ETHIOPIAN MANGOES, THE RESOURCEFUL RAW MATERIAL FOR THE MANGO SEED KERNEL OIL PRODUCTION Mustefa Kemal1, Anuradha Jabasingh S1,*, Abubeker Yimam1 1Process Engineering Division, School of Chemical and Bio Engineering, Addis Ababa Institute of Technology, Addis Ababa University, Ethiopia ∗Corresponding author‘s E-mail: [email protected] ABSTRACT Drug Administration (FDA) defines cosmetics as intended to be applied to the human body for Oil extracted from the mango seed kernel, one of cleansing, beautifying, promoting attractiveness, the byproducts of juice processing industry, have or altering the appearance without affecting the application in the cosmetics industry, due to its body's structure or functions [2]. The total value antioxidant, skin whitening and anti-wrinkle of the cosmetics market in Ethiopia reached properties. The main aim of this research is to $25milion up to June 2012, according to figures determine the optimum operating condition for from the country‘s Ministry of Trade and the extraction of oil from the mango seed kernel. Industry, with the average growth rate over the A general factorial design was applied to last three years at 10%. Imported products investigate the effect of process variables on the account for around 90% of the market, with the oil yield. The optimum operating conditions for remaining 10% sourced from domestic the extraction were a particle size range of 0.25- manufacturers. Mango seed kernel oil has been 0.5 mm and extraction time of 6 h. At these used as an ingredient in soaps, shampoos and conditions, the maximum oil yield with hexane as lotions as it is a good source of phenolic solvent was 84.81% and the minimum yield was compounds [3]. Presence of high unsaponifiable 57.41%. The maximum and minimum yield for matter guarantees the use of mango kernel oil in the same operating conditions, when petroleum cosmetics industry [4]. It also has a protective ether was used as solvent was found 83.33% and effect against the harmful UV radiations [5]. 61.48%, respectively, while ethanol as solvent results a maximum yield of 57.04% and minimum The high content of stearic acid allows its yield of 23.70%. The physicochemical properties application as a preservative. Hence, it has wide of the mango oil were determined and the results applications, especially in the stearin guarantee the use of mango kernel oil for manufacturing, confectionery and soap industry cosmetic application. [6]. To start with the study, the world‘s top ten mango producers with their main varieties were Keywords: Extraction, Hexane, Mango seed identified and provided in Table.1. In the context kernel, Oil, Petroleum Ether, Yield. of Ethiopia, mango is produced in the southern and western parts of the country. The total INTRODUCTION production of mango in Ethiopia is 72,187 tons Natural oils are used in a wide variety of in 2013/14 [8]. This accounts for 7219 tons of cosmetic products including personal care as mango seed kernel, annually. The production of well as makeover products. They consist of mango at Arba Minch and Zuria Woreda is ethereal salts of glycerin with a large number of 126,800 qt with total area coverage of 634 organic acids such as citric acid, oleic acid, and hectares. Mango farmsteads in Asossa produce palmitic acid. They are excellent emollients and an average of 13,500 mangoes per farmstead [9]. are derived from a variety of plants [1]. Food and Journal of EEA, Vol. 36, July, 2018 1 Mustefa Kemal et al., Table 1. World‘s top ten mango producers, 2015 [7] The Ethiopian government has a plan to expand mango production by distributing high yielding No. Country Variety Production varieties for small scale farmers, especially, in (tons/year) the Southern region and Oromia region, by 1 India Alphonso, 16,337,400 grafting mangos of known and high yielding Badami, varieties. In Ethiopia, there are many large and Chaunsa, small scale mango juices processing industry Dasheri, Kesar, [10]. During mango processing, peel and kernel Jauhari, Lucknowi, constitute about 17-22% of the fruit. The Fazli, Totapuri, production of oil from the mango seed kernel Banganapalli, could be an efficient method of utilizing the Sindhuri, waste seed kernels. The operating conditions, Kalmi, Neelam, including the particle size, extraction time, and Langra solvent type, solid to solvent ratio, temperature 2 China Zillate, 4,351,593 and moisture content were proved to have an Mallika, Deshehari,Edw effect on the oil yield. This research aims to find ard, Saigon, optimum operating conditions to maximize the R2E2, Spooner, oil yield for the production of oil from the mango Bambaroo seed kernel. 