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The purpose of the present study was to examine the inactivation of Salmonella enterica (50 μL; 109 CFU g−1), Listeria monocytogenes (50 μL; 109 CFU g−1), and murine norovirus (MNV-1; 50 μL; 107 50% tissue culture infectious dose (TCID50) mL−1) on whole and fresh-cut strawberries after 2 min disinfection treatments (water (H2O), chlorine 200 mg L−1 (NaClO), water-assisted ultraviolet-C (UV-C) (WUV), and the combination WUV and 40 mg L−1 of PA (WUV + PA)) in a water tank (15 L) equipped with 4 UV-C lamps (17.2 W each), and after 7 days of cold storage (4 and 10 °C). For MNV-1, dry UV-C treatment (DUV) was also tested. For all UV-C treatments, an irradiation dose of 1.3 kJ m−2 was used. RESULTS: When strawberries were washed with WUV, L. monocytogenes and S. enterica were reduced by 2.8 and 2.2 log CFU g−1, respectively. The addition of 40 mg L−1 of PA to WUV (WUV + PA) increased the reduction range of L. monocytogenes and S. enterica by 1.9 and 0.8 log, respectively. Regarding the wash water, no pathogens were recovered after the WUV + PA treatment (detection limit 50 CFU mL−1). Depending on storage conditions (7 days at 4 or 10 °C), reductions observed were 0.5 to 2.0 log for S. enterica and 0.5 to 3.0 log for L. monocytogenes. The reductions in MNV-1 titer after disinfection treatments ranged from 1.3 to 1.7 log. No significant differences between storage conditions were observed for MNV-1: titers did not decline or were reduced up to 0.3 log after 7 days of cold storage. CONCLUSION: The three-way action for disinfecting strawberries by UV-C irradiation and PA, plus the physical removal of the microorganisms by agitated water, are effective against foodborne pathogens on strawberries and water wash. During storage, WUV had a larger impact on the inactivation kinetics of S. enterica. Storage had little impact on MNV-1 inactivation. The authors are grateful to the Spanish government (Ministerio deEconomía y Competitividad, research project AGL2016-78086-R)and the Centres de Recerca de Catalunya (CERCA) Programmeof‘Generalitat de Catalunya’for itsfinancial support. J. Ortiz-Solàthanks the University of Lleida for its PhD grant (BOU186-243/2017 UdL) and M. Anguera thanks them for their techni-cal support. I. Nicolau-Lapeña is in receipt of a predoctoral grantawarded by the‘Ministerio de Economía, Industria y Competitivi-dad’(grant number BES-2017-079779). The authors gratefullyacknowledged the assistance of Gloria Sánchez and Susana Guixfor teaching them the methodologies related to MNV-1 andRAW 264.7 assays.

Foodborne pathogens represent a major concern for the food industry, which needs to ensure that products are safe for consumers. Predictive microbiology is a multidisciplinary area of food mi crobiology, which is devoted to studying and predicting, by means of mathematical models, the cffects of extrinsic factors (temperature, salt, preservatives, etc.) on microbial behaviour in foods. The present chapter is an overview of the successive steps to follow for the successful development and implementation of a predictive model, as well as the most common types of secondary mod­els used in food microbiology. The chapter continues with a general review of the most powerful predictive microbiological tools (tertiary models) that are currently available on the worldwide web for foodborne patho­gens, and concludes by commenting on the direct implications and applications of predictive microbiology in food safety and microbial risk assessments., Funding was provided by the European Project (VII Framework Program: KBBE 22738 BASELINE), the Spanish Government (projects AGL2009-07436/ALI, AGL2010-l549 and AGL2010-15529 partially financed by European regional development funds, ERDF) and Junta de Andalucía (Excellence Project CTS-08-03620 and through financial support to group AGR-125 and AGR-170). J. Bautista-Gallego and F.N. Arroyo-López thank the ltalian and Spanish governments for their Assegno di Ricerca and Ramón y Cajal postdoctoral research contracts, respectively.

