Flow Charts from Videos as a Teaching Resource in Food Technology

Resúmenes IV Congreso VetDoc de Docencia Veterinaria, León 2017 (6-7 de Julio)[ES] La materia que se imparte en la asignatura de Tecnología de los Alimentos en el grado en Veterinaria de la Universidad de León (ULE) comprende el análisis y estudio de los procesos tecnológicos utilizados en la industria alimentaria para la obtención de los distintos alimentos de origen animal. Actualmente existen en Internet una gran variedad de vídeos de acceso libre, que muestran el proceso industrial de fabricación de alimentos concretos que se lleva a cabo en la fábrica y en los que se puede apreciar el funcionamiento de los equipos implicados así como las actividades desarrolladas por los trabajadores en la línea de producción

Evaluation of the performance of a three-strains lactic acid bacteria cocktail for the control of Listeria monocytogenes on marinated lean pork

[EN] The aim of this study was to evaluate the addition of a cocktail of three lactic acid bacteria (LAB) (Lactococcus lactis, Lacticaseibacillus paracasei and Lactiplantibacillus plantarum) as a protective culture into marinated pork. The pork was artificially inoculated with two Listeria monocytogenes strains and stored for 12 days. Two packagings were used: vacuum or modified atmosphere packaging (MAP). LAB, L. monocytogenes, psychrotrophic bacteria, pH, aw, color, the metataxonomic profile and the sensorial quality of the product were evaluated. The growth of L. monocytogenes under vacuum and MAP was reduced with the use of the LAB up to 0.8 and 0.7 log10 CFU/g, respectively. LAB counts gradually increased, which was accompanied by a slight decrease in pH. In LAB samples, psychrotrophic bacteria showed a reduction at day 12 as compared to non-inoculated samples. Some minor differences were also observed among samples for color and sensory parameters. Regardless of the type of packaging, the microbiota of the marinated pork was dominated initially by Photobacterium and subsequently during storage by a diversity of LAB. The application of LAB could help to obtain a safe product, although further evaluation would be required to optimize the application of the LAB cocktail in real-scale commercial scenarios.SIPublicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL

Susceptibility and transcriptomic response to plasma-activated water of Listeria monocytogenes planktonic and sessile cells

[EN] Plasma-Activated Water (PAW) was generated from tap water using a surface dielectric barrier discharge at different discharge power (26 and 36 W) and activation time (5 and 30 min). The inactivation of a three-strain Listeria monocytogenes cocktail in planktonic and biofilm state was evaluated. PAW generated at 36 W-30 min showed the lowest pH and the highest hydrogen peroxide, nitrates, nitrites contents and effectiveness against cells on planktonic state, resulting in 4.6 log reductions after a 15-min treatment. Although the antimicrobial activity in biofilms formed on stainless steel and on polystyrene was lower, increasing the exposure time to 30 min allowed an inactivation >4.5 log cycles. The mechanisms of action of PAW were investigated using chemical solutions that mimic its physico-chemical characteristics and also RNA-seq analysis. The main transcriptomic changes affected carbon metabolism, virulence and general stress response genes, with several overexpressed genes belonging to the cobalamin-dependent gene cluster.S

The implementation of continuous evaluation methodologies improves the academic performance of Food Technology students

Resúmenes IV Congreso VetDoc de Docencia Veterinaria, León 2017 (6-7 de Julio)[ES] La información recabada en los Planes de Acción Tutorial permite concluir que algunos alumnos del grado de Veterinaria de la Universidad de León se encuentran insatisfechos con las calificaciones obtenidas y creen merecer mejores resultados para el esfuerzo de estudio empleado. Nuestra experiencia como docentes de la asignatura Tecnología de los Alimentos también nos permitió detectar que alumnos con dedicación similar al estudio obtienen rendimientos muy dispares, lo que confirmó que los hábitos de estudio tienen un papel muy significativo en el éxito o fracaso del estudiante y que las estrategias de aprendizaje empleadas por gran parte del alumnado no eran adecuadas para las metodologías docentes existentes. En particular, pudimos comprobar que el alumnado de Tecnología de los Alimentos no realizaba un estudio continuado de la asignatura a lo largo del semestre, sino que concentraba sus esfuerzos en la/s semana/s previas a las pruebas escritas

