¹H NMR-based metabolic profiling of green beans of Coffea arabica var. sigararutang with different postharvest treatments

Metabolite profiles of green beans of Coffea arabica var. sigararutang processed with three different treatments, including dry, semi-dry, and wet postharvest methods, were evaluated with ¹H NMR spectroscopy analysis coupled with multivariate data analysis. Partial least square discriminant analysis (PLSDA) models successfully classified the green coffee beans based on the postharvest methods. S-plots of two-classes orthogonal projection to latent structure-discriminant analysis (OPLSDA) revealed that the dry-processed coffee was characterized with fructose and GABA, while the wet-processed coffee was represented by chlorogenic acids (caffeoyl quinic acids, CQAs), malic acid, and sucrose. Meanwhile, the green coffee beans processed with semi-dry postharvest method possessed the intermediary metabolite profile between the dry and the wet coffees. Generally, the semi-dry coffee exhibited the highest antioxidant activity compared to the other coffee samples. In this report, ¹H NMR-based metabolic profiling successfully evaluated metabolite profiles of green coffee beans treated with three different postharvest methods and also revealed the characteristic compounds for each coffee samples.