Teff Grain Research Articles

Comparative assessment of levels and dietary intake of mineral nutrients and toxic metals in different varieties of teff from Hidabu Abote, Ethiopia

Ethiopia is the largest teff (Eragrostis teff Zucc) producer in the world. This research was intended to determine the levels of mineral nutrients and non-essential metals in the teff samples. After optimization, the samples were wet-digested using reagents (5 mL HNO3 and 1 mL HClO4), at a temperature of 230 °C for 2:30 h. Inductively coupled plasma optical emission spectrometry was used for the analysis of mineral nutrients and toxic metals in the teff samples. Under the optimum procedure, the coefficients of determination (R2) ranged between 0.9980 and 0.9999. The limits of detections (LODs) and limits of quantifications (LOQs) were in the range of 0.036–14.49 mg/kg and 0.111–43.93 mg/kg, respectively. The recovery ranged from 80.72 % to 107.79 %. The overall mean concentration in the three types of teff samples determined (mg/kg) was in the range of P (3890–4853), K (3040–3784), Ca (1906–1959), Mg (1402–1698), Fe (128–305), Mn (64–127.8), Na (50–136.5), Zn (19.8–27.3), B (1.8–21.9), Cu (4.17–6.9), Ni (2.6–4.05), Hg (1.8–4.0), Pb (0.048–3.7), Cd (0.012–2.09), As (0.02–0.24), with% RSD ranging between 0.017 and 11.1 %. The results obtained revealed that teff grain is a good source of minerals and contains a significant amount of toxic elements like Cd, Hg, As, and Pb.

Influence of Heat Moisture, Ultrasonication, and Gamma Irradiation on Pasting, Thermal, Morphological, and Physicochemical Properties of Indian Teff (Eragrostis tef) Starch

AbstractThe present work is conducted to study the effect of heat‐moisture treatment (HMT), ultrasonication (US), and gamma‐irradiation (GI) on various properties of teff starch. Starch is subjected to HMT at 28% moisture level, US at a frequency of 20 kHz for 30 and 60 min, and GI at 5 and 10 kGy. US has an increased swelling power (8.22–9.39 g g−1) and solubility (9.5–10.5%). Water binding and Oil binding capacity are improved in modified starches than native. The highest amylose content (24.94–25.24%) is observed in US than native (20.82%). Thermal characteristics show an increment in the modified teff starches with enthalpies varied from 2.30 to 3.81 J g−1. Significant differences in starch gel textural properties are identified. Similar outcomes for native and modified findings are seen in Fourier transform infrared spectroscopy spectra. X‐ray diffraction shows a similar X‐ray pattern with crystallinity decreases for HMT (28.07%) and gamma irradiated starches (30.21%) and increases for ultrasonicated samples (32.23%). The morphological changes in teff starch are observed after physical modification. All in all, significant improvements have been reported in modified teff starch, which not only increases its industrial application but also improves the utilization of teff grain globally.

Standardization of teff (Eragrostis teff) injera making process conditions for better physicochemical and sensory quality.

Injera is a type of flatbread that is fermented, naturally leavened, and native to Ethiopia. However, injera quality can vary depending on the processing steps used, even if the same variety of teff is used. This research was conducted to optimize the prebaking processing and baking conditions to produce better quality teff injera suitable for industrial and export purposes. Four experiments were conducted to optimize the injera-making process. The first two phases focused on optimizing the prebaking processing conditions (fermentation temperature and time, absit mixing ratio, absit cooking time, and secondary fermentation time). The best physicochemical qualities were obtained at a primary fermentation temperature of 25°C for 64 h, an 8% mixing ratio of absit with 10 min of cooking, and a secondary fermentation time of 4 h. In the third phase, baking temperature (195 ± 5, 215 ± 5, 235 ± 5, and 255 ± 5°C) and time (1, 2, and 3 min) were evaluated. The results showed that the best response variables were obtained at a temperature of 255 ± 5°C for 2 min or 235 ± 5°C for 3 min. Finally, the optimized conditions were validated on five different varieties [DZ-Cr-387, DZ-Cr-2124, white (T-BT), white (T-GK), and sergegna teff (T-E)] of teff grain. The results indicated that the optimized conditions could produce better quality and consistent teff injera on a large commercial scale, which would suit both local and export markets.

