Effect of seasonal variations and collection form on antioxidant activity of propolis from San Juan, Argentina.

ISLA M.I, CARRASCO JUÁREZ B., NIEVA MORENO M.I., ZAMPINI I, ORDÓÑEZ R., SAYAGO J, CUELLO S., ALBERTO M.R., BEDESCARRABURE E., ALVAREZ A., COCCINI F., MALDONADO L.M.

JOURNAL OF MEDICINAL FOOD

MARY ANN LIEBERT INC

Lugar: USA, Canada; Año: 2009 vol. 12 p. 1334 - 1342

1096-620X

Propolis was included in the Argentine Food Code as functional food. The chemical parameters and antioxidant properties of propolis samples from the same colonies of Apis mellifera in San Juan (Cuyo region, Western Argentine) were compared every month for one year using two collection methods. Chemical parameters were analyzed by spectrophothometric method and fingerprint using high performance liquid chromatography-ultraviolet detection (HPLC-UV). The antioxidant activities of propolis samples were measured using model systems including the analysis of the scavenging activities on ABTS and DPPH radicals and the â-carotene bleaching assay. The results showed that propolis had a higher free radical scavenging and lipid peroxidation inhibitory capacity than BHT and quercetin, antioxidants used in the pharmaceutical and food industries. The SC50 values (concentration required to scavenge 50% of free radicals) differed depending on the sample collection month. Samples collected in November had the highest antioxidant capacity. In all cases, SC50 values of propolis samples obtained by scraping were similar to those collected from a plastic mesh (5 µg/mL for ABTS and 20 to 30µg/mL for DPPH radicals). A significant positive correlation was found between the antioxidant capacity and flavonoid content of each analyzed extract. The chemical profiles were very similar. Galangin (3,5,7-trihydroxyflavone), an antioxidant compound, was detected in all samples as major compound. The chromatographic profile, suggest that of Baccharis sp, would be one of botanical source of the propolis from western Argentina and the content of galangin can be used as parameter for propolis quality. Our results suggest that Argentine propolis from Cuyo is a promising source of bioactive compounds as ingredients for developing functional foods with a beneficial impact on oxidative stress.