Metabolite profiles and antidiabetic activity of the green beans of Luwak (civet) coffees

Abstract

Metabolite profiles of green beans (the caged and the wild) Luwak (civet) coffees were evaluated by NMR techniques combined with chemometrics. The bioactivities of the green coffee beans were examined with antioxidant tests and an alpha-glucosidase inhibitory assay. Both are invitro tests related to the antidiabetic properties. Our results showed the civet coffees possessed unique metabolomes and were different from the regular arabica coffee. Both civet coffees were characterized by higher concentrations of alanine, citrate, lactate, malate, and trigonelline. Lactate and lipids were found as the most important compounds discriminating the caged civet coffee from the wild civet coffee. Bioactivity assays exhibited the antidiabetic activities of the civet coffees were better than the activity of the regular coffee. These results suggested that the civet coffees are promising functional foods reducing the diabetes risk. It is the first report evaluating metabolite profiles of both civet coffees using 1 H NMR-based metabolomics.