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Articles 1 - 18 of 18
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Copper(Ii) Complexes Of Coumarin-Derived Schiff Bases And Their Anti-Candida Activity, Bernadette S. Creaven, Michael Devereux, Dariusz Karcz, Andrew Kellett, Malachy Mccann, Andy Noble, Maureen Walsh
Copper(Ii) Complexes Of Coumarin-Derived Schiff Bases And Their Anti-Candida Activity, Bernadette S. Creaven, Michael Devereux, Dariusz Karcz, Andrew Kellett, Malachy Mccann, Andy Noble, Maureen Walsh
Articles
The condensation of 7-amino-4-methyl-coumarin (1) with a number of substituted salicylaldehydes yielded a series of Schiff bases (2a–2k) in good yields. Subsequent reaction of these ligands with copper( II) acetate yielded Cu(II) complexes (3a–3k) and some were characterised using X-ray crystallography. All of the free ligands and their metal complexes were tested for their anti-Candida activity.
Enzymatic Synthesis Of Galactooligosaccharides From Whey Permeate, Federica Manucci
Enzymatic Synthesis Of Galactooligosaccharides From Whey Permeate, Federica Manucci
Masters
Galactooligosaccharides (GOS) are prebiotics that have a beneficial effect on human health by promoting the growth of probiotic bacteria in the gut. GOS are commonly produced from lactose in a reaction catalysed by β-galactosidase, termed transglycosylation. In the present work the synthesis of GOS from Whey Permeate (WP) using commercially available β-galactosidases was studied. The enzymes used were from Kluyveromyces lactis (Maxilact® L2000) and Escherichia coli. Initially, a novel quantitative TLC-based assay to monitor GOS synthesis was developed. This method was employed for kinetic analysis but precision and bias problems in quantification were observed. An HPLC assay was subsequently developed …
The Effects Of Acid Adaptation On Escherichia Coli Inactivation Using Power Ultrasound, Sonal Patil, Paula Bourke, Bridget Cullen, Jesus Maria Frias, Patrick Cullen
The Effects Of Acid Adaptation On Escherichia Coli Inactivation Using Power Ultrasound, Sonal Patil, Paula Bourke, Bridget Cullen, Jesus Maria Frias, Patrick Cullen
Articles
Inactivation of Escherichia coli in liquids was carried out using power ultrasound. Parameters examined included amplitude levels (0.4µm, 7.5 µm, 37.5 µm), treatment time, cell condition (non-adapted cells, acid adapted cells), liquid media (TSB, model orange juice and model apple juice) and E. coli strain (ATCC 25922, NCTC 12900). The efficacy of ultrasound treatment was found to be a function of amplitude level, treatment time and media (p0.95), with the highest inactivation achieved using an amplitude of 37.5 µm. The D-values of E. coli 25922 at all amplitudes in model orange juice were not significantly different than in TSB media. …
Modelling Browning And Brown Spotting Of Mushrooms (Agaricus Bisporus) Stored In Controlled Environmental Conditions Using Image Analysis, Catherine Barry-Ryan, Jesus Maria Frias, Leixuri Aguirre, Helen Grogan
Modelling Browning And Brown Spotting Of Mushrooms (Agaricus Bisporus) Stored In Controlled Environmental Conditions Using Image Analysis, Catherine Barry-Ryan, Jesus Maria Frias, Leixuri Aguirre, Helen Grogan
Articles
Mushrooms have a short postharvest shelf life compared to most vegetables, due to a very high metabolic activity and high water content, making them prone to microbial spoilage and to exhibit enzymatic browning. Storage conditions and natural product variability are both important factors that affect the management of mushrooms, and both of them can be managed using monitoring systems. In order to study the effect of the temperature and relative humidity on the whiteness decrease and appearance of brown spotting, an image analysis system was employed. Twenty five batches of mushrooms were subjected to combinations of three storage temperatures (T) …
Orange Juices Enriched With Chitosan: Optimisation For Extending The Shelf-Life, Catherine Barry-Ryan, Ana Belen Martin-Diana, Daniel Rico, J. Barat
Orange Juices Enriched With Chitosan: Optimisation For Extending The Shelf-Life, Catherine Barry-Ryan, Ana Belen Martin-Diana, Daniel Rico, J. Barat
Articles
