H-1 NMR metabolic fingerprinting of Chapada Diamantina/Bahia (Brazil) coffees as a tool to assessing their qualities

摘要

Coffees from the Chapada Diamantina (State of Bahia, Brazil) are considered high quality, due to the use of high-quality production and processing criteria throughout the entire process. This work uses Nuclear Magnetic Resonance Spectroscopy to study the metabolic fingerprinting of these coffees, to contrast them to coffee from other regions. We analyzed 37 commercial samples, which are classified according to their quality (traditional, superior and gourmet). In the Principal Components Analysis scores plot, we observed four groups. The gourmet/superior group is formed by Chapada Diamantina coffees with the highest commercial value, Colombian coffees and some Brazilian ones with similar quality standards, and they present higher levels of caffeoylquinic acids and trigonelline. The group formed exclusively by Chapada Diamantina coffees presented higher lipid levels than the others. The Bahia group (except Chapada Diamantina coffees) presents very low intensities of caffeoylquinic acids signals. The coffees from other Brazilian states present higher quinine levels in comparison to those from Bahia, and lower levels of caffeoylquinic acids than those from Chapada Diamantina group. The results show that H-1 NMR, coupled with chemometric methods, is a very effective tool to discriminate coffees, allowing us to obtain the most important information from the data set.