Increase the yield of bioactive compounds from elder bark and annatto seeds using ultrasound and microwave assisted extraction technologies.

We describe techniques to rapidly increase the yield of bioactive compounds from plant sources such as elder bark and annatto seeds using microwave dielectric heating and ultrasonic cavitation bubbles, a substantial improvement over conventional heating methods. For elder bark, the optimal extraction parameters were obtained with ethanol, using 0.01 L g−1 of solvent to material and extracting for at least an hour at 55 °C. Ursolic acid was found to be more abundant in barks. Under the optimal conditions, the yields of oleanolic acid and ursolic acid were about 86% while using ultrasound assisted extraction and about 92% while using microwaves, respectively. Using the optimal extraction parameters for annatto seeds: ethyl acetate, the ratio of solvent to material at 0.05 L g−1 and at least 30 min. extraction time, the yield of bixin reached about 85% with sonication and 95% with microwave heating. Assisted extraction techniques, with microwave assisted extraction being the most optimal technique, enhanced the extraction efficiencies and extracted higher concentrations when compared to standard methods. [ABSTRACT FROM AUTHOR]