Influence of teff variety and wheat flour strength on breadmaking properties of healthier teff-based breads

Assessment of harvest and postharvest losses of teff (Eragrostistef (Zucc.)) and methods of loss reduction: A review

Teff [Eragrostistef (Zucc.)] is one of the most important cereal crops in Ethiopia which is part of the traditional dish of the people in the form of Injera. Interest in Teff has increased noticeably due to its very attractive nutritional profile and the gluten-free nature of the grain. It is a gluten-free cereal, among the major cereal crops, Teff accounts for the largest average annual acreage in the country. It also accounts for the second-largest average annual production, next to maize. The study endeavored to review the harvest and postharvest losses, the causes of these losses, and possible solutions to reduce the postharvest losses of the Teff crop in Ethiopia. There are inadequate postharvest research works conducted in Ethiopia, and most of the limited studies are focused on cereals other than Teff. Teff farming in Ethiopia is dominated by traditional methods of harvesting and postharvest handling. The application of modernharvest and postharvest technologies during Teff production and handling is critically low. As a result, a considerable loss of Teffgrain (16-30 %) in the harvest and postharvest stages has been recorded. The largest share of this loss is observed during the harvesting stage due to shattering, scattering, animal feeding, and contamination with unwanted parts. Lack of awareness of postharvest losses, limited access and availability of postharvest technologies, and low attention given to postharvest research, extension, and infrastructure have also contributed their share to these losses. Transforming the traditional practice into mechanized farming, modern postharvest technologies, and supporting the system by further research works and pieces of training on loss prevention methods could potentially minimize the harvest and postharvest losses of Teff in the country.

Twin-Screw Extrusion as Hydrothermal Technology for the Development of Gluten-Free Teff Flours: Effect on Antioxidant, Glycaemic Index and Techno-Functional Properties

Gluten-free products (GFP) currently are the fastest-growing category of baked goods probably due to the high worldwide incidence of celiac disease (CD). Refined rice is one of the most used cereal flour for GFP development, due to its high content in starch and good technological aptitude. However, its low content in fibre, protein and minerals has awakened a recent interest as alternative to balance the GF flour formulas. Teff is a cereal with high levels in fibre and antioxidants compounds but the lack of gluten results in very limited techno-functional properties. Extrusion is a thermal technology that allows to combine flours, overcoming negative impacts on quality characteristics. This study evaluated the effect of twin-screw extruder on rice-teff (white and brown) mixtures with different teff concentrations (25, 50 and 75%) on their antioxidant, glycaemic index and techno-functional properties. The results showed than the high shear−temperature process produced important modifications on the flour, which were confirmed using scanning electron microscopy (SEM). Significant increases in total dietary fibre (16 to 100% increase) were observed in teff containing flours, due to carbohydrate−lipid−protein complexes, which lead to resistant starch, with no significant increase in rice flour. Hydration and pasting properties were significantly (p > 0.05) affected by extrusion, and the effect was related to the concentration of teff used. The thermal process showed a decrease in total phenol (TP) content for rice; however, extrusion enhanced the release of total phenol in rice-teff blends, which was reflected on the antioxidant activities of blend flours, especially those prepared with brown teff.

Fatty Acid Profile, Lipid Quality and Squalene Content of Teff (Eragrostis teff (Zucc.) Trotter) and Amaranth (Amaranthus caudatus L.) Varieties from Ethiopia

Teff and amaranth are gluten-free cereals with significant nutritional and health benefits. However, they are underutilized and known in limited areas of the world. The present study evaluated the fatty acid profile, crude fat, squalene content and lipid quality of seven teff (Eragrostis teff (Zucc.) Trotter) and three amaranth (Amaranthus caudatus L.) varieties from Ethiopia. The fat content ranged from 2.92 to 3.34% (averaging 3.06%) and from 8.28 to 9.21% (averaging 8.6%) for teff and amaranth, respectively. Linoleic, oleic and palmitic acid were predominant in both teff and amaranth, accounting for approximately 89 and 85% of total fatty acid content, respectively. The saturated to unsaturated fatty acids ratio ranged from 0.30 to 0.32 in teff and from 0.38 to 0.40 in amaranth. The parameters used to describe lipid quality, i.e., thrombogenicity and atherogenicity indices, show that teff was superior over amaranth, suggesting a preference for the former for healthy food formulation. The squalene content of white amaranth (486.54 mg/100 g DM) was significantly higher than that of the other two varieties (327.54 and 340.81 mg/100 g DM for red and brown amaranth, respectively). In general, both gluten-free crops should be exploited for their potential as ingredients for the development of novel functional foods.

