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Articles 61 - 90 of 95
Full-Text Articles in Food Microbiology
Antimicrobial, Antioxidant And Free Radical-Scavenging Capacity Of Brown Seaweed Himanthalia Elongata From Western Coast Of Ireland, Gaurav Rajauria, Amit Jaiswal, Nissreen Abu-Ghannam, Shilpi Gupta
Antimicrobial, Antioxidant And Free Radical-Scavenging Capacity Of Brown Seaweed Himanthalia Elongata From Western Coast Of Ireland, Gaurav Rajauria, Amit Jaiswal, Nissreen Abu-Ghannam, Shilpi Gupta
Articles
Water,methanol and mixtures (20–80%) thereof have been used for the extraction of phenolic compounds from Irish brown seaweed Himanthalia elongata for studying its antimicrobial and antioxidant properties.The 60%methanolic extract exhibited significantly (P < 0.05) the highest value of yield (6.8 6 0.24%), total phenol (286.0 6 4.61 mg gallic acid equivalents/g), flavonoid (109.8 6 2.68 mg quercetin equivalents/g) and condensed tannin content (35.6 6 1.03 mgcatechin equivalents/ g). Antimicrobial activity of 60% methanolic extract tested from disc diffusion and broth dilution methods was effective against various food spoilage and pathogenic bacteria studied.The same extract exhibited statistically highest reducing power and antioxidant capacity againstDPPHradical,metal ions, lipid peroxides and hydrogen peroxide radicals. The UV-visible spectroscopy showed absorption maxima at 205 and 260 nm and the presence of hydroxyl group (3,431 cm-1) and an aromatic ring (around 1,465, 1,505 and 1,624 cm-1) in Fourier Transform Infrared spectroscopy, suggested the presence of phenolic compounds in the extract.
Optimization Of Lactic Acid Fermentation Of York Cabbage For The Development Of Potential Probiotic Products, Amit Jaiswal, Shilpi Gupta, Nissreen Abu-Ghannam
Optimization Of Lactic Acid Fermentation Of York Cabbage For The Development Of Potential Probiotic Products, Amit Jaiswal, Shilpi Gupta, Nissreen Abu-Ghannam
Articles
In the present study, York cabbage was used as the sole substrate for the lactic acid (LA) fermentation with Lactobacillus plantarum. York cabbage was blanched at 95°C for 12min to inactivate surface microflora prior to fermentation. To achieve an optimal fermentation condition which would result in higher release of phytochemicals and antioxidant (AO) capacity in the broth, Box-Behnken design integrating a desirability approach was used. A second-order polynomial equation was developed indicating the effect of solute/liquid ratio, agitation rate and fermentation time on desired parameters. The optimized factors were used for fermenting York cabbage to obtain maximum bacterial growth, …
Optimisation Of Accelerated Solvent Extraction Of Antioxidant Compounds From Rosemary (Rosmarinus Officinalis L.), Marjoram (Origanum Majorana L.) And Oregano (Origanum Vulgare L.) Using Response Surface Methodology, M. Hossain, Catherine Barry-Ryan, Ana Belen Martin-Diana, N. Brunton
Optimisation Of Accelerated Solvent Extraction Of Antioxidant Compounds From Rosemary (Rosmarinus Officinalis L.), Marjoram (Origanum Majorana L.) And Oregano (Origanum Vulgare L.) Using Response Surface Methodology, M. Hossain, Catherine Barry-Ryan, Ana Belen Martin-Diana, N. Brunton
Articles
The present study optimised the accelerated solvent extraction (ASE) conditions (Dionex ASE® 200, USA) to maximise the antioxidant capacity of the extracts from three spices of Lamiaceae family; rosemary, oregano and marjoram. Optimised conditions with regard to extraction temperature (66–129 °C) and solvent concentration (32–88% methanol) were identified using response surface methodology (RSM). For all three spices results showed that 129 °C was the optimum temperature in order to obtain extracts with high antioxidant activity. Optimal methanol concentrations with respect to the antioxidant activity of rosemary and marjoram extracts were 56% and 57% respectively. Oregano showed a different response to …
Hyperspectral Imaging For The Detection Of Microbial Spoilage Of Mushrooms, Edurne Gaston, Jesus Maria Frias, Patrick Cullen, Colm O’Donnell, Aoife Gowen
Hyperspectral Imaging For The Detection Of Microbial Spoilage Of Mushrooms, Edurne Gaston, Jesus Maria Frias, Patrick Cullen, Colm O’Donnell, Aoife Gowen
Conference papers
Brown blotch, caused by pathogenic Pseudomonas tolaasii, is the most problematic bacterial disease in Agaricus bisporus mushrooms; it reduces their consumer appeal in the market place, thus generating important economical losses worldwide. The mushroom industry is in need of fast and accurate evaluation methodologies to ensure that only high quality produce reaches the market. Hyperspectral imaging (HSI) is a non-destructive technique that combines imaging and spectroscopy to obtain spatial and spectral information from an object. The aim of this study was to investigate the potential of Vis-NIR HSI to identify microbiological damage in mushrooms and to discriminate it from …
