# Headspace Solid-Phase Microextraction Analysis of Volatile Components in Peanut Oil
## 1 Introduction  
Peanut is an annual herb of the Leguminosae or Fabaceae family and genus _Arachis_ that is native to South America, Mexico, and Central America. It is widely distributed in tropical and temperate regions [1, 2]. It is rich in fatty acids that are primarily comprised of unsaturated fatty acids such as oleic acid (40-56%) and linoleic acid (16%) [3]. Peanuts are one of the main oil crops produced throughout the world [4], and they possess a variety of biologically active compounds that make them an important source of economic crops and plant proteins [5].  
Roasting of oil prior to pressing has been demonstrated to be an effective means of improving the flavor of aromatic oils. This is due to the presence of many complex reactions that occur during roasting, including the Maillard reaction, Strecker degradation, lipid oxidation, and caramelization, which all serve to produce a large number of volatile compounds [6, 7] that affect the flavor of oil products. The use of hot pressing increases the oil yield of peanuts and produces a nutty aroma. Peanuts exhibit a strong nutty flavor under heat treatment at 100-150 \({}^{\circ}\)C [8]. Hot-pressed peanut oil is subjected to material selection, roasting, and physical pressing that is facilitated by natural fiber filtration [9], and the method for squeezing peanut oil includes taking roasted peanuts that have been crushed and steamed before filling them into round cake molds that are subsequently arranged and stacked. The spilled grease is then squeezed with an external force [10]. The volatilecompounds in oil are key indicators that determine the organoleptic properties of vegetable oils [11]. Aromatic roasted peanut oil is a traditional Chinese edible oil [12] that possesses a unique strong nutty taste that distinguishes it from different edible vegetable oils [11], and the Maillard reaction and lipid oxidation are very important for flavor formation. Most volatile compounds with odor activity are lipid derivatives and intermediate products of the Maillard reaction [6].  
The solid-phase microextraction method (SPME) has been steadily growing since 1990 [13]. It is the most used technique for the extraction of volatile compounds because of its easy, fast, and solvent-free operation [14]. [PERSON] et al. [15] used HS-SPME combined with GC-MS-O to identify volatile compounds in hot-pressed peanut oil; [PERSON] et al. [11] used HS-SPME combined with GC-MS to observe the changes in volatile composition of the roasted peanut oil during the roasting process.  
According to the literature regarding different processing conditions for other nuts such as pistachios, the nut variety, pressing position, and baking temperature all affect the volatile components of the oil [16]. Peanut oil produces an aroma when heated. Although numerous studies exist examining the aroma of peanut oil, there are only a few studies regarding the effect of processing conditions on the aroma of peanut oil. Therefore, this study used HS-SPME combined with GC and GC-MS to explore the differences in the volatile components of peanut oil using different roasting temperatures, peanut varieties, and pressing conditions. The results of this study can serve as a reference for related agriculture and oil processing fields.