Noves tecnologies per a un millor suc de taronja

Investigadors del Centre Especial de Recerca - Planta de Tecnologia dels Aliments (CeRPTA) a la UAB estan investigant en l'aplicació de tecnologies alternatives a les tradicionals per obtenir aliments que siguin segurs i lliures de bacteris però que, a la vegada, conservin les seves propietats nutritives i sensorials. Aquest grup del CeRPTA ha estudiat la tècnica de la homogeneïtzació per pressions ultra-altes (UHPH) pel suc de taronja. Aquesta tecnologia pot ser una alternativa viable a la pasteurització habitual pels sucs de fruita, fet que afectarà molt menys les seves qualitats.Investigadores del Centre Especial de Recerca - Planta de Tecnologia de los Aliments (CeRPTA) en la UAB están investigando la aplicación de tecnologías alternativas a las tradicionales para obtener alimentos que sean seguros y libres de bacterias pero que, a la vez, conserven sus propiedades nutritivas y sensoriales. Este grupo del CeRPTA ha estudiado la técnica de la homogeneización por presiones ultra-altas (UHPH) para el zumo de naranja. Esta tecnología puede ser una alternativa viable a la pasteurización habitual por los zumos de frutas, lo que afectará mucho menos sus cualidades

Noves tecnologies per fer més segurs els aliments

En els darrers anys s'han estat estudiant tecnologies alternatives als tractaments tèrmics convencionals per aconseguir aliments segurs que conservin les qualitats nutritives dels aliments frescos. En aquesta recerca s'ha observat que l'homogenització per pressió permet reduir de forma significativa la presència d'una perillosa bactèria, l'Escherichia coli.En los últimos años se han estudiado tecnologías alternativas a lostratamientos térmicos convencionales para conseguir alimentos segurosy que conserven las calidades nutritivas de los alimentos frescos. Enesta investigación se ha observado que la homogenización por presiónpermite reducir de forma significativa la presencia de una peligrosabacteria, la Escherichia coli

Effect of ultra-high-pressure homogenization processing on the microbiological, physicochemical, and sensory characteristics of fish broth

The effect of ultra-high-pressure homogenization (UHPH) treatments at 300 MPa at inlet temperatures (Ti) between 45 and 75 °C on the microbiological, physical, and sensorial characteristics of fish broth was evaluated. Before the application of UHPH treatments, different fish broth formulations were tested, selecting the formula with the best organoleptic and nutritional characteristics and the lowest cost, containing 45% monkfish heads and rock fish in the same proportion. The microbiological shelf-life of fish broth during cold storage at 4 and 8 °C was extended by a minimum of 20 days by applying UHPH treatments at inlet temperatures (Ti) between 45 and 65 °C. Fish broth UHPH-treated at Ti = 75 °C was microbiologically sterile during storage at 4 °C, 8 °C, and room temperature. Fish broth UHPH-treated was physically stable, significantly reducing the particle size. Color showed higher luminosity and lower yellowness as the inlet temperature increased. In fish broth UHPH-treated at Ti = 75 °C, selected for its microbiological stability, no differences were observed in the nutritional composition, antioxidant activity, and sensorial perception compared to untreated fish broth. Hence, UHPH treatments showed to be an alternative to preserving fish broth with an improved microbiological shelf-life and good sensorial characteristics.Postprint (published version

Short Wave Ultraviolet Light (UV-C) Effectiveness in the Inactivation of Bacterial Spores Inoculated in Turbid Suspensions and in Cloudy Apple Juice

Liquid foods might present interferences in their optical properties that can reduce the effectiveness of short-wave ultraviolet radiation (UV-C) treatments used for sterilization purposes. The effect of turbidity as UV-C interference factor against the inactivation of bacterial spores was analysed by using phosphate-buffered saline solutions (PBS) of different turbidity values (2000, 2500, and 3000 NTU) which were adjusted with the addition of apple fibre. These suspensions were inoculated with spores of Bacillus subtilis and Alicyclobacillus acidoterrestris. While higher UV-C doses increased the inactivation rates of spores, these were reduced when turbidity values increased; a dose of 28.7 J/mL allowed inactivation rates of B. subtilis spores of 3.96 Log in a 2000-NTU suspension compared with 2.81 Log achieved in the 3000-NTU one. Spores of B. subtilis were more UV-C-resistant than A. acidoterrestris. Cloudy apple juice inoculated with A. acidoterrestris spores was processed by UV-C at different doses in a single pass and with recirculation of the matrix through the reactor. Inactivation increased significantly with recirculation, surpassing 5 Log after 125 J/mL compared with 0.13 Log inactivation after a single-pass treatment at the same UV-C dose. UV-C treatments with recirculation affected the optical properties (absorption coefficient at 254 nm and turbidity) of juice and increased browning as UV-C doses became higher

