EFFECT OF THE SOLVENT COMPOSITION ON ULTRASOUND-ASSISTED EXTRACTION OF BIOACTIVE COMPOUNDS FROM PURSLANE (Portulaca oleracea)

Purslane (Portulaca oleracea) is a widely distributed unconventional food plant in Brazil. Although the health benefits of purslane are well-documented in the literature, its consumption and technological applications remain underexplored. Consequently, developing extraction processes utilizing emerging technologies, such as ultrasound-assisted extraction (UAE), presents a promising approach. This study aimed to extract bioactive compounds from dried and milled purslane (DMP) using UAE. UAE was performed with ethanol, water, and a 50% ethanol-water mixture (w/w) at a fixed solvent-to-feed (S/F) ratio of 25, an extraction time of 6 minutes, and nominal ultrasound power of 600 W. The global yield of UAE was calculated as the mass ratio between the dry extract and the initial DMP. Total reducing capacity (TRC) was determined using the Folin-Ciocalteu reagent, while antioxidant activity was assessed with the FRAP method. Global yields varied, with water as a solvent yielding the highest (22.54 ± 0.60 g extract/100 g DMP) and ethanol the lowest (3.77 g extract/100 g DMP). TRC values ranged from 1.23 ± 0.07 mg GAE/g DMP for water to 3.65 ± 0.01 mg GAE/g DMP for the 50% ethanol mixture. FRAP results followed a similar trend, with the 50% ethanol solvent producing the highest value (5.59 ± 0.34 mg TE/g DMP). These findings indicate that, while water as a solvent achieved the highest overall extraction yield, the 50% ethanol-water mixture was more effective for TRC and FRAP recovery. This preliminary study suggests that UAE could be an effective method for extracting valuable compounds from purslane, enhancing its potential application in food and nutraceutical industries.