## 1 Introduction  
Goji (_Lycium barbarum_ L.) is an important economic crop widely cultivated in the northwestern regions of China [1]. Goji berries are consumed as a functional food due to their multiple health properties [2]. They have been reported to have the capacity to decrease the incidence of vision, liver, kidney, and immune system problems because of their high levels of functional ingredients, such as polysaccharides, flavonoids and carotenoids [3; 4; 5].  
Goji berries are indefinite infloreserences, and the fruits normally mature between June and August. Therefore, ripe goji berry fruits have to be harvested several times a year. Fresh goji berries readily spoil during storage, and therefore the majority (about 90%) of fresh goji berries are normally processed into dried products. Additionally, the goji berry wine fermentation industry has attracted attention in China, since goji berry wine can preserve the nutritional value of goji berry and extend the shelf-life [6].  
The overall aroma determines the sensory feature and quality of any fruit wine. The overall aroma in fruit wine is comprised of the primary, secondary, and tertiary aromas [7]. The primary aroma consists of volatile compounds derived from the fruit [7]. Fermentation results in the production of volatile compounds with fermented notes [8]. The evolution of volatiles during the aging process can bring aging odors to wine [8]. Fruit-derived aromatic compounds essentially determine the typical flavor of fruit wine [9]. Several strategies have been applied in the wine industry to investigate their effect on the extraction of fruit-derived volatiles. For example, pressing treatment is a physical approach to disintegrate the structure of fruit cells, enhancing the release of aromatic compounds and volatile precursors in juice. It has been reported that the pressed juice contained higher levels of C\({}_{6}\) alcohols compared to the free-run juice [10]. Besides, odorless volatile precursors exist in fruit with a large amount [9]. Glycosidase can cleave the sugar moieties from bound volatiles to release free volatiles that can contribute to the overall aroma of wine [9; 11; 12; 13]. For example, terpene alcohols are the major volatile aglycones released from their precursors by glycosidase in grape wine, and these aromatic compounds can improve the floral and fruity notes of the overall aroma of grape wine [9; 11; 12; 13].  
The effect of pressing and glycosidase on the evolution of volatile composition during grape wine production has been well studied [9; 14]. However, such investigations on goji berry wine production have barely been documented. More importantly, fresh goji berry is always processed into a dried form. The drying process can cause dramatic changes in the volatile composition and aromatic precursors in dried goji berry, which may alter the aromatic profile in goji berry wine. Therefore, we selected dried and fresh goji berries, and applied pressing and glycosidase treatments during the goji berry wine-making process. The objective of this study was to investigate the effect of goji berry raw material, pressing treatment, and glycosidase application on the volatile composition of goji berry wine, which could provide practical knowledge on quality development of goji berry wine fermentation. More importantly, the findings from this study could also provide a useful reference on material selection and fermentation processing development using fruits different from grapes.