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1.
Ecol Evol ; 12(5): e8844, 2022 May.
Article in English | MEDLINE | ID: mdl-35600683

ABSTRACT

A new hermit crab species of the genus Diogenes with reddish-orange cheliped, Diogenes erythromanus sp. nov., is described and illustrated based on specimens from the Mediterranean coasts of the Iberian Peninsula, southern Spain. In addition, a second morphotype originating from Mauritanian waters and morphologically very close to D. erythromanus sp. nov. is described as a different species, D. arguinensis sp. nov. The new species are here compared to morphologically similar congeners, especially to those inhabiting the same geographical range. Diogenes erythromanus sp. nov. is distinguishable from other Diogenes primarily by the shape and armature of the left cheliped, with a palm slightly higher than long, with a ridge of spines running along the proximal lower margin that continues with a series of spinose rows forming a central band parallel to the upper margin of the palm. The palm in D. arguinensis sp. nov. is longer than high and shows similar proximal ridge, but without central spinose ridge. The shape of the cheliped is also different in D. arguinensis sp. nov., with long dactylus, which is also flattened and twisted. Sequences from two mitochondrial and one nuclear genes, and comparative analyses with other available sequences for the genus, are also included. Molecular phylogenetic analyses support the morphological delimitation, with D. erythromanus sp. nov. and D. arguinensis sp. nov. forming a separate group, more related to other tropical species, which raises different possible explanations for its presence in the Iberian Peninsula.

2.
Zootaxa ; 5209(4): 426-440, 2022 Nov 18.
Article in English | MEDLINE | ID: mdl-37045380

ABSTRACT

One male and two female specimens of an undescribed species of the heterogeneous hermit crab genus Pagurus Fabricius, 1775, were found during the study of the collections of the Oceanographic Institute of Cádiz, containing specimens from African and European coasts collected during the scientific cruises carried out between in years 2008-2013. The new species is named Pagurus pectinidactylus n. sp., in reference to the presence of a well-developed toothless pectinate masticatory border in the dactylus of the left cheliped, composed by a row of tightly placed bristles forming a brush-like structure. The new species is compared to morphologically similar congeners, especially those that are genetically closest. Molecular phylogenetic analyses support the morphological delimitation, with P. pectinidactylus n. sp. forming a separate clade, more closely related to a group of South African species belonging to the Pagurus anachoretus group.


Subject(s)
Anomura , Male , Female , Animals , Phylogeny , Africa, Western , Africa, Northern
3.
Stud Health Technol Inform ; 280: 100-105, 2021 Jun 28.
Article in English | MEDLINE | ID: mdl-34190068

ABSTRACT

Use of 3D ultrasound (US) scanners to detect and monitor scoliosis have been validated. The Cobb angle, axial vertebral rotation, spinal flexibility, curvatures in the sagittal profile and the Cobb angle on the plane of maximum curvature (PMC) can be measured from coronal, transverse and sagittal planes of ultrasound images. However, traditional 3D ultrasound scanners are relatively bulky and expensive. 2D US handheld and low-cost scanners are widely available. To adapt the 2D scanners for scoliosis applications, a position and orientation system is integrated with the scanner. The objective of this study was to validate a newly developed 3D handheld US system to image the spine. The wireless handheld US scanner (C3-HD, Clarius, Canada) was selected because of its high resolution and availability of raw data. A wireless tracking system based on electromagnetic (G4 system, Polhemus, USA) was integrated with the Clarius ultrasound. During scanning, the ultrasound information was synchronized with the scanner's position and orientation by using custom developed software. Both information were streamed wirelessly to a laptop. Custom software reconstructed and displayed the 3D spinal image in real-time. A single 3D printed vertebra, two full plastic spine phantoms from T1-T12 vertebrae and a non-scoliotic volunteer were scanned. The 3D reconstruction process of a spine image was less than 3 seconds. The dimensional and the angle errors were 1 mm and 3°, respectively. This study demonstrated that a low-cost ($11,000 USD) handheld 3D ultrasound system was developed and validated. Clinical trials on subjects attending will be the next step.


