Multiwave go

Plastic bottles containing 20 mL of EVOO were centrifuged at 3500 g for 5 min. In order to avoid any disturbance of the pomace precipitated on the bottom of the bottles, EVOO supernatant was carefully removed with a pipette using acid-cleaned tips. Extra virgin olive oil samples were weighed (0.5 g) and digested in a mixture of 5 mL HNO 3 (69% v/v Fluka TraceSELECT ® , Steinheim, Germany) and 1 mL of Milli-Q ® water in a microwave oven (Multiwave GO, Anton Paar, Graz, Austria, maximum power 850 W). A microwave-assisted heating program included 20 min of ramp time and 10 min of hold time at 180 °C.
Ten pomace samples (0.05 g) were digested in a mixture of 5 mL HNO 3 (69% v/v Fluka TraceSELECT ® , Steinheim, Germany) and 2 mL of Milli-Q ® water in a microwave oven (Multiwave GO, Anton Paar, Graz, Austria) with a heating program including 20 min of ramp time and 10 min of hold time at 160 °C. A risk of explosion during oil and pomace digestion limited the mass of sample and necessitated the use of a Multiwave GO microwave that is suitable for highly reactive samples.

0.1 g of dried phycocyanin cake was mixed with 10 ml of solvent in a pressure vessel HVT50 (Multiwave GO, Anton Paar GmbH, Graz, Austria). Three vessels were loaded into a microwave digestion system (Multiwave GO, Anton Paar GmbH, Graz, Austria). Each run consisted of a 5 min heating ramp, kept at the target temperature for the desired amount of time and finally cooled down to 40 ºC during 15 min. The reaction was stopped by submerging the flask in an ice bath for 15 min. The reaction mixture was filtered and the resulting deep blue solution was analysed. The dry mater content in the solution determined as described in section 2.2.1.