A comparison of the antioxidant properties of two different Brazilian propolis

Abstract

Propolis is a resinous substance of complex chemical composition, varied color and consistency, with high antioxidant potential. This study aimed to investigate the content of phenolic, flavonoids, condensed tannins, and antioxidant potential present in two kinds of propolis: green propolis (GP) (Apis mellifera), and Mandaçaia propolis (MP) (Melipona quadrifasciata anthidiodes), through ultrasound-assisted extraction by three different methods. All extraction methods used equal propolis mass/solvent volume ratio. The EA method kept the mixture under stirring solvation (25 °C/48 h), and the mixture was submitted to sonication (1 h). The second EB method was performed by sonication (1 h) before solvation (25 °C/48 h) and again sonication (30 min). The third EC method was sonicated with a cell disruption ultrasonic probe (10 min), followed by stirring solvation (25 °C/1h). Related to the phenolic content and antioxidant activity, the GP extracts obtained for methods EA and EC were similar. In contrast, the EA method was more effective for MP extracts. In addition, the results indicated a diversified phenolic profile for the extracts obtained highlighting: 3,4-dihydroxybenzoic, caffeic, p-coumaric acids, myricetin, kaempferol, and catechin for the GP extracts. In contrast, MP extracts highlighted: ellagic, vanillic, caffeic acids, myricetin, kaempferol, and hesperetin. The EA method is the most cost-effective, especially for Mandaçaia propolis extracts, while the EC method is recommended when time efficiency is a priority. The results obtained will promote advanced studies to evaluate the antioxidant effect of propolis extracts in pharmaceutical and food industries, such as active packaging, capsules, and other possible applications of this important bioactive material.