Extração de compostos bioativos da amora-preta e do guaraná com micro-ondas e ultrassom

Abstract

The industrialization of products such as blackberry and guarana seeds in the form of extracts and juices are alternatives to take advantage of their benefits, such as the high antioxidant capacity of anthocyanins and the stimulant properties of caffeine. Therefore, microwave and ultrasound were used to increase the efficiency of extraction of bioactive compounds from the samples of interest. To this end, these technologies were applied in three different approaches: (i) ultrasonic bath was used as a pre-treatment to increase the extraction of anthocyanins in blackberry juices obtained by pressing; (ii) ultrasound was also applied as a pre-treatment to favor the humidification and the extraction of caffeine from guarana by MHG (Microwave hydrodiffusion and gravity); (iii) adaptation of MHG to be performed in home microwave by employing a tea infuser (Bag-MHG) cooled with an ice bath. The results showed that the content of extracted anthocyanins was increased in the blackberry juice using the ultrasonic bath, and the efficiency of caffeine extraction from guarana was increased with the combination of ultrasound and MHG. Furthermore, with the adaptation of MHG to Bag-MHG, satisfactory results were achieved, since with this new technique an anthocyanin-rich extract similar to that extracted with MHG was obtained.