Quantitative Assessment Of The Shelf-Life Of Ozonated Apple Juice, Sonal Patil, Vasilis Valdramidis, Brijesh Tiwari, Patrick J. Cullen, Paula Bourke
Quantitative Assessment Of The Shelf-Life Of Ozonated Apple Juice, Sonal Patil, Vasilis Valdramidis, Brijesh Tiwari, Patrick J. Cullen, Paula Bourke
Articles
Sterile apple juice inoculated with S. cerevisiae ATCC 9763 (103 CFU/mL) was processed in a bubble column with gaseous ozone of flow rate of 0.12 L/min and concentration of 33-40 µg/mL for 8 min. The growth kinetics of S. cerevisiae as an indicator of juice spoilage was monitored at 4, 8, 12 and 16 ºC for up to 30 days. The kinetics were quantitatively described by the primary model of Baranyi and Robert’s and the maximum specific growth rate was further modeled as a function of temperature by the Ratkowsky type model. The developed model was successfully validated for …
The Effect Of Untreated And Enzyme-Treated Commercial Dairy Powders On The Growth And Adhesion Of Streptococcus Mutans, Rachel Halpin, D.B. Brady, E.D. O’Riordan, M. O’Sullivan
The Effect Of Untreated And Enzyme-Treated Commercial Dairy Powders On The Growth And Adhesion Of Streptococcus Mutans, Rachel Halpin, D.B. Brady, E.D. O’Riordan, M. O’Sullivan
Articles
Dental caries is a common bacterial infection, but the progression of this disease can be delayed by preventing initial attachment of cariogenic bacteria such as Streptococcus mutans to tooth surfaces. This study firstly compares the effect of untreated (UT) and enzyme-treated (ET) dairy powders on the adherence of S. mutans to hydroxylapatite (HA), an analogue of tooth enamel. A fluorescence-based method was used to quantify adherence of S. mutans to HA both in the presence (S-HA) and absence (PBS-HA) of saliva. Secondly, binding of proteins present in the test materials to HA was quantified using bicinchonic acid assays and SDS-PAGE. …
Application Of Principal Component And Hierarchical Cluster Analysis To Classify Different Spices Based On In Vitro Antioxidant Activity And Individual Polyphenolic Antioxidant Compounds, M. Hossain, A. Patras, Catherine Barry-Ryan, Ana Belen Martin-Diana, N. Brunton
Application Of Principal Component And Hierarchical Cluster Analysis To Classify Different Spices Based On In Vitro Antioxidant Activity And Individual Polyphenolic Antioxidant Compounds, M. Hossain, A. Patras, Catherine Barry-Ryan, Ana Belen Martin-Diana, N. Brunton
Articles
This study investigated the variations in antioxidant profiles between spices using pattern recognition tools; classification was achieved based on the results of global antioxidant activity assays (2,2-diphenyl-1-picrylhydrazyl [DPPH], oxygen radical absorbance capacity [ORAC], ferric reducing antioxidant power [FRAP], microsomal lipid peroxidation [MLP] and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) [ABTS]), levels of different polyphenolic compounds (gallic acid [GA], carnosol [CAR], carnosic acid [CRA], caffeic acid [CA], rosmarinic acid [RA], luteolin-7-O-glucoside [LOG], apigenin-7-O-glucoside [APOG] and total phenols [TP]) of spices namely rosemary, oregano, marjoram, sage, basil, thyme, fennel, celery, cumin and parsley, commonly consumed in Ireland were analyzed. Rosemary showed the highest antioxidant activity measured …
Effect Of Processing Conditions On Phytochemical Constituents Of Edible Irish Seaweed Himanthalia Elongata., Sabrina Cox, Nissreen Abu-Ghannam, Shilpi Gupta
Effect Of Processing Conditions On Phytochemical Constituents Of Edible Irish Seaweed Himanthalia Elongata., Sabrina Cox, Nissreen Abu-Ghannam, Shilpi Gupta
Articles
Seaweed iswell recognized as an excellent source of phytochemicals. This study was a preliminary screening to investigate the effects of various food processing methods on the phytochemicals of Himanthalia elongata. Hydrothermal processing was carried out until an edible texture was achieved. The total phenolic content (TPC) of fresh H. elongata was 175.27 mg gallic acid equivalent (GAE)/100 g fresh weight (FW) while boiling significantly reduced the TPC to 25.4 mg GAE/100 g FW
(P < 0.05).A drying pretreatment before boiling reduced the cooking time therefore leading to less leaching of antioxidants upon boiling. In terms of extract, drying of H. elongata followed by boiling had the most significant effect on the phytochemicals as TPC increased by 174%. Boiled extracts had the most effective 2, 2-diphenyl- 1-picrylhydrazyl scavenging activity (EC50 of 12.5 mg/mL). As a comparison, seaweed subjected to the same treatments was studied in terms of antimicrobial activity.Overall, extracts fromfresh H. elongata achieved the highest inhibition.
