Thesis--University of Wisconsin--Madison. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 129-133).

Teff (Eragrostis tef (Zucc.)) is an annual, warm-season cereal crop most notable for its gluten-free, nutrient-packed seed. Experiments were conducted in two regions of Virginia (Blacksburg and Steeles Tavern) in 2010 and 2011 to determine the grain production potential of two teff varieties (brown and white). Additionally, commercially purchased teff flour was evaluated for its suitability in producing a satisfactory baked product. Teff varieties were planted in early June and July at a seeding rate of 6 kg PLS ha??. Nitrogen fertilizer was applied at planting in the form of urea at a rate of 56 kg ha??. The experimental design was a randomized complete block with a two-way factorial treatment structure (variety and planting date) and four replications. Grain yield and nutritive value, straw yield and quality, and plant height were evaluated for each variety and planting date at Steeles Tavern in 2010. Due to failure in crop establishment and difficulties involved in threshing and processing the harvested crop, no data is available in 2010 or 2011 for Kentland or in 2011 for Steeles Tavern. In 2010 at Steeles Tavern, grain yield was significantly higher for the brown variety (367 kg ha??) compared to the white variety (97 kg ha??) for both planting dates. There was no significant difference in straw yield between varieties or planting dates with straw yield averaging 2645 and 2475 kg DM ha?? for brown and white varieties, respectively. Precipitation accumulation at Steeles Tavern was higher in 2010 (greater than 10 cm) during June and July compared to 2011 and the historic average. This may explain why the plots in 2010 were able to successfully establish and out compete weeds. In the lab, four types of baked products were tested to determine the suitability of teff for baked goods. Cakes, cookies, biscuits and bread were tested with varying treatments of teff: control (100% wheat flour) and 10, 20, 30, 40 and 100% teff flour. Each treatment was replicated three times for each product. Generally, bread and cake volumes decreased as the percent of teff increased. Teff flour was best suited for use in cookie and biscuit products compared to cakes and breads since cookies and biscuits require less leavening. Overall, both experiments (field and laboratory) demonstrated the potential of teff as an alternative grain crop in Virginia. However, additional research is needed to overcome problems associated with establishment, harvest, threshing and processing. / Master of Science

Master of Science / Department of Animal Sciences and Industry / Barry J. Bradford / Declining ground water supplies are putting significant pressure on the dairy industry in the United States. The water needed for forage production represents the great majority of total water use on most dairy farms, posing a major challenge in the pursuit of improved drought resilience. Teff (Eragrostis tef), a drought-tolerant annual grass (C4 physiology) native to Ethiopia, could prove an attractive alternative to traditional forage crops. While teff grass has potential to fit the needs for forage production in water-stressed regions, very little is currently known about its nutritional characteristics and whether it can support high levels of milk production by dairy cattle. An experiment was conducted to investigate the effects of variety and cutting age on dry matter yield, nutritive values, and digestibility of teff grass. Eighty pots were blocked by location in a greenhouse and randomly assigned to 4 teff varieties (Tiffany, Moxie, Corvallis, and Dessie) and to 5 cutting ages (40, 45, 50, 55, or 60 d after planting [DAP]). Results from this study indicate that, under greenhouse conditions, the first cutting of teff grass should be harvested at 45 to 50 DAP to optimize forage yield, quality, and digestibility in that cutting and in subsequent cuttings. A second experiment was conducted to assess the productivity of lactating dairy cows fed diets with teff hay as the sole forage. Nine multiparous Holstein cows were randomly assigned treatment sequence in a 3 × 3 Latin square design. Diets were either a control, where dietary forage consisted of a combination of corn silage, alfalfa hay, and prairie hay, or 1 of 2 teff diets, where teff hay was the sole forage. The teff diets maintained yields of milk and milk fat while increasing milk protein yield. Together, these two studies suggest that teff-based diets have potential to maintain high levels of milk production while improving the resilience of the dairy industry to future water shortages.

Diploma thesis Sensory evaluation of teff and products from it in the theoretical part describes the cereal Eragrostis teff as a food with rich nutritional composition, suitable not only for gluten-free diet, high content of minerals - especially iron and also high fiber content. Overall, it improves the nutritional composition of the food. The practical part is evaluated sensory, spectrophotometrically and the texture of baked teff biscuits. The aim of the work was to compare the sensory evaluation of biscuits with different addition of teff light and dark flour and their acceptance by evaluators. It was found that teff biscuits can also be consumed as 100% teff, rated as delicate, typical, pleasant smell, slightly bite, forming a wholly bite. Teff flour does not change textural parameters depending on its addition and there is no difference in texture between dark and light teff flour. Adding teff flour improves nutritional properties.

Thesis (PhD(Agricultural Economics))--University of Pretoria, 2008. / Includes bibliographical references (leaves 148-172).

