engleski

Effect of spices on Vibrio parahaemolyticus survival and growth

In this study antibacterial activity of total 16 spices at final concentration of 2.5%against V. parahaemolyticus at two different temperatures of 5 and 37 ºC was screened. Aniseseed, chili, clove, cinnamon, coriander seed, cumin, curry, garlic, ginger, oregano, paprika, black and white pepper, rosemary, thyme and turmeric, were collected from retail from thesame producer. Prior to antibacterial screening, spices were analyzed using standardmicrobiological procedures for: aerobic spore forming bacteria, sulfite-reducing clostridia, yeast and moulds, Enterobacteriaceae, Escherichia coli, coagulase-positive staphylococci, and presence of Salmonella spp. and Listeria monocytogenes. For detection of anti- Vibrioactivity, to the 5% suspension of spices, the same amount of V. parahaemolyticus culture inNaCl-BHI broth, in a number of 104 cfu/mL, was added and incubated for 24 h and theninoculated on TCBS agar. After screening, minimal inhibitory concentrations were determinedfor spiced which showed strong antimicrobial activity. Salmonella spp., Listeriamonocytogenes, E. coli and coagulase-positive staphylococci were not detected in any ofspice samples. Aerobic spore forming bacteria were present in 93.7%, sulfite reducingclostridia in 43.7%, yeasts in 12.5%, , moulds in 62.5% and Enterobacteriaceae in 18.7% ofthe spice samples. At 5 °C, all spices accept anise and coriander seed showed antibacterialactivity against V. parahaemolyticus with viable count reduced for at least 1 log ; strongantibacterial activities at this temperature were found for oregano, garlic, thyme, clove, cinnamon, curry, rosemary, ginger and turmeric. Oregano, garlic, thyme, clove and cinnamonshowed strong antibacterial activity at 37 °C. The lowest minimal inhibitory concentration at37 °C was 0.078% in clove, and at 5 °C was 0.0012% in turmeric. Effect of accompanyingmicroflora of spices on the number of V. parahaemolyticus was not observed. This resultshowed that some spices have potential for reducing risk of contaminating V.parahaemolyticus in seafood combined with low temperature.

Vibrio parahaemolyticus; spices; antibacterial activity

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