High ascorbic acid content and antioxidant activity are known characteristics of camu‑camu (Myrciaria dubia) fruits. These compounds were extracted with two nonconventional techniques and one conventional technique using ethanol. Ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE) were studied using a 23 experimental design to evaluate temperature, solvent-to-solid ratio, amplitude or flow rate, and compared to dynamic maceration (DM). In addition to yield and antioxidant activity, the optimum extract (obtained with PLE at 35 ºC, flow rate 7 mL min-1, and solvent-to-solid ratio of 22 mL g−1) was characterized according to its ascorbic acid and phenolic content, and antimicrobial activity. The mean yields for UAE and PLE were approximately 33%, which is 15% higher than DM. The time was significantly reduced when the nonconventional techniques were used. PLE also enabled the highest antioxidant activity and ascorbic acid content (57 g 100 g-1 extract). This result is promising since it would allow the efficient isolation of a valuable compound in a more economical and environmentally friendly way.
Pereira et al. (Wed,) studied this question.