Subject(s)
Scoliosis , Canada , Humans , Imaging, Three-Dimensional , Phantoms, Imaging , Scoliosis/diagnostic imaging , Spine/diagnostic imaging , Ultrasonography
4.
Ultrason Sonochem ; 70: 105319, 2021 Jan.
Article in English | MEDLINE | ID: mdl-32889411

ABSTRACT

Nowadays, rapid freezing is sought to favor the formation of small ice crystals. Several studies have shown that the application of ultrasounds (US) accelerates the processes of energy and mass transfer when they are applied through immersion systems. However, there are hardly any studies on its application in direct systems without the use of a liquid medium for its transmission. Therefore, the objective of this work was to evaluate the potential of the application of US for improving the freezing process of chicken breast samples. First, the application of intermittent US treatments at different net sonication times of 7, 17, 37, 50 and 67% during the freezing of distilled water samples in a conventional freezer was evaluated. It was observed that net sonication times of 37, 50 and 67% reduced the phase change period by 30.0, 21.4, 27.0%, respectively. The effective freezing time was also reduced by 12.4 and 12.8% by applying net sonication times of 37 and 50%. Considering these results, an intermittent US treatment with a net sonication time of 37% was chosen for chicken breast freezing in an air-forced cooling tunnel at ambient temperatures from -13 to -22 °C. The length of all the freezing phases was reduced upon application of US, leading to an overall process time reduction of approx. 11%. On the other hand, no significant differences were found either in the Water Holding Capacity (WHC) or Cooking Loss (CL) values between control and US assisted frozen chicken breast samples. Furthermore, in vitro experiments showed that US-assisted freezing did not influence protein digestibility of chicken meat samples. This study demonstrates the potential of the application of US by direct contact to favor energy transfer processes during freezing of water and chicken breasts samples. However, its effect on the quality of the frozen products should be further studied.


Subject(s)
Freezing , Poultry Products , Sonication/methods , Animals , Chickens
5.
Food Chem ; 323: 126824, 2020 Apr 15.
Article in English | MEDLINE | ID: mdl-32334308

ABSTRACT

This research aims to evaluate whether the electroporation of Rhodotorula glutinis fresh biomass improved the subsequent extraction of carotenoids from dry biomass using supercritical CO2 and traditional solvent extraction. Supercritical CO2 extraction yields were low after all treatments assayed. Similarly, solvent extraction of carotenoids from untreated or PEF treated cells that were immediately freeze-dried after the pre-treatment was neither effective (extraction yield < 20% total content). Conversely, PEF-treatment and subsequent intermediate incubation in aqueous buffer for 24 h, followed by freeze-drying and extraction, led to a large improvement with the three solvents assayed (acetone, hexane, ethanol). Ethanol was the most efficient, reaching an extraction yield of 80% of total carotenoid, which represents a recovery of 267 µg/gdw. Torularhodin esters constituted the main carotenoid found in the extracts. This is of great interest, as ethanol is eco-friendly solvent and potential applications of torularhodin range from food to medical purposes.

