, soluble protein, free amino acids; pH and titratable acidity were determined for the flour samples. Textural profile analysis for hardness, and springiness, and surface color and relative oil uptake measurements were performed for fried buns.
Results indicated that malting and fermentation pretreatments had a significant effect (p < 0.05) on the amounts and levels of reducing sugars, soluble proteins and free amino acids, pH and titratable acidity levels but had no effects on the textural properties of the buns or on their color and oil uptake.
Sorghum variety had no effect (p >0.05) on the amounts and levels of reducing sugars, soluble proteins and free amino acids, oil uptake, pH and titratable acidity levels but had a significant effect on the surface color of the buns.
A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Food Science and Technology, Under the Supervision of Professor Curtis L.Weller. Lincoln, Nebraska: May 2011
Copyright 2011 Onesmo Mella