Determination Of The Effect Of Dairy Powders On Adherence Of Streptococcus Sobrinus And Streptococcus Salivarius To Hydroxylapatite And Growth Of These Bacteria, Rachel Halpin, D.B. Brady, E.D. O’Riordan, M. O’Sullivan
Determination Of The Effect Of Dairy Powders On Adherence Of Streptococcus Sobrinus And Streptococcus Salivarius To Hydroxylapatite And Growth Of These Bacteria, Rachel Halpin, D.B. Brady, E.D. O’Riordan, M. O’Sullivan
Articles
Dental caries is a highly prevalent disease caused by colonisation of tooth surfaces by cariogenic bacteria, such as Streptococcus sobrinus and Streptococcus salivarius. Reducing initial adherence of such bacteria to teeth may delay onset of caries. Many foods, such as milk, can inhibit microbial adherence. In this investigation, the effect of untreated (UT) and enzyme-treated (ET) dairy powders on adherence of S. sobrinus and S. salivarius to hydroxylapatite (HA), an analogue of tooth enamel, was examined. Untreated (UT) acid whey protein concentrate (AWPC) 80 inhibited streptococcal adherence to phosphate-buffered saline-coated HA (PBS-HA) and saliva-coated HA (S-HA) by >80% at …
Growth Inhibition Of Common Food Spoilage And Pathogenic Microorganisms In The Presence Of Brown Seaweed Extracts, Shilpi Gupta, Sabrina Cox, Gaurav Rajauria, Amit Jaiswal, Nissreen Abu-Ghannam
Growth Inhibition Of Common Food Spoilage And Pathogenic Microorganisms In The Presence Of Brown Seaweed Extracts, Shilpi Gupta, Sabrina Cox, Gaurav Rajauria, Amit Jaiswal, Nissreen Abu-Ghannam
Articles
The possibility of using extracts from brown seaweed, Himanthalia elongata, as a natural antimicrobial agent for food preservation is presented. The effect of different concentrations of seaweed extract on the growth kinetics of four common food spoilage (Pseudomonas aeruginosa and Enterococcus faecalis) and food pathogenic micro-organisms (Listeria monocytogenes and Salmonella abony) was examined. Seaweed extract at a concentration of 6% inhibited the growth of all four of the studied organisms. Lower concentrations of seaweed extract prolonged the lag phase and reduced both the exponential growth rate and final population densities of the culture. Suitability of three kinetic models, Baranyi-Roberts, Modified …
Metabolic Profiling And Fingerprinting For The Detection And Discrimination Of Mechanical Damage In Mushrooms (Agaricus Bisporus) During Storage, Aoife O'Gorman
Metabolic Profiling And Fingerprinting For The Detection And Discrimination Of Mechanical Damage In Mushrooms (Agaricus Bisporus) During Storage, Aoife O'Gorman
Doctoral
Horticultural products such as mushrooms are exposed to external agents during their postharvest life, which are going to affect product quality. Loss of whiteness during storage is particularly important in the mushroom industry. Rough handling and distribution of crops, fruiting body senescence, bacterial and viral infection are among the causes of mushroom discolouration. The aim of this work was to study the use of metabolic fingerprinting and metabolic profiling tools for the detection and discrimination of mechanical damage on mushrooms. This research involved: 1. Investigating whether the chemical changes induced by mechanical damage and ageing of mushrooms could be (a) …
