Apparent Recovery of Naturally Occurring Epoxy Fatty Acids from Alchornea cordifolia Seeds Across Solvents and Extraction Times: A Mass-balance Analysis of Batch Extractions

Abstract

Alchornea cordifolia seed oil is naturally enriched in a C20 epoxy fatty acid, but solvent comparisons may be misleading when extract composition is treated as equivalent to target-mass recovery. This study applied an explicit mass-balance approach to a batch-extraction screening dataset. Ground seeds (10 g) were extracted at 27–28 °C and 300 rpm with 60 mL of chloroform, n-hexane, methanol, 95% ethanol, or chloroform–methanol (1:1, v/v) for 15–150 min. Epoxy-fatty-acid content was inferred from a four-point GC-FID/oxirane calibration, and estimated apparent recovery was calculated from gravimetric extract yield and the inferred epoxy-fatty-acid mass fraction. Chloroform at 15 min produced the highest observed apparent recovery, 32.08 g per 100 g seed. In contrast, the highest estimated epoxy-fatty-acid concentration, 50.73%, occurred with n-hexane at 60 min but corresponded to an apparent recovery of only 14.63 g per 100 g seed. Thus, extract concentration and recovered target mass generated different descriptive rankings. Because each solvent–time condition comprised one observation, the crude gravimetric extracts were not independently confirmed as pure lipid, and the alcohol-derived estimates were based on values below the calibration interval, the findings support descriptive screening rather than exact recovery estimation, kinetic inference, or identification of a statistically confirmed optimum. Chloroform should therefore be regarded as an analytical benchmark rather than a production solvent. The mass-balance framework supports subsequent replicated optimisation using safer solvent systems.