Investigation of elemental composition in red teff grains using inductively coupled plasma optical emission spectroscopy (ICP OES), Sire District, Arsi zone, Ethiopia

BackgroundMinerals are important not only for better plant growth and development but also for human and animal nutrition. It is known that east and west Gojam in the Amhara region and east and west Shoa areas in the Oromia region Ethiopia's most teff growing areas. However, there is no information on the mineral content and nutritional worth of Teff Sire district, Arsi zone, Ethiopia. Since ICP OES is a powerful technique to examine elemental compositions even in lower concentration, it is used in this work to investigate the elemental composition of red teff samples. MethodsThe elemental compositions of red Teff grain samples were determined using ICP-OES from three sites: S1, S2, and S3 of Sire district, Arsi zone, Ethiopia. Wet digestion of the teff samples was carried out by weighing 0.5 g red teff sample and digested with 8 ml HNO3 and 2 ml H2O2 (30%) for 3:00 h at a temperature of 100℃ on hot plate. The investigations of method validation, limit of detection and limit of quantification were also carried out. ResultsThe average amount of elements in red teff sample obtained as 172–280 mg/kg Fe, 13–76 mg/kg Mn, 8.2–8.5 mg/kg Cu, 24–26 mg/kg Zn, and toxic trace elements 0.12–0.29 mg/kg Pb and 0.15–0.22 mg/kg Cd. The limit of detection found in ranges from 0.21 mg Kg−1 to 10.44 mg Kg−1 whereas quantification limit resulted in 0.7 mg Kg−1 to 34.8 mg Kg−1 for the metals under consideration. The method was validated by its linear range in the concentration range of 0.028–1.4 ppm or 0.056–2.8 ppm and excellent recovery result was achieved in the range of 90–120%. ConclusionThis study aimed to investigate the mineral content in red teff cultivated in Ethiopia specifically Arsi zone by using ICP OES. From the obtained results, Iron was the first abundant essential element in red teff compared to Mn, Cu and Zn. The level of trace elements: Cd and Pb in the samples slightly above the acceptable limit, possibly due to agricultural practices like usage of fertilizers, pesticides, and other industrial products. Overall, this red teff elemental composition information contributes to the nutrition database and food safety in Ethiopia and beyond.

Nutritional and Microbial Quality of teff Grain as Influenced by Economically Motivated Adulteration Along the Supply Chain

Teff is a gluten-free cereal crop widely cultivated in Ethiopia and is a critical ingredient in making injera, a unique flatbread. However, there is a significant issue with adulteration of teff, impacting its safety and quality. This study evaluated economically-driven adulteration effects on teff grains' nutritional and microbial quality. A preliminary survey revealed that it is a common practice to adulterate teff grains with inexpensive and inedible materials throughout the supply chain in the study area. One hundred and thirty teff grain samples were collected from producers, collectors, whole-sellers, and retailers in the cities of Tulu bolo and Jimma to determine the types and extents of adulterants present and their effect on the nutritional and microbial quality of the grains. They were mixed separately to create composite samples representing different supply chain actors. Standard protocols were used to evaluate nutritional and microbial quality. The results showed significant differences among the supply chain actors regarding identified adulterants, nutritional content, and microbial quality. The study identified chaff, soil + sand, and dukkaa (a combination of nonedible substances separated from teff grains in milling houses and warehouses) as the significant adulterants, with mean ranges of 1.17–8.07%, 1.29–7.23%, and 8.93–37.13% respectively. The study also evaluated the proximate composition and microbial load of the teff samples collected from different supply chain actors. The ranges of values for moisture, protein, fat, ash, fiber, carbohydrate, and energy were 8.33–10.53%, 6.49–9.42%, 2.29–3.86%, 2.33–6.39%, 2.42–3.95%, 70.9–73.76%, and 333.52–361.9 kcal, respectively. The microbial load showed ranges of 6.92–7.98, 3.17–3.22, 1.78–2.04, 6.73–7.89, and 6.88–7.93 log CFU/g for Total Plate Count, Escherichia coli, Salmonella, mold, and yeast, respectively. The results showed an increase in teff adulteration from producers to Jimma retailers, indicating multiple-stage adulteration throughout the supply chain, posing a threat to product safety and quality. The study recommends good coordination among the bodies responsible for food safety, producers, and consumers to mitigate this issue effectively.

