Suchergebnisse

[SPA] Listeria monocytogenes es actualmente una de las principales preocupaciones de la industria alimentaria. Aunque el número de casos reportados en la Unión Europea es relativamente, tiene una gran gravedad, con unas tasas de hospitalización y mortandad del 97% y del 16,7%, respectivamente. Debido a la ubicuidad de este microorganismo y su capacidad de crecer en numerosas matrices alimentarias, las empresas agroalimentarias deben aplicar tratamientos que inactiven las células de L. monocytogenes. En este trabajo, se estudió la cinética de inactivación de L. monocytogenes aislada de productos marinos sometida a un tratamiento combinado de PEAV con un aceite esencial de orégano. Los resultados demuestran esta sinergia, ya que se consiguió una mayor inactivación microbiana con un campo de 20 kV/cm, 1 Hz de frecuencia, 150 pulsos y una concentración de orégano de 1/2 MIC, superior a la obtenida en las muestras control. Llegando a la conclusión de que los PEAV impulsan el efecto del orégano sobre la membrana de la bacteria. [ENG] Nowadays Listeria monocytogenes is one of the main concerns of the food industry. The number of cases reported in the European Union is relatively low it is very serious, with rates of hospitalization and mortality of 97% and 16.7%, respectively. Due to the ubiquity of this organism and its capacity to grow in many food matrices, agri-food companies must apply treatments that inactivate the cells of L. monocytogenes. In this work, it was studied the kinetics of inactivation of L. monocytogenes isolated from marine products subjected to a combined treatment of PEF with an essential oil of oregano. The results show this synergy, since it got a greater inactivation microbial with a field of 20 KV/cm, 1 Hz frequency, 150 pulses and an oregano concentration of 1/2 MIC, higher than that obtained in control samples. Concluding that the PEF promote the effect of oregano on the bacterial cell membrane. ; Investigación apoyada por el MICINN (es) y FEDER a través de los proyectos ...

The sensory, microbial and bioactive quality changes of untreated (CTRL) and mild heat−treated (HT; 90 ºC/45 s) smoothies were studied and modelled throughout storage (5, 15 and 25 ºC). The overall acceptability was better preserved in HT samples being highly correlated (hierarchical clustering) with the flavour. The sensory quality data estimated smoothie shelf−life (CTRL/HT) of 18/55 (at 5 ºC), 4.5/12 (at 15 ºC), 2.4/5.8 (at 25 ºC) days. The yeast and moulds growth rate was lower in HT compared to CTRL while a lag phase for mesophiles/psychrophiles was observed in HT−5/15 ºC. HT and 5 ºC−storage stabilized the phenolics content. FRAP reported the best correlation (R2=0.94) with the studied bioactive compounds, followed by ABTS (R2=0.81) while DPPH was the total antioxidant capacity method with the lowest adjustment (R2=0.49). Conclusively, modelling was used to estimate the shelf−life of a smoothie based on quality retention after a short time−high temperature heat treatment that better preserved microbial and nutritional quality during storage. ; The financial support of this research was provided by the Ministerio Español de Economía y Competitividad MINECO (Projects AGL2013−48830−C2−1−R and AGL2013−48993−C2−1−R) and by FEDER funds. G.A. González−Tejedor thanks to Panamá Government for the scholarship to carry out his PhD Thesis. A. Garre (BES−2014−070946) is grateful to the MINECO for awarding him a pre−doctoral grant. We are also grateful to E. Esposito and N. Castillejo for their skilful technical assistance.

Heat resistance of microorganisms can be affected by different influencing factors. Although, the effect of heating rates has been scarcely explored by the scientific community, recent researches have unraveled its important effect on the thermal resistance of different species of vegetative bacteria. Typically heating rates described in the literature ranged from 1 to 20°C/min but the impact of much higher heating rates is unclear. The aim of this research was to explore the effect of different heating rates, such as those currently achieved in the heat exchangers used in the food industry, on the heat resistance of Escherichia coli. A pilot plant tubular heat exchanger and a thermoresistometer Mastia were used for this purpose. Results showed that fast heating rates had a deep impact on the thermal resistance of E. coli. Heating rates between 20 and 50°C/min were achieved in the heat exchanger, which were much slower than those around 20°C/s achieved in the thermoresistometer. In all cases, these high heating rates led to higher inactivation than expected: in the heat exchanger, for all the experiments performed, when the observed inactivation had reached about seven log cycles, the predictions estimated about 1 log cycle of inactivation; in the thermoresistometer these differences between observed and predicted values were even more than 10 times higher, from 4.07 log cycles observed to 0.34 predicted at a flow rate of 70 mL/min and a maximum heating rate of 14.7°C/s. A quantification of the impact of the heating rates on the level of inactivation achieved was established. These results point out the important effect that the heating rate has on the thermal resistance of E. coli, with high heating rates resulting in an additional sensitization to heat and therefore an effective food safety strategy in terms of food processing. ; This research was financially supported by the Ministry of Economy and Competitiveness of the Spanish Government and European Regional Development Fund (ERDF) through project AGL2013-48993-C2-1-R

Food safety criteria for Listeria monocytogenes in ready‐to‐eat (RTE) foods have been applied from 2006 onwards (Commission Regulation (EC) 2073/2005). Still, human invasive listeriosis was reported to increase over the period 2009–2013 in the European Union and European Economic Area (EU/EEA). Time series analysis for the 2008–2015 period in the EU/EEA indicated an increasing trend of the monthly notified incidence rate of confirmed human invasive listeriosis of the over 75 age groups and female age group between 25 and 44 years old (probably related to pregnancies). A conceptual model was used to identify factors in the food chain as potential drivers for L. monocytogenes contamination of RTE foods and listeriosis. Factors were related to the host (i. population size of the elderly and/or susceptible people; ii. underlying condition rate), the food (iii. L. monocytogenes prevalence in RTE food at retail; iv. L. monocytogenes concentration in RTE food at retail; v. storage conditions after retail; vi. consumption), the national surveillance systems (vii. improved surveillance), and/or the bacterium (viii. virulence). Factors considered likely to be responsible for the increasing trend in cases are the increased population size of the elderly and susceptible population except for the 25–44 female age group. For the increased incidence rates and cases, the likely factor is the increased proportion of susceptible persons in the age groups over 45 years old for both genders. Quantitative modelling suggests that more than 90% of invasive listeriosis is caused by ingestion of RTE food containing > 2,000 colony forming units (CFU)/g, and that one‐third of cases are due to growth in the consumer phase. Awareness should be increased among stakeholders, especially in relation to susceptible risk groups. Innovative methodologies including whole genome sequencing (WGS) for strain identification and monitoring of trends are recommended.

Under current European hygiene legislation, food businesses are obliged to develop and implement food safety management systems (FSMS) including prerequisite programme (PRP) activities and hazard analysis and critical control point principles. This requirement is especially challenging for small food retail establishments, where a lack of expertise and other resources may limit the development and implementation of effective FSMS. In this opinion, a simplified approach to food safety management is developed and presented based on a fundamental understanding of processing stages (flow diagram) and the activities contributing to increased occurrence of the hazards (biological, chemical (including allergens) or physical) that may occur. The need to understand and apply hazard or risk ranking within the hazard analysis is removed and control is achieved using PRP activities as recently described in the European Commission Notice 2016/C278, but with the addition of a PRP activity covering 'product information and customer awareness'. Where required, critical limits, monitoring and record keeping are also included. Examples of the simplified approach are presented for five types of retail establishments: butcher, grocery, bakery, fish and ice cream shop.