6.
Food Microbiol ; 76: 374-381, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30166163

ABSTRACT

The present work was performed to evaluate the potential of electron beam ionizing radiation for the inactivation of three psychrophilic spore forming bacteria (Bacillus mycoides, Bacillus weihenstephanensis and Psychrobacillus psychrodurans) isolated from ready-to-eat brown crab (Cancer pagurus). Inactivation curves for the three spores were performed in both types of crab meat, brown and white. Also the effect of pH and water activity (aw) on the lethal efficacy of ionizing radiation, for the three different psychrophilic spore forming bacteria, was evaluated. The effects of pH, aw and their possible interactions were assessed in citrate-phosphate buffers of different pH, ranging between 7 and 4, and aw, ranging from <0.99 to 0.80. A reduction of aw increased the spores resistance between >0.99 and 0.90, while an aw reduction from 0.90 to 0.80 had a minor impact on their resistance. In contrast to aw, the effect of pH showed a greater variability depending on the spore species. While pH did not affect the resistance of B. weihenstephanensis at any aw, B. mycoides showed slightly higher resistance at pH 5.5 at aw of 0.90 and 0.80. pH showed a significant effect on the resistance of P. psychrodurans. For the two types of crab meat, slightly differences were observed in 6D values. B. weihenstephanensis was the most resistant, requiring 7.3-7.6 kGy to inactivate 6 Log10-cycles of this spore forming bacterium, while for B. mycoides and P. psychrodurans 6.1-6.3 and 5.4-5.3 kGy respectively were necessary to reach the same inactivation level in crab meat. An agreement between spore resistance in crab meats and lab media, with similar characteristics in pH and aw, was also observed. The results obtained in this research demonstrated the potential for ionizing radiation to achieve an appropriate inactivation level of spores naturally present in brown crab with the application of doses lower than 10 kGy.


Subject(s)
Bacteria/radiation effects , Brachyura/microbiology , Food Irradiation/methods , Meat/microbiology , Shellfish/microbiology , Spores, Bacterial/radiation effects , Animals , Bacteria/genetics , Bacteria/growth & development , Bacteria/isolation & purification , Radiation, Ionizing , Shellfish/analysis , Spores, Bacterial/genetics , Spores, Bacterial/growth & development , Spores, Bacterial/isolation & purification
7.
Ultrason Sonochem ; 48: 550-554, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30080584

ABSTRACT

The consumption of crustaceans is correlated with certain health risks, particularly due to several highly toxic elements they contain, including cadmium (Cd). Although Cd content in one sole crab generally exceeds the total weekly recommended intake of cadmium as established by EFSA (especially in brown meat), efficient modern strategies to reduce Cd content in crabs still have not yet been developed. The objective of this research was therefore to evaluate the potential use of ultrasound technology in combination with temperature (50°-80 °C) with the purpose of releasing Cd from brown crab (Cancer pagurus), thereby reducing the Cd content in its meat. Female crabs were immersed in a water bath at 50, 65, and 80 °C in presence or absence of ultrasound; Cd concentration in the water was monitored along time. At the end of the process, Cd content in brown and white crab meat was likewise quantified. Treatment temperature did not bear an influence on the release of Cd in absence of ultrasound, but proved to be an important variable when ultrasound assisted the process. Ultrasound increased Cd release rates 8.7-, 2.1- and 2.7-fold in conjunction with the treatments at 50, 65 and 80 °C, respectively. The maximum percentage of Cd extracted (22.8%) was observed at 50 °C for an ultrasound input power of 200 W. These results have demonstrated for the first time that the application of ultrasound during the crab-cooking process could serve as an effective physical procedure for reducing the Cd content of crabs, thereby improving the product's safety for consumers.


Subject(s)
Brachyura/metabolism , Cadmium/isolation & purification , Hot Temperature , Ultrasonic Waves , Water Pollutants, Chemical/isolation & purification , Animals , Cadmium/metabolism , Water Pollutants, Chemical/metabolism
8.
Biomed Res Int ; 2015: 436030, 2015.
Article in English | MEDLINE | ID: mdl-26539493

ABSTRACT

This investigation established the process criteria for using UV-C light and mild heat (UV-H treatment) to inactivate 5-Log10 cycles (performance criterion) of common foodborne pathogen populations, Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus, when inoculated in chicken broth. To define the target microorganism and the proper UV-H treatment conditions (including UV dose, treatment time, and temperature) that would achieve the stated performance criterion, mathematical equations based on Geeraerd's model were developed for each microorganism. For the sake of comparison, inactivation equations for heat treatments were also performed on the same chicken broth and for the same microorganisms. L. monocytogenes was the most UV-H resistant microorganism at all temperatures, requiring a UV dose between 6.10 J/mL (5.6 min) and 2.26 J/mL (2.09 min) to achieve 5-Log10 reductions. In comparison with UV treatments at room temperatures, the combination of UV and mild heat allowed both the UV dose and treatment time to be reduced by 30% and 63% at 55 °C and 60 °C, respectively. Compared to heat treatments, the UV-H process reduced the heating time for 5-Log10 reductions of all the investigated microorganisms in chicken broth from 20-fold to 2-fold when the operating temperature varied from 53 to 60 °C.


