Green solvent extraction of pitaya (Stenocereus spp.) seed oil.

Pitaya fruit (Stenocereus spp.) is recognized for its nutritional benefits and antioxidant profile. This fruit is usually consumed as fresh pulp. The seeds and peel are agroindustrial wastes and comprise between 22 and 29% of the fruit's mass. The oil derived from pitaya seeds is of great interest for various industrial applications. This study aims to evaluate the impact of different green solvents on the efficiency of pitaya seed oil extraction, thereby enhancing the valorization of these agroindustrial wastes. The green solvents evaluated included ethanol and supercritical CO2 (SC CO2), with hexane used as a reference. The extraction methods included the Soxhlet technique using ethanol and hexane, while SC CO2 extraction was conducted under two conditions: 180 bar at 50 °C (C1) and 250 bar at 35 °C (C2). Oil yield was determined by weight differences for each method, revealing yields ranging from 4.9% to 24.7%. Hexane showed the highest yield (24.7 ± 0.5%), followed by SC CO2 (C2: 15.3 ± 0.1%, C1: 5.0 ± 0.1%) and ethanol (6.8 ± 0.8%). These findings underscore the varying efficiencies of each solvent in extracting pitaya seed oil. By supporting the circular bioeconomy, this research promotes the utilization of agricultural by-products, aligning with current trends toward environmentally friendly practices. The subsequent phase involves evaluating the fatty acid profile of the oil obtained using green solvents.