Physicochemical Characteristics of Brazilian Green Propolis Evaluated During a Six-Year Period.

BACKGROUND: Propolis has been used as a natural health product mainly due to the presence of polyphenols, flavonoids, phenolic aldehydes, amino acids, vitamins and others bioactive constituents. To this natural substance are attributed different biological and pharmacological properties which are influenced by its chemical composition and organoleptic properties. The aim of this work was to evaluate the physicochemical properties and parameters of green propolis collected during a period of six years (2008-2013) in the state of Minas Gerais, located at the southeastern region of Brazil. METHODS: The methodology were in accordance with Brazilian legislation on the identity and quality standards of propolis. The evaluated parameters of hydroalcoholic from green propolis were total flavonoids, antioxidant activity - DPPH method, oxidation index, wax content, humidity and insoluble impurities. RESULTS: Propolis samples collected in different seasons during the years 2008 to 2013 presented mean values of total flavonoids (3.4 ± 0.11 mg/g), antioxidant activity DPPH (4.76 ± 0.16 µg/mL), oxidation index (3, 4 ± 0.33 seconds) and wax (15.14 ± 0.78% m/m), which are in accordance with Brazilian legislation. CONCLUSION: Green propolis did not show abrupt seasonal changes during the six years of investigation, and may be considered as an adequate functional ingredient.

Green Propolis: Thirteen Constituents of Polar Extract and Total Flavonoids Evaluated During Six Years through RP-HPLC.

In order to verify the chemical qualities of polar extract of Green Propolis produced in the State of Minas Gerais, Brazil, was analyzed by means of RP-HPLC, the concentration of eleven flavonoids, Artepillin C and p-coumaric acid were analyzed by means of RP-HPLC. Samples were collected in the months of February, March, May, July, September, and October, during a period of six years (2008 to 2013) and the results compared with purchased standards. Artepillin C was the main constituent (80-90%) found in all samples. Lower concentrations of p-coumaric acid, chrysin and kaempferide were observed in March, and of ricin and galangin in September. Respectively, these months correspond to the end of Summer and Spring period in Brazil. The variation in concentration of the analyzed constituents always occurred in the same month, during the entire six years of evaluation period. All thirteen constituents of Green Propolis were detected throughout the study period, and the average concentration of each one was similar in relation to the respective monthly collection period of each year. Due to similarities among chemical constituents of Green Propolis with those present in B. dracuncufolia, this plant was identified as being the principal source of Green Propolis.