A binary solvent for the simultaneous Calophyllum oil-resin extraction and purification

Abstract

Sustainable biodiesel production can be realised by the use of a low-cost feedstock, efficient energy and renewable raw materials. The simultaneous Calophyllum oil-resin extraction and its purification using a binary solvent (n-hexane mixed with alcohol) were examined to meet those aspects. The extraction conditions effect was investigated to determine the optimal oil yield and quality. n-Hexane mixed with alcohol was extracted and purified effectively the oil from Calophyllum seeds. The oil yield and its quality were mainly affected by the n-hexane-to-alcohol ratio. The oil yield enhanced as the n-hexane-to-alcohol ratio enlarged from 1:1 to 2.5:1. The acid value and density of the oil improved as the n-hexane-to-alcohol ratio declined from 2.5:1 to 1:1. The n-Hexane-to-alcohol ratio of 2.5:1 provided the best yield (59%) of the oil extracted at 40°C for 5 hours. The oil presented its best quality at 0.893 g·cm<sup>–3</sup> of density, 41.0 mPa·s of viscosity, 8.8 mg KOH·g<sup>–1</sup> of the acid value, 88.3 g per 100 g of the iodine value, < 1% of moisture content and < 0.04% of ash content. The oil also had an inhibitory activity against Staphylococcus aureus.

Optimisation of concurrent Calophyllum oil-resin extraction and separation

“…For a moisture content of 2.6 ± 0.02%, the oil content of the seeds was 67.7 ± 1.03 dry matter basis % (db). This was higher than the 54-64.5 db.% used in the previous research (Kartika et al 2018(Kartika et al , 2019, possibly because the seeds aged during the storage of the Calophyllum fruits, so their oil content increased. The seeds were also rich in proteins (6.8 ± 0.4 db.%) and poor in ashes (1.7 ± 0.09 db.%).…”

“…The extraction condition variables investigated in this study were the extraction time (4-6 h) and stirring speed (200-600 rpm). The appropriate range of these variables was determined on the basis of previous studies (Kartika et al 2016(Kartika et al , 2018(Kartika et al , 2019. The central composite design gave a total of eleven experiments, and the central point experiment was conducted with three replications.…”

“…The highest yields of oil (51%) and resin (18%) have been attained at 50 °C, 800 rpm and a 2:1 ratio of n-hexane to methanol over a duration of 5 h (Kartika et al 2018). However, for the same time and stirring speed, a higher oil yield (59%) has recently been obtained at a higher n-hexane-to-methanol ratio (2.5 : 1) (Kartika et al 2019). The percentage of the oil separated from the resin was more than 88%, and it was low in impurities.…”

“…Currently, the coincident extraction and purification method using a binary mixture of polar and nonpolar solvents efficiently extracts the oil and resin from Calophyllum seeds, and separates them in a direct stage (Kartika et al 2018(Kartika et al , 2019. The highest yields of oil (51%) and resin (18%) have been attained at 50 °C, 800 rpm and a 2:1 ratio of n-hexane to methanol over a duration of 5 h (Kartika et al 2018).…”

Purification trials of Tamanu (Calophyllum inophyllum L.) oil

“…Triacylglycerols make the main class of components; eleven fatty acids have been reported: saturated fatty acids with a relative high percentage of stearic acid (25-35%) together with palmitic acid (8-14%); unsaturated fatty acids, comprising oleic and linoleic acids, each one accounting for 25-40% (Nguyen and Tran, 2016;Raharivelomanana et al, 2018). However, this figure is highly dependent on the extraction process and on the country where the nuts are harvested (Crane et al, 2005;Kartika et al, 2019). Polar lipids have been also reported: five phospholipids and even four glycolipids were identified (Hemavathy and Prabhakar, 1990).…”