Influence of factors and interactions in ultrasound-assisted extraction and conventional maceration on aqueous extract of Psidium guajava leaves

Background: Extraction techniques of phenolic compounds (PC), such as conventional maceration (CM) has been associated with high consumption organic solvents and time. Objective: The objective this study was to evaluate the effects interactions variables involved in aqueous extraction from Psidium guajava leaves by CM ultrasound-assisted (UAE). Methods: A split-plot design developed according interest. For time, temperature, dilution were considered for UAE wave amplitude included. Response following parameters: yield, total compounds, flavonoid antioxidant capacity measured radical uptake ABTS DPPH.Results: results show that UAE, treatment 1 g/ 50 mL, 50ºC 30% amplitude, 20 min a higher reporting 125.84 mg acid gallic equivalents/ g PC, 381.18 quercetin equivalents/g flavonoids 85.28% DPPH 40.2% expressed scavenging activity. On other hand, method reported best using mL dilution, temperature 10h achieving 62.04 289 flavonoids, 95.9% 48% regarding activity.Conclusion: ultrasound process more effective extracting their extracts had highest capacity. Keywords: guajava, extraction, ultrasound.