Landscape and Micronutrient Fertilizer Effect on Agro-Fortified Wheat and Teff Grain Nutrient Concentration in Western Amhara

Agronomic biofortification, encompassing the use of mineral and organic nutrient resources which improve micronutrient concentrations in staple crops is a potential strategy to promote the production of and access to micronutrient-dense foods at the farm level. However, the heterogeneity of smallholder farming landscapes presents challenges on implementing agronomic biofortification. Here, we test the effects of zinc (Zn)- and selenium (Se)-containing fertilizer on micronutrient concentrations of wheat (Triticum aestivum L.) and teff (Eragrostis tef (Zucc.) Trotter) grown under different landscape positions and with different micronutrient fertilizer application methods in the western Amhara region of Ethiopia. Field experiments were established in three landscape positions at three sites, with five treatments falling into three broad categories: (1) nitrogen (N) fertilizer rate; (2) micronutrient fertilizer application method; (3) sole or co-application of Zn and Se fertilizer. Treatments were replicated across five farms per landscape position and over two cropping seasons (2018 and 2019). Grain Zn concentration ranged from 26.6 to 36.4 mg kg−1 in wheat and 28.5–31.2 mg kg−1 in teff. Grain Se concentration ranged from 0.02 to 0.59 mg kg−1 in wheat while larger concentrations of between 1.01 and 1.55 mg kg−1 were attained in teff. Larger concentrations of Zn and Se were consistently attained when a foliar fertilizer was applied. Application of ⅓ nitrogen (N) yielded significantly larger grain Se concentration in wheat compared to a recommended N application rate. A moderate landscape effect on grain Zn concentration was observed in wheat but not in teff. In contrast, strong evidence of a landscape effect was observed for wheat and teff grain Se concentration. There was no evidence for any interaction of the treatment contrasts with landscape position except in teff, where an interaction effect between landscape position and Se application was observed. Our findings indicate an effect of Zn, Se, N, landscape position, and its interaction effect with Se on grain micronutrient concentrations. Agronomic biofortification of wheat and teff with micronutrient fertilizers is influenced by landscape position, the micronutrient fertilizer application method and N fertilizer management. The complexity of smallholder environmental settings and different farmer socio-economic opportunities calls for the optimization of nutritional agronomy landscape trials. Targeted application of micronutrient fertilizers across a landscape gradient is therefore required in ongoing agronomic biofortification interventions, in addition to the micronutrient fertilizer application method and the N fertilizer management strategy.

Multielement analysis coupled with chemometrics modelling for geographical origin classification of teff [Eragrostis tef (Zuccagni) Trotter] grains from Amhara Region, Ethiopia

Teff [Eragrostis tef (Zuccagni) Trotter] is an indigenous crop in Ethiopia, and Amhara region is the predominant teff producing region in the country. This study was aimed at developing an analytical methodology useful to determine the geographical origin of teff produced in the Amhara Region, based on multielement analysis combined with multivariate statistical techniques. For this, a total of 72 teff grain samples were collected from three zones (West Gojjam, East Gojjam, and Awi) and analysed for K, Na, Mg, Ca, Mn, Cu, Fe, Co, Ni, Zn, Cr, and Cd contents using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The digestion and ICP-OES analysis method were accurate, with percentage recovery ranging 85.5 to 109% across the different metals analysed. Principal component analysis (PCA) and linear discriminant analysis (LDA) were applied to discriminate samples based on their production regions. Magnesium, Ca, Fe, Mn, and Zn were the most discriminating elements among the samples. The LDA model provided 96% correct classification of samples into production regions and varietal types, with an average prediction ability of 92%. Hence, the multielement analysis combined with statistical modeling can be used in the authentication of the geographical origin and varietal type of teff from Amhara region.

