Crambe seed oil: Extraction and reaction with dimethyl carbonate under pressurized conditions

Abstract

In this study, the efficiency of dimethyl carbonate as a solvent in the pressurized liquid extraction (PLE) of crambe seed oil and also as the acyl acceptor in the transesterification reaction using the mixture obtained, simulating a sequential process, was investigated. In the PLE process, the effect of temperature (140–180 °C) on the yield and quality of the oil was evaluated, and the results were compared to data obtained applying Soxhlet extraction. The reaction of the PLE mixture was conducted from 250 to 350 °C. The results showed greater oil removal from the seeds under pressurized conditions, reaching a yield of ∼45%, which was higher than the yield obtained with Soxhlet extraction. The fatty acids and acylglycerols composition of the extracts obtained with the two methods were similar. However, the phytosterols and tocopherols contents of the oil obtained by PLE were around ∼62% and ∼574% higher, respectively, compared with the oil from the Soxhlet extraction. The best results in the reaction step for ester yield (66.5%) and triglyceride conversion (98.5%) were obtained at 300 °C.