Adsorbents Selection for Caffeine Removal from Green Tea Extract

Tea (Camellia sinensis) is well known for bioactive metabolites especially polyphenols and caffeine, providing numerous health benefits, but the overconsumption of caffeine causes health risks to vulnerable people. The traditional decaffeination methods are primarily concerning potential chemical residues, the loss of beneficial compounds, the costly and complex processing. This study aims to evaluate an alternative decaffeination method by different adsorbents (Purolite C100, Mixbed and Mordenite Zeolite). In simulated caffeine solutions (400–2000 mg/L), the optimal adsorbent was MOR zeolite, Mixbed and Purolite C100. MOR Zeolite was applied in real green tea extract, yielding a caffeine removal rate of 85.895 ± 0.03% and adsorption capacity of 10.194 ± 0.004 mg/g, while polyphenol removal rate of 21.079 ± 0.076% and adsorption capacity of 6.459 ± 0.023 mg/g. The kinetics models of MOR zeolite for caffeine systems were well represented by the pseudo-second-order (PSO) model, while the pseudo-first-order (PFO) model fitted for polyphenol.