Fatty Acid Profile, Total Phenolic Content, and Antioxidant Activity of Niger Seed (Guizotia abyssinica) and Linseed (Linum usitatissimum)

Fatty acid composition and antioxidant content are major determinants of vegetable oil quality. Antioxidants are important food components, and there is an increasing interest of replacing synthetic antioxidants with those from natural sources for food industry. The objective of this study was to evaluate fatty acid composition, total phenolic, carotenoid and chlorophyll contents, and antioxidant capacity of different varieties of two oilseed crops. Five niger seed and eight linseed varieties were used. For the analysis of fatty acid composition of the seed oil, gas chromatography method was used. Standard methods were used for total phenolic, carotenoid and chlorophyll contents, and antioxidant properties. In niger seed oil, linoleic acid (C18:2) was the dominant fatty acid, accounting for 73.3% (variety Esete) to 76.8% (variety Ginchi) of the total fatty acids. In linseed oil, linolenic acid (C18:3) was the dominant fatty acid accounting for 55.7 (variety Chilalo) to 60.1 (variety Belaye-96). The total phenolic content ranged from 22.4 mg GAE/g (variety Esete) to 27.9 mg GAE/g (variety Ginchi) in niger seed and from 20.5 mg GAE/g (variety Belay-96) to 25.4 mg GAE/g (variety Ci-1525) in linseed. In niger seed, variety Fogera had the highest values for FRAP and radical scavenging activity. The carotenoid content also showed significant variation among the varieties ranging from 2.57 (Esete) to 8.08 (Kuyu) mu mol/g for niger and 4.13 (Tole) to 8.66 (Belay-96) mu mol/g for linseed. The FRAP assay showed that variety Fogera of niger seed and variety Chilalo of linseed came on top among their respective varieties with values of 57.2 and 30.6, respectively. Both niger seed and linseed were shown to be rich in bioactive compounds. However, significant variation was observed among the varieties of each crop and among the two crops in their total phenolic and carotenoid contents as well as ferric reducing potential and radical scavenging capacity. Principal component analysis revealed the presence of more than one group in both niger seed and linseed. Hence, genetic variation among the varieties should be utilized for improving their desirable characteristics through breeding. Both oil crops can be used as the source of antioxidants for replacing synthetic compounds

Mineral and Anti-Nutritional Contents of Niger Seed (Guizotia abyssinica (L.f.) Cass., Linseed (Linumusitatissimum L.) and Sesame (Sesamumindicum L.) Varieties Grown in Ethiopia

Oilseeds are rich sources of micronutrients and contribute to combating malnutrition caused by micronutrient deficiency. The objective of this study was to investigate the mineral and anti-nutritional contents of different varieties of niger seed, linseed and sesame. Five niger seed, eight linseed and ten sesame varieties were used. Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) was used for mineral analysis and the standard method was adopted to estimate tannin and phytate. Twelve mineral elements; Ca, K, Mg, Na, P, B, Cu, Fe, Mn, S, Se and Zn were analyzed for each oilseed variety. In niger seed, phosphorous was the most abundant mineral element ranging from 661 to 867 mg/100 g and selenium was the least, ranging from 0.1 to 0.33 mg/100 g. Potassium was recorded in the range of 502 to 732 mg/100 g for linseed varieties. Calcium was the most common mineral element in sesame (1112 to 1787 mg/100 g). The average phytate contents of niger seed, linseed and sesame varieties were353 mg/100 g, 104 mg/100 g and 285 mg/100 g, respectively. Tannin ranged from 91 to 201 mg/100 g, 96 to 695 mg/100 g and 85 to 660 mg/100 g in niger seed, linseed and sesame, respectively. In conclusion, there is a significant variation among the varieties within each crop species as well as among the different oilseeds in terms of their mineral and anti-nutritional contents

Seedling survival and plantation success in the drylands of Northern Ethiopia

Abstract We studied tree seedling survival rates and plantation success of the Growth and Transformation Plan I—GTP I (2011–2015) in the drylands of Northern Ethiopia. The study was carried out in six randomly selected districts of Tigrai region that represent three agro-ecological zones: the highland, midland and lowland. A biophysical survey was conducted to assess the survival rates of tree seedlings and the success rate of the plantation interventions. The study employed both primary and secondary data sources. Results revealed that there were variations (P < 0.05) in the survival of planted tree seedlings among plantation sites of the same village, between the villages of the same district and among the districts. The regional mean survival rate of planted tree seedlings was 53%. The planting interventions were not encouraging due to lack of pre- and post-planting management, moisture stress, poor soil and site conditions, planting an unmanageable number of seedlings, weak law enforcement and lack of proper monitoring and evaluation mechanisms. In the study areas, four types of ownership were identified: private, communal, state and youth groups. Among the ownership types, private ownership had the highest rate of success, whereas community ownership had the lowest rate. For sustaining successful plantation development, watering, pre- and post-planting management of planted tree seedlings and permanent employment of guards are important