**2.3 Caffeine and EGCG measurements**

For caffeine and EGCG quantification, samples were centrifuged at 2,500 g for 10 mins, a 1:2.5 dilution was made using 12.5% acetonitrile, and then samples were filtered through 0.45 μm, 13 mm diameter HPLC nylon syringe filters. All samples were stored at 4°C for no greater than 24 hours prior to performing HPLC. For caffeine and EGCG measurement, a Kinetex 5u XB-C18 (5 μm, 150 × 4.6 mm) column maintained at room temperature was used. Detection was via analysis at UV wavelength 254 nm.
