Cold Hydraulic Extraction Optimization and Characterization of Balanites aegyptiaca and Ceiba pentandra Seed Oils

Non-edible vegetable oils have a huge potential for many industrial applications. Most of them are expressed by mechanical pressing, but data on the different operating conditions to achieve optimal extraction yields and high-quality oil are scarce. Hence, the objective of this study was to optimize key hydraulic extraction parameters at ambient temperature (25 °C) of Balanites aegyptiaca and Ceiba pentandra oils by increasing the oil recovery. Optimal holding time, applied pressure, compression speed, and press cage charge were determined for whole and crushed oleaginous material. The results indicate that the B.aegyptiaca kernels and C.pentandra seeds contained 2.7 and 5.7% moisture, as well as 46.3 and 26.2% fat, respectively. Under the optimal operating conditions, the oil recovery (wt.%. d.b.) from whole (crushed) material was 73.4 (69.8) B.aegyptiaca kernels and 38.2 (41.2) C.pentandra seeds. The extracted oils have a high content of unsaturated fatty acids including of about 74 wt.% for B. aegyptiaca and 69 wt.% for C.pentandra. They were particularly rich in linoleic ω-6 acid, 45.32 and 38.77 wt.%, respectively. The chemical characteristics of cold-extracted B. aegyptiaca and C.pentandra oils were 10 and 20 ppm phosphorus, 2.8 and 3.5 ppm iron, 0.0 ppm copper, 0.06 and 0.1% water-volatile matter, respectively. These valuable material properties make the B.aegyptiaca and C.pentandra oils an ecological and renewable resource for multipurpose applications.