Propolis Apis bee resin

Summary

Design

Two raw propolis samples — Orange Propolis and Black Propolis — were each extracted by two complementary methods, giving four extracts, so the two routes could be compared on identical starting material.

Sample preparation

Raw materials were weighed, dried to constant weight with moisture content recorded, and milled before loading. Extract fractions were weighed and dissolved in methanol for the spectrophotometric assays.

Extraction

Co-solvent assisted supercritical CO₂ extraction (SFE-EtOH) ran at 350 bar and 50 °C with 15 % v/v food-grade ethanol as co-solvent, in dynamic mode, for a total extraction time of 180 minutes, with the extract collected through a single decompression separator. Subcritical water extraction (SWE) ran at 140 °C and 40 bar in dynamic mode for 30 minutes; the water-soluble extract was recovered after depressurisation and freeze-dried.

Analysis

Total phenolic content was measured by the Folin–Ciocalteu protocol at 765 nm against a gallic acid calibration curve; total flavonoid content by the aluminium chloride colorimetric assay at 415 nm against a quercetin curve; and antioxidant activity as DPPH radical scavenging across seven extract concentrations, with IC₅₀ obtained by linear interpolation at the 50 % scavenging level. Only IC₅₀ values whose calibration reaches R² > 0.99 are treated as reliable.

Measured results are reported in the full application note (PDF above).

At a glance

Plant material

Propolis — Apis bee resin

Target compounds

CAPE, pinocembrin, galangin

Compound class

Polyphenols

Published

August 2025

Document

PDF, free download