Optimisation of the incorporation of chitosan in orange juice was accomplished by the evaluation of quality and nutritional markers. Response surface methodology was applied to obtain quadratic and second degree response surface model equations. The analyses showed that increases in chitosan concentration extended the quality of the orange juice significantly (p < 0.05), reducing enzymatic and non-enzymatic browning and controlling the spoilage during the storage time; however, concentrations N 1 g L− 1 produced a significant (p < 0.05) reduction in the concentrations of ascorbic acid and carotenoids associated with the positive charge of chitosan and its ability to flocculate and coagulate negatively charged substances. Also, concentrations N 1 g L− 1 were scored as unacceptable for the sensory panel due to an increase in bitterness. The study recommends the use of chitosan at concentrations up to 1 g L− 1 to extend quality and preserve ascorbic acid and carotenoids during storage time of fresh orange juice, thus avoiding the use of standard thermal treatments which produces a negative impact on the nutritional value. Industrial relevance: One of the major problems of fresh orange juice is its limited shelf-life. Spoilage and quick degradation of vitamins are two of the most important causes of quality loss during the shelf-life of this product. Moreover, the U. S. Food and Drug Administration issued a warning to consumers against drinking unpasteurised orange juice products because of the potential contamination with Salmonella typhimurium and its association with an outbreak of human disease caused by this organism [FDA issues nationwide health alert on Orchid Island unpasteurised orange juice. Products Recalls, Market Withdrawals and Safety Alerts.]. The main objective of this study was the study of chitosan as a natural preservative for extending the shelf-life of orange juice and as an alternative to pasteurisation.
Identification Of Volatile Quality Markers Of Ready-To-Use Lettuce And Cabbage, Catherine Barry-Ryan, Michael Devereux, Julien Lonchamp
Identification Of Volatile Quality Markers Of Ready-To-Use Lettuce And Cabbage, Catherine Barry-Ryan, Michael Devereux, Julien Lonchamp
Articles
Volatile emission changes of ready-to-use vegetables directly result from minimal processing and can reflect the sensory changes occurring in the product. Based on the detection of key volatile compounds, novel on-line and consumer quality-monitoring methods can be developed. The aim of this study was to identify volatile biomarkers for a range of leafy green ready-to-use vegetables (Butterhead and Iceberg lettuce and Irish York cabbage). Headspace volatile compounds were monitored using gas chromatography/mass spectrometry (GC/MS). The sensory quality of the products was evaluated at days 1, 7 and 14 using sensory and analytical measurements. Changes of volatile concentrations and sensory attributes …
Preparation, Characterization And Ecotoxicological Evaluation Of Four Environmentally Relevant Species Of N-Isopropylacrylamide And N-Isopropylacrylamide-Co-N-Tert-Butylacrylamide Copolymer Nanoparticles, Pratap Naha, Alan Casey, Tiziana Tenuta, Iseult Lynch, Kenneth Dawson, Hugh Byrne, Maria Davoren
Preparation, Characterization And Ecotoxicological Evaluation Of Four Environmentally Relevant Species Of N-Isopropylacrylamide And N-Isopropylacrylamide-Co-N-Tert-Butylacrylamide Copolymer Nanoparticles, Pratap Naha, Alan Casey, Tiziana Tenuta, Iseult Lynch, Kenneth Dawson, Hugh Byrne, Maria Davoren
Articles
Poly N-isopropylacrylamide and N-isopropylacrylamide / N-tert-butylacrylamide copolymer nanoparticles of 50 to 70 nm were prepared by free radical polymerisation. The particle sizes of the copolymer nanoparticles were measured in the test media Milli-Q water, Algae Media, Daphnia Media and Microtox Diluent as a function of temperature. Whereas in Milli-Q water the particle size was seen to decrease above the lower critical solution temperature of the thermoresponsive polymer, in the test media it was seen to increase significantly, indicative of aggregation. At the temperatures employed for the ecotoxicological studies all particles, with the exception of the 50:50 copolymer existed as nanoparticles, …
