IDENTIFICAÇÃO DE CAFEÍNA E ÁCIDOS CLOROGÊNICOS EM CAFÉ ATRAVÉS DE FTIR E DRX

Abstract

Coffee is a plant of the genus Coffea, originated in Ethiopia, where it was called kahwa, currently in Brazil the most cultivated and commercialized species are: C. canephora and C. arabica, which represent 26% and 74%, respectively. of national production. Brazil has a large coffee production park with about 2.2 million hectares, comprising 15 states, the largest producers are Minas Gerais and Espirito Santo. Coffee quality depends on several factors such as: chemical composition, grain conservation, roasting and brewing method, each species will have its own chemical composition, so the raw beans of different species after the roasting process generate different drinks, with its own sensory characteristics. Chemical components can be volatile and nonvolatile, directly influencing flavor and aroma, phenolic compounds are responsible for volatile aroma, within phenolics there are chlorogenic acids that have antioxidant capacity, caffeine is an important alkaloid for taste and aroma. aroma of coffee drink. Identification of organic compounds and crystallinity can be done using Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD), respectively. The objective of the present work is to identify caffeine and chlorogenic acids in arabica and conilon coffee by FTIR and XRD. The arabica and conilon coffee beans were donated by the Ouro Verde Coffee Industry and Trade, roasted at 170 ° C for 12 minutes, then ground by hand grinder. Identification analyzes were performed by FTIR and crystallization was obtained by XRD. From the generated FTIR spectra it was observed the presence of caffeine and chlorogenic acids in the coffees, but less expressive than the standard. For the XRD spectra, the characteristic caffeine peak of 11.7 ° was not observed in the coffee spectra, due to the interaction with other compounds that interfere with caffeine expression. Thus, through the FTIR method it was possible to identify caffeine bands and chlorogenic acids in coffees, by XRD it was not possible to identify caffeine peak in the samples.