## 1 Introduction  
Wine aroma, which mainly consists of alcohols, ethers, fatty acids, aldehydes, ketones and terpenes [1], is a key aspect of wine quality [2], and is also one of the most influential properties for consumers when buying wine [3]. The aroma is the result of the combined contribution of various volatile compounds and can rarely be attributed to a single, specific component [4]. The volatile compounds have a wide concentration range varying from hundreds of mg/L to the ug/L or ng/L level [5; 6], but their contribution to the overall wine aroma is not proportional to their content [7]. Why are there such big differences in the aroma? For young wines, the composition and content of the aroma compounds largely depend on the vineyards, also referred to as the \"terroir\" [8]. The term \"terroir\" in French includes such characteristics as soil type, climate (sunlight, temperature and rainfall) and topography [9]. There has been much research demonstrating regional wines typicality. Some authors in Brazil have found that the aroma profiles of Cabernet Sauvignon wines from five vineyards of Santa Catarina State, Brazil, were established using gas chromatography-olfactometry (GC-O). Two wines have totally different aroma characteristics in sensory analysis, one with vegetative characteristics (Sao Joaquim vineyard) and one with red fruits and jam aromas (Bom Retiro vineyard) [10]. [PERSON] et al. explored the relationship between the sensory characteristics and wine composition of Cabernet Sauvignon wines in relation to Australian geographical indications [11]. Another study compared the flavor characteristics of Vidal icewines from China and Canada. The Vidal icewines from China generally had more nut and honey aromas, while the Canadian Vidal icewines had more caramel and rose aromas [12]. As a rapidly developing wine-making country, China has formed a serious of special grape-growing regions, and has a large consumer population. These grape-growing regions are distributed from east to west, across China with a distance of over 3000 km [13]. In 2017, China consumed 1.79 million kiloliters of wine, which is the fifth highest amount in the world, and produced 1.08 million kiloliters of wine, which is the seventh highest amount in the world (International Organization of Vine and Wine, OIV). The Loess Plateau region is located in the middle reaches of the Chinese Yellow River. As it is easy to form a microclimate in unique plateau areas, this has a great influence on the quality of the grape and the wine. The Loess Plateau region has been recognized as one of the best areas for grape growing in China. Cabernet Sauvignon is the main variety in this region. However, limited information is available on the sensory and chemical composition of the wines there [14]. Chemical and sensory analyses are powerful tools that permit one to know the flavor of the wines. As is well known, gas chromatography has been extensively applied for measuring volatile components in the aroma of the wine [15]. In addition, GC-O can be considered a useful tool for the identification of the odor-active compounds in wine and a combination between sensory and instrumental analyses [16; 17; 18]. Many methods such as dilution methods and time-intensity methods have been applied to determine the olfactometric indices [19]. While sensory analysis can involve the odorant's synergistic effect, GC-O analysis cannot. It includes the description of the qualitative and quantitative sensory components of wine by a trained panel. Additionally, the compounds in GC-O analysis were significantly separated and concentrated before sniffing, thus differing to the authentic wines. Descriptive analysis (DA) has proven particularly useful in studies of sensory evaluation in wines and can offer a complete description for all the sensory properties of wine [20]. The aim of this study was to identify the aroma characteristics of Cabernet Sauvignon wines made from five young vineyards of Loess Plateau, which is a new grape growing region of China.