## 1 Introduction  
Banana is one of the most important crops in tropical and sub-tropical areas [1]. Banana is also the second largest fruit crop, and China is one of the three biggest producers in the world [1, 2]. Brazilian (_Musa_ spp. AAA group) is a banana cultivar widely cultivated in China due to its high productivity, large fruit and good long-term storage properties, but it is susceptible to diseases, and peel-browning. Fenjiao (_Musa_ ABB Pisang Awak) is more popular because of its good flavor and abiotic stress resistance. It is also widely cultivated in many areas in China [3]. Fenjiao fruit have good taste, high sugar content, rich nutrition, and a unique and pleasant aroma, which is different from other cultivars. However, Fenjiao fruit has a short shelf-life after harvest, which leads to serious deterioration in fruit quality [4]. Aroma is an important indicator of fruit flavor and an important characteristic of fruit. It can be used to distinguish different types of fruits or different fruit cultivars [5, 6]. Fruit aromas are particularly sensitive to compositional alterations and can be altered by a wide range of pre-harvest or postharvest conditions [7, 8]. For instance, banana fruit-flavor quality is affected by a series of ripening processes. The factors that influence fruit flavor and the possible mechanisms have been reviewed, including genotype, cultural practice, the stages of ripening, and storage conditions [9]. Studies on aromatic compounds provide chemical information about the fruit aroma composition, the in vivo aroma biosynthetic pathway, the accumulation and evolution of aromatic compounds,as well as providing helpful guidance for plant breeding, fruit processing, crop storage and regulation of aromatic compounds [6; 10]. The aromatic properties of banana are important for its attractiveness as a fresh fruit. Banana fruit has a pleasant flavor and is widely consumed throughout the world. The typical flavor compounds of banana are produced during a short ripening period, and its aroma composition fluctuates during different stages, forming unique aroma signatures [11]. Several studies on the aroma compositions of banana during ripening have been reported, but most focused on the chemical compositions of the aroma at the mature period or during fruit processing [11; 12]. The changes in aroma composition at different fruit-ripening stages have also been reported [13], which are helpful to understand the formation of aromatic compounds during fruit ripening. The predominant volatile components of different banana cultivars vary, which gives them their own unique flavor. For example, the volatile component 3-methylbutyl butanoate is the predominant ester of the Cavendish cultivar [14]. In general, esters give a fruity note aroma [7]; for example, isoamyl butanoate, 3-methylbutyl acetate and isoamyl isovalerate contribute to the banana's fruity odor [15; 16]. It was reported that 246 volatile compounds have been identified in banana fruit, including 112 esters, 57 alcohols, 39 acids, 10 aldehydes, and 10 ketones, but only 12 compounds contribute significantly to banana aroma [16]. The Fenjiao (_Musa_ ABB, group) banana variety has been widely consumed throughout the world and is becoming more popular due to its nutritional value and pleasant flavor [17]. Most studies on the aromatic components of fresh banana fruit have focused only on the _Musa_ AAA cultivars, and little is known about the aroma components for Fenjiao [13; 16]. In this work, we showed that Fenjiao and Brazilian banana fruit have significantly different aromatic profiles during fruit ripening. The objectives of this study were to characterize the aromatic profiles of Brazilian and Fenjiao during the fruit ripening process using solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) and to compare the differences in the volatile components at different stages of ripening.