Extraction, Characterization and Optimazation of Essential Oil From Ethiopian Black Cumin Seed Varieties by Solvent Extraction
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Date
2016-06
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Addis Ababa University
Abstract
Black cumin seed oil has a long history of uses for food flavors, perfumes, medicinal value, cosmetics industry and in production of liquid soap, shampoos and essential ingredient in soup component, sausages, cheese, cakes, candies and for preparation curries, bread, katikala, preservation of butter and flavor food. The objective of this thesis was proximate and mineral analysis, investigation of the effects of extraction time and particle size, identification of the essential oil by GC-MS and FT-IR and extraction of essential oil was from black cumin seed varieties and characterized of psycho-chemical analysis of iodine value, saponification, acid value, pH, kinematics viscosity and specific gravity. The extraction was carried out using Soxhlet method, and determination of proximate compositions, physicochemical and functional properties of two improved black cumin essential oil seed varieties was done, Soxhlet extraction using n-hexane was chosen to investigate the effect of time and particle size on yield and quality of the extracted oil. A general full factorial design was applied to both seed varieties, and 54 experimental runs were performed followed by optimization of the two varieties of essential oil. The values of moisture content, crude protein content, crude fat, crude fiber, total ash and carbohydrate of Eden seed were 5.29 g/100g , 19.83 g/100g, 41.3 g/100g, 18.96 g/100g, 5.10 g/100g and 9.52 g/100g whereas Dirshaye registered 5.43 g/100g , 19.95 g/100g, 40.3 g/100g, 14.28 g/100g, 4.35 g/100g and 14.69 g/100g, respectively. The mineral analysis indicated that potassium is the dominant one (829.11mg/100g, 746.27mg/100mg) followed by phosphorous, calcium, sodium, iron and zinc in Eden and Dirshaye varieties. The results obtained from the experiment were analyzed using Design Expert software. The minimum oil yield was found to be 46.77% in Dirshaye variety whereas Eden contained 49.57%, after the extraction time of 2 hours with a particle size of 1.4-2.5mm. A maximum oil yield of 91.08 and 94.767% was found for Dirshaye seed and Eden Seed, respectively at the extraction time of 6 hours and at a particle size of 0.25-0.5mm. Finally GC-MS and FT-IR analysis has been carried out on the two seed oil varieties contains of linoleic, oleic and palmitic acids were the dominant fractions respectively and both seed varieties of the dominant functional component contain p-cymene but longifoline available only in Dirshaye oil by 0.51 %. Generally due to the presence of Linoleic acid, thymoquinone and high saponification value of oil suggests and guarantees the use of oil for cosmetics industry. Due to the above properties and characteristics Eden varieties have been found to possess higher yield variety and preferable for making cosmetics.
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Component, Sausages, Cheese, Cakes, Candies