Antioxidant activity and polyphenol contents in Brazilian green propolis extracts prepared with the use of ethanol and water as solvents in different pH values

Abstract

Propolis is a natural product with a variable and complex chemical composition associated with its high concentration on polyphenolic compounds. The effect of pH variation (2.0, 3.0, 4.3, 6.0 and 8.0) during aqueous and ethanolic propolis extraction was studied for up to 10 days. Total phenols and flavonoids contents were measured for the extracts by spectrophotometric assays. Antioxidant activity was measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and ferric thiocyanate (FTC) methods. The best time of extraction was up to 5 days for all samples. Basic aqueous extracts (pH 8.0) resulted in a higher concentration of compounds than the extract without pH modification, reaching an increase of 160% in flavonoids and 25% in phenols. Ethanolic extracts with pH variation resulted in an extract with 50% less polyphenols and 6% less flavonoids than extract without pH modification. The antioxidant activity was highest for ethanolic extract at pH 4.3 and aqueous extract at pH 8.0 almost 90% and 45%, respectively, in DPPH methodand was related to the level of polyphenols by Pearson's correlations.Gallic acid equivalents. Means with different letters within a column are significantly different at P < 0.05.

Orally Disintegrating Films Containing Propolis: Properties and Release Profile

“…The ethanol extract of propolis showed a phenolic compound concentration of 55.5 ± 1.6 mg gallic acid per gram of extract. The concentration of these compounds can vary with different types of propolis, the region, and the environmental conditions in which the resin is collected, as well as the parameters of solvent used for the extraction . Ahn et al observed values between 42.9 and 302.0 mg gallic acid per gram of extract for propolis from different regions of China.…”

“…The concentration of these compounds can vary with different types of propolis, the region, and the environmental conditions in which the resin is collected, 44 as well as the parameters of solvent used for the extraction. 45 Ahn et al 46 observed values between 42.9 and 302.0 mg gallic acid per gram of extract for propolis from different regions of China. Potkonjak et al 47 observed values similar to those obtained in this study for an extract of propolis produced in Serbia.…”

Effects of seasonal variations and collection methods on the mineral composition of propolis from Apis mellifera Linnaeus Beehives

“…It is collected by bees from flowers, buds, and exudates of plants and is known to have a broad spectrum of biological properties (Mello and Hubinger, 2012;Toreti et al, 2013).…”

“…The quality and amount of propolis produced are linked to seasonal variations, methods of collection (Inoue et al, 2007;Toreti et al, 2013), geographical diversity, plant sources, and bee species (Mello and Hubinger, 2012).…”

Benefits of superfine grinding method on antioxidant and antifungal characteristic of Brazilian green propolis extract

“…Additionally, flavonoids and phenolic acids in green propolis have antifungal activities for typical agricultural, food, medical and odontological fungi (Ngatu et al, 2011;Freires et al, 2016;Martini et al, 2017). However, propolis is a tough resin that cannot be consumed in its natural form; thus, resin is typically transformed into a powder and extracted in an alcoholic or aqueous medium (Mello and Hubinger, 2012). Process conditions are important to allow extraction of most bioactive compounds.…”