Effect Of Hydrothermal Processing On Colour, Antioxidant And Free Radical Scavenging Capacities Of Edible Irish Brown Seaweeds, Gaurav Rajauria, Amit Jaiswal, Nissreen Abu-Ghannam, Shilpi Gupta
Effect Of Hydrothermal Processing On Colour, Antioxidant And Free Radical Scavenging Capacities Of Edible Irish Brown Seaweeds, Gaurav Rajauria, Amit Jaiswal, Nissreen Abu-Ghannam, Shilpi Gupta
Articles
The effect of heat processing on change in colour (ΔE), level of bioactive compounds and overall antioxidant capacity in raw and heat processed Irish brown seaweeds was investigated. Raw seaweeds were heated at 85, 95, 100, 110 and 121 °C for 15 min in an autoclave and the samples were extracted with 60% methanol. Total phenol (TPC), total tannin (TTC), DPPH• scavenging and metal chelating ability (FIC) were significantly higher (p < 0.05) at 85 °C while the value of ΔE, total flavonoid (TFC), total sugar (TSC), lipid peroxidation and H2O2 scavenging capacity were higher at 95 °C, as compared to raw seaweeds, in all the species studied. Results showed that heat treatment affects not only the content of bioactive compounds in seaweeds but also beneficial biological activity associated with these compounds which can suggest new processing for the application of seaweeds extract as nutraceutical.
An Assessment Of The Antioxidant And Antimicrobial Activity Of Six Species Of Edible Irish Seaweeds, Sabrina Cox, Nissreen Abu-Ghannam, Shilpi Gupta
An Assessment Of The Antioxidant And Antimicrobial Activity Of Six Species Of Edible Irish Seaweeds, Sabrina Cox, Nissreen Abu-Ghannam, Shilpi Gupta
Articles
Six species of edible Irish seaweeds; Laminaria digitata, Laminaria saccharina, Himanthalia elongata, Palmaria palmata, Chondrus crispus and Enteromorpha spirulina were screened for potential bioactivity. Extraction of secondary metabolites was carried out using different solvents to determine antioxidant and antimicrobial properties of the dried extracts. The total phenolic contents of dried methanolic extracts were significantly different (p < 0.05). H. elongata exhibited highest phenolic content at 151.3 mg GAE/g of seaweed extract and also had the highest DPPH scavenging activity (p < 0.05) with a 50% inhibition (EC50) level at 0.125μg/ml of extract. H. elongata also had the highest total tannin and total flavonoid contents (p < 0.05) of 38.34 mg CE/g and 42.5 mg QE/g, respectively. Antimicrobial activity was determined using a microtitre method which allowed detection of bacterial growth inhibition at low levels. All methanolic seaweed extracts inhibited the food spoilage and food pathogenic bacteria tested; Listeria monocytogenes, Salmonella abony, Enterococcus faecalis and Pseudomonas aeruginosa, except C. crispus extracts. It was found that dried methanolic extracts of red and green seaweeds had significantly lower antimicrobial activity than the brown species; H. elongata had the highest antimicrobial activity with up to 100% inhibition. In the studied work, the antimicrobial activity of red and green seaweed extracts significantly increased when ethanol and acetone were used as extraction solvents (p < 0.05). Inhibition of E. faecalis with C. crispus extracts increased from 39.28 to 100% when ethanol and acetone were applied as solvents.
