Pathogen reduction by E-beam
The application of E-beam at doses of 1- 2 KGy has been demonstrated to be a very useful approach to reach the Food Safety Objectives (FSO) in relation with L. monocytogenes and S. Enteritidis in several ready-to-eat (RTE) meat products (cooked and dry ham, beef jerky, fermented sausages and fresh poultry), without changes in the sensory attributes.
Light pulses reduced 2–3 logs the L. monocytogenes load when 8.4 J/cm2 were applied. LP can pass through packaging films at least 60 μm thick but they are only useful for the decontamination of smooth surfaces (e.g. cooked ham slices).
Enteric viruses were highly resistant and, in cooked ham, only 1 D reduction was obtained with a dose (KGy) of about 3.18 (hepatitis A), 7.66 (murine norovirus), 15.18 (human norovirus I) and 12.58 (human norovirus II).
Pathongen reduction by high presure
HPH (300 & 400 MPa for 15 min) reduced the Salmonella sp. load in TSA & SSA for 3 & 5 D & 4 y >6 D, respectively. In cooked ham, HHP was effective to reduce the levels of pathogens (Salmonella spp. & L. monocytogenes) and spoilage (D. hansenii & E. coli) organisms, except for S. aureus and a slime lactic acid bacterium. To assure the absence of L. monocytogenes and Salmonella and to reduce S. aureus counts, the combination with some bacteriocins was needed. In Tris buffer, Lactoferrin (LF), amidated LF and pepsin digested LF was bactericide for the spoilage Ps. fluorescens, but the lethal effect was inhibited in meat by the presence of Ca++ y Mg++.
Antimicribial effect of lactoferrin (LF) and derivates (PDLF and AMILF)
Se ha descrito propiedades antimicrobianas para la lactoferrina (LF) y de forma más notable para sus derivados PDLF (Pepsin digested LF) y AMILF (Amidated LF). En este trabajo se ha testado la actividad bactericida frente a Pseudomonas flurescents de la LF y sus dos derivados, en tampón Tris y en carne picada, de cara a su posible aplicación como conservantes en carne y productos cárnicos y se ha tratado de identificar aquellos factores que podrían delimitar su eficacia.
Microbial variavility studies
Se ha estudiado la variabilidad de la concentración bacteriana final después de distintos tratamientos térmicos para L. innocua, E. faecalis, S.Enteritidis y P. fluorescens. Se ha observado que existe una relación lineal entre la variabilidad del número de microorganismos supervivientes al tratamiento conservante y la reducción logarítmica de la población. Esta dependencia es importante para la evaluación de los riesgos microbiológicos que la industria alimentaria esté dispuesta a asumir.
The variability of the final bacterial concentration after several heat treatments was studied for L. innocua, E. faecalis, S. Enteritidis and P. fluorescens. A linear relationship between the variability of the log of the final bacteria load and the logarithmic reduction of the population was found. This dependence is important for quantitative microbial risk assessment.
