## Introduction  
Orange fruits are the most popular ones for consumers throughout the world due to their pleasant flavors and nutritional value [1]. The fruits are both consumed fresh and industrially processed. The pulps, which are rich in soluble sugars, significant amounts of vitamin C, pectin, fiber and different organic acids, are mainly used to process into juice. Orange peels containing abundant fragrant substances are extensively applied for processing into essential oils which are used commercially for flavoring foods, beverages, perfumes, cosmetics, etc. Analytical research on the aroma compounds in orange fruit has been carried out for many years. Many researchers have studied the volatile compounds of this fruit using different analytical methods [2-7]. As a result of these studies, more than 200 components have been described as components of the flavor of sweet orange, and the major aroma compounds found in orange juice are hydrocarbons, alcohols, aldehydes, esters, and ketones. The presences of terpen with traces of oxygenated components are the aromatic character in the orange essential oil and peel oil [8-13]. Only a small part of all volatiles present in food has a primary impact on aroma [14]. The aromatic quality of the fruit is primarily dependent on the aroma active compounds. Gas chromatography-olfactometry (GC-O) analysis is a valuable method for the detection of aroma active compounds from a food matrix [15-17]. The three main GC-O methods are the dilution analysis, detection frequency and perceived intensity method [18-19], and these techniques have been employed by various researchers to determine the aroma impacting compounds in orange juice [20-23]. Solid phase microextraction (SPME) is a rapid, solvent-free, low-cost, simple extracting method [24-25], and usually combined with GC-O analysis. The amounts of flavor compounds absorbed on the SPME coating were greatly influenced by the diffusion of flavor components through orange juice into the headspace and the headspace gas reach to the SPME coating. Therefore, the high correlations between the concentrations and GC peak area were not obtained for all the volatile compounds [26]. It is also difficult to perform the dilution analysis such as AEDA using SPME extracts. [PERSON] _et al_. varied the GC injector split ratio to achieve dilution stepwise of the flavor compounds in HS-SPME-GC-O using an aqueous model system and yuzu tea. The research only demonstrated that serial dilution of the four flavor compounds in yuzu can be achieved successful through the increase of GC split ratio, other aroma compounds was not be mentioned [27]. Some researchers conducted the intensity method or frequency method combined with SPME to analysis orange juice flavor. [PERSON] _et al_. stated that ethyl butanoate, mycrene, _trans_-2-nonenal, decanal, octanal, terpinen-4-ol, _cis_-hex-3-renal and three unknown compounds were aroma active compounds in unpasteurized juice and heated juice, using SPME extraction and intensity method [20]. [PERSON] _et al_. used frequency detection method and SPME to find twenty-two odor active compounds in hand-squeezed juices of Moro, Tarocco, Washington navel and Valencia late oranges [23]. GC-O procedure has also been conducted to characterize the aroma active components in some citrus essential oils. [PERSON] and [PERSON] detected 38 aroma-active compounds in commercial cold-pressed grapefruit oil using a time-intensity GC-O procedure and concluded that the greatest aroma intensity compounds were1, 8-cineole, octanal, dodecanal, _trans_-4,5-epoxy-(_E_)-2-decenal, \(\beta\)-sinensal and nootkatone [28]. [PERSON] and [PERSON] found 55 aroma active compounds of the detected 95 volatile compounds in orange essence oil. The flavor compounds in orange peel oil extracted by SPME have never been reported [11]. Jinchen is a native sweet crop of _Citrus Sinensis_. It originated from the Sichuan province and has been widely planted in the middle and upper regions of the Yangtze River.