Inactivation Of Escherichia Coli By Ozone Treatment Of Apple Juice At Different Ph Levels, Sonal Patil, Vasilis Valdramidis, Patrick J. Cullen, Jesus Maria Frias, Paula Bourke
Inactivation Of Escherichia Coli By Ozone Treatment Of Apple Juice At Different Ph Levels, Sonal Patil, Vasilis Valdramidis, Patrick J. Cullen, Jesus Maria Frias, Paula Bourke
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 …
Study Of The Microbial Diversity And Antimicrobial Properties Of Irish Edible Brown Seaweeds, Shilpi Gupta, Gaurav Rajauria, Nissreen Abu-Ghannam
Study Of The Microbial Diversity And Antimicrobial Properties Of Irish Edible Brown Seaweeds, Shilpi Gupta, Gaurav Rajauria, Nissreen Abu-Ghannam
Articles
Brown Irish edible seaweeds, Himanthalia elongata, Laminaria sachharina and Laminaria digitata, were evaluated for the microbiota in raw and heat processed form. Raw seaweeds showed complete absence of aerobic mesophiles, halophiles, yeasts and molds. However, heating at 85 C for 15 min resulted in spore germination. Bacterial counts as high as 107 were observed for aerobic mesophiles and halophiles. Heating above 95 C for 15 min resulted in complete inactivation of surface microflora. Bacteria belonging to Bacillaceae, Paenibacillaceae, Moraxellaceae and Enterobacteriaceae family were identified by 16S rRNA sequencing. In vitro antimicrobial activity of the methanolic extracts of the seaweed on …
Growth And Kinetics Of Lactobacillus Plantarum In The Fermentation Of Edible Irish Brown Seaweeds, Shilpi Gupta, Nissreen Abu-Ghannam, Amalia G.M. Scannell
Growth And Kinetics Of Lactobacillus Plantarum In The Fermentation Of Edible Irish Brown Seaweeds, Shilpi Gupta, Nissreen Abu-Ghannam, Amalia G.M. Scannell
Articles
The aim of the present study was to see the applicability of using brown edible seaweeds as a sole source of nutrition for the growth of lactic acid bacteria. Growth kinetics of lactic acid bacteria (LAB; Lactobacillus plantarum) was studied using three species of edible Irish brown seaweeds Himanthalia elongata, Laminaria digitata and Laminaria saccharina. As part of the screening process, growth of the LAB was carried out on raw and heat treated forms of seaweeds. The seaweed species in their raw state could not support the growth of L. plantarum. Heat treatment resulted in almost 4 times increase in …
Ozone Inactivation Of Acid Stressed Listeria Monocytogenes And Listeria Innocua In Orange Juice Using A Bubble Column, Sonal Patil, Vasilis Valdramidis, Jesus Maria Frias, Patrick J. Cullen, Paula Bourke
Ozone Inactivation Of Acid Stressed Listeria Monocytogenes And Listeria Innocua In Orange Juice Using A Bubble Column, Sonal Patil, Vasilis Valdramidis, Jesus Maria Frias, Patrick J. Cullen, Paula Bourke
Articles
Orange juice inoculated with Listeria monocytogenes strains ATCC 7644, NCTC 11994 and Listeria innocua NCTC 11288 (106 CFU/ml) as challenge microorganisms was treated with direct ozone at 0.098mg/min/ml for different time periods (0-8 min) using an ozone bubble column. Ozone treatment of mild acid stressed and mild acid stress-habituated (pH 5.5) cells of L. monocytogenes resulted in higher inactivation times compared to control non-acid stressed cells. Additionally acid stressed cells habituated in orange juice (ATCC 7644 & NCTC 11288), showed higher inactivation times during ozonation by comparison with the control as well as the mild-acid stressed cells. Overall the …
Effect Of Drying Method On The Antioxidant Capacity Of Six Larniaceae Herbs, M. Hossain, Catherine Barry-Ryan, Ana Belen Martin-Diana, N. Brunton
Effect Of Drying Method On The Antioxidant Capacity Of Six Larniaceae Herbs, M. Hossain, Catherine Barry-Ryan, Ana Belen Martin-Diana, N. Brunton
Articles
The present study investigated the changes in total phenols (TP), rosmarinic acid content and antioxidant capacity of six Lamiaceae herbs (rosemary, oregano, marjoram, sage, basil and thyme) after three drying treatments (air-, freeze- and vacuum oven-drying) stored for 60 days at −20 °C and compared to fresh samples. Ferric reducing antioxidant property (FRAP) and oxygen radical absorbance capacity (ORAC) were used as markers for antioxidant capacity. Air-dried samples had significantly (p < 0.05) higher TP, rosmarinic acid content and antioxidant capacity than had freeze-dried and vacuum oven-dried samples throughout the storage period. Fresh samples had the lowest values for the parameters tested. Vacuum oven-drying resulted in higher TP and FRAP values in rosemary and thyme during 60 days of storage than did freeze-drying. In ORAC assay, the difference was significantly higher only in thyme. Storage did not show any effect on the dried samples for the parameters tested.