Introduction/aims: Satisfaction of inpatients with served food within a hospital care system still constitutes one of the main attempts to modernize food services. The impact of type of menu, food category, hospital centre and timetable on the meals wastage produced in different Spanish healthcare settings, was evaluated. Methods: Meal wastage was measured through a semiquantitative 5-point scale ("nothing on plate"; "¼ on plate"; "half on plate"; "¾ on plate" and "all on plate"). The study was carried out in two periods of three months each in 2010 and 2011. A trained person took charge of measuring plate waste classified into 726 servings belonging to 11 menus. In total 31,392 plates were served to 7,868 inpatients. A Kruskal-Wallis non-parametric test (P < 0.05) was applied to evaluate significant differences among the variables studied. Results: The menus were satisfactorily consumed because more than 50% of the plates were classified as "nothing on plate". Regarding food categories, 26.78% of the plates corresponded to soups and purées, while pasta and rice, and prepared foods were only distributed in 45% of the servings. Desserts were mostly consumed, while cooked vegetables were less accepted by the inpatients evaluated. Other factors such as hospital centre influenced plate waste (P < 0.05) but timetable did not (P > 0.05). Conclusion: Visual inspections of plate waste might be useful to optimize type and quality of menus served. The type of menu served and the food category could have a great influence on food acceptability by the inpatients studied. Introducción/objetivos: La satisfacción de los pacientes con el servicio de comidas continúa siendo uno de los principales retos dirigidos a la modernización de los sistemas de distribución de alimentos. En el presente estudio se evaluó el impacto del tipo de hospital, horario, categoría de alimento y tipo de menú sobre el desecho de comida producido en diferentes recintos hospitalarios españoles. Métodos: El desecho de alimentos se midió a través de una escala semicuantitativa con 5 niveles para evaluar la aceptabilidad del alimento ("nada en plato"; "¼ en plato"; "mitad en plato"; "¾ en plato" y "todo en plato"). El estudio se llevó a cabo en dos periodos de tres meses cada uno durante 2010 y 2011. Una persona entrenada se encargó del pesaje de platos, los cuales se clasificaron en 726 servicios pertenecientes a 11 menús diferentes. En total, se sirvieron 31.392 platos a 7.868 pacientes. Como prueba estadística se utilizó un test estadístico no paramétrico de Kruskal-Wallis (P < 0,05). Resultados: Los menús se consumieron de forma satisfactoria ya que más del 50% de los platos se clasificaron dentro de la categoría "nada en plato". Con respecto a las categorías de alimento, un 26,78% de los platos servidos se correspondieron con sopas y purés, mientras que los platos de pasta, arroz y alimentos listos para el consumo fueron distribuidos en un 4-5% de los servicios. Los postres fueron los platos más consumidos, mientras que los vegetales hervidos fueron menos aceptados. Otros factores como el tipo de hospital influyeron sobre el desecho de alimentos (P < 0,05) aunque el horario de servicio de comidas no (P > 0,05). Conclusión: La inspección visual del desecho de alimentos puede ser útil a la hora de optimizar el tipo y calidad de los menús servidos. El tipo de menú y la categoría de alimento podrían tener una gran influencia sobre la aceptabilidad de los platos por los pacientes.

The establishment of validated methodologies for the determination of food shelf-life is currently demanded by both food industries and Health Authorities at national and international scale. It is well known that most foods are perishable, since they are subjected to modifications in their structure, composition and properties during storage before consumption. These changes are of physico-chemical origin attributed to food composition together with the action of intrinsic and extrinsic environmental factors, and also microbiological, where spoilage flora play an important role. These modifications are “translated into“ sensorial deterioration at a specific time point. In this respect, food-borne bacteria, despite representing a threat for consumers´ health, do not affect sensorial changes

En la presente Tesis Doctoral se estudia el comportamiento de un microorganismo patógeno de interés alimentario. Listeria monocytogenes, a través del desarrollo de diferentes tipos de modelos predictivos y su posterior aplicación en un esquema de Evaluación Cuantitativa del Riesgo Microbiano (ECRM). En primer lugar, se procede a la estimación de los principales parámetros de crecimiento microbiano (fase de latencia, tasa máxima de crecimiento y densidad máxima de población), así como la probabilidad de crecimiento bajo diferentes condiciones ambientales sobre medios de cultivo. Posteriormente se monitoriza la calidad microbiológica y sensorial de espárragos blancos pasteurizados a diferentes temperaturas de almacenamiento, junto con la incidencia y evolución de crecimiento de L.monocytogenes. A través de la información obtenida, y junto con una recopilación de datos procedentes de la literatura científica, se aborda la aplicación de los modelos predictivos desarrollados en un esquema de ECRM mediante la estimación del número final de células presentes en el momento de consumo y el número de casos/año sobre una población. La metodología seguida en la presente Tesis doctoral constituye una vía relativamente sencilla de evaluar la seguridad microbiológica de un proceso alimentario mediante la integración modelos matemáticos dentro de un esquema de ECR

