## 1 Introduction  
In recent times, there has been a significant evolution in the coffee industry. The cost of coffee beans has surged to its peak in a decade, reaching approximately USD 2.0429/lb, and the consumption of 10,060 tons of coffee beans was achieved in 2022 [1]. Presently, coffee beans hold a status beyond that of a mere staple commodity. Consumers are in pursuit of coffee beans characterized by their premium quality, which promises to afford them enriched drinking experiences and health benefits. Hence, coffee that offers novel sensory perceptions and nutritional quality is greatly covered by consumers. There are diverse elements such as coffee bean genetics, post-harvest processing, brewing, and serving techniques that can exert influence on the quality of coffee beans [2].  
The variety of coffee beans could be linked to their chemical properties. Among the numerous Coffea species, _Coffea arabica_ and _Coffea caenophora_ stand out as the most widely cultivated species globally. _Coffea arabica_ is characterized by a smoother, sweeter taste with flavor notes reminiscent of chocolate, making it more preferred in the market. On the other hand, _Coffea canephora_ exhibits a stronger and harsher taste, often with bitter undertones, along with grainy or rubbery nuances [3]. Coffee beans contain a rich variety of bioactive compounds. Caffeine, the most well-known and extensively studied component, is responsible for the stimulating effects associated with coffee consumption [4]. Additionally, coffee beans contain other noteworthy bioactive compounds such as chlorogenic acid (CGA), cafestol, and kahwebol, all of which could exert significant biological and pharmacological impacts on human health [5; 6]. The presence of polyphenols, including feruloylquinic acid, dicaffeoylquinic acid, and CGA lactones, has been documented in substantial quantities within coffee bean extracts [7]. Notably, the occurrence of these bioactives and polyphenols in coffee beans could affect the overall taste of the brewed coffee [8].  
The processing of coffee beans involves two primary methods: the dry method (DP), also known as the natural process, and the wet method. After harvesting, coffee cherries are meticulously chosen and sorted via either manual selection or immersion in water. Then, after selection, for the dry process (DP), which is also referred to as the natural process, the cherries are dried directly using sunlight or artificial technologies, followed by stripping the dried cherry to obtain the underlying green coffee beans (GCB) [2]. In the wet method, the cherries are initially depulped to remove their outer skin and incubated for a period to allow fermentation to happen; then, after fermentation, the beans are washed, dried, and depulped for the green coffee beans [9]. Fermentation serves a dual purpose, as it removes any residual mucilage adhering to the beans and concurrently contributes to enhancing the beverage flavor. This enhancement occurs via the generation of microbial metabolites, which can act as precursors to volatile compounds that develop during the roasting process [10].  
Thus, the objective of this study was to assess the differences in phenolic content and phenolic profiles between fermented and unfermented Arabica coffee beans. The antioxidative potential of the phenolic profiles within the coffee beans was measured using various spectrophotometric methods. Furthermore, phenolic compound characterization was accomplished via liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS), followed by the semi-quantification of volatile compounds utilizing headspace/gas chromatography-mass spectrometry (HS-SPME-GC-MS). Additionally, an assessment of the physicochemical differences between the fermented and unfermented coffee beans was conducted. The findings from this study will contribute to the contrasting antioxidant potential and the profiles of the phenolic and volatile compounds exhibited in fermented and unfermented coffee beans.