Master of Science / Department of Human Nutrition / Kadri Koppel / Products must be tolerant to many conditions, particularly when those products are prepared by consumers. Consumers may not measure added ingredients, they may add or leave out ingredients specified in recipes, or change cooking and holding times for foods. Fortified blended food (FBFs) are used as a source of nutrition for disaster or famine relief in developing countries and sorghum is looked at as a potential alternative to wheat and corn based products that are currently being used as FBFs. Porridge products are the most common dishes prepared from FBFs with a wide range of solids content, cooking times and variations in added ingredients such as sugar and fruit. This study was intended to evaluate the tolerance to preparation variations for a porridge product made as a FBF intended for food aid. Whole Sorghum Soy Blend (WSSB), a fortified, extruded, ground cooked cereal was selected as the FBF for this study. Descriptive sensory analysis was performed to evaluate the tolerance of porridge products made from variations in ingredients and cooking procedures. In this study, most sensory properties were only marginally affected by variations in ingredients or procedures. However, as expected, large differences occurred in some properties such as thickness when solids content varied or sweetness and fruit flavor when fruit was added. Tolerance testing showed that the sensory properties of WSSB had high tolerance to variations in cooking procedures, a positive aspect for product use and development. This means that the product can be modified during preparation by consumers without having a major impact on most sensory properties.

Doctor of Philosophy / Department of Grain Science and Industry / Sajid Alavi / The feasibility of using a wheat flour mill to refine corn, sorghum and cowpea was studied. Milling of white sorghum grain resulted in decrease in fiber content from 1.89% to 0.38% and 0.45% in raw, finely milled and coarsely milled sorghum respectively. Similarly, there was a reduction in fat (3.17% to 1.75% and 0.51%) content from raw to fine and coarse milled fractions. Starch content increased from 61.85% in raw to 69.80% in fine and 72.30% in coarse fractions. Protein content was almost unchanged at about 7.40% in all the fractions. In de-hulling and milling of cowpeas, starch and protein content increased whereas fiber, fat and ash content decreased. There was a significant difference in expansion characteristics between whole and decorticated binary blends on account of different levels of inherent starch content. Sorghum cowpea (SC) blends had the highest specific mechanical energy (SME) range (285.74 – 361.52 kJ/kg), followed by corn soy (CS) (138.73 – 370.99 kJ/kg) and the least SME was found in sorghum soy (SS) blends (66.56 – 332.93 kJ/kg). SME was found to be positively correlated to starch content in the blends. SC blends had the most stable process followed by SSB and CSB in that order. The milling of expanded extrudates was found to be dependent on bulk density and low bulk density extrudates had bigger particle size and vice-versa. The water absorption index (WAI) for SC was 4.17 g/g to 5.97 g/g, SS ranged from 2.85 g/g to 5.91 g/g and CS ranged from 2.63 g/g to 5.40 g/g. Starch gelatinization ranged from 85.42 – 98.83% for SC, 90.70 – 96.27% for SS, and 72.57 – 95.49% for CS. The starch digestibility increased after extrusion and cooking but there was no significant change in protein digestibility. There was a significant reduction in anti-nutritional factors – phytic acid (26.06 – 44.03%), tannins (18.69 – 26.67%) and trypsin inhibitor (16.55 – 50.85%) after extrusion. Thus, the study showed that high protein blends with superior nutrition density needed for preparation of FBFs could be produced by using existing/traditional milling capabilities and extrusion process.

Master of Science / Department of Food, Nutrition, Dietetics, and Health / Brian L. Lindshield / Fortified-blended foods (FBFs), grain-legume porridges (most commonly corn and soy), are frequently used for food aid purposes. Sorghum and cowpea have been suggested as alternative FBF commodities because they are drought-tolerant, grown locally in food aid receiving countries, and are not genetically modified. The objective of this thesis was to determine the protein quality and iron bioavailability of newly formulated, extruded FBFs in broiler chickens, which have been suggested as a good model for assessing iron bioavailability. Five FBFs were formulated to contain whey or soy protein to compare protein quality, sugar, oil, and an improved micronutrient premix. These included three white sorghum-cowpea FBFs; two were extruded with either whey protein concentrate (WSC) or soy protein isolate (WSC+SPI) added, one was non-extruded (N-WSC). Two others were white sorghum-soy (WSS) and corn-soy (CSB14) FBFs. Two additional white-sorghum cowpea FBFs were reformulated and “over-processed” to contain no sugar, less whey (O-WSC) or soy protein (O-WSC+SPI), and less oil, thus producing a less expensive FBF. Two studies were performed using prepared (Prep) or dry (Dry) FBFs, along with the United States Agency for International Development (USAID) corn and soy blend FBF, CSB+, fed to chickens for 3 and 2 weeks, respectively; food intake, body weights, hemoglobin, and hepatic iron were assessed. In the Prep study, new FBFs significantly increased caloric and protein efficiency compared to CSB+, despite similar food intake and body weight gain. In the Dry study, CSB+ significantly decreased food intake and caloric efficiency, with the exception of O-WSC+SPI, and nonsignificantly reduced body weight gain and protein efficiency compared to new FBFs. CSB+ significantly reduced hepatic iron content compared to all FBFs in the Dry study, and was nonsignificantly decreased compared to new FBFs in the Prep study. In conclusion, sorghum and cowpea FBFs performed similarly to corn and soy FBFs, suggesting these commodities are suitable replacements for corn and soy. Soy protein isolate (WSC+SPI) was an effective alternative to whey protein concentrate (WSC), suggesting SPI can be a less expensive protein supplement in FBFs. Surprisingly, non-extruded sorghum and cowpea (N-WSC) was equally efficacious to extruded WSC. However, N-WSC did not meet viscosity requirements and is not precooked, which limits its viability as an FBF. O-WSC+SPI resulted in poorer outcomes compared to other FBFs, which suggests the protein quality of cowpea may be inferior and the inclusion of whey protein is needed in this formulation, as O-WSC with whey performed similarly to other FBFs. Overall, new FBFs, with the exception of O-WSC+SPI, resulted in improved food efficiency and hepatic iron outcomes compared to CSB+, suggesting they are of higher nutritional quality. However, further research is needed to refine and identify the best FBF formulations.

