Propolis extract and oregano essential oil as biofungicides for garlic seed cloves: in vitro assays and synergistic interaction against Penicillium allii.

AIMS: This study aimed to evaluate in vitro individual and combined antifungal activity of propolis extract (PE) and oregano essential oil (OEO) against Penicillium allii, causal agent of blue mould disease. The chemical characterization of both products was also included. METHODS AND RESULTS: Chromatographic analysis of PE and OEO confirmed the presence of bioactive compounds. The antifungal susceptibility assays showed that PE and OEO were highly active against the mycelial growth and conidial germination of P. allii. PE and OEO MICs were 12·5 and 1·5 µl ml-1 , respectively. The MFCs of these products were 50 and 3·1 µl ml-1 , respectively. PE acted mainly through diffusion, while OEO acted by a mixed contribution of vapour and diffusion. Synergism and additive effect between both products were found in some combination ratios. CONCLUSION: PE and OEO, both natural products with different chemical composition, have a strong antifungal activity against P. allii and show a favourable interaction causing synergism. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this study indicated the potential use of PE combined with OEO as a non-conventional strategy towards the formulation of a biofungicide to control blue mould disease in garlic seed-cloves.

[Honeys from the Ventania mountain range: microbiological quality evaluation at different points of the honey-processing plant]. / Mieles del sistema serrano de Ventania: evaluación de la calidad microbiológica dentro del circuito de la planta de extracción.

One stage of honey production is extraction. Honey is a product with minimal types and levels of microorganisms; however it could be contaminated during its manipulation. The aim of this work was to evaluate the microbiological contamination of honey at different processing points. Mould and yeast, total coliform number as well as the presence of Salmonella spp. were determined in 50 samples. All comb and centrifugal honey-extractor samples showed low levels of mould and yeast (< or = 10 CFU/g of honey) and an absence of total coliforms. Contamination problems were observed at the uncapping stage of beeswax-capped honey separation, showing that the "unheated" honey process would imply more risks. Ten to fifty CFU/g of honey of mould and yeast were observed in four out of 30 samples from the honey pump and drums. The present work shows the importance of preventing contamination at the beeswax-honey separation stage, and also highlights the need to perform microbiological studies in the honeyhouse, which would contribute to determine critical points in control quality systems.

Mieles del sistema serrano de Ventania: evaluación de la calidad microbiológica dentro del circuito de la planta de extracción / Honeys from Ventania system: microbiological quality evaluation at different points of honey-processing

La miel es un producto natural que presenta una carga microbiana muy baja. No obstante, durante el procesamiento empleado para transformarla en un producto comercial, que incluye una etapa de extracción, puede contaminarse. El objetivo de este trabajo fue evaluar la contaminación microbiológica en diferentes puntos del circuito dentro de las plantas de extracción de miel. En 50 muestras se cuantificó el número de hongos filamentosos y levaduras, así como el de coliformes totales, y se determinó la presencia de Salmonella spp. Todas las muestras provenientes de los panales y de los extractores centrífugos presentaron un recuento de hongos filamentosos y levaduras ≤ 10 UFC/g de miel, y ausencia de coliformes. Sin embargo, se evidenciaron problemas de contaminación en la etapa de separación cera-miel de los opérculos, con indicios de que el sistema "en frío" implicaría mayores riesgos. De un total de 30 muestras procedentes de la bomba o de los tambores, 4 presentaron recuentos de hongos filamentosos y levaduras entre 10 y 50 UFC/g de miel. El presente trabajo muestra la importancia de prevenir contaminaciones provenientes de la separadora cera-miel y también la necesidad de realizar estudios microbiológicos en las plantas de extracción, ya que éstos podrían contribuir a determinar los puntos críticos en los sistemas de control de calidad.

One stage of honey production is extraction. Honey is a product with minimal types and levels of microorganisms; however it could be contaminated during its manipulation. The aim of this work was to evaluate the microbiological contamination of honey at different processing points. Mould and yeast, total coliform number as well as the presence of Salmonella spp. were determined in 50 samples. All comb and centrifugal honey-extractor samples showed low levels of mould and yeast (≤10 CFU/g of honey) and an absence of total coliforms. Contamination problems were observed at the uncapping stage of beeswax-capped honey separation, showing that the "unheated" honey process would imply more risks. Ten to fifty CFU/g of honey of mould and yeast were observed in four out of 30 samples from the honey pump and drums. The present work shows the importance of preventing contamination at the beeswax-honey separation stage, and also highlights the need to perform microbiological studies in the honeyhouse, which would contribute to determine critical points in control quality systems.