Comparative analysis of quality characteristics, composition, antioxidant activity, and volatile profiles of seven Camellia oleifera seed oils

Camellia oleifera seed oil (CSO) is widely appreciated for its nutritional and functional properties, yet its quality is strongly affected by processing and storage conditions. In this study, seven CSO samples originating from different sources were systematically evaluated for physicochemical properties, bioactive compounds, lipid composition, antioxidant capacity, and volatile flavor profiles. Pronounced differences were observed among the samples. Sample S5 exhibited the highest oxidative deterioration due to long-term storage, with elevated acid value (2.27 mg KOH/g) and peroxide value (2.98 g/100 g). In contrast, sample S2 showed the greatest oxidative stability (induction period of 10.88 h) and superior in vitro antioxidant capacity (DPPH and ABTS), which was closely associated with its higher contents of carotenoids, tocopherols, and total phenolics. All CSO samples were characterized by a high oleic acid content (76.19%-81.99%). The lipidomic analysis revealed 5 classes and 32 subclasses of lipids among 354 species, with triacylglycerols and fatty acids as the dominant types. Volatile analysis using HS-SPME-GC-MS identified 81 aroma compounds, with aldehydes, alcohols, acids, lipid-derived compounds, and furans as the main contributors. This study elucidated the intrinsic quality differences among various CSO and provided a robust theoretical foundation for a comprehensive understanding of their nutritional attributes and sensory diversity.