A microencapsulation-based technology platform for effective delivery of multiple micronutrients for food fortification has been developed. The technology, consisting of extrusion agglomeration followed by encapsulation through surface coating, has been successfully tested on three size scales in typical staple foods: as a surface treatment on salt and sugar, on 20-100µm scale; in salt on a 300-1200 μm scale; and on reconstituted rice on the 5-10 mm scale. The process results in effective delivery systems for one or more active ingredients with organoleptic properties that are unnoticeable to the average consumer. Particularly, salt double fortified with iodine and iron using the microencapsulated ferrous fumarate premix made by the extrusion-based agglomeration process had acceptable sensory properties and stability when stored at 40oC and 60% relative humidity (RH) for up to a year. In these tests >85% of iodine and >90% of ferrous iron were retained. Reconstituted Ultra Rice® grains made by extrusion stabilized by internal gelation has resulted in improved grain integrity and a much simplified process, compared to the original, patented surface crosslinking technique. The most effective internal gelation system is composed of alginate, calcium sulphate (CaSO4), and sodium tripolyphosphate (STPP) at a best ratio of 3%:3%:0.6% (w/w). It is feasible to incorporate folic acid into the existing fortification programs using the technology platform developed in this study. The results indicate that the potential interactions of folic acid with other added micronutrients or with the food vehicles could be prevented by incorporating folic acid as a premix made by the extrusion-based technology. Virtually no folic acid was lost after 9 months storage at 40oC and 60% RH when the folic acid premix was added into salt or sugar samples. The technical feasibility of the microencapsulation-based technology platform has been successfully demonstrated for micronutrient delivery in food vehicles of different size ranges, resulting in fortified staple foods with desired physical, chemical, nutritional, and organoleptic properties. The technology should be adaptable to formulating customized delivery systems of active ingredients for broader applications, and promises to bring immediate benefits in combatting micronutrient deficiencies, that will have far reaching effects in health and social development.

A microencapsulation-based technology platform for effective delivery of multiple micronutrients for food fortification has been developed. The technology, consisting of extrusion agglomeration followed by encapsulation through surface coating, has been successfully tested on three size scales in typical staple foods: as a surface treatment on salt and sugar, on 20-100µm scale; in salt on a 300-1200 μm scale; and on reconstituted rice on the 5-10 mm scale. The process results in effective delivery systems for one or more active ingredients with organoleptic properties that are unnoticeable to the average consumer. Particularly, salt double fortified with iodine and iron using the microencapsulated ferrous fumarate premix made by the extrusion-based agglomeration process had acceptable sensory properties and stability when stored at 40oC and 60% relative humidity (RH) for up to a year. In these tests >85% of iodine and >90% of ferrous iron were retained. Reconstituted Ultra Rice® grains made by extrusion stabilized by internal gelation has resulted in improved grain integrity and a much simplified process, compared to the original, patented surface crosslinking technique. The most effective internal gelation system is composed of alginate, calcium sulphate (CaSO4), and sodium tripolyphosphate (STPP) at a best ratio of 3%:3%:0.6% (w/w). It is feasible to incorporate folic acid into the existing fortification programs using the technology platform developed in this study. The results indicate that the potential interactions of folic acid with other added micronutrients or with the food vehicles could be prevented by incorporating folic acid as a premix made by the extrusion-based technology. Virtually no folic acid was lost after 9 months storage at 40oC and 60% RH when the folic acid premix was added into salt or sugar samples. The technical feasibility of the microencapsulation-based technology platform has been successfully demonstrated for micronutrient delivery in food vehicles of different size ranges, resulting in fortified staple foods with desired physical, chemical, nutritional, and organoleptic properties. The technology should be adaptable to formulating customized delivery systems of active ingredients for broader applications, and promises to bring immediate benefits in combatting micronutrient deficiencies, that will have far reaching effects in health and social development.

