INTEGRATED ASSESSMENT OF THE CHEMICAL COMPOSITION AND BIOACTIVE POTENTIAL OF ARABICA COFFEE (Coffea arabica) HUSK BEVERAGES PREPARED USING CONVENTIONAL INFUSION METHODS

Coffee processing generates large volumes of byproducts, especially coffee husks, which constitute a significant source of phenolic compounds with potential applications in the food industry. In this context, the utilization of this material through various conventional methods for preparing infusions shows promise, although there are still gaps regarding the standardization of these conditions. Thus, this study aimed to evaluate the bioactive potential of infusions made from Arabica coffee husks of the Bourbon cultivar, obtained using different extraction times and conventional methods, with an emphasis on chemical profiles, as well as antioxidant and hypoglycemic activities. Four conventional infusion methods were evaluated at three extraction times, including the traditional method (Trad05: 5, Trad07: 7, and Trad09: 9 minutes), boiling (Boil02: 2, Boil03: 3, and Boil04: 4 minutes), microwaving (Wave02: 2, Wave04: 4, and Wave06: 6 minutes), and cold brewing (Cold12: 12, Cold18: 18, and Cold24: 24 hours). The data were subjected to analysis of variance (ANOVA) and the Tukey test (p < 0.05). The infusion methods differed significantly from one another, and the extraction time also influenced the results under specific conditions. 9 organic acids were quantified, predominantly acetic acid; 5 sugars, mainly fructose and glucose; and 19 nonvolatile compounds, including 17 phenolics, caffeine, and fumaric acid. The Boil04 and Trad09 samples had higher concentrations of phenolics and sugars, particularly naringin. Cold24 exhibited the highest concentrations of organic acids, including malic and succinic acids, and favored the retention of minor phenolics that are thermolabile to oxidation, such as gallic acid, 2,4-dihydroxybenzoic acid, quercetin, and caffeic acid. Although thermally unstable, epicatechin and caffeine remained abundant under greater thermal exposure, with smaller reductions than the other compounds, suggesting that extraction outweighed degradation during the time periods evaluated. The antioxidant assays differed from one another, with the Boil04 sample (75.94%) exhibiting the highest DPPH activity. In the ABTS assay, there was no difference among the heat treatments, with the highest activity observed in Boil04 (83.60%). In the FRAP assay, Boil04 exhibited the highest activity (22.50%), and a reduction was noted in the cold infusions. α-Amylase inhibition was independent of phenolic content and antioxidant capacity, ranging from 43.30% to 80.11%, with Trad07 standing out. Overall, the extraction method and time influenced the chemical composition and bioactive responses of the infusions, with the Boil04 sample standing out due to the most favorable combination of the evaluated parameters. These results reinforce the viability of using coffee husks, adding value to this byproduct and promoting its sustainable use in the production chain.

Acknowledgments: CNPq.