Physicochemical study of Camellia oleifera Abel. seed oils produced using different pretreatment and processing methods

In this study, the effects of different pretreatment (microwave or roasting) and processing (cold pressing, hexane extraction, or aqueous enzymatic extraction) methods on the physicochemical properties, minor components, and antioxidant capacity of Camellia oleifera Abel. seed oil (COSO) were investigated. The results revealed that the fatty acid profiles of COSO were not affected by the different processing methods, while hexane extraction resulted in the highest lipid yield (41.30–44.42 g/100g), saponification value (195.23–197.33 mg/g), and polyphenol content (7.25–8.23 mg/kg). Hierarchical cluster analysis proved that the processing method had a more significant effect than the pretreatment method on the chemical composition of COSO. Principal component analysis of the antioxidant capacity revealed that the microwave–hexane extraction method resulted in the highest content of α-tocopherol (144.7 mg/kg) and polyphenols (8.17 mg/kg) in COSO, indicating a high antioxidant activity (OSI: 6.23 h; DPPH-oil: 237, DPPH-nonpolar: 150, DPPH-polar: 670, FRAP: 77.4, ABTS: 45.9 μmol TE/kg). Consequently, hexane extraction is a promising method for future COSO processing.