3 Thailand Brahm Kai 2,550,600 Meu MATERIALS AND METHODS 4 Pakistan Anwar Ratol, 1784,300 Langra , Sindhri, Materials Chaunsa, Fajri, Asossa mango varieties were purchased from Samar Bahist, Kenuma and Akea juice processing house, Addis Dasehri, Saroli Ababa. Hexane, Petroleum ether, Ethanol, 5 Mexico Ataulfo, Haden, 1,632,650 Sodium hydroxide, potassium hydroxide, Tommy Atkins, hydrochloric acid, Folin Ciocalteu reagent, Kent, Keitt Gallic acid, Sodium carbonate, acetone, and 6 Indonesia Arumanis, 1,313,540 phenolphthalein were procured from Merck, Gedong 7 Brazil Espada, Rosa, 1,188,910 Germany. Bourbon, Uba 8 Bangladesh Gopalbhog, 1,047,850 Deseeding and processing Himsagar, The mangoes were peeled and deseeded. The Khirsapat, seeds were sun dried for five days. The hard Langra, Fasli, cover of the seed was decorticated manually to Ashwina, obtain the seed kernel. The seed kernel was dried Amropali 9 Philippine Champagne 823,576 in the oven at 50°C for 18 h. The dried mango mangoes seed kernel was milled in centrifugal miller with 10 Nigeria Kerosene, 790,200 a sieve size of 4 mm. Then the sample was Sherri sieved using a vibrating shaker for 15 min. Journal of EEA, Vol. 36, July, 2018 2 Ethiopian Mangoes, the Resourceful Raw Material … Moisture content of the kernel value, peroxide value and total phenolic content Seven samples of the kernel were randomly were determined. weighed and dried in an oven at 105°C and the weight was measured every 2 h. The procedure Moisture and volatile matter of oil was repeated until a constant weight was 5 g of oil was weighed and dried in an oven at obtained. The percentage moisture content of the 105 °C for 1 h. The dish was removed from the kernel was calculated using the following oven, cooled in a dissector and weighed. The formula. process was repeated until a constant weight was observed. The moisture and volatile matter was ( ) ( ) calculated using the following formula. w1 and w2 are the weight of the sample before ( ) drying and after drying respectively. Where w1 and w, are the reduction in the weight Mango oil extraction of the dried sample and the initial weight of the The experimental work was conducted using sample in g. soxhlet extractor in triplicate with three different solvents: hexane, petroleum ether and ethanol. 75 Specific gravity g mango seed kernel at three different particle The density of oil was determined using a sizes (3-1.5mm, 1.5-0.5mm and 0.5-0.25mm) specific gravity bottle. A clean and dry density were extracted using Soxhlet extracter with 300 bottle of 25 mL capacity at 30°C was weighed, mL solvents with varying treatment times (2 h, 4 filled with water and extracted oil, separately and h and 6 h). weighed again. The specific gravity was calculated using the following formula. The resulting extracts, were purified by simple distillation. The obtained fractions were weighed ( ) and physicochemical properties determined. ( ) ( ) Mango seed kernel had an oil content of 12%. Hence this was used for the calculation of yield. Where A, B and C are the weights of the specific The percentage yield was calculated as follows gravity bottle with oil, empty specific gravity bottle and empty specific gravity bottle with ( ) ( ) water at 30°C. ( ) Kinematic viscosity ( ) Kinematic viscosity of the oil was measured ( ) ( ) using Vibro viscometer. 35 mL oil sample was heated to 30°C and fed to the sample holder. The sensor of the viscometer was immersed into the Physical and chemical characterization oil, which measures the dynamic viscosity of oil. Physical properties including the moisture The kinematic viscosity is calculated using content, volatile matter, specific gravity, ( ) viscosity, pH value, refractive index and chemical properties including the saponification Where, μ and ρ are the dynamic viscosity and value, un saponifiable matter, iodine value, acid density of oil respectively. Journal of EEA, Vol. 36, July, 2018 3 Mustefa Kemal et al., Determination of pH was transferred into another separating funnel 2 g of the oil sample was added to 25 mL beaker and the extraction was repeated three times using and 13 mL of hot distilled water was added to the 50 mL portion of petroleum ether. To insure the sample in the beaker and stirred slowly. It was ether extract was free of alkali, the combined cooled in a cold water bath to 25°C. The pH ether extract was washed three times with 50 mL electrode was standardized with a buffer solution aqueous alcohol followed by 25 mL distilled and immersed into the sample [11]. water. The ether solution was transferred to 250 Ml beaker and the ether was evaporated. When Saponification value all the ether is evaporated, 3 mL of acetone was 2 g of sample was added to 250 mL flask. 25 mL added, followed by drying at 100°C for 30 min of alcoholic potassium hydroxide solution was [12]. The residue was dissolved in 50 mL of added and the flask was connected to reflux warm ethanol and titrated with 0.02 N sodium condenser, kept on the water bath and boiled hydroxide.