This study provides the first comparative analysis of the physicochemical and functional properties of oil body suspensions derived from different parts—entire fruit (EOB), peel (POB), and seed (SOB)—of Idesia polycarpa Maxim (IPM) during in vitro simulated gastrointestinal digestion. Results demonstrated that the properties of the different suspensions exhibited significant difference during digestion stages. The average particle size of all suspensions decreased, with the most significant reduction observed in POB (91.50%), which was attributable to its lower interfacial protein content and inferior stability. The absolute ζ-potential decreased in the model of gastric digestion (MGD) due to interface disruption but increased in the model of intestinal digestion (MID) following the adsorption of bile salts. Throughout the simulated digestion process, the protein hydrolysis degree, free fatty acid (FFA) release rate, reducing power, and inhibition rates against α-amylase and α-glucosidase all increased, concurrently with a decrease in DPPH radical scavenging activity. Notably, the POB suspension exhibited the highest extent of lipid digestion, with the highest cumulative FFA release rate (27.83%). In contrast, the SOB suspension showed the most significant enhancement in total reducing power (increased by 199.32% after intestinal digestion) and the highest α-glucosidase inhibitory activity. These findings clarify that the part source is a critical factor influencing the digestive properties and functional activities of IPM oil bodies, providing a theoretical foundation for the targeted application in functional foods.

As a novel woody oilseed, the application of Idesia polycarpa in oil processing has been limited by the lack of systematic research. In this study, the effects of different drying methods, impurity contents, and filtration cycles on the quality of Idesia polycarpa virgin oil were evaluated using physicochemical indicators such as acid value (AV), phospholipid content, color, etc. The thermal stability of the obtained Idesia polycarpa virgin oil was also assessed under high-temperature heating conditions in comparison with refined oil, soybean oil, and rapeseed oil. The results indicated that oil with higher transparency was obtained by microwave vacuum drying with zero impurity content and five filtration cycles with a peroxide value of 11.03 meq/kg and a phospholipid content of 1.07 mg/g. After high-temperature heating, lower total oxidation values (TOTOX = 106.05 ± 1.63) and polar compounds (7.99 ± 0.54 meq/kg) were detected in Idesia polycarpa virgin oil (IPVO) compared with soybean oil and rapeseed oil, confirming superior thermal stability. Overall, IPVO yield was improved and exceptional thermal stability was achieved by this pretreatment, underscoring its potential as a functional cooking oil for high-temperature culinary applications.

Conjugated linoleic acid (CLA) was efficiently produced from Idesia polycarpa oil by alkaline isomerization (conversion rate 99.34 ± 0.12 %) and microencapsulated with soy protein isolate (SPI) and maltodextrin (MD) by spray drying to obtain IP-CLA-ME. The microcapsules exhibited high encapsulation efficiency (82.38 ± 2.5 %), mean particle size of 781 ± 23 nm, and good electrokinetic stability (−33.9 ± 4.6 mV). SEM and CLSM revealed uniform oil distribution, while FTIR and XRD confirmed structural integrity and wall–core interactions. Encapsulation markedly improved oxidative induction time (260 ± 8 min vs. 161 ± 5 min for IP-CLA) and thermal resistance. In vitro digestion showed a biphasic release, reaching 76.33 ± 0.87 % at 360 min, best fitted by a zero-order model (R² = 0.9234). These results demonstrate that SPI–MD microencapsulation effectively stabilizes CLA and enables sustained release, supporting its potential for functional food and nutraceutical applications.

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 Camellia oleifera seed oil processing.