Açaı Pulp Treatment in a Continuous-Loop Ultrasonic Reactor: Effect on Enzymatic Activity, Color, and Bioaccessibility of Phenolic Compounds

Açaı́ pulp is known for its rich content of bioactive compounds. This study aimed to explore the effects of a continuous-loop ultrasonic system on the enzymatic activity, phenolic profile, antioxidant activity, color, and bioaccessibility of acaı́ pulp to improve processing and potential health benefits. The main operating parameters of a continuous-loop reactor (residence time and ultrasonic power density) were evaluated by applying an experimental design. The continuous processing increased the flavonoid content (452 mg of GAE/100 g). Enzyme activity was inhibited by 42% for peroxidase and 62% for polyphenol oxidase. Lower enzyme activity and higher anthocyanin content (10.94 mg of C3GE/100 g) contributed to the intensification of the color. Treatments performed at 2700 W/L for 50 s and at 1800 W/L for 100 s increased the bioaccessibility of some phenolic compounds, with a consequent increase in antioxidant activity. The use of the continuous-loop ultrasonic system resulted in a high-quality product due to the short processing times and improved the nutritional and sensory quality of açaı́ pulp.