Quality And Safety Assessment During The Ozonation Of Cloudy Apple Juice, Sonal Patil, B. Torres, Brijesh Tiwari, Hilda Wingaard, Paula Bourke, Patrick J. Cullen, C. O'Donnell, Vasilis Valdramidis
Quality And Safety Assessment During The Ozonation Of Cloudy Apple Juice, Sonal Patil, B. Torres, Brijesh Tiwari, Hilda Wingaard, Paula Bourke, Patrick J. Cullen, C. O'Donnell, Vasilis Valdramidis
Articles
Traditionally, ozone processing within the food industry has focused on solid foods by either gaseous treatment or washing with ozonated water. However, with the FDA’s approval of ozone as a direct additive to food, the potential for liquid applications has emerged. This study investigates the effect of ozone processing on microbial inactivation (E. coli ATCC 25922 and NCTC 12900), and quality parameters (colour, phenolic content) of apple juice. Apple juice samples were ozonated at room temperature (20±1.5oC) with an ozone concentration of 0.048 mg O3 min-1 ml-1 and treatment time of 0 to 10 …
The Effects Of Acid Adaptation On Escherichia Coli Inactivation Using Power Ultrasound, Sonal Patil, Paula Bourke, Bridget Cullen, Jesus Maria Frias, Patrick J. Cullen
The Effects Of Acid Adaptation On Escherichia Coli Inactivation Using Power Ultrasound, Sonal Patil, Paula Bourke, Bridget Cullen, Jesus Maria Frias, Patrick J. 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. …
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 J. Cullen, Bridget Cullen, Jesus Maria Frias, Paula Bourke
Extrinsic Control Parameters For Ozone Inactivation Of Escherichia Coli Using A Bubble Column, Sonal Patil, Patrick J. 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 …
Application Of Natural Antimicrobials For Food Preservation, Brijesh Tiwari, Vasilis Valdramidis, Colm O' Donnell, Kasiviswanathan Muthukumarappan, Patrick J. Cullen, Paula Bourke
Application Of Natural Antimicrobials For Food Preservation, Brijesh Tiwari, Vasilis Valdramidis, Colm O' Donnell, Kasiviswanathan Muthukumarappan, Patrick J. Cullen, Paula Bourke
Articles
In this review, antimicrobials from a range of plant, animal, and microbial sources are reviewed 10 along with their potential applications in food systems. Chemical and biochemical antimicrobial 11 compounds derived from these natural sources and their activity against a range of pathogenic and 12 spoilage microorganisms pertinent to food, together with their effects on food organoleptic proper- 13 ties, are outlined. Factors influencing the antimicrobial activity of such agents are discussed 14 including extraction methods, molecular weight, and agent origin. These issues are considered in 15 conjunction with the latest developments in the quantification of the minimum inhibitory (and …
Antimicrobial Activity Of Plant Essential Oils Using Food Model Media: Efficacy, Synergistic Potential And Interaction With Food Components, Jorge Gutierrez, Catherine Barry-Ryan, Paula Bourke
Antimicrobial Activity Of Plant Essential Oils Using Food Model Media: Efficacy, Synergistic Potential And Interaction With Food Components, Jorge Gutierrez, Catherine Barry-Ryan, Paula Bourke
Articles
The aim of this study was to optimise the antimicrobial efficacy of plant essential oils (EOs) for control of Listeria spp. and spoilage bacteria using food model media based on lettuce, meat and milk. The EOs evaluated were lemon balm, marjoram, oregano and thyme and their minimum inhibitory concentrations (MIC) were determined against Enterobacter spp., Listeria spp., Lactobacillus spp., and Pseudomonas spp. using the agar dilution method and/or the absorbance based microplate assay. MICs were significantly lower in lettuce and beef media than in TSB. Listeria strains were more sensitive than spoilage bacteria, and oregano and thyme were the most …
Inactivation Of Escherichia Coli In Orange Juice Using Ozone, Sonal Patil, Paula Bourke, Jesus Maria Frias, Brijesh Tiwari, Patrick J. Cullen
Inactivation Of Escherichia Coli In Orange Juice Using Ozone, Sonal Patil, Paula Bourke, Jesus Maria Frias, Brijesh Tiwari, Patrick J. 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 …
Synthesis And Antimicrobial Evaluation Of Carbohydrate And Polyhydroxylated Non-Carbohydrate Fatty Acid Ester And Ether Derivatives, Aoife Smith, Patricia Nobmann, Gary Henehan, Paula Bourke, Julie Dunne
Synthesis And Antimicrobial Evaluation Of Carbohydrate And Polyhydroxylated Non-Carbohydrate Fatty Acid Ester And Ether Derivatives, Aoife Smith, Patricia Nobmann, Gary Henehan, Paula Bourke, Julie Dunne
Articles
A series of fatty acid ester and ether derivatives have been chemically synthesised based on carbohydrate and non-carbohydrate polyhydroxylated scaffolds. The synthesised compounds, along with their corresponding fatty acid monoglyceride antimicrobials, were evaluated for antimicrobial activity against Staphylococcus aureus and Escherichia coli. Of the derivatives synthesised several of the carbohydrate based compounds have antimicrobial efficacy comparable with commercially available antimicrobials. The results suggest that the nature of the carbohydrate core plays a role in the efficacy of carbohydrate fatty acid derivatives as antimicrobials.