In 2003 the Department of Health of South Africa embarked on a mandatory fortification programme of maize meal as part of the Integrated Nutrition Program (INP) to alleviate malnutrition. The aim of this study was two-fold: firstly, to determine the vitamin A content of South African fortified white maize meal as purchased and the maize porridge as traditionally prepared from it as consumed and secondly, to determine the relative efficacy of the daily consumption of maize meal in sustaining or improving vitamin A status. Maize meal samples for analysis were purchased from various supermarkets and small retail outlets. A High Performance Liquid Chromatograph-Diode Array Detector system with a Reverse Phase C-18 column and isocratic elution was used for separation and quantification of vitamin A. The highest mean vitamin A concentration measured in the maize meal was 261 μgRE/100g and the lowest mean vitamin A concentration was <19 μgRE/100g. Pertaining to the regulations the final minimum level of vitamin A in fortified maize meal must not be less than 187.7 μgRE/100g. The average retention of vitamin A in maize porridge as the difference in vitamin A concentration measured between raw maize meal and cooked porridge was calculated at 39.8%. One of the considerations in a fortification program is the availability of certain micronutrients in the fortified foods, with the focus in this project on vitamin A. An animal model, namely chickens, closely relating the metabolism of vitamin A in humans was used. Chickens are very susceptible to vitamin A deficiencies with similar symptoms. Growth and vitamin A status was evaluated by the weight, feed conversion and liver retinol stores of chickens on five different maize based diets over a six week period. No significant difference in vitamin A levels in the livers of birds on diets with fortified white maize meal, compared to the normal poultry diet consisting of yellow maize meal with added vitamin A was found. It can thus be concluded that the fortificant in the white maize meal is as bioavailable as the vitamin A in the premix used in poultry nutrition. The results of this study show that the vitamin A added as fortificant is absorbed and available to the body. Therefore, fortification of commonly eaten staple foods in the country can significantly improve the vitamin A intake of the population and will improve the overall micronutrient density of their diets. Fortification should be set at levels to include losses incurred through packaging and during transportation, shelf losses and preparation losses. It is also important that the vitamin A content of the product as purchased and consumed must be regularly monitored and regulated by government. Valid and reliable evaluation data are needed to evaluate a program’s success, and to make timeous adjustments for optimal efficiency. / Thesis (PhD)--University of Pretoria, 2011. / Animal and Wildlife Sciences / unrestricted

This thesis estimates the impact of non-tariff measures (NTMs) notified by the importing countries on agricultural trade. The non-tariff measures constitute the technical measures notified under the SPS and TBT agreements and the non-technical measures to trade. Two approaches are used; the inventory approach and the econometric approach which makes use of the gravity model. The inventory results suggest that African countries face more restrictions on their exports than what they impose on their imports. Also, Uganda, Senegal and Mali are among the top twenty most affected importers. The empirical results suggest that the impact of the overall group on non-tariff measures is ambiguous but when measures are disaggregated into technical and non-technical measures, the results show that the technical measures promote agricultural trade and that the non-technical measures restrict trade. Also, imports of industrialized nations from fellow industrialized nations are promoted by the technical measures but are restricted by non-technical measures, while those from non-industrialized countries are affected negatively by both technical and non-technical measures. Out of the five regions considered, Africa faces the largest negative impact by both technical and non-technical measures. / Master of Science

D. Tech. (Food Service Management, Dept. of Hospitality, Tourism and PR management), Vaal University of Technology / The main objective of this study was to develop a cost-effective, culturally acceptable, nutrient-dense food multimix (FMM) based on local food staples for pregnant women in the Vaal region. The impact of the consumption of the multimix on the nutritional status of the women, dietary diversity and outcomes of pregnancy was assessed in an intervention study by measuring the same variables as for a pilot study where the nutritional status of pregnant women was determined. Compliance was measured through monitoring of the FMM consumption and sensory evaluation tests. Quantitative food frequency questionnaires (QFFQs) and 24-hour recall questionnaires were completed in interviews. Anthropometric and biochemical measurements were recorded. The pilot study indicated that the mean total iron intake was 9,74 mg/day, below the estimated average requirement (EAR) of 22 mg/day for pregnant women. Therefore, 41,7 per cent of the women were found to be iron deficient and 50 per cent suffered from iron deficiency anaemia. Food consumed supplied little iron. Eighty per cent of the women were overweight before falling pregnant. Based on the pilot study, the FMM was developed and subjected to the following processes: chemical analysis, shelf life tests, recipe development and sensory evaluation. The product was then implemented in an intervention programme. A control group of pregnant women received soup powder. The respondents were relatively healthy and did not suffer from any chronic diseases. According to the nutrient intakes measured by the QFFQ, indicating usual dietary intakes, the iron intake of 87,5 per cent of the experimental group and 94 per cent of the control group fell below the EAR before intervention. After the intervention it improved in that the iron intake of 35,2 per cent of the experimental group and 33,3 per cent of the control group fell below the EAR. The top 10 items consumed by the experimental group during pre- and post-intervention were mainly rich in carbohydrates. Food containing iron absorption inhibitors such as tannin in tea and phytates in maize meal and bread were among the top 10 foods listed. The highest number of individual food items consumed by an individual in seven days was 39 before the intervention and 52 after the intervention, among the experimental group. The individual food variety improved after the intervention. The reason for this could be the inclusion of the FMM in their diets. The majority of the respondents consumed eight to nine of the nutritious food groups before and after the intervention. The mean food variety score (FVS) for the control group was 38,9 (±10,5) before the intervention, which decreased to 35,8 (±8,39) after the intervention. No improvement in FVS was observed after the intervention in the control group and the FVS indicated medium dietary diversity (30-60 food items). The post-intervention results show that there was an improvement in most of the iron variables. The experimental group showed statistically significant differences between pre- and post-intervention measurements in transferrin and haematocrit levels and the control group in haematocrit levels. All the babies born to the mothers of both the experimental and control groups were healthy with measurements in the normal range. The reason for this could be that the inclusion of the FMM and soup powder in the diets of the experimental and control group, respectively, made the women more aware of the importance of pregnancy monitoring. Furthermore, the attention given to the women by the clinic sisters and the researchers could have contributed to all the improvements mentioned.

