INFLUÊNCIA DO TEOR DE ÁGUA E DO ESTÁDIO DE MATURAÇÃO NA TAXA RESPIRATÓRIA DO CAFÉ

The aim of this work was to evaluate the influence of moisture content and maturity stage over the respiration rate and dry matter loss of coffee (Coffea arabica L.). Coffee fruits were utilized, variety "Catuai Vermelho", harvested in different maturity stages (green, "verdoengo" and cherry). A portion of the fruits in the cherry stage were manually dehulled. The samples were dried in a forced air circulation chamber at 40 oC until the desired moisture contents. Them, they were weighed, conditioned in glass jars and the respiration rate was measured, through the determination of the carbon dioxide quantity produced in an hour, at 25 oC, in a respirometer brand Sable Systems International. The values of CO2 production were used to determine the consumption of dry matter through stoichiometry of the respiration equation (C6H12O6 + 6O2 → 6CO2 + 6H2O + 2835 kJ). Through the obtained results, all samples had an increment in the respiration rate and dry matter loss in function of the moisture content. To moisture contents above 15 % w.b., this increase was more pronounced. The green coffee presented the highest values of CO2 production, followed by "verdoengo" and cherry coffee, respectively. By means of the model identity technique, it was concluded that the models to describe the respiration rate evolution of coffee fruit and parchment did not differ among each other, being able to use a single equation to represent this trend.