Subject(s)
Food Microbiology , Foodborne Diseases/prevention & control , Ultraviolet Rays , Animals , Chickens , Escherichia coli O157/pathogenicity , Escherichia coli O157/radiation effects , Foodborne Diseases/microbiology , Hot Temperature , Listeria monocytogenes/pathogenicity , Listeria monocytogenes/radiation effects , Salmonella typhimurium/pathogenicity , Salmonella typhimurium/radiation effects , Staphylococcus aureus/pathogenicity , Staphylococcus aureus/radiation effects
9.
Zootaxa ; 3790: 401-24, 2014 Apr 22.
Article in English | MEDLINE | ID: mdl-24869875

ABSTRACT

The freshwater shrimp genus Atyaephyra de Brito Capello, 1867 is a complex of cryptic species with morphologically overlapping features, which has led to invalid identifications until recently. The genus is distributed around the entire Mediterranean Basin and surrounding areas. In 2009 we used a molecular approach with 16S and Cox1 genes to identify the European and African populations and to show the existence of different species and groups of haplotypes (García Muñoz et al. 2009). Christodoulou et al. (2012) recently identified four species in Greece (Atyaephyra stankoi, A. thyamisensis, A. strymonensis and A. acheronensis) based on morphology and some partial sequences of Cox1. In the present study we analyse several Greek populations of Atyaephyra spp. using morphology and two mitochondrial markers (16S and Cox1). Our molecular data confirm the taxonomic validity of A. stankoi, A. thyamisensis and A. strymonensis but show that A. acheronensis should be considered a synonym of A. desmarestii. The limited distribution of A. desmarestii in only a few rivers in the Ionian region is probably the result of a posterior introduction from neighbouring European areas. After the genetic identification and as a consequence of the high variability observed within species and between rivers, mainly in A. thyamisensis, we re-describe this species and provide morphological data for the other species. We also give information on the chromatophore pattern in larvae, which could be very useful in the future for recognizing species and their distribution. The distribution of Greek Atyaephyra species seems to be related to the very complex paleogeographical history of the Paratethys and Mediterranean Sea in the Balkan Peninsula. Three areas can be recognized in relation to the distribution of these species: a global region, a western region separated from the eastern region by the Pindos Mountains, and a Macedonia-Thracian region. 


Subject(s)
Biodiversity , DNA, Mitochondrial , Decapoda/genetics , Genetic Speciation , Animals , Decapoda/anatomy & histology , Decapoda/classification , Female , Greece , Male
10.
Zootaxa ; 3753: 25-46, 2014 Jan 03.
Article in English | MEDLINE | ID: mdl-24872277

ABSTRACT

Study of hermit crabs from Alboran Sea has allowed recognition of two different morphological forms under what had been understood as Pagurus forbesii. Based on morphological observations with various species of Pagurus, and molecular studies, a new species is described as P. pseudosculptimanus. An overview of species of Pagurus from the eastern Atlantic and Mediterranean Sea is provided.