Impact Of Plant Essential Oils On Microbiological, Organoleptic And Quality Markers Of Minimally Processed Vegetables, Jorge Gutierrez, Paula Bourke, Julien Lonchamp, Catherine Barry-Ryan
Impact Of Plant Essential Oils On Microbiological, Organoleptic And Quality Markers Of Minimally Processed Vegetables, Jorge Gutierrez, Paula Bourke, Julien Lonchamp, Catherine Barry-Ryan
Articles
The objectives of this study were to evaluate the efficacy of plant essential oils (EOs) for control of the natural spoilage microflora on ready-to-eat (RTE) lettuce and carrots whilst also considering their impact on organoleptic properties. Initial decontamination effects achieved using EOs were comparable to that observed with chlorine and solution containing oregano recorded a significantly lower initial TVC level than the water treatment on carrots (p < 0.05). No significant differences were found between the EO treatments and chlorine considering gas composition, color, texture and water activity of samples. The sensory panel found EO treatments acceptable for carrots throughout storage, while lettuce washed with the EO solutions were rejected for overall appreciation by Day 7. Correlating microbial and sensory changes with volatile emissions identified 12 volatile quality markers. Oregano might be a suitable decontamination alternative to chlorine for RTE carrots, while the identification of volatile quality markers is a useful complement to sensory and microbiological assessments in the monitoring of organoleptic property changes and shelf-life of fresh vegetables. Industrial relevance There is industrial demand for natural alternatives to chlorine, which is commonly used for decontamination of fresh produce but which has limitations with respect to antimicrobial efficacy and possible formation of carcinogenic compounds in water. Plant essential oils have proven antimicrobial and other bioactive properties, however their usefulness in foods can be mitigated by their high sensory impact. This study examined the application of EOs for fresh produce decontamination addressing control of spoilage microflora and improving shelf-life characteristics whilst also considering the impact on organoleptic properties. The effectiveness of oregano as a decontamination treatment was comparable with that of chlorine. Carrot discs treated with the EO regimes were acceptable in terms of sensory quality and appreciation, therefore oregano could offer a natural alternative for the washing and preservation of fresh produce. Combining EOs with other natural preservatives might minimize doses and reduce the impact on organoleptic properties of fresh vegetables.
Extrinsic Control Parameters For Ozone Inactivation Of Escherichia Coli Using A Bubble Column, Sonal Patil, Patrick Cullen, Bridget Cullen, Jesus Maria Frias, Paula Bourke
Extrinsic Control Parameters For Ozone Inactivation Of Escherichia Coli Using A Bubble Column, Sonal Patil, Patrick Cullen, Bridget Cullen, Jesus Maria Frias, Paula Bourke
Articles
Aims: To investigate the effect of extrinsic control parameters for ozone inactivation of E. coli in a bubble column. Methods and Results: Ozone inactivation of Escherichia coli ATCC 25922 in Tryptic Soya Broth was examined. The parameters studied included temperature (ambient, 20, 25 and 30°C), exposure time (up to 30 min), gas flow rate (0·03, 0·06, 0·12, 0·25, 0·5 and 0·75 l min−1) and concentration level (five different levels). The efficacy of ozone treatment was a function of the parameters investigated and optimum control parameters of flow rate (0·12 l min−1), temperature (ambient) and ozone concentration (75 μg ml−1) resulted …
Convergence In Human Dialogues Time Series Analysis Of Acoustic Feature, Spyros Kousidis, David Dorran, Ciaran Mcdonnell, Eugene Coyle
Convergence In Human Dialogues Time Series Analysis Of Acoustic Feature, Spyros Kousidis, David Dorran, Ciaran Mcdonnell, Eugene Coyle
Conference papers
Convergence of acoustic/prosodic (a/p) features between two speakers is a well-known property of human dialogue. It has been suggested that this particular aspect of human interaction should be implemented in spoken dialogue systems, so that they can be perceived as more “humanlike”. This paper presents a quantitative analysis method that can provide information required for modeling the phenomenon of convergence. The analysis is a combination of TAMA, a previously introduced data extraction method, and bivariate time series analysis. Results show significant correlation of a/p features between speaker dyads in the recorded dialogues analyzed, and indicate a significant,amount of feedback, which …