Master of Science / Department of Grain Science and Industry / Sajid Alavi / Sorghum, millets and teff are important staple crops worldwide, especially in semi-arid regions of Africa and India because of their drought tolerance. However, lack of research and other limitations have restricted their usage in food products. This study is focused on extrusion processing of low and high tannin sorghum varieties, millet and teff for high and low moisture applications, and to investigate process characteristics such as residence time distribution and specific mechanical energy, physico-chemical properties of resultant food products (such as pre-cooked pasta and expanded snacks) and their resistance starch content. Results from preliminary lab scale extrusion, including optimization of starch type and level for pre-cooked pasta and in-barrel moisture for expanded snacks, were used to design pilot-scale studies on a twin-screw extruder. In the first pilot-scale experiment, decorticated white sorghum blends prepared with addition of mono-glycerides (0.5%, 1% and1.5%) and salt (1%) were processed at three different in-barrel moisture contents 40%, 44% and 48% (wet basis) for processing of precooked pasta. The optimum formulation containing 1% mono-glycerides and process conditions corresponding to 48% in-barrel moisture were also used to develop precooked teff and millet pasta. The non-traditional grain based pastas were investigated for cooking quality, thermal characteristics using differential scanning calorimeter, pasting properties using rapid visco analyzer and texture profile analysis. In general, increasing in-barrel moisture led to reduction in solid losses (ranging from 4.0-8.2% for all treatments), indicating improvement in cooking quality. On the other hand, increase in mono-glycerides concertation led to higher cooking losses, and also affected pasting and textural properties significantly. Sorghum-based precooked pasta was of best quality while millet pasta was poorest in cooking quality, visual and textural attributes. Cooking loss for control pre-cooked pasta produced in this experiment using semolina was 4.5%, and commercial semolina pasta was 3.2%. Residence time distribution in pilot-scale twin screw extruder, during high moisture process conditions used for pre-cooked pasta, was also investigated at three different in-barrel moistures (40%, 44% and 48%) and monoglycerides/ lipid (0.5, 1% and 1.5%) concentrations. Increase in in-barrel moisture significantly decreased mean residence time. For example, mean residence time was 4.47 min at 40% moisture, 3.89 min at 44% and 3.74 min at 48%. On the contrary, residence time significantly increased with lipid level. For example, mean residence time was 3.87 min at 0.5% concentration of mono-glycerides, 4.48 min at 1% and 4.70 min 1.5%. In the second experiment focusing on low moisture applications, pilot-scale twin screw extrusion was used to process decorticated white sorghum and high tannin sumac sorghum for expanded snacks. The addition of sumac bran decreased the specific mechanical energy input (366-578 kJ/kg) and expansion ratio (6.4-7.9), and resulted in higher piece density of extrudates. Use of sumac bran and sumac flour led to increase in resistant starch content, although it was less than 1% for all treatments. Therefore, extrusion with ingredients having high tannin content does not provide value, despite tannins being associated with resistant starch at least in raw materials.

Teff (Erogrostis tef (Zucc.)), an annual warm-season grass from Ethiopia, has potential to provide forage during periods when cool-season grass growth is limited by high temperatures. An experiment was conducted at three Virginia locations in 2009 and 2010 to determine the effect of nitrogen (N) fertilization rate and source on the yield, nutritive value, and nitrate content of teff. Nitrogen (N) was applied at 0, 45, 90, and 135 kg plant available N ha-1 as a single application of either ammonium nitrate (AN) or broiler litter (BL) at seeding. The experimental design was a randomized complete block with a two-factor factorial treatment design (N rate and source) and four replications. Biomass yield typically peaked at the 90 kg N ha-1 rate, but rarely showed an increase beyond the 45 kg N ha-1 rate. Yield ranged from 2325 to 7542, 1477 to 6151, and 1805 to 8875 kg DM ha-1 for the Blacksburg, Southern Piedmont, and Shenandoah Valley locations, respectively. Crude protein and total digestible nutrients ranged from 70 to 240 g kg-1 and 460 to 700 g kg-1, respectively. Nitrate concentrations increased with increase in N fertilization but source had no effect on nitrate concentration. Typically, nitrates only posed a health risk for ruminant livestock at N rates above 90 kg N ha-1, but dangerous levels were present occasionally at the 0 and 45 kg N ha-1 rates. The results from this study indicate that teff responds to moderate rates of N and could provide summer forage for grazing livestock in the mid-Atlantic region. / Master of Science in Life Sciences

