Enhancing decaffeination selectivity in arabica coffee via microwave-assisted extraction: A case study of trade-offs, parameter effects, and kinetic modeling

• Green decaffeination with MAE removes caffeine while preserving chlorogenic acid 85.7% • Optimized efficiency achieving 94.2% decaf at 450 W 10 min with 40% energy savings • Kinetic insights where Power Law model R² 0.9896 supports scale-up and optimization • Selective process as CA degrades slower 0.021 min⁻¹ than caffeine 0.038 min⁻¹ ensuring retention • Sustainable solution reducing chemical use and energy in line with green processing trends The rising demand for decaffeinated coffee, driven by health concerns over excessive caffeine consumption, has prompted the need for greener, more selective decaffeination processes. This study investigates the use of Microwave-Assisted Extraction (MAE) as a sustainable method for selectively removing caffeine (CF) from Coffea arabica while preserving chlorogenic acid (CA), a key bioactive compound. Experiments were conducted at three microwave power levels (300, 450, and 600 W), with extraction times ranging from 2 to 12 minutes and feed-to-solvent (F/S) ratios of 0.100, 0.125, and 0.150 g/mL. The extraction behaviors of both caffeine and CA were modeled using three kinetic models: First-Order, Peleg’s, and Power Law. Among these, the Power Law model exhibited the best fit for both compounds, characterized by the highest determination coefficients (R² up to 0.9896), low root means square error (RMSE, as low as 0.0012), and statistically non-significant p-values. The B and n parameters in the Power Law model indicated that increasing microwave power and F/S ratio improved decaffeination efficiency while accelerating caffeine removal kinetics. Additionally, CA showed slower degradation, indicating selective retention under optimized conditions. These kinetic insights provide a quantitative foundation for coffee producers to optimize MAE parameters (power, time, and F/S ratio) at industrial scale, enabling the production of high-quality decaffeinated coffee that retains antioxidants, while improving energy efficiency compared to conventional methods. This study highlights the potential of MAE as a green, efficient, and tunable technology for producing functional decaffeinated coffee, offering valuable kinetic insights for industrial process optimization.