Selection of lactic acid bacteria as biopreservation agents and optimization of their mode of application for the control of Listeria monocytogenes in ready-to-eat cooked meat products

[EN] In order to meet consumers´demands for more natural foods and to find new methods to control foodborne pathogens in them, research is currently being focused on alternative preservation approaches, such as biopreservation with lactic acid bacteria (LAB). Here, a collection of lactic acid bacteria (LAB) isolates was characterized to identify potential biopreservative agents. Six isolates (one Lactococcus lactis, one Lacticaseibacillus paracasei and four Lactiplantibacillus plantarum) were selected based on their antimicrobial activity in in vitro assays. Whole genome sequencing showed that none of the six LAB isolates carried known virulence factors or acquired antimicrobial resistance genes, and that the L. lactis isolate was potentially a nisin Z producer. Growth of L. monocytogenes was successfully limited by L. lactis ULE383, L. paracasei ULE721 and L. plantarum ULE1599 throughout the shelf-life of cooked ham, meatloaf and roasted pork shoulder. These LAB isolates were also applied individually or as a cocktail at different inoculum concentrations (4, 6 and 8 log10 CFU/g) in challenge test studies involving cooked ham, showing a stronger anti-Listerial activity when a cocktail was used at 8 log10 CFU/g. Thus, a reduction of up to ~5.0 log10 CFU/g in L. monocytogenes growth potential was attained in cooked ham packaged under vacuum, modified atmosphere packaging or vacuum followed by high pressure processing (HPP). Only minor changes in color and texture were induced, although there was a significant acidification of the product when the LAB cultures were applied. Remarkably, this acidification was delayed when HPP was applied to the LAB inoculated batches. Metataxonomic analyses showed that the LAB cocktail was able to grow in the cooked ham and outcompete the indigenous microbiota, including spoilage microorganisms such as Brochothrix. Moreover, none of the batches were considered unacceptable in a sensory evaluation. Overall, this study shows the favourable antilisterial activity of the cocktail of LAB employed, with the combination of HPP and LAB achieving a complete inhibition of the pathogen with no detrimental effects in physico-chemical or sensorial evaluations, highlighting the usefulness of biopreservation approaches involving LAB for enhancing the safety of cooked meat products.S

Durability Assessment of a Plasma-Polymerized Coating with Anti-Biofilm Activity against L. monocytogenes Subjected to Repeated Sanitization

Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).[EN] Biofilm formation on food-contact surfaces is a matter of major concern causing food safety and spoilage issues to this sector. The aim of this study was to assess the durability of the anti-biofilm capacity of a plasma-polymerized coating composed of a base coating of (3-aminopropyl) triethoxysilane (APTES) and a functional coating of acrylic acid (AcAc). Coated and uncoated AISI 316 stainless steel (SS) plates were subjected to five sanitization cycles with sodium hypochlorite (0.05%) and peracetic acid (0.5%). The effectiveness of the coating for the inhibition of multi-strain Listeria monocytogenes biofilm formation was confirmed using a three-strain cocktail, which was grown on the SS plates at 12◦ C for 6 days. Compared to the uncoated SS, relative biofilm productions of 14.6% on the non-sanitized coating, 27.9% on the coating after sanitization with sodium hypochlorite, and 82.3% on the coating after sanitization with peracetic acid were obtained. Morphological and physicochemical characterization of the coatings suggested that the greater anti-biofilm effectiveness after sanitization with sodium hypochlorite was due to the high pH of this solution, which caused a deprotonation of the carboxylic acid groups of the functional coating. This fact conferred it a strong hydrophilicity and negatively charged its surface, which was favorable for preventing bacterial attachment and biofilm formation.SIThis publication is based upon work from COST Action CA19110—PlAgri, supported by COST (European Cooperation in Science and Technology-www.cost.eu). XPS tests were conducted by the Advanced Microscopy Laboratory (LMA) of The Institute of Nanoscience of Aragón (INA), University of Zaragoza. The authors are thankful to the LMA-INA for the access to their equipment and their expertise. The AFM images were taken by the Central Research Support Service (SCAI) of the University of Málaga (UMA). The author P. Fernández-Gómez is grateful to Junta de Castilla y León and the European Social Fund (ESF) for awarding her a predoctoral grant (BOCYL-D-15122017-4). The author M. Oliveira is in receipt of a Juan de la Cierva contract IJC2018-035523-I awarded by the Spanish Ministry of Science, Innovation, and Universities MCIN/AEI/10.13039/501100011033. The author E. Sainz-García, as researcher of the University of La Rioja, is thankful to the postdoctoral training program funded by the Plan Propio of the University of La Rioja. The authors I. Muro-Fraguas and A. Sainz-García are thankful to the program of pre-doctoral contracts for the training of research staff that is funded by the University of La Rioja.This study is part of the Research, Development and Innovation projects AGL2017-82779- C2-R and PID2020-113658RB-C2, funded by MCIN/AEI/10.13039/501100011033 and by ERDF “A way to make Europe”