Dispersion Medium Modulates Oxidative Stress Response Of Human Lung Epithelial Cells Upon Exposure To Carbon Nanomaterial Samples, Eva Herzog, Hugh Byrne, Maria Davoren, Alan Casey, Albert Duschl, Gertie Janneke Oostingh
Dispersion Medium Modulates Oxidative Stress Response Of Human Lung Epithelial Cells Upon Exposure To Carbon Nanomaterial Samples, Eva Herzog, Hugh Byrne, Maria Davoren, Alan Casey, Albert Duschl, Gertie Janneke Oostingh
Articles
Due to their large specific surface area, the potential of nanoparticles to be highly reactive and to induce oxidative stress is particularly high. In addition, some types of nanoparticles contain transition metals as trace impurities which are known to generate reactive oxygen species (ROS) in biological systems. This study investigates the potential of two types of single-walled carbon nanotube samples, nanoparticulate carbon black and crocidolite asbestos to induce ROS in lung epithelial cells in vitro. Carbon nanotube and carbon black samples were used as produced, without further purification or processing, in order to best mimic occupational exposure by inhalation of …
Reflection Contributions To The Dispersion Artefact In Ftir Spectra Of Single Biological Cells., Paul Bassan, Hugh Byrne, Joe Lee, Franck Bonnier, Colin Clarke, Paul Dumas, Ehsan Gazi, Michael Brown, Noel Clarke, Peter Gardner
Reflection Contributions To The Dispersion Artefact In Ftir Spectra Of Single Biological Cells., Paul Bassan, Hugh Byrne, Joe Lee, Franck Bonnier, Colin Clarke, Paul Dumas, Ehsan Gazi, Michael Brown, Noel Clarke, Peter Gardner
Articles
Fourier transform infrared spectra of a single cell in transflection geometry are seen to vary significantly with position on the cell, showing a distorted derivative-like lineshape in the region of the optically dense nucleus. A similar behaviour is observable in a model system of the protein albumin doped in a potassium bromide disk. It is demonstrated that the spectrum at any point is a weighted sum of the sample reflection and transmission and that the dominance of the reflection spectrum in optically dense regions can account for some of the spectral distortions previously attributed to dispersion artefacts. Rather than being …
Raman Spectroscopy: A Potential Platform For The Rapid Measurement Of Carbon Nanotube-Induced Cytotoxicity, Peter Knief, Colin Clarke, Eva Herzog, Maria Davoren, Fiona Lyng, Aidan Meade, Hugh Byrne
Raman Spectroscopy: A Potential Platform For The Rapid Measurement Of Carbon Nanotube-Induced Cytotoxicity, Peter Knief, Colin Clarke, Eva Herzog, Maria Davoren, Fiona Lyng, Aidan Meade, Hugh Byrne
Articles
In this study the suitability of Raman spectroscopy for the determination of carbon nanotube mediated toxicity on human alveolar carcinoma epithelial cells (A549) is explored. The exposure of this cell line represents the primary pathway of exposure in humans, that of inhalation. Peak ratio analysis demonstrates a dose dependent response which correlates to previous toxicological studies. Principal component analysis is employed to further classify cellular response as a function of dose and to examine differences between spectra as a function of exposed concentration. To further illustrate the potential of Raman spectroscopy in this field, Partial Least Squares (PLS) regression and …
Monitoring Convergence Of Temporal Features In Spontaneous Dialogue Speech, Spyros Kousidis, David Dorran
Monitoring Convergence Of Temporal Features In Spontaneous Dialogue Speech, Spyros Kousidis, David Dorran
Conference papers
This paper presents ongoing research on convergence of speech features in human dialogues, in view of simulating this behaviour in spoken dialogue systems. The TAMA method (time-aligned moving average), previously used on monitoring convergence of acoustic prosodic (a/p) features, is applied to temporal properties of speech (between-turn pauses and overlaps). The results are compared to those of an older study on the same features.
