Comparative Analysis of Key Odorants and Aroma Characteristics in Hot-Pressed Yellow Horn (_Xanthoceras sorbifolia bunge_) Seed Oil Via Gas Chromatography-Ion Mobility Spectrometry and Gas Chromatography-Mass Spectrometry  
[PERSON]  
1  
[PERSON]  
1  
[PERSON]  
2 National Engineering Research Centre for Intelligent Electrical Vehicle Power System (Qingdao), College of Mechanical & Electronic Engineering, Qingdao University, Qingdao 266071, China 2  
[PERSON]  
1  
[PERSON]  
2 National Engineering Research Centre for Intelligent Electrical Vehicle Power System (Qingdao), College of Mechanical & Electronic Engineering, Qingdao University, Qingdao 266071, China 2  
[PERSON]  
1  
[PERSON]  
1  
[PERSON]  
1  
[PERSON]  
1  
1  
1  
1  
Aldehydes and heterocyclic compounds are considered pivotal compounds in oils, contributing to the distinctive fragrance [12]. It has been reported that 2-methylpyrazine, 2,5-dimethylpyrazine, 2-ethyl-3-methylpyrazine, and 2,6-dimethylpyrazine could be produced by heating virgin rapeseed oil at 100 \({}^{\circ}\)C and contributed toasted, nutty, woody, and burnt profiles [13]. The aroma of cold-pressed and hot-pressed walnut oil was studied using GC-IMS and GC\(\times\)GC-O-MS. It was concluded that the key aroma active compounds in cold-pressed walnut oil were identified as 1-octene-3-ol, cyclohexanol, and benzaldehyde. Conversely, the main aroma components in hot-pressed walnut oil were 3-methylbutyraldehyde, (E, E)-2, 4-nonadien, and nonanal [14]. Gas chromatography-ion mobility spectrometry (GC-IMS), gas chromatography-olfactometry-mass spectrometry (GC-O-MS), and electronic nose (E-nose) are commonly employed in food aroma research for the detection of volatile compounds (VOCs) due to their low limits of detection, high selectivity, robust operational stability, rapid analysis capabilities, and cost-effectiveness [15; 16]. GC includes both a mobile phase and a stationary phase. The components of the sample are separated in the chromatographic column based on their different forces in the two-phase system. IMS is a method capable of detecting volatile and semi-volatile compounds at parts per billion (ppb) [17]. These compounds are distinguished based on the mobility of ions in the electric field of neutral buffer gas under atmospheric pressure [18]. GC-IMS not only exploits the high separation capacity of GC but also capitalizes on the high sensitivity and rapid response properties of IMS. Olfactory (O) employs human sense of smell as a detector to identify aroma contributions in food [19]. Combined with the advantages of GC-O and GC-MS, GC-O-MS enables rapid and accurate identification of VOCs while also allowing for the recording of substances' aroma through olfactometer export [20; 21]. In recent years, the combination of multiple analytical methods to identify the key aroma compounds in oils has been used in various studies of oil flavor substances. The results obtained from these different methods are cross-verified to enhance accuracy, scientific rigor, and reliability. For example, [PERSON] et al. [12] used both GC-IMS and GC-MS to analyze the aroma substances generated during different microwave treatment times of camellia seed oil and found that the primary odors varied with different treatments. According to a report [21], analyses using GC-MS and GC-O revealed that aldehydes and pyrazines were the primary aroma active compounds in roasted walnut oil. Yellow horn seed oil has garnered increasing attention due to its valuable nutrients and distinct aroma, yet there is still a gap in the study of its aroma substances. Therefore, this study aims to identify unknown VOCs in yellow horn seed oil using GC-IMS and GC-O-MS, followed by determining the key aroma compounds by evaluating their contribution. Additionally, the impact of the roasting temperature on the aroma of the yellow horn seed oil is also discussed.