“Club del Trabajo Fin de Grado”: método de role-playing en Ciencia y Tecnología de los Alimentos

[ES] El juego de roles, un método de enseñanza innovador, ha sido considerado como una herramienta muy eficaz en la educación. Se utilizó esta metodología con el fin de ayudar a los estudiantes del último curso del Grado en Ciencia y Tecnología de Alimentos a afrontar con confianza y éxito la defensa de su Trabajo Fin de Grado. Además, se utilizó Twitter como herramienta de difusión de los conocimientos científicos adquiridos por los alumnos. Para poder conocer la opinión de los participantes, se distribuyó un cuestionario de satisfacción en relación con la experiencia de innovación docente. Todos los alumnos consideraron que esta actividad aumentó su confianza a la hora de enfrentarse a la defensa real del Trabajo Fin de Grado y les ayudó a mejorar su comunicación oral en comparación a si no hubieran realizado esta actividad. Por ello, sería interesante implementar esta metodología de aprendizaje activo en próximos cursos académicos, pudiendo incluso extrapolarlo en otros grados

Elaboración de bebidas a partir de la castaña

Conferencia impartida en la II Feria de Castañicultura en el Bierzo (BioCastañea) del 17 al 20 de noviembre de 201

Bebidas de castaña

Biocastanea 2012 - III Feria de la Castañicultura en el Bierzo: Conferencia impartida por Montserrat González Raurich (Universidad de León. Departamento de Higiene y Tecnología de los Alimentos

Durability assessment of a plasma-polymerized coating with anti-biofilm activity against l. Monocytogenes subjected to repeated sanitization

Biofilm formation on food-contact surfaces is a matter of major concern causing food safety and spoilage issues to this sector. The aim of this study was to assess the durability of the anti-biofilm capacity of a plasma-polymerized coating composed of a base coating of (3-aminopropyl)triethoxysilane (APTES) and a functional coating of acrylic acid (AcAc). Coated and uncoated AISI 316 stainless steel (SS) plates were subjected to five sanitization cycles with sodium hypochlorite (0.05%) and peracetic acid (0.5%). The effectiveness of the coating for the inhibition of multi-strain Listeria monocytogenes biofilm formation was confirmed using a three-strain cocktail, which was grown on the SS plates at 12 °C for 6 days. Compared to the uncoated SS, relative biofilm productions of 14.6% on the non-sanitized coating, 27.9% on the coating after sanitization with sodium hypochlorite, and 82.3% on the coating after sanitization with peracetic acid were obtained. Morphological and physicochemical characterization of the coatings suggested that the greater anti-biofilm effectiveness after sanitization with sodium hypochlorite was due to the high pH of this solution, which caused a deprotonation of the carboxylic acid groups of the functional coating. This fact conferred it a strong hydrophilicity and negatively charged its surface, which was favorable for preventing bacterial attachment and biofilm formation