Extraction of Anthocyanins Using a Laboratory Robot and Innovative Extraction Technologies

Solid-liquid extraction using a laboratory robot, where anthocyanins are leached from dried red vine leaves, is evaluated with respect to precision and accuracy. The solid handling of the robot results in standard deviations between ± 0.6 and ± 1.8 depending on the particle size. For liquid handling the standard deviations are slightly higher depending on the volatility of the solvents. The validated, fully automated natural plant extraction robot achieves varying yields based on dry matter for methanol, water, and ethanol which are improved with increasing particle size. Manually performed extraction kinetics experiments are compared with the robot. With respect to process intensification, a comparison of yields obtained by microwave- and ultrasonic-supported extraction compared to laboratory robot shaking and stirred single-stage batch experiments was performed.