Obtenção e caracterização de extrato de sumagre (Rhus coriaria L.) assistida por ultrassom: avaliação de compostos bioativos

Abstract

Sumac is a reddish dried condiment obtained from the dried berries (fruit) of a wild shrub whose scientific name is Rhus coriaria L., native to the Middle East. Many studies highlight the content of bioactive compounds present in dried sumac fruit, especially phenolic compounds and flavonoids, which exhibit significant antioxidant activity. In this context, the production of extracts rich in these compounds has attracted interest due to their potential for application in the food, pharmaceutical, and cosmetic industries. The objective of this study was to optimize the production of sumac extracts via ultrasound-assisted extraction, using the Box-Behnken experimental design. Three independent variables were evaluated: mass of the dried sumagre fruit sample, extraction time, and ethanol solvent concentration, resulting in an experimental design consisting of 15 trials. The response variables determined were the extraction yield, the total phenolic compound content, and the total flavonoid content of the extracts obtained. Initially, the sumagre fruits were degreased with hexane and subsequently extracted using an ultrasonic bath, according to the conditions established by the experimental design. Total phenolic compounds were determined using the Folin-Ciocalteu method, and flavonoids were determined using a colorimetric method with catechin as the standard. The phenolic compound contents ranged from 304.36 ± 12.30 to 531.03 ± 55.35 mg EAG L⁻¹ of extract, while the flavonoid contents ranged from 71.96 ± 5.29 to 112.09 ± 3.27 μg EC L⁻¹ of extract. Extraction yields ranged from 6.37 to 22.57%. Statistical analysis indicated significant mathematical models for yield and flavonoid content, with coefficients of determination of R² = 0.8370 and R² = 0.8176, respectively, while phenolic compounds did not show a significant mathematical model. The results demonstrated that ultrasound-assisted extraction is an efficient technique for obtaining sumac extracts rich in bioactive compounds; optimization indicated the following ideal conditions: 5.563 g of sample, 13.264 min of extraction, and a hydroethanolic solution containing 20% ethanol.