Subject(s)
Anomura/anatomy & histology , Anomura/classification , Animal Distribution , Animals , Anomura/genetics , Anomura/physiology , Arthropod Proteins/genetics , Arthropod Proteins/metabolism , Atlantic Ocean , Electron Transport Complex IV/genetics , Electron Transport Complex IV/metabolism , Female , Male , Mediterranean Sea , Molecular Sequence Data , Phylogeny , Polymerase Chain Reaction , RNA, Ribosomal, 16S/genetics , RNA, Ribosomal, 16S/metabolism , Sequence Analysis, DNA , Spain
11.
Crit Rev Food Sci Nutr ; 54(11): 1415-26, 2014.
Article in English | MEDLINE | ID: mdl-24580538

ABSTRACT

Processing unit operations that seek to inactivate harmful microorganisms are of primary importance in ascertaining the safety of food. The capability of pulsed electric fields (PEF) to inactivate vegetative cells of microorganisms at temperatures below those used in thermal processing makes this technology very attractive as a nonthermal pasteurization process for the food industry. Commercial exploitation of this technology for food pasteurization requires the identification of the most PEF-resistant microorganisms that are of concern to public health. Then, the treatment conditions applicable at industrial scale that would reduce the population of these microorganisms to a level that guarantees food safety must be defined. The objective of this paper is to critically compile recent, relevant knowledge with the purpose of enhancing the feasibility of using PEF technology for food pasteurization and underlining the required research for designing PEF pasteurization processes.


Subject(s)
Electricity , Food Handling/methods , Food Microbiology , Food Preservation/methods , Pasteurization/methods , Food Safety , Hot Temperature , Humans
12.
Appl Environ Microbiol ; 78(23): 8353-61, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23001665

ABSTRACT

The aim of this investigation was to study the efficacy of the combined processes of UV light and mild temperatures for the inactivation of Salmonella enterica subsp. enterica and to explore the mechanism of inactivation. The doses to inactivate the 99.99% (4D) of the initial population ranged from 18.03 (Salmonella enterica serovar Typhimurium STCC 878) to 12.75 J ml(-1) (Salmonella enterica serovar Enteritidis ATCC 13076). The pH and water activity of the treatment medium did not change the UV tolerance, but it decreased exponentially by increasing the absorption coefficient. An inactivating synergistic effect was observed by applying simultaneous UV light and heat treatment (UV-H). A less synergistic effect was observed by applying UV light first and heat subsequently. UV did not damage cell envelopes, but the number of injured cells was higher after a UV-H treatment than after heating. The synergistic effect observed by combining simultaneous UV and heat treatment opens the possibility to design combined treatments for pasteurization of liquid food with high UV absorptivity, such as fruit juices.


Subject(s)
Microbial Viability/radiation effects , Salmonella enteritidis/physiology , Salmonella enteritidis/radiation effects , Salmonella typhimurium/physiology , Salmonella typhimurium/radiation effects , Ultraviolet Rays , Culture Media/chemistry , Hydrogen-Ion Concentration , Temperature
13.
Food Microbiol ; 30(2): 393-9, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22365352

ABSTRACT

This paper evaluates the lethal effectiveness on 7 different Salmonella serovars of the application, in static and continuous conditions, of pulsed electric fields (PEF) followed by heat treatments in liquid whole egg (LWE) with additives (EDTA or triethyl citrate-TC-). Compared to heat treatments, the PEF (25 kV/cm and 75-100 kJ/kg) followed by heat (52°C/3.5', 55°C/2', or 60°C/1') in LWE with 2% TC permitted the reduction of heat treatment time from 92 fold at 52°C to 3.4 fold at 60°C, and 4.8 fold at 52°C in LWE with EDTA for a 9-Log(10) reduction of the population of Salmonella Enteritidis. The new designed treatments inactivated more than 5 Log(10) cycles of Salmonella serovars Dublin, Enteritidis 4300, Enteritidis 4396, Typhimurium, Typhi, Senftenberg, and Virchow, both in static and continuous conditions. Conversely, current heat pasteurization treatments of 60°C/3.5' and 64°C/2.5' reduced 5 Log(10) cycles of various serovars of Salmonella but only 2 and 3-4 Log(10) cycles of Salmonella Senftenberg and Salmonella Enteritidis 4396, respectively. Soluble protein content (SPC) decreased 1.8%, 1.3%, and 5.0% after the successive application of PEF followed by heat at 52, 55, and 60°C in the presence of 2% TC, respectively, whereas 1.6% and 9.4% of SPC were reduced after heat pasteurization at 60 and 64°C, respectively. Results indicate that designed treatments could be an alternative to current heat pasteurization of LWE as showed higher lethal effectiveness against Salmonella serovars with a similar or even lower decrement of the soluble protein content.