Master of Science / Department of Agronomy / Robert M. Aiken / Doohong Min / Finding a high-value forage crop with limited water requirements to produce livestock feed is becoming increasingly important as producers adapt to restricted water supply conditions. Our objectives were to determine the forage yield, nutritive values, and crop water productivity (CWP) of teff grass (Eragrostis tef [Zucc.] Trotter) under field conditions when compared to sorghum sudangrass (SS, S. x drummondii[(Nees ex. Steud.) Millsp. & Chase]) and pearl millet (PM, P. glaucum [L.]R.Br.). Crop water productivity was determined by dividing above-ground biomass by crop water use. Crop water use was determined by the summation of soil water depletion, precipitation, and irrigation. Yield was determined by quadrat area clippings of above-ground biomass. Nutritive value was determined using wet chemical analysis. Cultivars showed significant differences in biomass production and CWP in both years. Excalibur teff grass variety had the greatest CWP (418 kg ha-1 cm-1) 40 days after planting (DAP) in 2016, and was similar to SS and PM for the rest of the season until 58 DAP. Pearl millet had the greatest overall CWP (443 kg ha-1 cm-1) at 44 DAP. In 2017, sorghum sudangrass had significantly greater CWP than teff grass and pearl millet throughout most of the season. Among the teff varieties, Haymore had the greatest CWP (239 kg ha-1 cm-1) when harvested 10 days after boot stage (DAB). Crude protein values of teff grass varieties ranged from 9.3% to 21.3%, depending on the harvest date and year. Teff grass showed equivalent or greater nitrogen use efficiency (27.8 – 88.8 kg biomass kg-1 N applied) in our study than previously reported. Teff grass demonstrated potential to provide producers with a fast-growing and competitive forage crop with less overall water use due to a shortened growing season.

Please read the abstract in the section 00front of this document / Thesis (PhD (Food Science))--University of Pretoria, 2006. / Food Science / unrestricted

Starch is used in many food applications as thickeners, texturisers and fat substitutes. Native starches, although useful, have low stability to conditions such as high shear, extreme pH and high temperatures encountered during food processing. Starches are modified to make them more suitable for processing conditions. The modification of starch by the use of a naturally occurring compound (for example stearic acid) may produce desirable properties and also removes the risk of a chemical residue in the starch. Starch can be from several grain sources. Teff grain is highly underutilized and underresearched. The work conducted in this project investigates the pasting properties, gelling tendencies, clarity and flow properties (using a rheometer) of teff starch pastes treated with stearic acid, in comparison to maize starch pastes. X-Ray Diffraction (XRD) and Confocal Laser Scanning Microscopy (CLSM) were also used to investigate the possible impact of stearic acid on the structure of the starch granules and pastes. Starch suspensions containing stearic acid (0.25% - 4%) were pasted in a Rapid Visco Analyser using a short pasting cycle of approx. 30 min (held for 5 min at 91°C). Maize starch (treatments) showed a reduced peak viscosity within the holding period, while teff starch (treatments) did not. Teff starch showed increasing viscosity without reaching a peak during the holding time. The pasting cycles were then extended (holding time extended to 2 hr) to investigate the pasting behaviour of teff starch. The extended pasting cycle resulted in a reduced first viscosity peak for maize starch with added stearic acid. Teff starch with added stearic acid showed a large increase in viscosity without the formation of the first viscosity peak. However, both starches displayed a second pasting peak. The addition of stearic acid resulted in an increase in the viscosity of the second pasting peak from about 175 Rapid Visco Units (RVU) to 228 RVU for maize starch, and from 113 RVU to 250 RVU for teff starch. The final viscosity of maize starch increased from 186 RVU to 227 RVU, while that of teff starch increased from 194 RVU to 261 RVU. The second viscosity peak was not observed with waxy maize starch (approx. 97% amylopectin). This suggests that amylose-stearic acid complexation might have been responsible for the formation of this peak. Complexation Index (CI) values increased as the concentration of stearic acid was increased. This further suggests that some interaction between amylose and stearic acid had taken place. The pastes of maize and teff starches modified with stearic acid were more opaque and showed reduced gelling compared to their non-modified counterparts. Maize and teff starches and their stearic acid-treated counterparts followed the Power-Law Model and were shear thinning (n < 1). However, teff starch pastes (control and treatment) seemed to be less shear thinning than their maize starch paste counterparts. An increase in consistency, k, after the extended pasting cycle was used (compared to the short pasting cycle) for the treated starches, reflects the increased viscosities obtained during extended pasting. XRD further suggested that amylose-lipid complexes may have been present in the starch pastes (after extended pasting) due to the occurrence of the 4.4 Å and 12 Å peaks (characteristic of V-type starches). CLSM showed that stearic acid diffused into maize starch granules but not into teff starch granules. This was probably due to the pores of the surfaces of maize starch granules which may have facilitated the diffusion process. In contrast, teff starch granules do not have pores on their surfaces. This structural difference may be attributed for the pasting differences between teff and maize starches. The effects of stearic acid on the pasting (effect on first and second peaks and final viscosity), and functional properties (reduced gelling and increased opacity of pastes) of maize and teff starches have been attributed to the formation of amylose-lipid complexes. These high viscosity and low gelling starches may be extremely useful as fat replacers. Teff starch has the added benefit of its small starch granules which may add to its ability mimic the mouthfeel of fat globules. / Dissertation (MSc)--University of Pretoria, 2011. / Food Science / unrestricted