Application of Commercial Pectinase as a Biocatalyst During Self-Induced Anaerobic Fermentation of Coffee (Coffea arabica L. var. Typica)

This study investigated the impact of enzyme treatment on the physicochemical parameters and volatile and bioactive composition of Arabica coffee beans during self-induced anaerobic fermentation (SIAF). The physicochemical parameters of the beans treated with the enzyme solution were monitored over a 120 h fermentation period. The results showed that increasing enzyme concentration reduced the levels of reducing sugars and phenolic compounds, leading to decrease in antioxidant activity. Pectin lyase activity was highest in beans treated with 10 U.·mL−1, while polygalacturonase activity fluctuated throughout fermentation. The highest caffeine content (722.09 ± 3.7 mg·100g−1) was found in beans treated with 5 U.mL−1 after 72 h of fermentation. In contrast, trigonelline (1028.75 ± 31.4 mg·100g−1) and 5-O-caffeoylquinic acid (5CQA) (423.46 ± 40.3 mg·100g−1) were more prominent in unfermented beans. Volatile formation showed a positive correlation with enzyme concentration, with beans treated with 10 U·mL−1 exhibiting a more diverse volatile profile in the first 24 h. These findings suggest that enzymatic treatment modulates coffee’s volatile and bioactive composition, enhancing levels of aromatic compounds that are directly linked to the sensory quality of the coffee beverage.