Ascorbic Acid Content and Antioxidant Activities of White and Brown Teff [Eragrostic tef (Zucc.)Trotter] Grains and Injera.

Teff [Eragrostis tef (Zuccagni) Trotter] is a cereal grain originating in Ethiopia as a staple food for millions of people. Its grain is a gluten-free superfood and got acceptance as a medicinal ingredient. Therefore, it is worthwhile to determine the antioxidative activities and L-ascorbic acid contents of teff grain and its baked food (injera). This study aimed to determine the ascorbic acid contents and antioxidant activities in the aqueous extract of the white and brown teff grains and their injera samples using iodimetric titration and UV-Vis spectrophotometric methods, respectively. The ascorbic acid contents in the white and brown teff ranged from 67.9-112.6 mg/100 g and 69.2-117.2 mg/100 g, respectively, and those in injera of the selected teff samples ranged from 30.5-32.9 mg/100 g and 37.3-43.0 mg/100 g, respectively. The antioxidant activities ranged from 1.26-7.04 μmol AAE/g for the white teff grains, 1.44-6.29 μmol AAE/g for the brown teff grains, 1.81-2.47 μmol AAE/g for white teff injera, and 3.89-4.86 μmol AAE/g for the brown teff injera samples. Findings of the present study have revealed that white teff and brown teff grains and their injera were found to have a higher content of ascorbic acid than commonly consumed grains and vegetables. No significant difference (α = 0.05) has been observed between the two varieties of teff grains with respect to the ascorbic acid content and antioxidant activities. However, there was a statistically significant difference (α = 0.05) in the ascorbic acid content and antioxidant activities between the teff grains and their injera samples. Therefore, this study indicated that teff grains and injera are rich in ascorbic acid content and antioxidant activities as compared to other cereal grains and are very crucial for human nutrition and health.

Water-soluble total sugars and total free amino acids of the two varieties of teff [Eragrostic tef (Zuccagni) Trotter] cultivated in different regions of Ethiopia

ABSTRACT. Teff [Eragrostis tef (Zuccagni) Trotter] is cereal grain native to Ethiopia as staple food to millions of people. However, no research work has been reported for characterization with respect to water-soluble total sugars and total free amino acids in white and brown teff grains. The main objective of this study was to determine water-soluble total sugars and total free amino acids (TFAA) in the white and brown teff grain varieties. The determined water-soluble total sugar contents of white and brown teff grain sample extract was ranged between 2.69±0.12 – 4.56±0.08 g GE/100 g and 2.22±0.04 – 4.74±0.19 g GE/100 g, respectively. The mean TFAA contents for white and brown teff samples was found in the range between 181.4±30.0 – 638.9±42.6 mg AE/100 g and 471.7±37.0 – 927.1±32.4 mg AE/100 g, respectively. The mean value of the TFAA in brown teff samples was found higher than that of white teff samples. Pearson correlation was in the opposite direction, indicating that the biosynthetic pathways for the water-soluble total sugars and TFAA in both white and brown teff varieties might be opposite. Therefore, the present study indicated that teff is rich in the water-soluble total sugars and TFAA.
 
 KEY WORDS: Teff, Sugars, Amino acids, Glucose, Ninhydrin, UV-Vis spectrophotometry
 
 Bull. Chem. Soc. Ethiop. 2023, 37(2), 299-313. 
 DOI: https://dx.doi.org/10.4314/bcse.v37i2.5

Development of Green UV-Vis Method for Direct Determination of Total Sugars in the Aqueous Extract of Teff (Eragrostis tef (Zuccagni) Trotter) Grains and Other Cereals.

