To the hibiscus, in the form it was bought (5 g), a solution of water/ethanol/acetic acid (70:29.7:0.3 v/v/v) (10 mL) was added, and the resulting mixture was maintained with irradiation protection at low temperature (~4 °C), for 72 h [38 ]. Then, the mixture was filtered, and the solvent was subject to partial evaporation under reduced pressure using the rotary evaporator (Rotavapor® R-210, BÜCHI Labortechnik AG, Flawil, Switzerland) at 40 °C. At that point, the extract was subjected to freezing at −80 °C and lyophilization (Alpha 1-4 LD Plus—Christ freeze dryer, Martin Christ Gefriertrocknungsanlagen GmbH, Osterode am Harz, Germany) over five days, to produce the corresponding dry extract, which was put in storage in a desiccator until use.
The red radish was hand-peeled and the peels were cut into small pieces. To these small pieces (25 g), a solution of water/acetic acid (95:5, v/v) (100 mL) was added, and the mixture was kept at low temperature (~4 °C) for 18 h. After that, the mixture was filtered, the solvent was partially evaporated, and the resulting extract was subjected to freezing at −80 °C followed by lyophilization, according to a similar procedure as described above for hibiscus [39 (link)].
The red radish was hand-peeled and the peels were cut into small pieces. To these small pieces (25 g), a solution of water/acetic acid (95:5, v/v) (100 mL) was added, and the mixture was kept at low temperature (~4 °C) for 18 h. After that, the mixture was filtered, the solvent was partially evaporated, and the resulting extract was subjected to freezing at −80 °C followed by lyophilization, according to a similar procedure as described above for hibiscus [39 (link)].