Combined effects of ultra-high pressure homogenization and short-wave ultraviolet radiation on the properties of cloudy apple juice

This work addresses the physicochemical, enzymatic and sensory changes in cloudy apple juice treated by ultra- high pressure homogenization (UHPH) and short-wave ultraviolet radiation (UV–C) applied at 20 ¿C. Those technologies were applied in single and combined treatments at different UHPH pressures (200–300 MPa) and UV-C doses (14.3–27.8 J/mL). UV-C treatments could not effectively inactivate enzymes, but treatments at 300- MPa UHPH reduced pectin methylesterase activity to a 24.6%, and polyphenol oxidase activity was not detected. Those samples presented a higher antioxidant capacity (283% measured by FRAP, and 286.4% by DPPH) than in non-treated juice, and after a combination with 28.7 J/mL of UV-C the polyphenols content augmented to 277.6%. Sensory evaluation revealed that UHPH at 300 MPa and UV-C at 21.5 J/mL significantly changed perceptible odour and overall flavour of cloudy apple juice, while treatments at 200 MPa didn’t produce any significant changes in the different parameters.Postprint (published version

Avenços en tecnologia no tèrmica per tractar aliments líquids

A la cerca de tecnologies per mantenir les propietats organolèptiques originals dels aliments amb un processament mínim que garanteixi alhora la inactivació de microorganismes, en els últims anys s'estan investigant solucions no tèrmiques. El Centre d'Innovació, Recerca i Transferència en Tecnologia dels Aliments (CIRTTA) de la UAB ha incorporat una d'aquestes tecnologies: un equip de radiació ultraviolada d'ona curta (UCV), amb què els investigadors han obtingut resultats d'alta efectivitat en sucs, brous i infusions. Ara el centre de recerca prepara una jornada de demostració que tindrà lloc el primer trimestre del pròxim any.En busca de tecnologías para mantener las propiedades organolépticas originales de los alimentos con un procesado mínimo que garantice a la vez la inactivación de microorganismos, en los últimos años se están investigando soluciones no térmicas. El Centro de Innovación, Investigación y Transferencia en Tecnología de los Alimentos (CIRTTA) de la UAB ha incorporado una de estas tecnologías: un equipo de radiación ultravioleta de onda corta (UCV), con el que los investigadores han obtenido resultados de alta efectividad en zumos, caldos e infusiones. Ahora el centro de investigación prepara una jornada de demostración que tendrá lugar el primer trimestre del próximo año

Evaluation of Continuous UVC Treatments and its Combination with UHPH on Spores of Bacillus subtilis in Whole and Skim Milk

The aim of this study was to evaluate the effectiveness of different UVC treatments, alone or in combination with ultra-high pressure homogenization (UHPH) on Bacillus subtilis spores in milk. Spores of B. subtilis (CECT4002) were inoculated in whole and skim milk to an initial concentration about 6 log CFU/mL. Milk was subjected to different ultraviolet radiation treatments at 254 nm (UVC) using a concentric tubular reactor in a dose ranging from 10 to 160 J/mL. Different number of passes were used to adjust the final dose received by the matrix. In general, increasing the number of passes (defined as number of entries to the tunnel-NET) increased the inactivation of spores of B. subtilis. The best lethality results (above 4 Log CFU/mL) were obtained by applying doses from 100 J/mL with several NET. When the same doses were achieved with a single pass lethality in most cases did not exceed 1 log CFU/mL. Increasing the NET also increased the likelihood for the spores to remain longer in the effective distance from the UVC source, estimated as 0.02 mm for whole milk and 0.06 mm for skim milk. Combination of UHPH and UVC did not clearly increase the efficiency of a single UVC treatment, and a lower lethality was even observed in some cases. UHPH treatments increased the turbidity and absorption coefficient (254 nm) of both whole and skim milk

Drastic Microbial Count Reduction in Soy Milk Using Continuous Short-Wave Ultraviolet Treatments in a Tubular Annular Thin Film UV-C Reactor