There is no ultraviolet visible (UV-Vis) spectrophotometric method for the direct determination of total sugars in the aqueous extract of teff grain samples. Therefore, the objective of this study was to develop a green UV-Vis spectrophotometric method to determine total sugars in the aqueous extract of white teff, brown teff, white rice, and red wheat grain samples. The calibration curve was established in the range of 20.11-7,907 mg/L using sucrose as a standard with R 2 = 0.9996. The limit of detection and limit of quantification were 4.4 and 14.6 mg/L, respectively. The relative standard deviation (6.9%) of the method for the sucrose standard was within the acceptable range indicating that the method is precise. The amount of total sugars determined in the white teff (5.48-9.44% (w/w), brown teff (6.17-10.32% (w/w)), white rice (3.19% (w/w)), and red wheat (9.22% (w/w)) grain samples was comparable with other reported cereal grains. Furthermore, the accuracy of the developed analytical method was also evaluated by spiking the known amount of the sucrose standard solution to the white teff, brown teff, white rice, and red wheat sample extracts, and percentage recoveries found were in the acceptable range (85 ± 2 - 105 ± 4%) with an average recovery of 93%, confirming that the new green method is quantitatively reproducible. Hence, a fast, simple, inexpensive, widely used, selective, sensitive, precise, and accurate green UV-Vis method was developed and validated for the direct determination of total sugars in the aqueous extract of teff, white rice, and red wheat grain samples.

Total phenolics and antioxidant capacity of the white and brown teff [Eragrostic tef (Zuccagni) trotter] varieties cultivated in different parts of Ethiopia

ABSTRACT. This study was aimed to determine the total phenolics contents and antioxidant capacity of white and brown teff grain samples. The free total polyphenolic content (TPPC), bound TPPC and total flavonoids content ranged from 62.1–129.9, 84.6–189.6 mg GAE/100 g and 84.4–195.1 mg QE/100 g, respectively, in white teff samples, and, 118.6–196.7, 141.1–195.1 mg GAE/100 g and 97.8–202.5 mg QE/100 g, respectively, in brown teff samples. Besides, the free 2,2-diphenyl-1-picrylhydrazyl (DPPH) and bound DPPH ranged from 74.8–98.3, 77.1–99.9 mg AAE/100 g, respectively, for white teff samples, and, 68.7–93.1 and 71.2–99.4 mg AAE/100 g, respectively, for brown teff samples. This study revealed that total phenolics content was higher in brown teff samples than white teff samples and is in agreement with other reports. However, their DPPH scavenging activities were nearly equal, indicating that both varieties of teff are relevant for human nutrition and health. Furthermore, the dendrogram has shown sharp separation of the samples based on their origin and variety related to the total phenolics parameters. Hence, findings of this study can help consumers appreciate the nutritional value of white and brown teff grains; provide them guidance for teff purchase and production.
 
 KEY WORDS: Teff, Phenolics, Gallic acid, Ascorbic acid, Anti-oxidant, DPPH
 
 Bull. Chem. Soc. Ethiop. 2022, 36(4), 749-766. 
 DOI: https://dx.doi.org/10.4314/bcse.v36i4.3

Determinant Factors of Teff Production in Lokka Abbaya Woreda of Sidama Regional State: Ethiopia

One of the important sectors in low-income nations like Ethiopia is agriculture. To provide for the needs of its population in terms of food is the foundation of an economy. It is essential to the nation's economy and gives the people of the nation sources of work. Many people on the African continent rely on the agricultural industry. Agriculture employs 85% of the labor force, accounts for 50% of GDP, 90% of total exports, and supplies 70% of the country's raw materials to the agro-industrial sector (World Bank 2011). Teff, a cereal with small grains that was once produced for human consumption. It has been grown for thousands of years in East Africa (D. Andrea 2008). In Africa, it is a necessary food item. It has been growing under certain climatic circumstances, including those that range from sea level to 2800 meters above sea level, the necessary temperature, rainfall, and soil requirements (D. Milkias and A. Abdulahin 2018). The average output of teff grain per hectare in Ethiopia was 1228 kg. It anticipates increasing production by 2500 kg ha-1 with the employment of modern farming techniques and management strategies (Wato T. 2019). Therefore, the goal of this study is to examine determining factors that affect small farmers' ability to produce teff in the Lokka abbaya woreda of Sidama regional state, as well as to look at related difficulties and challenges in order to provide solutions. The researcher surveyed farmers and obtained questionnaires from the participants. The sample size was determined to be 63 out of all household heads from three kebele.Agriculture is a significant sector in low-income countries like Ethiopia. An economy's cornerstone is its ability to provide the food needs of its population. It provides the people of the nation with sources of employment and is crucial to the nation's economy. On the African continent, the agricultural sector supports a large population. 85 percent of the workforce is employed in agriculture, which also generates 50 percent of the country's GDP, 90 percent of its exports, and provides 70 percent of its raw materials to the agro-industrial sector (World Bank 2011). Small-grain cereal called teff, which was formerly created for human consumption. In East Africa, it has been grown for countless years (D. Andrea 2008). It is a necessary food staple in Ethiopia. Keywords : Agriculture, sector, Teff production, Ethiopia, determine factors DOI: 10.7176/JNSR/13-14-03 Publication date: July 31 st 2022