La presente Tesis Doctoral estudia la viabilidad de nuevas elaboraciones de aceitunas de mesa con variedades autóctonas del Valle del Guadalhorce, como son el caso de la Aloreña de Málaga y la Campiñesa. Para ambas variedades se ha hecho un seguimiento fisicoquímico, microbiológico, y sensorial del proceso de elaboración como verdes al estilo español, principal tipo de elaboración a nivel mundial de aceitunas de mesa, además de la realización de estudios de genotipado al final de la etapa fermentativa. Esta Tesis Doctoral también incluye el estudio de la influencia de la metodología de envasado sobre la estabilidad fisicoquímica, microbiológica y organoléptica de aceitunas Aloreñas curadas ecológicas. En la actualidad las aceitunas Aloreñas de Málaga se procesan como verdes naturales, debido a su bajo contenido en oleuropeína, compuesto responsable del amargor de las aceitunas, no necesitando tratamiento alcalino. Existe un porcentaje de aceitunas de esta variedad que por su pequeño tamaño no cumplen los estándares de calidad que se establecen para ser procesadas con el sello de la DOP, se destinan a la producción de aceite, mismo destino del 100 % de la producción de aceitunas de la variedad Campiñesa, aceitunas con una producción muy localizada en este entorno. La gran demanda existente de aceitunas de mesa ha llevado a pensar que ambas variedades podrían ser elaboradas como aceitunas de mesa al estilo español innovando en el tipo de procesado que se emplea en la actualidad, aumentando así la oferta de productos en el mercado. Para evaluar la viabilidad de las dos variedades elaboradas al estilo español, durante la campaña 2018/2019 se estudiaron los parámetros influyentes en la calidad de las aceitunas de mesa, prestando especial atención a la etapa de cocido, ensayándose diferentes concentraciones de hidróxido de sodio. Asimismo, tras el cocido y el lavado, se hizo un seguimiento y estudio de los diferentes parámetros microbiológicos y fisicoquímicos durante la fermentación que fue dirigida por la adición del cultivo iniciador OleicaStarter® (compuesto por dos cepas de Lactiplantibacillus pentosus 13B4 y 119). Tras la fermentación se estudió el efecto de la conservación con altas concentraciones de cloruro de sodio, y la influencia del tipo de envasado, frasco de vidrio con salmuera (durante 8 meses) y bolsa de plástico con atmósfera modificada de nitrógeno (durante 6 meses), para conocer la posible viabilidad comercial de estas aceitunas. Durante la segunda campaña se desarrollaron modelos predictivos para la variedad Aloreña de Málaga calibre perdigón, que cuantificaron la evolución del comportamiento microbiano y los parámetros fisicoquímicos durante la fermentación para dos tratamientos de cocido, con el objetivo de conocer la influencia de los factores y formulaciones empleadas sobre la cinética en las salmueras de fermentación. Con respecto a las aceitunas Campiñesas, el ensayo de la segunda campaña se enfocó, en el uso de diferentes cultivos iniciadores de bacterias ácido lácticas (OleicaStarter® y Lp309) con el objetivo de favorecer el desarrollo de una fermentación láctica y conseguir una mayor estandarización del proceso. El estudio con aceitunas Aloreñas curadas ecológicas con sello DOP ha tenido como objetivo el desarrollo de nuevas técnicas de envasado, en las que se usaron diferentes líquidos de gobierno (agua de mar, agua de manantial o agua de red), diferentes aliños (oleorresinas o especias naturales), y solo una parte de los envasados fueron sometidos a tratamiento térmico de pasterización. A lo largo de la vida de mercado se evaluaron los parámetros fisicoquímicos y microbiológicos junto con estudios organolépticos de los nuevos productos elaborados. Se concluye, que las aceitunas de la variedad Aloreña de Málaga con calibre perdigón, pueden elaborarse como aceitunas verdes al estilo español, resultando un producto seguro que cumple con las exigencias de calidad y seguridad alimentaria. Además, la etapa de fermentación pudo ser descrita de forma precisa a través del desarrollo de modelos predictivos. Por el contrario, las aceitunas Campiñesas presentaron mayores dificultades en su elaboración, siendo necesario la utilización de cultivos iniciadores de bacterias ácido lácticas más resistentes a las condiciones de las salmueras que ayudaron al desarrollo correcto de la fermentación y a la rápida estabilización del producto. Asimismo, si