Integrated Microwave-Assisted Fractionation of the Caatinga Oilseed Licuri (Syagrus coronata) for Biomass Valorization

Oilseed extraction is usually assessed by oil yield alone, with the residual solid treated as a by-product. This study compared microwave-assisted extraction (MAE; 50 °C, 175 W, 45 min) with Soxhlet extraction (78.5 °C, 8 h), both using ethanol, as fractionation routes for licuri (Syagrus coronata), an underused Caatinga oilseed, characterizing both process streams on a common mass basis. Soxhlet gave the higher oil yield (63.64 versus 53.27 g/100 g kernel), whereas MAE raised time-based productivity 8.9-fold under the standard operating conditions of each apparatus; mass balances closed at 97.3% and 95.0%. The productivity gain required a 3.4-fold higher initial ethanol charge. Fatty acid composition, protein and ash contents were equivalent between the two routes, and saponification values matched the value calculated from the fatty acid profile to within 1%. The routes differed in the minor bioactive fraction of the oil and in the composition and functionality of the solid: the MAE oil carried 4.5-fold more α-tocotrienol and 11.8-fold more β-carotene at a lower peroxide value, while the MAE solid carried 67% more phenolics and absorbed 27% more water. Per 100 g of kernel processed, MAE delivered 1.86-fold more phenolics and 1.74-fold more ferric-reducing capacity despite its lower oil yield. Both MAE streams were incorporated into cassava starch formulations as a proof of concept.