PROPOLIS ETHANOLIC EXTRACT AS NATURAL BEE POLLEN LOAD PRESERVATIVE

MARÍA SOLEDAD GARCÍA PAOLONI; KREPPER, GABRIELA; CIBANAL IRENE L.; FERNÁNDEZ LETICIA A.; MARÍA EUGENIA CENTURIÓN; MARÍA SUSANA DI NEZIO; MARCELO PISTONESI

ANNALS OF NUTRITION AND METABOLISM

KARGER

Lugar: Basel; Año: 2017 vol. 71 p. 1207 - 1207

0250-6807

Bee-products are recognized worldwide as natural functional foods mainly owing to it high polyphenols content. Additionally, it had been already study the antimicrobial properties presented on propolis ethanolic extracts (PEE) and their use as food conservator. The Argentine Alimentary Code considers bee-pollen (BP) as a dietary supplement and regulates their quality parameters. Prior to their commercialization, a drying process is taken place, in order to avoid microbiological development and hence a larger shelf life. However, this critical step might affect the final bee-pollen phenolic content. The aim of this work was to determine the antimicrobial activity of PEE application over BP loads. The antimicrobial effect against bacteria and yeast/mould was tested separately using the percentage of contaminated pollen loads method. For this in vitro trial, 20 Petri plates (20 BP loads per plate) were divided in four treatments with five repetitions: one control (T1) with BP loads; other control (T2) with BP loads soaked with 7.50 µL of ethanol addition, and BP loads soaked with 5.00 µL (PEE 5) and 7.50 µL (PEE 7.5), respectively. The number of pollen loads with bacteria was studied at 35°C in Plate Count agar + nistatina while the count of mould/yeast was done in Sabouraud dextrose agar at 26°C.The results of the assay showed that were significant differences between both treatments and their controls after 48 hs. The fifty percent of BP loads from both controls showed fungal growth after 48 hours of incubation while treatments with PEE after 168 hours (seven days). The same results were obtained when measured antibacterial activity on BP loads from PEE treatments. The total of the BP loads from controls were contaminated by bacteria and fungus after 72 hs. In contrast, PEE5 and PEE7.5 never reached this percentage during the whole trial. This study allowed us to conclude that PEE present antimicrobial activity against bacteria and mould/yeast from fresh BP loads. Thus, PEE becames a new alternative that offers a preservation method for BP intended for consumption. Further investigations will reveal extra nutritional power conferred by PEE.