Microencapsulation of Camellia oleifera Seed Oil Emulsion By-Products: Structural Characterization and Lipidomics Analysis

To unlock the potential value of the emulsified by-product from the aqueous enzymatic extraction (AEE) of Camellia oleifera seed oil, this study introduced an innovative approach for its food industrial application. We applied spray-drying microencapsulation technology to convert the emulsion-phase (EP) by-product into value-added microcapsules (EPM). The properties of EPM were systematically compared with those of microcapsules derived from the oil phase (OPM). The encapsulation efficiencies of EPM and OPM were 83.94% and 86.53%, respectively. Scanning electron microscopy revealed the formation of irregular spheroids with smooth surfaces and intact structures, with EPM exhibiting superior particle uniformity (D₅₀ = 1.11 μm) compared to OPM (D₅₀ = 2.30 μm). Fourier-transform infrared spectroscopy confirmed the successful encapsulation of EP. Differential scanning calorimetry indicated good thermal stability of the microcapsules, and the oxidative stability of EPM (24.75 h) was 9.2 times higher than that of the unencapsulated EP and 13.15 h longer than that of OPM. Lipidomic analysis using LC-MS/MS identified 477 lipid species across five subclasses-glycerolipids, glycerophospholipids, fatty acids, prenol lipids, and sphingolipids-revealing distinct lipid profiles between EPM and OPM. This microencapsulation strategy offers a sustainable approach to valorize aqueous enzymatic extraction by-products, with promising applications in functional foods and nutraceuticals, thereby enhancing the economic and environmental sustainability of <i>Camellia oleifera</i> seed oil processing.