Subject(s)
Eggs/microbiology , Food Additives/pharmacology , Pasteurization/methods , Salmonella/growth & development , Egg Proteins/analysis , Eggs/analysis , Electricity , Hot Temperature
14.
Annu Rev Food Sci Technol ; 3: 263-82, 2012.
Article in English | MEDLINE | ID: mdl-22136126

ABSTRACT

The mass transfer phenomenon occurs in many operations of the food industry with the purpose of obtaining a given substance of interest, removing water from foods, or introducing a given substance into the food matrix. Pretreatments that modify the permeability of the cell membranes, such as grinding, heating, or enzymatic treatment, enhance the mass transfer. However, these techniques may require a significant amount of energy and can cause losses of valuable food compounds. Pulsed electric field (PEF) technology is a nonthermal processing method that causes permeabilization of cell membranes using low energy requirements and minimizing quality deterioration of the food compounds. Many practical applications of PEF for enhancing mass transfer in the food industry have been investigated. The purpose of this chapter is to give an overview of the state of the art of application of PEF for improving mass transfer in the food industry.


Subject(s)
Electrochemical Techniques , Food Handling/methods , Cell Membrane Permeability , Electroporation , Food Additives/chemistry , Food Handling/economics , Food, Preserved/adverse effects , Food, Preserved/analysis , Food, Preserved/economics , Plant Oils/analysis , Plant Oils/economics , Wine/analysis , Wine/economics
15.
Int J Food Microbiol ; 151(1): 29-35, 2011 Nov 15.
Article in English | MEDLINE | ID: mdl-21880388

ABSTRACT

The influence of temperature and the presence of N(α)-lauroyl ethylester (ethyl lauroyl arginate, LAE) on the inactivation caused by continuous pulsed electric field treatments (PEF) in Escherichia coli O157:H7 suspended in apple juice have been investigated to define treatment conditions applicable at industrial scale that promote an equivalent safety level when compared with thermal processing. In the range of experimental conditions investigated (outlet temperature: 20-40 °C, electric field strength: 20-30 kV, treatment time: 5-125 µs) at outlet temperatures equal or lower than 55±1 °C, the inactivation of E. coli O157:H7 treated in apple juice ranged from 0.4 to 3.6 Log10 cycles reduction and treated in apple juice supplemented with LAE (50 ppm) ranged from 0.9 to 6.7 Log10 cycles reduction. An empirical mathematical model was developed to estimate the treatment time and total specific energy input to obtain 5 Log10 cycles reduction in the population of E. coli O157:H7 suspended in apple juice supplemented with 50 ppm of LAE at different electric field strengths and inlet temperatures. Treatment conditions established for E. coli O157:H7 were validated with other PEF resistant Gram-positive (Listeria monocytogenes, and Staphylococcus aureus) and Gram-negative (Salmonella enterica serovar Typhimurium) strains. When the treatment was applied to the apple juice, a treatment of 25 kV/cm for 63 µs corresponding with an outlet temperature of 65 °C and input energy of 125 kJ/kg was required to achieve more than 5 Log10 cycles in the four strains investigated. The addition of LAE reduced the treatment time required to obtain an equivalent inactivation (>5 Log10 cycles) in the four microorganisms to 38.4 µs, the outlet temperature to 55 °C, and the input energy to 83.2 kJ/kg.