Vertisols in the Ethiopian Highlands: Interaction between Land Use Systems, Soil Properties, and Different Types of Fertilizer Applied to Teff and Wheat

Vertisols are among the most extensive soil types in the Ethiopian highlands, occurring in a wide range of agro-ecological zones where complex crop–livestock-based farming systems are practiced. Sustainable soil management on vertisols always meets with physical characteristics that are driven by clay mineralogy, swelling, shrinking, and risk of temporary waterlogging. The latter causes substantial spatial variability and turns vertisols into obnoxious study material, when compared to other soil classification orders. In this study, we have explored soil properties across different farming systems using soil profile and analytical data generated by the CASCAPE project; an action research project funded by the Dutch government for capacity building on the scaling up of evidence-based best practices for increased agricultural production in Ethiopia. In addition, the effects of variations in vertisol properties on crop yield and fertilizer response were examined through fertilizer trials in different locations. Teff (Eragrostis teff Zucc.) and wheat (Triticum aestivium), the two cereal crops commonly grown on vertisols, were used as test crops. Five treatments of NPSZnB—nitrogen, phosphorous, sulfur, zinc and boron containing blend (50, 100, 150, 200 and 300 kg/ha)—and two treatments comparing NPS and diammonium phosphate (DAP) with the blend containing Zn and B were included in a randomized complete block design with three replications. Results revealed that soil quality was generally poor under the highland cereal systems, i.e., sorghum–teff–livestock mixed system (FS1) and wheat–maize–teff–barley–livestock system (FS2) compared to the enset–coffee–cereal–livestock complex system (FS3), which cannot only be attributed to geological history, but also to the way the land use systems have shaped the soils. The emerging differences in soil properties significantly (p < 0.01) affected crop yields. The soil properties that had the largest influence on teff and wheat yield were soil pH, organic carbon (OC), available sulfur (S), exchangeable potassium (K) and some micronutrients (B, Fe, Mn and Cu). Teff grain and biomass yield were inversely related, unlike wheat. Regarding the rate of fertilizer application, wheat responded significantly up to the highest level (300 kg/ha), but teff yield leveled off earlier. The blend fertilizers did not perform any better than NPS or DAP alone. Given the extent and the importance of vertisols in Ethiopian agriculture, comprehensive future outlooks are needed, including the options for cluster farming and mechanization to realize economies of scale and more efficient use of capital and labor inputs.

GC-MS profiling of fatty acids and nutritional properties of the white and brown teff [Eragrostis tef (Zuccagni) Trotter] varieties cultivated in different parts of Ethiopia

The main objective of this study was to determine the fatty acid profiles and evaluate the nutritional properties of the white and brown teff grain samples using GC–MS method. The linoleic acid, oleic acid and palmitic acid, respectively, were the dominant compounds in the white and brown teff grain samples accounting for about 73 % and 72.2 % of the total fatty acid content, respectively. The ratio of ω-6/ω-3 found in the present study was 2.29–2.67 % and 2.23–2.54 % for the white and brown teff samples, respectively, and is comparable with the suggested 1–2:1 ratio for normal human growth and development. The atherogenicity and thrombogenicity indices used to determine the lipid quality of the teff grain samples has indicated excellent status of the grains compared to other cereal grains which are useful for the human nutrition and health.