por motivos logísticos estas variedades debieran ser conservadas en vez de envasadas, no existiría una merma sustancial en términos de calidad, pudiendo ser envasadas bajo demanda. El estudio de envasados de aceitunas curadas Aloreñas ecológicas, la no pasteurización de los distintos envasados produjo refermentaciones en algunas de las presentaciones estudiadas. Por tanto, se concluyó que el empleo de un tratamiento térmico mantiene el producto con mayor estabilidad durante el periodo de vida de mercado estudiado, obteniéndose mayor aceptación de consumo. This Doctoral Thesis studies the feasibility of new elaborations of table olives with autochthonous varieties of the Guadalhorce Valley, Aloreña de Málaga and Campiñesa. For both varieties, a physicochemical, microbiological, and sensory monitoring of the Spanish-style elaboration process has been carried out, being the main table olive processing worldwide. Besides, genotyping studies have been performed at the end of the fermentation stage. This Doctoral Thesis also includes the study of the influence of the packaging methods on the physicochemical, microbiological, and sensorial stability of organic cured Aloreña table olives. Table olives corresponding to the Aloreña de Málaga variety are currently processed as natural green olives, due to their low content of oleuropein, a compound responsible for the bitterness of the olives, not requiring alkaline treatment. There is a percentage of olives of this variety that, due to their small size, do not meet the quality standards established to be processed with the PDO certification. Thus, they are destined for production of olive oil, as 100% of the production of olives from the Campiñesa variety, having a very localized production in this environment. The increasing demand for table olives has led to think that both varieties could be elaborated as Spanish-style table olives. This would result in a processing type innovation, thus increasing the supply of products on the market. To assess the viability of the two varieties made in the Spanish-style, during the 2018/2019 season, the parameters influencing the quality of table olives were studied, deserving special attention to the lying treatment by using different concentrations of sodium hydroxide. Likewise, after lying and washing, the different microbiological and physicochemical parameters were monitored and studied during fermentation, which was directed by the addition of the OleicaStarter® starter culture (composed of two strains of Lactiplantibacillus pentosus 13B4 and 119). After fermentation, the effect of olives preservation was studied at different high concentrations of sodium chloride, as well as the influence of the type of packaging, i.e., glass jars with brine (for 8 months) and plastic bags with modified atmosphere of nitrogen (for 6 months), to know the commercial viability of these olives. During the second campaign, predictive models were developed for the small-sized Aloreña de Málaga variety. These models quantified the evolution of the microbial behavior and the physicochemical parameters during fermentation for two lying treatments, with the aim of understanding the influence of the factors and formulations used on the kinetics of fermentation brines. Regarding the Campiñesas olives, the trial of the second campaign focused on the use of different lactic acid bacteria starter cultures (OleicaStarter® and Lp309) with the aim of enhancing the development of lactic acid fermentation and process standardization. Regarding the study with organic cured Aloreñas olives with the PDO certification was the development of new packaging techniques using different brines (sea water, spring water or tap water), seasonings (oleoresins or natural spices), and the application or not of a pasteurization treatment. Throughout the shelf-life, the physicochemical and microbiological parameters were evaluated along with sensorial studies of the finished products. It is concluded that the small-sized Aloreña de Málaga can be produced as green Spanish-style table olives, resulting in a safe product meeting the quality and food safety standards. In addition, fermentation can be accurately described using different predictive models. On the contrary, the Campiñesas olives presented more difficulties for elaboration, being necessary the use of alternative lactic acid bacteria starter cultures more resistant to the conditions of the brines achieving a correct fermentation and a rapid stabilization of the product. Likewise, if for logistical reasons these varieties had to be preserved instead of packaged, there would be no substantial loss in terms of quality, and they could be packaged on demand. The study of packaging of organic Aloreña cured olives, the unpasteurized packages led to product refermentations in some of the studied presentations. Moreover, it was concluded that the use of a heat treatment maintains the product with greater stability during the studied shelf- life, achieving higher consumers’ acceptance.

