The Chemical Educator
ISSN: 1430-4171 (electronic version)
Abstract Volume 19
(2014) pp 091-095
A Quantitative Analytical Chemistry Research-based Experiment Involving Comparative Analysis of Amaranth Grain Oils Extracted from Embu and Meru Districts in Kenya
Joseph K. Rugutt*,†, Kevin Otieno Okoth‡, Ruth N. Wanjau‡, Nicholas K. Gikonyo‡, Alex Machocho‡, Kipgeno J. Rugutt§, Millie Chepkemoi Obel**, and Erick Mibei**
†Missouri State University-West Plains, Department of Chemistry,
128 Garfield, West Plains, MO 65775, JRugutt@MissouriState.edu; ‡Department of
Chemistry, Kenyatta University, School of Pure & Applied Sciences, P. O.
Box 43844-00100, Nairobi City, Kenya; §Illinois State University, Department of
Educational Administration and Foundations, College of Education, DeGarmo 331,
Campus Box 5900, Normal, IL 61790-5903; **School of Science &
Technology, Department of Biological Sciences, Kabianga University College, Main Campus, P.O.
Box 2030,20200, Kericho City, Kenya
Published: 21 March 2014
Abstract. Amaranthus cruentus grains from Meru and Nyeri regions in Kenya were milled and oil extracted by the Bligh and Dyer method. Samples of oil from grains in the same regions extracted by cold pressing method were obtained from All Grain Company in Nairobi. Triacylglycerides (TAG) was the major component of neutral lipids in oil extracted by the two methods. In Dyer and Bligh method, TAG had a mean of 76.12% while cold pressed oil had 72.09%. Phosphatidylethanolamine (PE) was the major polar lipids component in both methods of extraction. In both methods of oil extraction, linoleic acid was the most abundant fatty acid. Other fatty acids that were also found to be present in high amounts in the two methods included: oleic acid (30–34%), palmitic acid (20–23%), stearic acid (2–3%) and linolenic acid (0.8–1.2%). There was no significant difference in the saponification, acid, peroxide and iodine values. The saponification values were quite high, 187.61–189.90. The peroxide values from both methods ranged from 3.10 to 3.17 while acid values from the same analysis ranged between 1.74 and 3.92. Iodine value was found to be between 77.02 in cold pressed oil to 78.77 in oil from Dyer and Bligh method.
Key Words: In the Classroom; analytical chemistry; Amaranthus; oil; fatty acids
(*) Corresponding author. (E-mail: JRugutt@MissouriState.edu)