Levels of Trace and Other Selected Metals in Mixed Teff Grain Samples

Levels of Trace and Other Selected Metals in Mixed Teff Grain Samples

Pollen Study in Two Improved Varieties of Manihot esculenta Crantz

Teff [Eragrostis tef (Zuccagni) Trotter], is a cereal crop species unique to Ethiopia, where it is an important staple food crop. It is grown for its tiny nutritious seeds. Even though, it is highly adapted to different agro-ecological conditions, its yield is constrained by different factors including declining soil fertility and improper utilization of fertilizer. An experiment was conducted to validate blended fertilizer formulas and levels under limed and unlimed conditions on teff grain yield and soil chemical properties of Nedjo area, west Wollega, Ethiopia. The treatments were comprised of eleven different types and levels of fertilizers[Blanket NP recommended(RNP), NPSB, NPSZnB, modified NPSZnB, NPKSZnB, RNP+lime, NPSB+lime, NPSZnB+lime, modified NPSZnB+lime, NPKSZnB+lime (after Agricultural Transformation Agency, ATA) and Control(0)]. The most yielder teff variety Kuncho was used as a test crop and planted in 20cm row spacing. The experiment was laid out in RCB design with three replications. The result revealed that application of balanced fertilization (macro and micro nutrients) + lime (treatment no, 11) has significantly increased grain yield compared with other treatments. Treatment no 7 (Recommended NP + lime) gave better grain yield. Treatment number 11 and 7 increased the grain yield 1322% and 978% respectively compared to the control. Blended fertilizers which have lime in addition showed a gradual pH increase and a sharp decline of exchangeable acidity. The available phosphorous of the soil was improved from 5.508 to 6.748 ppm with the application of recommended NP and lime (treatment 7).Calcium content of the soil has showed an improvement with the application of lime. It is concluded that balanced fertilization with lime has significant and positive response to teff yield and improves some acid soil parameters in the study area. Hence, it is recommended to apply macro and micro nutrients (balanced fertilization) with lime in order to attain optimum grain yield of teff around Nedjo area western wollega. Keywords: Acidic soil, blended fertilizer, Eragrostis tef (Zucc.) Trotter , lime DOI : 10.7176/JNSR/9-1-01

Effect of roasting treatments on total phenol, antioxidant activity, fatty acid compositions, and phenolic compounds of teff grains

AbstractBackground and objectivesTeff grains are subjected to several treatments, such as cooking and baking, and studies on the impact of thermal treatments such as roasting on the bioactive properties, phenolic compounds, fatty acids, and minerals of teff grains are scarce. The objective of this study was to evaluate the effect of microwave and oven roasting processes on total phenol, antioxidant activity, fatty acid compositions, and phenolic compounds of teff grains.FindingsRoasting treatments greatly influenced the biochemical content and bioactive properties of teff grains. Roasting increased oil, carotenoids, total flavonoids, and antioxidant activity of teff grains with the highest values being observed in microwave‐roasted grains, except total flavonoids of soluble fraction which was highest in oven‐roasted grains. It also increased total phenolic of soluble fraction and most phenolic compounds in both soluble and bound fractions with the highest values being found in conventional oven‐roasted grains, except gallic acid, trans‐cinnamic acid, naringenin, and isorhamnetin which were high in control samples. In addition, oven roasting increased palmitic acid, linoleic acid, nickel, and boron, whereas microwave roasting increased the content of stearic acid, calcium, magnesium, sodium, iron, copper, zinc, and lead of teff grains compared to controls.ConclusionsThe findings of this study indicate that teff grains are suitable sources of nutrients and bioactive compounds that could be enhanced by roasting.Significance and noveltyThe teff grains have high nutritional value, antioxidants, fatty acids, and phenolic compounds which are improved by roasting treatment and hence probable potential application in functional foods. Studying the effects of processing treatments such as roasting of teff grain will help in promoting the worldwide utilization of this important gluten‐free cereal.