In a world of imbalance, food consumption exhibits great diversity among regions and countries. Although farmers in developed economies benefit from up-to-date agricultural technology and produce much more than they consume, households in the developing world are still combating food insecurity. This dissertation is composed of two manuscripts. One is about consumption in developing countries, while the other is related to promoting agricultural production in a developed economy. Chapter 1 applies a three-stage demand system to nationally representative household survey data to identify food demand behavior with an emphasis on food staples in two West Africa countries ‒ Niger and Nigeria. The third stage of the demand system offers demand elasticities of specific staple items. Instead of treating the population as a whole, the study distinguishes rural and urban households and households of different welfare status. Results confirm the complexity of the food and staples demand between rural/urban areas and among welfare quintiles. Therefore, researchers and policymakers should consider not only the average demand response but also its distribution among households. In addition to demand elasticities, the effects of household demographic characteristics on the structure of food consumption are also obtained. Chapter 2 estimates the rates of return to Virginia's public expenditure on agricultural research and extension (RandE) during 1949-2016 and attempts to address the ad hoc model selection problem common in previous studies. Among the econometric modeling strategies in previous literature, Bayesian Model Averaging (BMA) and Bayesian Hierarchical Model (BHM) are two promising methods to solve the issue of model uncertainty. The rate-of-return estimates by BHM are preferable because BHM imposes fewer restrictions on lag structures and offers more reasonable lag shapes. By BHM, the internal rates of return (IRR) of Virginia's public expenditures on agricultural RandE are 26% and 42%, respectively. Nineteen percent of Virginia's agricultural productivity growth during 1949-2016 results from its RandE investments, and the contribution of research to that growth is about twice of that of extension. One extra million dollar expenditure on research in 1992 would have brought a benefit of $4.5 million, and the same expenditure in 1983 would have brought $5.4 million in additional benefits. If the extra expenditure is spent on extension, it would have brought a benefit of $6.1 million and $6.3 million if the expenditure occurs in 1992 and 1983, respectively. Besides the modeling strategy, this study is distinguished from previous studies in that distributions of rates of return instead of only point estimates are obtained, which is missing in most studies. / Doctor of Philosophy / In a world of imbalance, food production and consumption exhibit great diversity among regions and countries. While farmers of developed economies benefit from up-todate agricultural technology and produce more than they consume, households in the developing world are still facing food insecurity. This dissertation is composed of two manuscripts. Chapter 1 is about food consumption in developing countries. It analyzes household food demand behavior in the two West Africa countries Niger and Nigeria with a focus on staple foods. Food demand behavior differs for rural and urban households and households of different income. Therefore, when evaluating the effects of policies and other impacts, policymakers and researchers should treat households with different attributes separately. Chapter 2 is on how to improve agricultural production within the context of a developed economy: it evaluates the returns to public expenditures on agricultural research and extension (R&E) in Virginia. Previous studies choose statistical models arbitrarily, and this study attempts to address this issue. It finds that Virginia’s investments in agricultural R&E contribute to nineteen percent of the productivity growth in 1949-2016, and the contribution of research is about twice of that of extension.