Subject(s)
Beverages , Escherichia coli O157/growth & development , Food Contamination/prevention & control , Pasteurization , Arginine/analogs & derivatives , Colony Count, Microbial , Electricity , Food Microbiology , Listeria monocytogenes/growth & development , Malus , Microbial Viability , Models, Theoretical , Salmonella typhimurium/growth & development , Staphylococcus aureus/growth & development , Temperature
16.
Food Sci Technol Int ; 17(2): 77-86, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21421675

ABSTRACT

Changes in the principal phenolic compounds during the maceration-fermentation process of Garnacha, Merlot and Syrah grapes cultivated in Aragón region (northeast of Spain) have been investigated. While Garnacha is a traditional grape variety cultivated in this region, Merlot and Syrah have been introduced recently. During fermentation, Syrah showed the highest concentration in anthocyanins, flavan-3-ols and flavonols (802.7 ± 0.5 mg/L, 74.7 ± 2.4 mg/L and 37.1 ± 1.5 mg/L at the end of fermentation, respectively). Unexpectedly, Garnacha, a variety with lower phenolic content, showed the highest amount of hydroxycinnamic acids (83.1 ± 5.6 mg/L at the end of fermentation). The overall results also indicated that the evolution during maceration-fermentation process of the different phenolic compounds and their concentrations were influenced by the varietal factor.


Subject(s)
Anthocyanins/analysis , Fermentation , Flavonols/analysis , Phenols/analysis , Wine/analysis , Anthocyanins/chemistry , Chromatography, High Pressure Liquid/methods , Coumaric Acids/analysis , Coumaric Acids/chemistry , Flavonols/chemistry , Phenols/chemistry , Spain , Vitis/chemistry
17.
Int J Food Microbiol ; 145(2-3): 476-82, 2011 Feb 28.
Article in English | MEDLINE | ID: mdl-21329997

ABSTRACT

This paper is an evaluation of the lethal effectiveness of a successive application of pulsed electric fields (PEFs) and heat treatment in liquid whole egg (LWE) in the presence of different additives on the population of Salmonella serovar Enteritidis. Synergistic reductions of the Salmonella Enteritidis population were observed when LWE samples containing additives were treated with PEF (25 kV/cm; 100 and 200 kJ/kg), heat (55 °C), or PEF followed by heat. The presence of additives, such as 10 mM EDTA or 2% triethyl citrate, increased the PEF lethality 1 log10 cycle and generated around 1.5 log10 cycles of cell damage, resulting in the reduction of undamaged cells of 4.4 and 3.1 log10 cycles, respectively. The application of PEF followed by heat treatment significantly (p < 0.05) reduced D(55 ºC) from 3.9 ± 0.2 min in LWE to 1.40 ± 0.06 min or 0.24 ± 0.02 min in the presence of 10 mM EDTA or 2% triethyl citrate, respectively. A PEF treatment of 25 kV/cm and 200 kJ/kg followed by a heat treatment of 55 °C and 2 min reduced more than 8 log10 cycles of the population of Salmonella Enteritidis in LWE combined with 2% triethyl citrate, with a minimal impact on its protein soluble content. The heat sensitizing effect of PEF treatments in the presence of 2% triethyl citrate on the Salmonella population could enable LWE producers to reduce the temperature or processing time of thermal treatments (current standards are 60 °C for 3.5 min in the United States), increasing the level of Salmonella inactivation and retaining the quality of non-treated LWE.


Subject(s)
Eggs/microbiology , Electricity , Food Microbiology/methods , Food Preservation/methods , Hot Temperature , Salmonella enteritidis/growth & development , Citrates/pharmacology , Colony Count, Microbial , Salmonella Food Poisoning/prevention & control , Salmonella enteritidis/drug effects
18.
Article in English | AIM (Africa) | ID: biblio-1263693

