Extraction of Avocado Peel Oil Using a Soxhlet Extractor and Investigation of Its Physicochemical Properties

Abstract This study investigates the extraction of avocado peel oil from avocado peel using a soxhlet extractor at different extraction times, temperatures, and solvent to avocado peel ratios using hexane solvent. The time for extraction ranges from 2 to 5 h, the extraction temperature ranges from 60 to 70°C at a temperature deviation of ± 2°C, and the hexane to avocado peel ratio ranges from 4 to 5 ml/g. Thus, the study reveals that the maximum amount of 29.93% w/w avocado peel oil was extracted at 3 h of extraction, at the boiling point of hexane, and at a 5 ml/g of hexane to avocado peel ratio. For varying extraction temperatures at constant hexane to avocado peel ratio, the optimum avocado peel oil was obtained at 70 ± 2℃ extraction temperature and 4.5 h of extraction time. Finally, the obtained oil was characterized for its physicochemical properties, from which an acid value of 2.8 mg KOH/g of oil and a free fatty acid of 1.4% were obtained from the study.