RFA: Nutritious and Health-promoting African Foods and Beverages
The development of high quality and affordable food products based on: African cereal grains, such as sorghum, maize and millets; legumes like cowpeas and marama bean; African leafy vegetables, and indigenous goat and cattle breeds is an imperative for Africa. As the continent becomes rapidly urbanized, people are consuming ever increasing quantities of foods such as bread, lager beer, dairy produce and meat. Because many of the grains needed to produce these products are having to be imported, this is economically ruinous and unsustainable as Africa population is predicted to double by 2050. Equally important is that African foods are now recognised for their unique nutritional and health-promoting potential as naturally Biofortified Foods, due to their slow digestibility, and high levels of micronutrients, and phytochemicals such as phenolics and policosinols.
Several interrelated topics are being researched, including:
• Combatting macro- and micronutrient Malnutrition with Biofortified African foods
• Combatting conditions and diseases associated with Overnutrition such as Metabolic syndrome, certain cancers and Type II diabetes with African foods
• Development of nutritious “gluten-free” breads and baked goods, based on African grains
• Development of novel malting and beverage science and technologies based on sorghum and other local grain and plant foods
• Development of novel food processing technologies to improve the utilisation of legumes
• Effect of novel food processing technologies on health-promoting properties of legume-based foods
Scientists responsible: Dr Gyebi Duodu, Prof Amanda Minnaar, Prof André Oelofse, and Prof John Taylor
RFA: Plant Biopolymer and Bioplastic Microstructures and Nanomaterials
Biopolymers based on proteins and polysaccharides such as starch, obtained from plants can be seen as natural and environmentally-friendly alternatives to synthetic plastic materials. They are also highly advantageous in that they can be edible and they are biodegradable. Importantly, they can often be produced from waste- or by-products of the food industry. The protein and starch molecules of African cereals such as sorghum and teff have unique functional properties that give them great potential for producing biopolymer microstructures and nanomaterials. Biopolymers also have the remarkably useful functional property of being able to capture and remove unpleasant aroma compounds or alternatively hold and release pleasant aroma compounds.
Topics being researched include:
• Isolation of starch nanomaterials using various indigenous African starches modified with lipids to produce amylose-lipid complexes. Characterisation of complexes at nano scale. Application of amylose-lipid complexes as a fat replacer to produce low-calorie foods to combat Lifestyle Diseases
• Understanding the mechanism of starch interaction with other food hydrocolloids in food systems. Determination of the rheological, thermal, functional properties: and micro- and nano-structures of starch-hydrocolloids interaction. Exploitation of starch-hydrocolloid interaction to be used in low GI and gluten-free food.
• Understanding the fundamental science of how kafirin (sorghum prolamin type) proteins and other proteins self-assemble to make biopolymer microstructures
• Comparing the flavour binding capacity of selected proteins in milk and preparing and comparing polymeric films that contain proteins as selective flavour absorbers
• Developing the University of Pretoria’s Kafirin Encapsulating MicroStructures (KEMS) invention into high value medical and related health-promoting products, including carriers for nutraceuticals and other biomolecules, and biomaterial scaffolds for human and animal tissue repair
Scientists responsible: Dr Naushad Emmambux, Dr Janet Taylor, Prof John Taylor, Prof Elna Buys
RFA: Sensory Science Research Contributing to Food, Nutrition and Well-being in Africa
Our Sensory Food Science research focuses on three challenges.
a. The need for food product development to meet the demands of a growing and more urbanized African population in transition.
b. The exploration of the incredible richness of sensory experiences in foods from Africa’s biodiversity of food sources.
c.The tailoring of the sensory properties of foods for sub-Saharan Africa to make them not only nutritionally adequate but also appealing and appetizing. The triple burden of disease (infectious diseases associated with underdevelopment, poverty and under-nutrition; chronic diseases linked to overnutrition and the HIV/AIDS epidemic) can be treated with medical intervention but quality of life also comes in the form of better nutrition.
Sensory Science provides the tools to understand the interaction between food perception, people and consumption situations to gain insight in fundamental food choices and consumption behaviour.
Current research projects in this area include:
• Effect of bacterial enzymes on sensory quality of long shelf-life milk
• Rancidity development in shelf-stable sauce emulsions
• Effect of micronisation on sensory properties and consumer acceptance of cowpeas
• Nutritional, rheological and sensory properties of extruded cassava-soy porridges
• Sensory perception of bitterness in marama bean (Tylosema esculentum)
• Sensory quality and consumer acceptance of nutritionally optimised biscuits from sorghum and legume flours
• Cross-disciplinary studies to profile products manufactured using traditional culinary practices e.g. bread in Lesotho
Scientists responsible: Prof Riëtte de Kock, in collaboration with Prof Amanda Minnaar, Prof John Taylor, Prof Elna Buys, Dr Gyebi Duodu, Dr Naushad Emmambux, Dr Gerrie Du Rand and Dr Janette Saidu