Control of Hanseniaspora osmophila and Starmerella bacillaris in strawberry juice using blueberry polyphenols

The aims of the present work were to isolate and identify the principal yeasts present in spoiled Argentine strawberry juice, identify polyphenols present in four blueberry cultivars and use these blueberry extracts in the control of yeasts using strawberry juice as food system model. Hanseniaspora osmophila and Starmerella bacillaris were identified for the first time in Argentine strawberry juice. The blueberry extracts assayed showed antifungal activity against H. osmophila and S. bacillaris through individual phenolic compounds such as quercetin, kaempferol and chlorogenic, ρ-coumaric and ellagic acid. The cytotoxicity assay demonstrated that the blueberries were not toxic to humans and that they did not modify the sensorial qualities of strawberry juice. No viable S. bacillaris and H. osmophila cells were detected after 7 days in strawberry juice supplemented with 150 μg/ml Blue Crisp or Millennium extract, inoculated with the isolated spoilage yeasts and conserved at 4 °C. This is the first evidence of S. bacillaris and H. osmophila in spoiled Argentine strawberry juice and blueberry extracts could be a good natural and non-toxic alternative to prevent growth of these yeasts. Blueberry extracts could be feasible alternatives to improve the microbiological quality without impact on the organoleptic properties of polyphenol-enriched strawberry juice.