Optimisation of concurrent Calophyllum oil-resin extraction and separation

This research optimised the application of a hexane-methanol mixture as a binary solvent for the concurrent oil-resin extraction and separation from Calophyllum seeds on a pilot scale, in a direct stage. The optimum oil and resin yields were determined by optimising the extraction conditions using response surface methodology and a second order polynomial model. The extraction conditions affected the oil and resin yields, with the extraction time as the biggest influencing factor. Optimum oil (65) and resin (16) yields were predicted to be obtained at 5.2 h and 433 rpm. The model validation with these extraction conditions showed that the predicted results and actual oil (62) and resin (15) yields were in passable agreement. The oil was composed of 75.4 triglycerides with a density of 0.874 g·cm–3, a viscosity of 26.4 mPa·s–1, an acid value of 46.4 mg KOH·g–1, an iodine value of 98.0 g iodine·100 g–1, trace water and sediment contents, and zero ash content. The resin had a viscosity of 4 694.8 mPa·s–1, a total phenolic content of a 4.51 gallic acid equivalent, an antioxidant activity of an 8.82 mg ascorbic acid equivalent·g–1, and an acid value of 126.2 mg KOH·g–1