La Aloreña de Málaga es una variedad de aceituna de mesa autóctona del Valle del Guadalhorce y la Sierra de las Nieves, con una demarcación muy concreta (19 municipios) siendo muy apreciada dentro y fuera de la provincia de Málaga. Fue la primera aceituna de mesa en España en obtener el sello de calidad de DOP (BOJA nº215, 2009). El volumen de producción de este tipo de especialidad de aceitunas de mesa es de aproximadamente 3.500- 4.000 ton/año según datos estimados por el Ministerio de Agricultura (http://www.aica.gob.es/) y contrastados con las declaraciones de los industriales, realizadas por el Consejo Regulador. Por lo tanto, la producción no es muy elevada comparada con otros tipos de elaboraciones como son las aceitunas verdes estilo español o sevillano. Sin embargo, su elaboración aún hoy en día se sigue realizando de manera muy artesanal (un aspecto este altamente valorado por los consumidores), y es llevado a cabo en industrias de pequeño tamaño (650). De este modo, se han estudiado los niveles poblacionales de aerobios mesófilos, levaduras, bacterias lácticas, enterobacterias, esporulados, presencia de Listeria, Salmonella, Clostridium y Staphylococcus coagulasa positivos. En base a los resultados obtenidos, se generó un modelo matemático que estimó el grado de cumplimiento higiénico-sanitario del proceso de elaboración de este tipo de aceituna de mesa mediante un sistema de ponderación (basado en la legislación presente y opiniones de expertos) y modelo probabilístico de gestión del riesgo. La contribución relativa de cada fase a la calidad y seguridad del producto final fue evaluada y ponderada por un panel de expertos (n=25) del ámbito científico y del sector de la Aloreña de Málaga. No se ha detectado en ninguna empresa la presencia de especies patógenas que puedan suponer un riesgo para los consumidores. La etapa de aliño ha resultado ser la más crítica dentro del proceso, ya que las hierbas aromáticas y diversos ingredientes que se utilizan en el mismo presentan una elevada carga microbiana que se añade directamente a los envasados sin ningún tipo de tratamiento previo. También es recomendable reducir el número de microorganismos en el ambiente y un mayor control de las aguas destinadas al consumo humano. Se observó asimismo que el grado de cumplimiento higiénico-sanitario determinado por el sistema de evaluación desarrollado aumenta conforme se acercan las etapas finales del proceso, las cuales resultan ser las más seguras. Con toda la información obtenida, se ha desarrollado un protocolo y procedimiento científico que puede ser utilizado por las empresas del sector para estandarizar sus procesos, valorar cuantitativamente el grado de cumplimiento higiénicosanitario de las diferentes etapas de producción y predecir los efectos de la introducción de medidas correctoras sobre la calidad y seguridad de los productos finales. The Aloreña de Málaga table olive is an autochthonous variety from Guadalhorce Valley and Sierra de las Nieves region, with a confined demarcation (19 municipalities) being well appreciated inside and outside Malaga province. It has been the first table olive with Protected Designation of Origin (PDO) in Spain (BOJA No. 215, 2009). The production volume of this table olive speciality is below 3,500-4,000 ton according to estimated records of the Ministry of Agriculture ((http://www.aica.gob.es/) and further verified with the interviews performed by the Regulatory Council to industrials. Thus, production is limited in comparison to other elaborations such as the Spanish table olive style. However, its elaboration is still very artisanal (which is highly appreciated by consumers), being carried out by SMEs with less than 20 operators. These industries have a great interest in optimizing and improving the transformation processes in order to obtain a valorised product with high quality and safety standards, which is currently requested by the large distribution chain. This Doctoral Thesis is focused on providing additional knowledge about the transformation processes of Aloreña de Málaga table olives as well as to evaluate the effect of new changes on quality and safety of final products. In this sense, the Doctoral Thesis is divided into two sections. In the first section, novel methodologies such as metagenomics and statistical modelling are applied with the aim to gain knowledge about how different modifications (reduction of sodium chloride, inclusion of resting periods to table olives, and application of heat treatments) can affect to the elaboration process. In the second section, the hazard analysis and critical control points from various industries were evaluated in different campaigns in order to determine the fulfilment of hygienic-sanitary conditions through the performance of physicochemical and microbiological analyses along the production chain. Information generated will allow the further development of a scientific procedure based on advanced mathematical models and different weighing values to improve food quality and safety management in industries. To study the effect of sodium chloride reduction