Chemical characterization of gurgueia nut (Dipteryx lacunifera Ducke) and press cake oil obtained by hydraulic pressing and supercritical extraction

Dipteryx lacunifera, known as gurgueia nut, is a potential crop for obtaining specialty oils. The processing of gurgueia nut to obtain the oil generates circa 635 g kg(-1) of cake, a biomass rich in residual oil. A sequential approach using hydraulic pressing (HP) and supercritical fluid extraction with CO2 (SFE-CO2) has been employed to maximize the oil recovery from gurgueia nut. High contents of b-sitosterol (55.8 mg 100 g(-1)), stigmasterol (38.6 mg 100 g(-1)), campesterol (13.9 mg 100 g(-1)), squalene (668.7 mg 100 g(-1)), total phenolics (6.1 mg GAE 100 g(-1)) and antioxidant potential (4.2 mg TE 100 g(-1) in FRAP; 5.4% in DPPH; and 54.3% in ILP) were observed in the oil from SFE-CO2 as compared to HP and Soxhlet oils. Significant contents of gamma- and beta-tocopherol (3.5-4.2, and 18.2-21.5 mu g g(-1)) were found in oils. Oleic (similar to 60%), palmitic (9.9-18.9%), and linoleic (11.6-12.9%) were the major fatty acids. As a result, the main triacylglycerols were OOO (23.0-35.5 wt%), POO (13.4-31.3 wt%), and OLO (2.1-15.6 wt%). Thermal analysis revealed two major exothermic events during crystallization and a single peak on melting, also showing that gurgueia oils are liquid at 20 degrees C. Combining sustainable technologies was useful for valorizing residual biomass from hydraulic pressing to obtaining a high-quality oil with potential uses in the food, cosmetic and pharmaceutical industries.

Automated summary

The combination of hydraulic pressing and supercritical fluid extraction techniques was effective in maximizing the oil recovery from gurgueia nut. The resulting oil contained high levels of β-sitosterol, γ- and β-tocopherol, and exhibited significant antioxidant potential. This high-quality oil has potential applications in the food, cosmetic, and pharmaceutical industries.