## 3 Results and Discussion
### Evaluation of the Effect of Starter Cultures on Bioactive Compounds and Carbohydrates
Glucose and fructose influenced the separation of PC1, and caffeine and chlorogenic acid influenced the separation of PC2 (Supplementary Material-Figure S2C). Unlike the coffees inoculated with _S. cerevisiae_ CA11, a different bioactive compound accumulation profile was observed. The Ametista variety and CA62  
Figure 4: Multivariate analysis of fermented coffee cultivars. Principal component analysis (PCA) (**A**): N; (**B**): CA11; (**C**): B10; (**D**): Hierarchical cluster analysis (HCA). accumulated trigonelline and caffeine at the end of fermentation. However, at 24 h, these varieties had the same concentrations of these bioactive compounds as noted at the start of fermentation. The metabolism of the starter culture may have influenced this. The CP and P2 varieties accumulated the highest concentrations of chlorogenic acid. The sugar consumption for _K. lactis B10_ differed from that observed for _S. cerevisiae_ CA11. After 24 h of fermentation, only 55.22% of glucose and fructose were consumed for coffee variety A (glucose: 0.30 g:L\({}^{-1}\); fructose: 0.65 g:L\({}^{-1}\)) and 70% (glucose: 0.24 g:L\({}^{-1}\); fructose: 0.52 g:L\({}^{-1}\)) for CP variety (Figure 4C). At the end of fermentation (48 h), 85% of carbohydrates were consumed for both varieties. There is a difference between _S. cerevisiae_ and _K. lactis_ in regulating mitochondrial respiration [32]. Although both are considered yeasts in the facultative aerobic group, _K. lactis_ is an aerobic respiratory yeast, not a fermentative one. Therefore, its tendency to consume sugars differs due to its preference for non-fermentable oxidative and oxidative-reductive pathways [33]. Concerning sugar consumption, the different microbial profiles for each studied coffee variety probably impacted the consumption of these sugars. The permanence and competition of starter cultures during fermentation are essential because their metabolic activity may be related to the differences in the chemical compounds evaluated in the coffee and possibly to the correlated sensory characteristics [30]. In general, a strong correlation (\(>\)\(-\)0.66) between the yeasts and the sugars, together with this starter culture, also helped the sugar consumption process (Supplementary Material--Figure S3). This is mainly because the yeasts enabled the symbiotic development of the LAB through cell autolysis. On the other hand, LAB can help in the fermentation process, mainly because they are involved in producing organic acids and consuming carbohydrates. This relationship impacts the flavor and aroma profile [12; 34]. Among the analyzed bioactive compounds, chlorogenic acid presented the highest content in all coffee varieties, followed by caffeine and trigonelline. Trigonelline, a bioactive compound, contributes mainly to the roasted coffee flavor because it gives rise to volatile compounds in the pyrrole and pyridine chemical classes. Caffeine confers bitterness to the beverage, and chlorogenic acid is responsible for pigmentation, astringency, and the production of volatile phenols since part of this compound is degraded when the beans are roasted [35; 36]. Considering their properties related to sensory characteristics, the accumulation of bioactive compounds in the presence of starter cultures will influence the flavor of the final coffee beverage. A strong and significant correlation with bioactive compounds was observed with increasing microbial population concentration, regardless of the starter culture and coffee variety. The retention of chlorogenic acid in coffee variety CA62 (0.74) may have been supported by mesophilic bacteria quantified using PCA agar. This group of microorganisms helps with the availability of chlorogenic acid by modulating precursors or intermediates related to this compound, favoring its retention or transformation into desirable bioactive compounds.