Doctor of Philosophy / Department of Human Nutrition / Brian Lindshield / Fortified blended foods (FBFs), in particular, corn-soybean blend (CSB), are food aid commodities widely used in infant and young children supplementary feeding programs. A United States Agency for International Development (USAID) Food Aid Quality Review report recommended developing novel FBFs using local alternative commodities such as sorghum and improving the nutritional quality of FBFs using extrusion processing. Extruded sorghum-cowpea, sorghum-soy and corn-soy FBFs were developed and compared with the non-extruded FBFs corn-soy blend 13 (CSB13) and corn-soy blend plus (CSB+) using the in-vitro digestion/Caco-2 cell model. Dry FBFs’ iron and vitamin A content ranged from 8.0 to 31.8 mg/100g and 0.54 to 1.67 mg/100g, respectively. Following in-vitro digestion, bioavailable iron and vitamin A levels were determined by measuring Caco-2 cell ferritin and vitamin A levels in response to 12-hour and 4-hour treatments, respectively, with aqueous fractions collected from digested FBFs. Most extruded FBFs’ aqueous fraction iron levels were 2- to 7-fold higher (p<0.05) than CSB13 and CSB+. However, Caco-2 cell ferritin and vitamin A levels were not significantly different among FBFs. These results suggest that consumption of newly developed extruded sorghum-cowpea, sorghum-soy and corn-soy FBFs will result in bioavailable iron and vitamin A levels comparable to traditional non-extruded CSB13 and CSB+. Thus, extruded sorghum-cowpea FBF may be a suitable alternative to corn-soybean based FBFs. Saw palmetto supplements are one of the most commonly consumed products by men with prostate cancer and/or benign prostatic hyperplasia (BPH). Some studies have found significant improvements in BPH with saw palmetto supplementation, whereas others found no benefits. The variation in the efficacy in these trials may be a result of differences in the putative active components, fatty acids and phytosterols, of the saw palmetto supplements. We quantified fatty acids and phytosterols in 20 commercially available liquid, powder, dried berry, and tincture saw palmetto supplements. Liquid saw palmetto supplements contained significantly higher (p<0.05) concentrations of total fatty acids (908.5 mg/g), individual fatty acids, total phytosterols (2.04 mg/g), and individual phytosterols, than the other supplement categories. Our findings suggest that liquid saw palmetto supplements may be the best choice for individuals who want to take a saw palmetto supplement.

Doctor of Philosophy / Food, Nutrition, Dietetics and Health / Edgar Chambers IV / Fortified blended foods (FBFs), which are the mixture of cereals and legumes fortified with micronutrients, have been widely used as supplementary foods for vulnerable populations such as infants and young children in developing countries around the world. The evaluation of current FBFs showed limited evidence on their effectiveness in treating childhood malnutrition, resulting the several recommendations on processing and formulation changes to improve their quality and ability to meet nutritional needs. Sensory properties are one of the important determinants for the success of the new FBFs. Therefore, sensory testing was conducted to determine the potential of novel FBFs to be used as supplementary food compared with FBF currently used in food aid programs. Descriptive sensory analysis was performed on novel FBFs along with the traditional FBF (Corn soy blend plus; CSB+) to determine sensory characteristics of each FBF. Results showed that novel FBFs had more pronounced toasted characteristics and higher sweetness than CSB+, due to the higher temperature during extrusion process and the addition of sugar in the novel formulation. In addition, novel FBFs that had higher amount of legumes (e.g. soybean, cowpea) in their formulations, especially for all sorghum cowpea blends, showed higher intensity in beany characteristics. Sensory shelf-life testing showed that novel FBFs could have shelf lives at least 2 years with no detection of off-note characteristics and these was comparable to the shelf life of the current FBF (CSB+). Sensory testing was also performed with target populations: children who eat the food and care givers who prepare it, during a 20-week field trial to determine the acceptability and preference of novel FBFs and current FBF. Results showed that all novel FBFs were highly preferred or accepted by children, even though, some of them might need longer time and more exposures to allow children to have more experience and be familiar with the food before being satisfied or preferred that food. In contrary, CSB+ that had bland flavor tended not to be well accepted and highly preferred by children compared to novel FBFs. Moreover, giving children more opportunities to consumed food prepared from CSB+ did not help to improve its acceptability or preference. Data from household visits and interview sessions showed that porridges prepared from novel FBFs required less cooking time than CSB+ and no additional ingredients needed to be added compared to CSB+ where sugar and milk were common additions. Finding from this research indicated that novel FBFs have high potential to be used successfully as supplementary food with comparable shelf life, and higher acceptability and preference to FBF currently used in food aid programs. In addition, the simple cooking of novel FBFs make them valuable to caregivers who have limited time and access to energy sources and nutrient-rich ingredients.