María-Camino García-Fernández

Review: Trisodium Phosphate (TSP) Treatment for Decontamination of Poultry

Use of trisodium phosphate (TSP) treatment for reducing levels of bacteria in poultry is discussed with reference to: health and economic consequences of poultry contamination, causes or routes of contamination, possibilities for reduction of microbial loads, mechanisms of action of TSP, sensory properties and quality of TSP-treated poultry, antimicrobial effectiveness, influences on shelf-life, and worldwide authorization of this process, with special reference to the situation in the European Union. A summary of the main results of microbial reductions on poultry following TSP treatment is shown for Salmonella, coliforms/Escherichia coli, Enterobacteriaceae, Campylobacter, Pseudomonas, total counts, Listeria, Staphylococcus aureus and Lactobacillus. The main results on microbial reductions assessed in foodstuffs other than poultry (beef, fruit, fish and shellfish) are also shown. En este artículo se discute el uso del tratamiento con fosfato trisódico (TSP) para reducir la contaminación bacteriana de la carne de ave con referencia a: consecuencias económicas y para la salud de la contaminación de la carne de ave, causas o rutas de contaminación, posibilidades de reducir la carga microbiana, mecanismos de acción del TSP, características organolépticas y calidad de la carne de ave tratada con TSP, eficacia antimicrobiana y factores que la afectan, influencia de este tratamiento en el tiempo de vida útil, y autorización de este proceso en el mundo, con especial referencia a la situación dentro de la Unión Europea. Se han resumido los resultados de las reducciones microbianas obtenidas en carne de ave tratada con TSP para Salmonella, coliformes/Escherichia coli, Enterobacteriaceae, Campylobacter, Pseudomonas, microorganismos totales, Listeria, Staphylococcus aureus y Lactobacillus. También se han contemplado los principales resultados obtenidos en otros alimentos distintos de la carne de ave (carne de vacuno, fruta, pescado y marisco).

Mycotoxins in two Spanish cheese varieties

Samples of cheeses naturally contaminated with moulds (12 samples of mouldy Manchego cheese and 10 of a naturally ripened blue cheese) were analysed for the presence of mycotoxins (aflatoxins BI and MI, sterigmatocystin, patulin, penicillic acid and mycophenolic acid in Manchego cheese, and mycophenolic acid and roquefortine in blue cheese). In addition, 24 Penicillium and Aspergillus strains isolated from the samples were assessed for their mycotoxigenicity. Four of Manchego cheese samples were positive to mycophenolic acid and one sample of blue cheese contained roquefortine. The rest of mycotoxins investigated were not found. One Aspergillus strain isolated from Manchego cheese showed the ability to produce aflatoxin MI. The rest of strains from these samples being no producers. In contrast, 7 out of 9 Penicillium (P. roqueforti) strains isolated from blue cheese were able to produce roquefortine, with one strain also producing mycophenolic acid.

The influence of manufacturing and drying conditions on the survival and toxinogenesis of Staphylococcus aureus in two Spanish dry sausages (chorizo and salchichón).

The effects of formulation, starter culture and fermentation temperature on growth and synthesis of toxin A (SEA) and TNase by Staphylococcus aureus during fermentation and drying of Spanish chorizo were investigated. Inhibitory factors able to inhibit SEA synthesis in culture media were unable to prevent SEA production in chorizo fermented at 20 and 30°C, though a lower temperature and starter culture SP318 (Lactobacillus sake, Pediococcus pentosaceous and Staphylococcus xylosus) decreased staphylococcal growth and SEA formation. Reduction and even disappearance of the SEA during ripening was observed. In most batches, TNase was a reliable indicator of staphylococcal growth and SEA production. Dextrose added to the salchichón formulation repressed S. aureus growth during drying. Lactobacillus curvatus in combination with dextrose was an effective anti-staphylococcal agent during fermentation.

Influence of strain and trisodium phosphate concentration on growth parameters of Listeria monocytogenes in vitro

Aims: The present study was conducted to determine the influence of strain and trisodium phosphate (TSP) concentration in the growth of Listeria monocytogenes in vitro.

Minimum water activity for the growth of Aeromonas hydrophila as affected by strain, temperature and humectant

The influence of water activity (adjusted with three humectants: sodium chloride, glycerol and polyethylene glycol) on the growth of three strains of Aeromonas hydrophila at 28, 10 and 3.8°C was studied. Minimum water activity for growth (MWAG) of Aer. hydrophila varied with strain, temperature and type of humectant. MWAG ranged from 0.940 to 0.973 (28°C), 0.959 to 0.980 (10°C) and 0.975 to 0.980 (3.8°C).