Effect of roasting temperatures and time on the chemical composition of coffee Efecto de las temperaturas y tiempos de tueste en la composición química del café

During the roasting process, coffee is subjected to different temperatures and times, which produces diverse fundamental chemical changes in the structure of the compounds responsible for the aroma and characteristic flavor of coffee. In this research, the effect of the interaction between roasting temperature and time on the quality of six varieties of improved Coffea arabica was evaluated. Five roasting curves were generated, the base curve had an initial temperature of 200°C, two curves had temperature increases at 215°C and 230°C, and two curves had temperature decreases at 185°C and 170°C. The final roasting times were found between 8 and 12 minutes and were defined by the roasted bean color 55-65 on the AGTRON/SCA scale. Analytical techniques such as UV-VIS spectrophotometry, high performance liquid chromatography - HPLC and GC gas chromatography were used to determine the chemical composition of coffee: lipids, fatty acids, aliphatic carboxylic acids, alkaloids, total chlorogenic acids and sugars. The interaction of roasting time and variety had an effect on lipids, acetic, quinic, malic and citric acids, oleic and palmitic fatty acids, caffeine and trigonelline. Total chlorogenic acids showed no effect of the treatments and average values between 1.54% and 1.69% were obtained.