Physicochemical characteristics of bread partially substituted with finger millet (Eleusine corocana) flour

Abstract Finger millet (Eleusine corocana) is a staple cereal grain available in most parts of Africa and India but it is an underutilized and neglected product. It has a low-glycemic index with some nutraceutical advantages. This study aimed to determine the physicochemical characteristics of bread made from wheat and finger millet (FM) composite flours. Wheat flour was blended with FM flour at 10%, 20%, 30% and 40% levels for bread production. Functional properties, pH of composite flours, physical properties and proximate composition of bread were determined. Water and oil holding capacity of flour blends increased from 130.61 to 135.06 and 120.55 to 125.43 g/g, respectively. However, packed and loose bulk density and emulsion stability decreased with inclusion level of FM flour. The pH values of flour blends increased from 5.88 to 6.11. The total color difference of composite bread in terms of crumb and crust increased with the addition of FM flour. Proximate composition of composite bread revealed decrease in moisture and protein contents and increase in ash, fiber, fat contents and carbohydrate at p < 0.05. Incorporation of FM flour decreased the volume and specific volume of bread from 400 to 256.67 mL and 2.69 to 1.81. mL/g, respectively. However, the weight of bread increased from 141.77 to 148.52 g.

Contents of Metal(loid)s in a Traditional Ethiopian Flat Bread (Injera), Dietary Intake, and Health Risk Assessment in Addis Ababa, Ethiopia

The traditional Ethiopian flat bread, injera, is a regular component of daily diets in Ethiopia and Eritrea. This bread is also popular among urban refugees particularly Eritreans in Addis Ababa. The levels of metal(loid)s in 40 composite (120 sub-samples) injera samples, representing 4 types of market establishments in Addis Ababa, were determined using inductively coupled plasma-mass spectrometry (ICP-MS) and portable X-ray fluorescence (PXRF). For ICP-MS analysis, the accuracy of the method was evaluated by the analysis of a certified reference material and recovery experiments. It was found that the correlations between the mean levels of Al and Fe and between Al and Mn in injera were highly significant (p < 0.001). It was also found that 1.5 fresh injeras would cover 48-75% of recommended dietary allowance (RDA) for Mg, 17-21% of RDA for K, 19-23% of RDA for Ca, and 60-72% of RDA for P for an adult group aged between 19 and 50. Daily intakes of Al, Fe, and Mn were found to be above the provisional tolerable daily intake (PTDI)/maximum tolerable daily intake (MTDI) values. The mean target hazard quotient (THQ) values for Fe and Mn were greater than 1. The total THQ values varied from 6.52 to 8.53 among market establishments. Estimating carcinogenic risk due to exposure to As, Cr, and Pb indicated that perennial injera consumers might remain at cancer risk. This would further escalate if other staple food items and spices are considered. Hence, there is a need for home-based strategies to reduce extrinsic soil-Al-Fe-Mn in injera/tef batter.

Nitrogen availability and genotype affect major nutritional quality parameters of tef grain grown under irrigation

Worldwide demand for tef (Eragrostis tef) as a functional food for human consumption is increasing, thanks to its nutritional benefits and gluten-free properties. As a result, tef in now grown outside its native environment in Ethiopia and thus information is required regarding plant nutrition demands in these areas, as well as resulting grain health-related composition. In the current work, two tef genotypes were grown in Israel under irrigation in two platforms, plots in the field and pots in a greenhouse, with four and five nitrogen treatments, respectively. Nutritional and health-related quality traits were analyzed, including mineral content, fatty acid composition, hydrophilic and lipophilic antioxidative capacity, total phenolic content and basic polyphenolic profile. Our results show that tef genotypes differ in their nutritional composition, e.g. higher phenolic contents in the brown compared to the white genotype. Additionally, nitrogen availability positively affected grain fatty acid composition and iron levels in both experiments, while negatively affecting total phenolics in the field trials. To conclude, nitrogen fertilization is crucial for crop growth and productivity, however it also implicates nutritional value of the grains as food. These effects should be considered when fertilizing tef with nitrogen, to optimize both crop productivity and nutritional effects.