Extraction Characterization of Oils Extracted from different Parts of Red and Yellow Varieties of Anacardium occidentale (Lin)

Abstract

The objective of this study was to extract and characterized the oils from different parts of red and yellow varieties of Anacardium occidentale after extractions using Soxhlet extractor and steam distillation techniques and characterization of the bioactive components using GC/MS analysis. Physicochemical parameters of the extracted oils were analyzed, and the bioactive compositions were also examined. The results showed that the oils extracted were within 0 and 0.5% moisture content and pH values ranged from 3.7 to 4.7.  The average relative densities of the extracted oils by Soxhlet extraction and steam distillation at temperature 25^oC were 0.887 and 0.8745 g/cm³ respectively, with average saponification value of 132.45 mgKOH/g for Soxhlet extraction and 127.98 mgKOH/g for steam distillation. The iodine values of all the oils were between 35 and 19.00 mg iodine/100g; while the refractive index was between 1.7 and 1.9. The acid values were within the range of 10.00 and 13.00 mgKOH/g, and peroxide value of 1.67 and 1.20 mmol/l. The oils had low viscosity which were within 28 and 32 mpa.s. The compounds identified from the GC-MS results showed that cashew nut shell oil contained cardol, anacardic acid, cardanol, 2-methyl cardol, triacconten and β-sitosterol. The main bioactive components of the extracted oil identified from the stem bark, root bark, and leaf were alkaloids, tannins, flavonoids, coumarins, terpenoids, and saponins. This study, therefore, showed that Soxhlet extraction could be a better extraction method for extraction of oil from cashew nut shell which had higher relative density; while cashew stem bark, root bark and the leaf which had lower density were selective based on the target products.