Effects of different preheat treatments on volatile compounds of camellia ( Camellia oleifera Abel .) seed oil and formation mechanism of key aroma compounds

In this study, volatile compounds of camellia seed oil (CSO) prepared by different preheat treatments (microwave, frying, roasting, and steaming) were identified by headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME/GC-MS). A total of 107 volatile compounds were identified in CSO samples, including aldehydes (16), alcohols (6), ketones (3), heterocyclic compounds (26), esters (23), hydrocarbons (15), and others (17). Among them, untreated CSO is mainly hydrocarbons, roasting and steaming CSO are mainly aldehydes and alcohols, while microwave and roasting CSO are dominated by aldehydes and heterocyclic compounds. Fourteen volatile compounds with high relative odor activity value (ROAV ≥ 1) were selected as key aroma compounds (KACs). Principal Component Analysis (PCA) and Cluster Analysis (CA) were performed on 14 KACs, which determined that there were 3, 3, 3, 7, and 6 characteristic aroma compounds (CACs) in untreated, microwaved, frying, roasting, and steaming CSO. Additionally, the potential formation pathways and mechanism of KACs were discussed. PRACTICAL APPLICATIONS: Flavor is an important factor for consumers to choose edible oils, and it is also one of the indicators of oil quality. Different flavors of CSO can cater to the needs of different consumers. CSO manufactories can choose different preheat treatments to produce CSO with various flavors to meet different customers' need. CSO with new flavor can extend its market share and increase its value.