Extraction, Physicochemical Characteristics and Fatty Acids Profile of Kernel Oil from Mangifera indica L. Cultivated in Sudan

Abstract

Aims: This study was aimed to investigate the physicochemical properties and fatty acids composition of Mangifera indica L. seed kernel oil; in addition to investigating the effect of solvent type and extraction duration on extracts properties.
 Study Design: Extraction of Mangifera indica L. seed kernel oil in different trials under the same conditions using two different solvents for different time of extraction, and determining their physicochemical properties and fatty acids constituents.
 Place and Duration of Study: This study was conducted at the Department of Applied and Industrial chemistry International University of Africa (IUA), Khartoum, Sudan, between July and November 2019.
 Methodology: The oil from Mangifera indica L. seed kernel was extracted using n-hexane and petroleum ether in a soxhlet apparatus for 4 and 7 h. the physicochemical properties of the extracted oils were determined using standard official methods. Fatty acid profile of n-hexane extract was identified by gas chromatography/mass spectrometer (GC/MS) after methylation. 
 Results: n-Hexane exhibits better extraction efficiency (11.40±0.66% for 7 h) than petroleum ether (10.80±0.44% for 7 h). The density and refractive index of the oil were 0.89±0.01 g/cm3 and 1.46 ± 0.01 at 28ºC respectively. The physicochemical properties of n-Hexane and petroleum ether extracts were acid value (3.35±0.54 and 2.52±0.13 mg KOH/g oil), peroxide value (4.32±0.65 and 5.11±1.03 meq O2/kg), saponification value (201.05±0.95 and 198.66±1.04 mg KOH/g oil), ester value (197.59±0.67 and 192.54±0.20 mg KOH/g oil) respectively. The statistical analysis of obtained data revealed no significant difference, at 95% confidence interval, between the standard deviation and the mean of two data sets of physicochemical properties of Mangifera indica L. seed kernel oils extracted with the two solvents used. GC/MS analysis revealed a total of 18 fatty acids were identified in which the majors are stearic acid (39.79%), oleic acid (36.77%), palmitic acid (10.34%), linoleic acid (6.02%) and eicosanoic acid (3.83%).
 Conclusion: The results suggest that mango seed kernel contains stable oil which can be potentially extracted by n-hexane; however, the solvent type has no significant effect on the physicochemical properties of the extracted oil and has the potential usefulness to be used in soap industry.