Coffee Pulp from Azores: A Novel Phytochemical-Rich Food with Potential Anti-Diabetic Properties

(This article belongs to the Special Issue Bioactive Compounds in Foods: New and Novel Sources, Characterization, Strategies, and Applications)

Coffee pulp, a by-product of wet coffee processing, shows significant potential in the food and health domains, but its real applications remain underexplored. This work investigated the chemical composition and bioactive properties of coffee pulp from São Miguel Island (Azores, Portugal). The studied coffee pulp exhibited high fiber content (52% dw), mostly insoluble; notable mineral levels (10.6%), mainly K, Ca, and Mg; and 6% dw of total amino acids, with hydroxyproline, aspartic acid, glutamic acid, and leucine in higher amounts. Despite containing low fat (1.6% dw), mainly saturated, it also showed considerable amounts of polyunsaturated fatty acids with a favorable n6/n3 ratio (1.40) and vitamin E (α-, β-, and γ-tocopherols). Its antioxidant capacity can be partially explained by the chlorogenic acid content (9.2 mg/g dw), and caffeine (0.98%) was present in similar amounts to those observed in some arabica coffee beans. A decrease in glucose uptake in Caco-2 cells was found, but not in fructose, suggesting selective inhibition of SGLT1 and potential antidiabetic effects. These results show that Azorean coffee pulp has potential as a sustainable and bioactive ingredient for incorporation into functional foods or dietary supplements.

Acknowledgments: J.A.B.P. gives thanks to FCT/MCTES and ESF (European Social Fund) through NORTE 2020 (Programa Operacional Região Norte) for her PhD grant, ref. SFRH/BD/07329/2021. L.E.S. is grateful to LAQV-Tecnologias e Processos Limpos-UIDB/50006/2020 for her grant (REQUIMTE 2023-49). N.A. and R.C.A. thanks FCT for funding through the Scientific Employment Stimulus—Individual Call (CEECIND/08492/2022 and CEECIND/01120/2017, respectively). The authors thank Quinta do Avô João (Azores, Portugal) for kindly providing the sample for the study.