Polyphenol Degradation Kinetics of Specialty Coffee in Different Presentations

Polyphenols are chemical compounds found in plants, and coffee is an important source of them. The objective of the study was to evaluate the kinetics of polyphenol degradation in a blend of specialty coffee (green, roasted and roasted-ground beans), packaged in eight different packages, under accelerated storage conditions. The samples were stored at 40, 50 and 60 °C for 12, 8 and 4 days, respectively. The degradation kinetics was modelled by determining the reaction order, rate constants (k), activation energies (Ea) using the Arrhenius model, and half-life. The degradation followed zero-order kinetics. The rate constant (k) varied between 0.437 and 9.534 days -¹ (40-60 °C). The Ea ranged from 49.321 to 118.04 kJ*mol -¹. The predicted longest half-life for daily storage at 25 °C was obtained for: vacuum packed green beans (27.16 months), vacuum roasted beans (3.14 months) and ground roasted coffee in trilaminated foil with valve (40.21 months). Polyphenol retention decreased significantly with increasing temperature. For green bean, roasted bean and roasted ground coffee, the packaging that showed the best protection for the coffee was vacuum packaging and trilaminate with valve respectively, being crucial for preserving these bioactive compounds.