ABSTRACT

The objectives of the study were (i) to evaluate the efficacy of combination drugs; such as artesunate + sulphadoxinepyrimethamine (AS + SP) and amodiaquine + sulphadoxine-pyripethamine (AQ+ SP) in treatment of uncomplicated falciparum malaria (ii) to differentiate recrudescence from reinfection by analysing msp-1 and msp-2 genes of Plasmodium falciparum in treatment failure cases. Methods. We carried out an in vivo study in the year 2005 in 206 children between 6 to 59 months age groups. Of the 206; 120 received AQ+ SP; and 86 received AS + SP. A clinical and parasitological followup during 14 days was undertaken. Finger-prick blood sample from each patient was taken onWhatman filter paper (no. 3) on days 0; 7; 14 and also the day when the parasite and symptoms reappeared for PCR analysis. Results. Late treatment failure was observed in 3.5(4/114) with AQ+ SP; and 2.5(2/79) with AS + SP. The success rate was 96.5with AQ+ SP and 97.5with AS + SP. No deaths and severe reactions were recorded. Out of the 6 treatment failure cases; one was reinfection as observed by PCR analysis of msp-1 and msp-2 genes on day 14. Discussion. Both the combinations found to be efficacious and safe and could be used as a first-line treatment for uncomplicated falciparum malaria in Equatorial Guinea


Subject(s)
Child , Drug Therapy , Equatorial Guinea , Malaria , Malaria/mortality
19.
Food Microbiol ; 27(7): 845-52, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20688225

ABSTRACT

This investigation evaluated the lethal efficiency of pulsed electric fields (PEFs) to pasteurize liquid whole egg (LWE). To achieve this aim, we describe the inactivation of Salmonella Enteritidis and the heat resistant Salmonella Senftenberg 775 W in terms of treatment time and specific energy at electric field strengths ranging from 20 to 45 kV/cm. Based on our results, the target microorganism for this technology in LWE varied with intensity of the PEF treatment. For electric field strengths greater than 25 kV/cm, Salmonella Enteritidis was the most PEF-resistant strain. For this Salmonella serovar the level of inactivation depended only on the specific energy applied: i.e., 106, 272, and 472 kJ/kg for 1, 2, and 3 Log(10) reductions, respectively. The developed mathematical equations based on the Weibull distribution permit estimations of maximum inactivation level of 1.9 Log(10) cycles of the target Salmonella serovar in the best-case scenario: 250 kJ/kg and 25 kV/cm. This level of inactivation indicates that PEF technology by itself cannot guarantee the security of LWE based on USDA and European regulations. The occurrence of cell damage due to PEF in the Salmonella population opens the possibility of designing combined processes enabling increased microbial lethality in LWE.


Subject(s)
Eggs/microbiology , Electric Stimulation , Food Preservation/methods , Salmonella Food Poisoning/prevention & control , Salmonella enteritidis/growth & development , Animals , Chickens , Colony Count, Microbial , Food-Processing Industry/methods , Food-Processing Industry/standards , Humans , Salmonella , Time Factors
20.
Food Microbiol ; 27(4): 550-8, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20417406

ABSTRACT

A study of the effect of pulsed electric fields (PEF) on the inactivation of Listeria monocytogenes STCC 5672 and Staphylococcus aureus STCC 4459 in McIlvaine buffer covering a range from pH 3.5 to 7.0 was conducted. Mathematical models based on the Weibull distribution were developed to describe the influence of the electric field strength, treatment time and pH of the treatment medium on the lethality of both Gram positive pathogenic bacteria after PEF treatments. Both microorganisms were more sensitive to PEF in media of low pH, although the influence of the pH on the PEF resistance was more significant in S. aureus. In the best cases scenario, the highest inactivation levels achieved were 3.3 and 6.1 log(10) cycles for L. monocytogenes and S. aureus respectively in pH 3.5 after 500 micros of 35 kV/cm. Based on these results and those observed in literature, L. monocytogenes STCC 5672 at any pH investigated has been shown as one of the most PEF resistant microorganism. Therefore, this microorganism should be considered as a possible target microorganism to define process criterion for PEF pasteurization.


Subject(s)
Electric Stimulation , Food Preservation/methods , Hydrogen-Ion Concentration , Listeria monocytogenes/growth & development , Staphylococcus aureus/growth & development , Colony Count, Microbial , Consumer Product Safety , Culture Media/chemistry , Electric Conductivity , Food Microbiology , Mathematics , Models, Biological , Time Factors
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