Relating Fractal Dimension To Branching Behaviour In Filamentous Microorganisms, David Barry, Onwuarolu Ifeyinwa, Shauna Mcgee, Raymond Ryan, Gwilym Williams, Jonathan Blackledge
Relating Fractal Dimension To Branching Behaviour In Filamentous Microorganisms, David Barry, Onwuarolu Ifeyinwa, Shauna Mcgee, Raymond Ryan, Gwilym Williams, Jonathan Blackledge
Articles
The productivity of an industrial fermentation process involving a filamentous microbe is heavily dependent on the morphological form adopted by the organism. The development of systems capable of rapidly and accurately characterising morphology within a given process represents a significant challenge to biotechnologists, as the complex phenotypes that are manifested are often not easily quantified. Conventional parameters employed in these analyses are of limited value, as they reveal little about the specific branching behaviour of the organism, which is an important consideration given the demonstrated link between branching frequency and metabolite production. More recently, fractal geometry has been employed in …
Transcriptional Regulation Of Cholesterol 24-Hydroxylase By Histone Deacetylase Inhibitors., Marjan Shafaati, Riona O'Driscoll, Ingemar Bjorkhem, Steve Meaney
Transcriptional Regulation Of Cholesterol 24-Hydroxylase By Histone Deacetylase Inhibitors., Marjan Shafaati, Riona O'Driscoll, Ingemar Bjorkhem, Steve Meaney
Articles
The mechanistic basis for the tissue specific expression of cholesterol elimination pathways is poorly understood. To gain additional insight into this phenomenon we considered it of interest to investigate if epigenetic mechanisms are involved in the regulation of the brain-specific enzyme cholesterol 24-hydroxylase (CYP46A1), a key regulator of brain cholesterol elimination. We demonstrated a marked time-dependent derepression of the expression of CYP46A1, in response to treatment with the potent histone deacetylase (HDAC) inhibitor Trichostatin A. The pattern of expression of the genes in the genomic region surrounding CYP46A1 was found to be diametrically opposite in brain and liver. Intraperitoneal injection …
Detection Of Numerous Verotoxigenic E. Coli Serotypes, With Multiple Antibiotic Resistance From Cattle Faeces And Soil, L. Scott, P. Mcgee, Ciara Walsh, Seamus Fanning, T. Sweeney, J. Blanco, M. Karczmarczyk, B. Earley, N. Leonard, J.J. Sheridan
Detection Of Numerous Verotoxigenic E. Coli Serotypes, With Multiple Antibiotic Resistance From Cattle Faeces And Soil, L. Scott, P. Mcgee, Ciara Walsh, Seamus Fanning, T. Sweeney, J. Blanco, M. Karczmarczyk, B. Earley, N. Leonard, J.J. Sheridan
Articles
Verotoxigenic E. coli (VTEC) belong to a diverse range of serotypes. Serotypes O157 and O26 are predominately identified in VTEC-associated disease in Europe, however due to difficulty in detection little is known about the epidemiology of non-O157 serotypes. This study reports the identification of 7 VTEC serotypes from cattle faeces and soil. Cattle faeces samples (n = 128) were taken from animals in 6 different farms, with soil samples (n = 20) obtained from 1 farm. After sample incubation in modified tryptone soy broth (mTSB) supplemented with streptomycin sulphate samples were plated onto sorbitol MacConkey (SMAC) also supplemented …
Inactivation Of Escherichia Coli In Orange Juice Using Ozone, Sonal Patil, Paula Bourke, Jesus Maria Frias, Brijesh Tiwari, Patrick Cullen
Inactivation Of Escherichia Coli In Orange Juice Using Ozone, Sonal Patil, Paula Bourke, Jesus Maria Frias, Brijesh Tiwari, Patrick Cullen
Articles
This research investigated the efficacy of gaseous ozone for the inactivation of Escherichia coli ATCC 25922 and NCTC 12900 strains in orange juice. Orange juice inoculated with E. coli (106 CFU mL-1) as a challenge microorganism was treated with ozone at 75-78µg mL-1 for different time periods (0-18 min). The efficacy of ozone for inactivation of both strains of E. coli was evaluated as a function of different juice types: model orange juice, fresh unfiltered juice, juice without pulp, and juice filtered through 500mm or 1mm sieves. Fast inactivation rates for total reduction of E. coli …