Assessment of the Yield and Bioactive Compounds of Jambu (Acmella oleracea) Flowers and Leaves Extracted with CO2, 1,1,1,2-Tetrafluoroethane (R-134a), and Propane

This study compares the extraction of oils and bioactive compounds from Acmella oleracea using supercritical CO2, pressurized R-134a, and propane under systematically designed experimental conditions. Extraction yields ranged from 1.16–3.35% for CO2, 1.90–2.35% for R-134a, and 1.30–5.42% for propane. Propane achieved the highest yields and the fastest plateau (~35 min), producing extracts dominated by unsaturated fatty acids (linoleic acid ≈ 85%). Supercritical CO2 generated the most diverse chemical profile, combining alkamides (spilanthol), triterpenoids (β-amyrone), and lipids, with a plateau at approximately 50 min, whereas R-134a selectively enriched β-amyrin acetate (~70%) with intermediate kinetics (~45 min). These yield values are typical for non-oilseed species, in which the low natural abundance of the target metabolites renders solvent selectivity more relevant than the total extract mass. Statistical modeling (R2 > 0.96) confirmed that pressure was the main driver of CO2 and propane extraction, whereas temperature dominated R-134a performance. The distinct selectivity patterns revealed by Gas chromatography–mass spectrometry (GC-MS) indicate that each solvent generates compositionally different extracts aligned with specific industrial applications in cosmetics, pharmaceuticals, and nutraceuticals. The unified comparison of these three fluids under a consistent experimental design provides practical insights for rational solvent selection: propane favors unsaturated lipids, CO2 preserves multifunctional compositions, and R-134a targets triterpenoid esters, supporting the economic feasibility of producing enriched, solvent-free plant extracts.