Tillage and crop management impacts on soil loss and crop yields in northwestern Ethiopia

Lack of appropriate agronomic practices is one of the major causes for soil erosion and low yields in teff (Eragrostis tef [Zucc.]) production in Ethiopia. A 3-yr study was conducted at the Aba Gerima watershed in northwestern Ethiopia, to investigate the effects of two tillage practices (reduced tillage [RT] and conventional tillage [CT]), two planting methods (row planting [RP] and broadcast planting [BP]), and two compaction options (with [+T] and without [–T] trampling) on soil loss and teff yields in a split-split plot arrangement. Sediment concentration ranged from 0.01 to 5.37 g L−1 (mean, 0.25 g L−1) in our study. Accordingly, the estimated total (August–October) soil loss ranged from 0.2 to 0.5 t ha–1 (mean, 0.3 t ha–1). The sediment concentration and total soil loss were significantly influenced (P < 0.05) by tillage, planting methods, and trampling only in the third monitoring year. RT reduced soil loss by 19% relative to that of CT, whereas RP resulted in a 13% reduction in soil loss over BP. The −T plots showed a 15% reduction in soil loss as compared to + T plots. Results revealed significant increase in soil total carbon and nitrogen in RT and –T. Less soil loss and greater teff grain yield were obtained in plots with improved agronomic practices (RT and RP) compared to conventional ones (CT and BP). Based on our findings we conclude that the use of RT, RP, and –T practices can effectively minimize soil loss without any crop yield penalty.

Levels of selected metals in teff grain samples collected from three different areas of Ethiopia by microwave plasma-atomic emission spectroscopy

The levels of selected essential and non-essential metals in the white, red, and mixed teff grains collected from Bure, Debre Markos and Bahir Dar (Ethiopia) were determined by microwave plasma-atomic emission spectroscopy (MP-AES). After proper sample pretreatment, the powdered teff was wet digested with the acid mixture (5 mL HNO3:1 mL HClO4) at 240 oC for 2:30 h over Kjeldhal digestion block. The accuracy of the optimized procedure was evaluated by analyzing the digest of the spiked samples with a standard solution of metals, and the percentage recoveries varied from 92% to 104%. The mean concentrations of metals determined (mg/kg, dry weight) were in the ranges of Al (713-1513) &gt; Fe (252-1195) &gt; Ca (233-348) &gt; Zn (69-102) &gt; Mn (20-45) &gt; Cu (13-15) &gt; Pb (1.8-2.8) &gt; Cd (0.8-1.8). In this study, Al and Cd were determined in the teff for the first time. Analysis of variance indicated no significant difference between the mean concentrations of Cu and Mn among the white teff samples, Mn among the red teff samples and Cd and Pb among the mixed teff samples, but there was a significant difference for the other studied metals among the corresponding teff samples at 95% confidence level.&#x0D; &#x0D; KEY WORDS: Teff grain, Eragrostistef (Zucc.) Trotter, Essential metals, Non-essential metals, Ethiopia&#x0D; &#x0D; Bull. Chem. Soc. Ethiop. 2020, 34(3), 449-462.&#x0D; DOI: https://dx.doi.org/10.4314/bcse.v34i3.2

Volatile compounds in two varieties of teff (Eragrostis tef (Zuccagni) Trotter) cultivated in Ethiopia by gas chromatography-mass spectrometry

ABSTRACT This study was aimed to investigate volatile compounds of white and brown teff grain samples using the hydro-distillation and its extract in dichloromethane and n-hexane by gas chromatography-mass spectrometry. The optimized time for the hydro-distillation of the white and brown teff grain samples was nine hours. The dominant volatile compounds identified in the white and brown teff grain samples of the dichloromethane extract corresponding to peak area proportion were furfural (29.9%, 38.1%) and 5-methyl-2-furancarboxaldehyde (15.1%, 23.8%), respectively. The relative amount of dominant volatile compounds determined in the white teff grain sample of the n-hexane extract were 10.2% and 7.27% for the 5-methyl-2-furancarboxaldehyde and 2-[(methylthio)methyl]furan, respectively, and 18.4%, 16.0%, 12.5% and 9.73%, for the furfural, 5-methyl-2-furancarboxaldehyde, 2-[(methylthio)methyl]furan and benzeneacetaldehyde, respectively, for the brown teff grain sample. This study revealed that dichloromethane was efficient to extract more volatile compounds in the white teff grain sample than in the brown teff grain sample, whereas n-hexane was efficient to extract almost equal number of volatiles in both white and brown teff samples. Besides, aldehydes were the major constituents of the white and brown teff grain samples in both dichloromethane and n-hexane extracts.