Entity

Time filter

Source Type


Santiago-Morales J.,University of Alcala | Rosal R.,University of Alcala | Rosal R.,IMDEA Madrid Institute for Advanced Studies | Hernando M.D.,Spanish National Institute for Agricultural and Food Research and Technology INIA | And 6 more authors.
Journal of Hazardous Materials | Year: 2014

This article deals with the degradation of a third-generation (G3) poly(amidoamine) (PAMAM) dendrimer under ozonation and irradiation. The identification and quantification of G3 PAMAM dendrimer and its transformation products has been performed by liquid chromatography-electrospray ionization-hybrid quadrupole time-of-flight-mass spectrometry. The dendrimer was completely depleted by ozone in less than 1. min. The effect of ultraviolet irradiation was attributed to hydroxyl-mediated oxidation. The transformation products were attributed to the oxidation of amines, which resulted in highly oxidized structures with abundance of carboxylic acids, which started from the formation of amine oxide and the scission of the C. N bond of the amide group. We studied the toxicity of treated mixtures for six different organisms: the acute toxicity for the bacterium Vibrio fischeri and the microcrustacean Daphnia magna, the multigenerational growth inhibition of the alga Pseudokirchneriella subcapitata, and the seed germination phytotoxicity of Licopersicon esculentum, Lactuca sativa and Lolium perenne. Ozonation and irradiation originated transformation products are more toxic than the parent dendrimer. The toxicity of the dendrimer for the green alga was linked to a strong increase of intracellular reactive oxygen species with intense lipid peroxidation. © 2013 Elsevier B.V. Source


Orgaz B.,Complutense University of Madrid | Puga C.H.,Complutense University of Madrid | Martinez-Suarez J.V.,Spanish National Institute for Agricultural and Food Research and Technology INIA | SanJose C.,Complutense University of Madrid
Food Control | Year: 2013

Listeria monocytogenes is able to form biofilms on surfaces of food industry premises. Once established at certain plant sites, this pathogen can persist there for months or years, risking the transfer to raw materials or processed food by direct contact or other mechanisms. Though persistence of certain strains of L. monocytogenes isolated from food industry surfaces has been reported in several cases, experimental evidence has so far been inconclusive about the association of persistence to features such as better biofilm forming ability or higher resistance to disinfectants. This work has aimed at checking another possible cause of persistence, the ability to recover after exposure to antimicrobial compounds. Damaged cells in the biofilms formed by twelve L. monocytogenes strains previously isolated from an Iberian pig slaughterhouse and processing plant, six persistent and six non persistent, were compared in their recovery of viable cell counts during the 24 h following exposure to chitosan or peracetic acid. Persistent strains showed a better resuscitation rate after chitosan damage. © 2013 Elsevier Ltd. Source


Ortiz S.,Spanish National Institute for Agricultural and Food Research and Technology INIA | Lopez V.,National Institute of Health Carlos III | Garriga M.,IRTA - Institute of Agricultural-Alimentary Research and Technology | Martinez-Suarez J.V.,Spanish National Institute for Agricultural and Food Research and Technology INIA
International Journal of Food Science and Technology | Year: 2014

Summary: This study reports the different effects of two bioprotective cultures on the growth of different Listeria monocytogenes strains by a rapid assay simulating the first stage of Iberian chorizo fermentation. Ground pork with or without protective cultures was inoculated with L. monocytogenes and incubated under two different conditions simulating the traditional, slow fermentation temperature (7 °C, 1 day) and a high, fast fermentation temperature (20 °C, 1 day), followed in both cases by storage at 7 °C for 13 days. Both bioprotective cultures reduced the growth of L. monocytogenes by at least 2 log CFU g-1 at the end of both incubation periods compared with a noninoculated culture control lot. The best results were obtained with the strain Lactobacillus sakei CTC494, which exerted a bactericidal effect on L. monocytogenes under both conditions assayed, achieving a 5.4-log reduction after 14 days compared with the control when the initial temperature was 20 °C. © 2013 Institute of Food Science and Technology. Source


Ulaszewska M.M.,IMDEA Madrid Institute for Advanced Studies | Hernando M.D.,Spanish National Institute for Agricultural and Food Research and Technology INIA | Ucles A.,University of Almeria | Rosal R.,University of Alcala | And 4 more authors.
Comprehensive Analytical Chemistry | Year: 2012

Dendrimers represent a class of polymers with promising applications as nanodevices in biomedicine and industry. This review provides a comprehensive summary of recent progress in their chemical characterization and toxicological assessment. Research into different toxicological and ecotoxicological approaches reveals correlations with a profile of hemolytic toxicity, cytotoxicity and hematological toxicity. This chapter provides a brief but complete synopsis of assays majorly applied such as cell viability assays and in vivo studies with aquatic species. The characterization techniques usually involved in dendrimers analysis were: scattering, microscopy, spectroscopy or spectrometry, and proved to be useful for effective evaluation of synthesis processes. In other relevant fields such as bioanalysis and toxicology, application of advanced mass spectrometry techniques can contribute providing enhanced characterization and quantification at trace levels. The last part is dedicated to present a new approach to characterize and quantify PAMAM dendrimers by liquid chromatography-mass spectrometry-based methods using LC-ESI-TOF-MS and LC-ESI-QTOF-MS systems. © 2012 Elsevier B.V.. Source


Ortiz S.,Spanish National Institute for Agricultural and Food Research and Technology INIA | Lopez V.,Spanish National Institute for Agricultural and Food Research and Technology INIA | Lopez V.,Spanish National Institute of Health Carlos III | Villatoro D.,Embutidos Fermin S.L. | And 3 more authors.
Foodborne Pathogens and Disease | Year: 2010

Contamination routes of Listeria monocytogenes were examined for 3 years in an Iberian pork-processing plant that produced high-quality ready-to-eat meat products. Molecular subtypes of L. monocytogenes were determined by polymerase chain reaction-based serotyping and pulsed-field gel electrophoresis (PFGE) restriction analysis. A total of 541 L. monocytogenes isolates were recovered from the environment and equipment (n=165), carcasses (n=28), raw products (n=321), and dry-cured products (n=27). Only 29 different PFGE types were identified, 3 of which were repeatedly found to be persistent types and accounted for 73% of the isolates. One PFGE type dominated (45% of the isolates) and was mostly recovered from intermediate manufactured products and the environment of the manufacturing area. L. monocytogenes persistence appeared strongly linked to the manufacture of products and not to its sustained entrance with the raw material. Some clones were found to survive in the manufacturing area for 3 years. Controlling the contamination of raw ingredients, improving the compartmentalization, and changing the cleaning protocols resulted in reduced prevalence rates of L. monocytogenes on products; two persistent PFGE types were eliminated from the processing plant, although eradication of other adapted strains has not been achieved. © Copyright 2010, Mary Ann Liebert, Inc. 2010. Source

Discover hidden collaborations