and the addition of a resting period of fruits during fermentation and posterior table olive preservation, 1,500 kg of olive fruits were collected and placed in containers with different preservation brines and varying concentrations of acetic acid, citric acid and salt, either directly or with a resting period of table olives at room temperature (72 h, 25ºC). Afterwards, the main physicochemical and microbiological parameters were monitored during 1 year. The presence of a high amount of acetic acid together with the absence of sodium chloride did not negatively affect the evolution of the main physicochemical parameters, though differences existed according to the assayed treatments. The elaboration process was marked by a rapid inhibition of Enterobacteriaceae population, as well as by a growth of lactic acid bacteria (just at the end of the process) and specially, by the yeasts growth, which were continuously present reaching concentration levels up to 6 log10 CFU/mL. One of the first applications in food microbiology of a functional data analysis model programmed in R was presented. The model allowed a smart comparison of the different assayed treatments, providing additional information on the rate and acceleration of changes in the elaboration process through the calculation of means, maximal and minimal values. Model fitting showed that yeasts population was very similar among the evaluated treatments, though significant differences existed for some fermentation treatment times. Nevertheless, larger differences were found for pH evolution, specially during the first 3- month process, being then stabilized after all treatments until a pH of 4.0 units approximately. Next Generation Sequencing techniques were subsequently applied to study fermentation and preservation processes of Aloreña de Málaga table olives. To do this, four fermentation containers were monitored (approximately 500 kg of table olives) at the food industry during a 4-month period by performing physicochemical and microbiological (Enterobacteriaceae, lactic acid bacteria and yeasts) analyses. From a microbiological point of view, fermentation took place normally, being yeasts the only population group showing growth while lactic acid bacteria and Enterobacteriaceae were not present during fermentation. During the 4-month fermentation period metagenomic analysis of brines and fruit samples were carried out with the aim of studying the ecology of bacterial (16S) and fungal populations (ITS). This methodology allowed detecting with relative frequency bacteria genera not being previously described in this product such as Celerinatantimonas, Pseudomonas and Propionibacterium among the bacterial groups, and Penicillium, Pichia and Zygotorulaspora among yeasts and moulds. There was not any pathogenic microorganism in the fermented table olives studied by what microbial food safety was ensured. Therefore, the application of this culture independent technique has extended the microbial spectrum of bacterial species not being previously detected by conventional culture dependent techniques. The potential role of these microbial groups on the final product quality is still to be determined. One-hundred kg. of cracked olives (destined to the elaboration of traditional table olives) and whole olives (destined to the elaboration of cured table olives) were collected to study the effect of a previous heat treatments on the fermentation process of olive fruits together with their organoleptical characteristics. These fruits were submitted to a heat treatment which consisted on a water immersion at 60ºC for 5 min before placing them in brine. Afterwards, fermentations were monitored during a study period longer than 5 months. Performance of this heat treatment in table olives previously to their transferring to brines enhanced lactic acid fermentation, with a higher sugars consumption, free acidity production and pH drop, which guaranteed the stability of olive fruits. In the heat-treated fermented table olives, population levels of lactic acid bacteria reached 5 log10 CFU/mL, while in those brines without a heat treatment, this microbial group was not detected. Improvement of fruit coloration (luminosity, green colour etc.) was observed in those fruits undergoing a heat treatment during fermentation and packaging steps. The great advantage of the applied heat treatment was subsequently confirmed by the improvement in the stability and acceptability of table olives once packaged. Indeed, 41 days after packaging, the products having the highest proportion of olive tasters who would consume them and would purchase the packaging, corresponded to the traditional heat-treated table olives. The acceptability percentages sparsely varied between 4 and 41 after packaging, which did not occur with the rest of assayed treatments. Finally, the metagenomic analysis performed at the end of the fermentation period to all elaboration types, and between treated and non-treated olive fruits revealed that the bacteria genera Lactobacillus, Pediococcus and Celerinatantimonas were present in all elaborations in