PHYSICOCHEMICAL EVALUATION AND FTIR CHARACTERISATION OF THE OIL EXTRACTED FROM AVOCADO SEED

Abstract

Oil from avocado seed was extracted via the AOAC standard method using n-hexane as the extracting agent. The main physico-chemical properties evaluated for includes saponification value, free fatty acid, iodine value, peroxide value, acid value and refractive index. The results revealed that the saponification value (mg KOH/g), acid value (mg KOH/g), iodine value (mg iodine/100g), peroxide value (mg/peroxide/kg), Free fatty acid(%), specific gravity and refractive index were found to be 150.348; 0.366; 3.81g/100g; 14 Meq/kg , 0.1833, 0.88g/cm3 and 1.447 respectively. The low acid value obtained of the oils shows the oil is an edible one. High saponification value obtained revealed that the oil has great potential in industrial applications such as cosmetics and soap making. The iodine values obtained from this research indicates that it is a non-drying oil and also suggest that the oil contain few unsaturated bonds while low peroxide value is an indication that the oil will have low susceptibility to rancidity and deterioration. The FTIR analysis also reveal the oil to contain basic functional group which include the CH2 asymmetric stretching of (2855.1 cm-1 -2922.2 cm-1), C=O stretching of carbonyl group (1744.4 cm-1) and C-H scissor stretching of alkane (1162.9 cm-1- 1461.1 cm-1)