Vegetative cells of Listeria monocytogenes and Escherichia coli and spores of Bacillus subtilis and Aspergillus niger were inoculated in soy milk at an initial concentration of ≈5 log CFU/mL. Inoculated and control (non-inoculated) soy milk samples were submitted to three types of treatments using a tubular annular thin film short-wave ultraviolet (UV-C) reactor with 1 mm of layer thickness. Treatments applied depended on the flow rate and the number of entries to the reactor, with UV-C doses ranging from 20 to 160 J/mL. The number of entries into the reactor tube (NET) was established as the most determining parameter for the efficiency of the UV-C treatments. Conidiospores of A. niger were reported as the most resistant, followed by B. subtilis spores, while vegetative cells were the most sensible to UV-C, with Listeria monocytogenes being more sensible than Escherichia coli. Treatments of just 80 J/mL were needed to achieve a 5 log CFU/mL reduction of L. monocytogenes while 160 J/mL was necessary to achieve a similar reduction for A. niger spores

Detección molecular del virus de la hepatitis E en hígados de cerdo destinados al consumo humano en el estado de Nuevo León, México

RESUMEN Objetivo. Detección molecular del virus de la hepatitis E (VHE) en hígado de cerdo para consumo humano en Nuevo León, México. Material y métodos. Se analizaron 127 hígados de cerdo (87 obtenidos de rastros TIF, y 40 de carnicerías) mediante RT-PCR semianidado para amplificar un fragmento de 212 pb del gen ORF2 del VHE. Resultados. El 19.5% (17) de los hígados de rastros y 22.5% (9) de carnicerías fueron positivos. La secuenciación mostró 94-95% de homología con el genotipo 3. Conclusiones. Los resultados indican que el VHE circula en granjas porcinas del estado, lo que constituye una probable fuente de contaminación para los productos cárnicos porcinos. ABSTRACT Objective. Molecular detection of HEV in pig livers destined for human consumption in Nuevo Leon, Mexico. Materials and methods. 87 livers were collected from pigs slaughtered in TIF and 40 livers from butchers. A 212 pb fragment of HEV ORF2 gene was amplified by semi-nested RT-PCR. Results. 19.54% (17) of tif’s and 22.5% (9) of buthcer’s livers were positive for HEV. Sequencing of the amplified products showed a 94%-95% homology with the sequences reported for genotype 3. Conclusions. Our results indicate that HEV is circulating in swine herds in the state, constituting a probable source of contamination of pig meat products

The efficacy and safety of high‐pressure processing of food

[EN]High-pressure processing (HPP) is a non-thermal treatment in which, for microbial inactivation, foods are subjected to isostatic pressures (P) of 400–600 MPa with common holding times (t) from 1.5 to 6 min. The main factors that influence the efficacy (log10 reduction of vegetative microorganisms) of HPP when applied to foodstuffs are intrinsic (e.g. water activity and pH), extrinsic (P and t) and microorganism-related (type, taxonomic unit, strain and physiological state). It was concluded that HPP of food will not present any additional microbial or chemical food safety concerns when compared to other routinely applied treatments (e.g. pasteurisation). Pathogen reductions in milk/colostrum caused by the current HPP conditions applied by the industry are lower than those achieved by the legal requirements for thermal pasteurisation. However, HPP minimum requirements (P/t combinations) could be identified to achieve specific log10 reductions of relevant hazards based on performance criteria (PC) proposed by international standard agencies (5–8 log10 reductions). The most stringent HPP conditions used industrially (600 MPa, 6 min) would achieve the above-mentioned PC, except for Staphylococcus aureus. Alkaline phosphatase (ALP), the endogenous milk enzyme that is widely used to verify adequate thermal pasteurisation of cows’ milk, is relatively pressure resistant and its use would be limited to that of an overprocessing indicator. Current data are not robust enough to support the proposal of an appropriate indicator to verify the efficacy of HPP under the current HPP conditions applied by the industry. Minimum HPP requirements to reduce Listeria monocytogenes levels by specific log10 reductions could be identified when HPP is applied to ready-to-eat (RTE) cooked meat products, but not for other types of RTE foods. These identified minimum requirements would result in the inactivation of other relevant pathogens (Salmonella and Escherichia coli) in these RTE foods to a similar or higher extent.S