both fruits and brines, and that prevalence of Lactobacillus was significantly higher in heat-treated olive fruits, which confirmed the improvement of lactic acid fermentation by the heat treatment applied. Finally, in the present Doctoral Thesis three representative companies of the Aloreña de Málaga table olive sector were visited during three consecutive campaigns (13/14, 14/15, y 15/16). Physicochemical and microbiological analyses (>650) were performed corresponding to environmental control samples, equipment surfaces, food handlers, olive fruits, olive dressings, brines, and potable water. In this way, population levels of mesophilic bacteria, yeasts, lactic acid bacteria, sporulated bacteria, together with presence of Listeria, Salmonella, Clostridium and coagulase positive Staphylococci, were analysed. Based on the obtained results, a mathematical model was developed to estimate a Performance Hygiene and Safety Score (PHSS) of the elaboration process of this table olive type by means of a weighing system (based on current legislation applied and experts opinions) together with a probabilistic decision-making model. The relative contributions of each processing step to final product quality and safety were evaluated and weighted by a scientific expert panel (n=25) together with industrials from the Aloreña de Málaga table olive sector. There was not any food company having presence foodborne pathogens during the whole study period. Addition of olive dressings has resulted to be most critical processing step, since aromatic herbs and diverse ingredients used presented a high microbial load which is directly added to the packaged products without a posterior heat treatment. It is also recommended to reduce the environmental contamination as well as a more intensive control of the potable water destined to human consumption. Likewise, it was observed that the PHSS values determined by the developed mathematical model increased according to the final processing steps, being the safest ones. With the information obtained, a protocol and scientific procedure was performed, which can be used by industrials in order to standardize their elaboration processes, to quantitatively assess the degree of fulfilment of hygienic-sanitary conditions of the different production steps and to predict the effect of corrective measures on final products quality and safety.

Premio extraordinario de Trabajo Fin de Máster curso 2012-2013.Agroalimentación La salmonelosis es una toxiinfección alimentaria muy importante, no sólo porque es la mayor causa de brotes gastrointestinales en España, la Unión Europea y EE.UU.; sino por las pérdidas económicas asociadas a ella entre otros factores. Una de las medidas más eficaces de prevención de esta enfermedad es la aplicación de tratamientos térmicos a nivel industrial tales como la pasteurización. El objeto de este estudio es conocer las curvas de inactivación de Salmonella Enterica en diversas matrices liquidas, a fin de optimizar los tratamientos térmicos industriales aplicados en estos productos y a la vez conseguir unos criterios microbiológicos en concordancia a la normativa vigente. Para ello el microorganismo en estudio fue sometido a temperaturas de 50ºC, 55ºC y 60ºC en diferentes matrices liquidas, como son medio de cultivo TSB, leche desnatada y zumo de naranja. Los datos observados fueron ajustados a modelos de inactivación de microorganismos gracias al programa DMfit y fueron obtenidos diversos parámetros de interés como son los valores de kmax y el valor D. entre los principales hallazgos encontrados caben destacar los siguientes. A medida que se aumenta la temperatura del tratamiento térmico la inactivación de Salmonella Enterica es más acusada y rápida, lo que se traduce en valores de kmax cada vez mayores y valores de D. menores. En TSB y leche a temperaturas de 50ºC se obtienen modelos de inactivación lineales, en cambio a 55ºC-60ºC se obtienen modelos de inactivación bifásicos. En zumo se consigue una inactivación bifásica en cualquiera de los tratamientos aplicados en este estudio. Las diferencias encontradas entre matrices distintas son las siguientes. En zumo se consigue una inactivación más acusada y rápida que en TSB y leche, esto pudiera ser debido a que el pH acido del zumo ejerce un efecto negativo en la supervivencia de Salmonella Enterica. En posteriores estudios cabria tratar con otras matrices liquidas; usar otros microorganismos presentes en los alimentos o realizar combinaciones de diferentes técnicas de inactivación para optimizar los tratamientos. Salmonelosis constitutes overall a highly important foodborne disease, being a major cause of gastrointestinal outbreaks in Spain, European Union and U.S.A. Besides, it is associated to economic losses and food waste among other factors. One of the most effective measures for prevention of this disease is the implementation of thermal treatments in food industries such as pasteurization. The purpose of this study was to determine the inactivation curves of Salmonella Enterica in various liquid matrices, in order to optimize industrial heat treatments