Combined effect of high hydrostatic pressure (HHP) and antimicrobial from agro-industrial by-products against S. Typhimurium

Abstract

The inactivation potential of HHP treatment (200 MPa-2 min) was evaluated against Salmonella enterica serovar Typhimurium in cauliflower and mandarin by-product infusions at 37 and 10 °C. By-product infusions exerted a strong antimicrobial effect used alone, achieving 5 log cycles of bacterial reduction for cauliflower by-product infusion after 10 hours and for mandarin by-product infusion after 80 hours, at 37 °C. The HHP treatment caused only one log cycle of cellular damage, but when inoculated cauliflower or mandarin by-product infusions were subjected to HHP treatment the antimicrobial effect against S. Typhimurium was enhanced, achieving 5 log cycles of inactivation in 6 hours at 37 °C in both cases. Inactivation curves were adjusted to the Weibull equation and the kinetic parameters (b and n) were obtained. When HHP treatment was combined with by-product infusions, the inactivation rates were greater than when either of the by-product infusions was added separately. In conclusion, a synergistic antimicrobial effect against S. Typhimurium appeared to take place when HHP treatment was combined with cauliflower or mandarin by-product infusion. These infusions could be considered as an additional microbial control measure to guarantee the food safety and food quality of pasteurized food products that are stored under refrigeration.

S. Typhimurium virulence changes caused by exposure to different non-thermal preservation treatments using C. elegans

“…Typhimurium with an initial concentration of 10 8 cfu/mL was treated with HHP (250 MPa five minutes). This is a sublethal treatment to S. Typhimurium that causes, mainly, cellular damage (Sanz-Puig et al, 2017). Between HHP treatments, the bacteria were grown in TSB and continuously shaken at 37 o C overnight to recover the damaged cells.…”

Occurrence of Salmonella typhimurium resistance under sublethal/repeated exposure to cauliflower infusion and infection effects on Caernohabditis elegans host test organism

“…Hurdle technology is a processing concept industrially well established to achieve efficient microorganisms reduction by the combination of different preservation techniques applied at slight intensive conditions maintaining natural valuable properties of foods treated products from a nutritional and sensory point of view (Pasha et al, 2014;Pina-Pérez et al, 2013;Sanz-Puig et al, 2017a). The combination of natural or chemical antimicrobials with other physical methods is one of the most commonly used practices to synergistically enhance microbial and enzymes reduction improving the safety and shelf-life of treated products (Guerrero et al, 2017;Sudhaus et al, 2012).…”

“…antioxidants, metabolites and synthetic compounds, could have on human health and their influence in the anti-aging process (Liu et al, 2016;Rollins et al, 2017;Wang and Wink, 2016). Silva et al (2015) Understanding the behaviour of foodborne pathogens exposed to sublethal concentrations of natural antimicrobials, and the possible implications in terms of bacterial resistance generation and changes in virulence are key questions to search for alternatives to conventional preservatives in food and to assess the safety of the hurdle technology processing application (Pina-Perez et al, 2013;Sanz-Puig et al, 2017a). Evaluation of some C. elegans phenotypic factors (such as lifespan, reproduction patterns, and mobility) under the exposure to pathogenic human bacteria could be a preliminary indicator of risks for consumers when these natural antimicrobials are used below the bactericidal dosage for food formulation with preservative objectives (Kastbjerg et al, 2010;Schroeder et al, 2017).…”

Incidencia y control de tipos patógenos de Escherichia coli (STEC y EPEC) en leche de vaca y quesos derivados en Castilla y León = Occurrence and control of pathogenic types of Escherichia coli (STEC and EPEC) in cow's milk and cheese in Castilla y León

“…Por tanto, la combinación de los dos tratamientos puede ocasionar un efecto sinérgico ya que el daño provocado en la membrana celular bacteriana por el tratamiento de APH deja a éstas susceptibles a los efectos de los AE. En los últimos años diversos estudios demostraran la eficacia de la combinación de los tratamientos de APH y AE en el control de bacterias patógenas (Evrendilek y Balasubramaniam, 2011;Pérez Pulido et al, 2012;Sanz-Puig et al, 2017;Stratakos et al, 2015).…”

“…El efecto sinérgico observado puede ser explicado por la acción de ambos tratamientos en la membrana celular de la bacteria (Stratakos et al, 2015), pues el tratamiento de APH provoca daño en la membrana celular que permite que las células bacterianas sean más susceptibles a los efectos de los aceites esenciales de TO. En los últimos años, diversos estudios demostraron la eficacia de la combinación de los tratamientos de APH y aceites esenciales en el control de bacterias patógenas (Evrendilek y Balasubramaniam, 2011;Pérez Pulido et al, 2012;Sanz-Puig et al, 2017;Stratakos et al, 2015). Figura VI.3.…”