applied to these products while achieving microbiological criteria in accordance with current regulations. For this study, the microorganism was subjected to 50ºC, 55ºC and 60ºC in different liquid matrices, such as Triptone Soja Broth (TSB), skimmed milk and orange juice. The observed data were fitted to primary inactivation models by means of the DMfit software, obtaining the correspondent kinetic parameters such as maximum inactivation rate (kmax), D values, and residual populations after the thermal treatments. Among the main findings obtained, as inactivation temperature increased, decrease in the population of Salmonella Enterica was more pronounced, thus resulting in higher values of kmax values and reduced D values. In TSB and skimmed milk, at 50ºC treatments, linear inactivation models were obtained, however at 55ºC-60ºC treatments, a biphasic behavior was observed in inactivation patterns due to the existence of a residual population. In juice, a biphasic inactivation was achieved in any of the temperature treatments used in this study. Significant differences were found between matrices (p

Los vegetales de IV Gama y productos cárnicos cocidos listos para el consumo sonalimentos básicos en los hogares y en los establecimientos de restauración colectiva;y a menudo se incluyen en la dieta destinada a niños, ancianos, enfermos, etc., por sufacilidad de preparación y valor nutricional. Sin embargo, son alimentos que norequieren de tratamiento térmico para su consumo, por lo que son muy vulnerables alas contaminaciones microbianas originadas fundamentalmente por prácticasinadecuadas de higiene y de manipulación tras el procesado. La contaminaciónmicrobiana producida por Escherichia coli y Staphylococcus aureus con frecuenciase originan en ambientes de restauración colectiva. Por ello, resulta conveniente elfortalecimiento de las medidas de prevención y los sistemas de Análisis de Peligros yPuntos de Control Crítico en estos centros, con la finalidad de garantizar lainocuidad de los alimentos y preservar la salud humana. Así, en un marco deEvaluación del Riesgo, la Microbiología Predictiva puede constituir una herramientamuy valiosa para una mejor gestión de las medidas de seguridad alimentaria.La presente Tesis Doctoral tiene como Objetivo General evaluar las condicioneshigiénico-sanitarias y la seguridad microbiológica, de los establecimientos derestauración colectiva de comedores escolares, centros geriátricos y hospitales, asícomo de platos mínimamente procesados y listos para el consumo (ensaladasvegetales y productos cárnicos cocidos) que son servidos en dichos establecimientos,y van dirigidos a una población consumidora más susceptible a los peligrosmicrobiológicos y de enfermar por razones de edad y estado fisiológico. Además,pretende cuantificar el comportamiento de los microorganismos patógenos másrepresentativos en estos alimentos, mediante el uso de herramientas deMicrobiología Predictiva y Evaluación del Riesgo Microbiológico.Los resultados obtenidos en la presente Tesis Doctoral han demostrado que losservicios de restauración de los comedores escolares, centros geriátricos y hospitalesestudiados, presentan ciertas deficiencias comúnmente relacionadas con los hábitos de higiene durante la manipulación de los alimentos, y la limpieza y desinfección deequipos y superficies de trabajo.Por otra parte, se confirma la importancia de los modelos predictivos en lacuantificación del comportamiento microbiano bajo determinadas condicionesambientales; donde la Temperatura fue el factor determinante en el desarrollo de losmicroorganismos estudiados. Los modelos predictivos de Probabilidad decrecimiento permitieron determinar que E. coli puede ser inhibido a 8ºC a nivelesbajos de pH (, Fresh cut vegetables and cooked meat products are basic foods in households andfoodservice establishments and often they are included in the diet aimed to veryyoung, elderly and inmunocompromised people by their ease of preparation andhigh nutritional value. However, these foods do not require heat treatments forconsumption after processing, which make them more vulnerable to microbialcontamination mainly caused by poor hygiene and handling practices. Frequently,the microbial food contamination produced by Escherichia coli and Staphylococcusaureus arise in foodservices environments. Therefore, is convenient to strengthenpreventive measures and HACCP systems in these centres in order to ensure thefood safety and to preserve the human health. Thus, the predictive microbiologycould be a valuable tool for better management of food safety measures within aframework of risk assessment.The major objectives of this dissertation were to evaluate the hygienic and sanitaryconditions and microbiological safety of foodservices of school canteens, long-termcare facilities and hospitals, and minimally processed and ready-to-eat foods(vegetables salads and cooked meat products) that served in these collective canteensaimed for more susceptible population groups to microbiological hazards andfoodborne illness due to age and physiological status. Furthermore, the Thesis aims...