The Anti-Microbial Efficacy Of Plant Essential Oil Combinations And Interactions With Food Ingredients, Jorge Gutierrez, Catherine Barry-Ryan, Paula Bourke
The Anti-Microbial Efficacy Of Plant Essential Oil Combinations And Interactions With Food Ingredients, Jorge Gutierrez, Catherine Barry-Ryan, Paula Bourke
Articles
The objective of this study was to evaluate the efficacy of plant essential oils (EOs) in combination and to investigate the effect of food ingredients on their efficacy. The EOs assessed in combination included basil, lemon balm, marjoram, oregano, rosemary, sage and thyme. Combinations of EOs were initially screened against Bacillus cereus, Escherichia coli, Listeria monocytogenes and Pseudomonas aeruginosa using the spot-on-agar test. The influence of varying concentrations of EO combinations on efficacy was also monitored using E. coli. These preliminary studies showed promising results for oregano in combination with basil, thyme or marjoram. The checkerboard method was then used …
Optimisation Of Steamer Jet-Injection To Extend The Shelf Life Of Fresh-Cut Lettuce, Daniel Rico, Ana Belen Martin-Diana, Catherine Barry-Ryan, Gary Henehan, J. Barat, Jesus Maria Frias
Optimisation Of Steamer Jet-Injection To Extend The Shelf Life Of Fresh-Cut Lettuce, Daniel Rico, Ana Belen Martin-Diana, Catherine Barry-Ryan, Gary Henehan, J. Barat, Jesus Maria Frias
Articles
Optimisation of short time blanching (steaming) was investigated using response surface methodology by analysing quality and microbial and nutritional markers over the shelflife of packaged fresh-cut lettuce. Steamer treatment time (5–10 s) and storage (1–10 days) were used as independent factors in order to optimise the process. Longer treatments (>10 s) were not feasible because of extensive damage caused to lettuce tissue. Significantly (p < 0.05) higher values of luminosity (L*), greenness (−a*) and sensory panel scores (fresh appearance, general acceptability and absence of browning) were obtained with samples treated for longer times with the steamer. Activity of browning-related enzymes present in photosynthetic tissue decreased in all the cases, however, longer treatment time (7.5–10 s) was needed with vascular tissues to reduce to similar activity values. These differences could be explained by the variation in tissue thickness. The longest steam treatment (10 s) reduced and maintained significantly (p < 0.05) lower mesophilic load than shorter treatments (5–8.5 s). However, significant (p < 0.05) decreases in vitamin C and carotenoids were observed in samples treated with longer treatments. Steamer treatment of 10 s could be considered the optimum time for maintaining the shelflife (mainly texture and browning) of fresh-cut lettuce for 7–10 days in optimum conditions.
Simultaneous Modelling Of The Thermal Degradationa Kinetics Of Pectin, Daniel Rico, Ana Belen Martin-Diana, Catherine Barry-Ryan, Gary Henehan, Jesus Maria Frias
Simultaneous Modelling Of The Thermal Degradationa Kinetics Of Pectin, Daniel Rico, Ana Belen Martin-Diana, Catherine Barry-Ryan, Gary Henehan, Jesus Maria Frias
Articles
The thermal degradation kinetics of pectin methylesterase (PME) from carrot and lettuce were studied. Fresh extracts were exposed to temperatures from 55 to 70 °C until the enzyme was inactivated. A model based on the presence of two forms of the enzyme, one active and one non-active, is proposed. The natural variability of the PME activity was taken into the model in the form of normally distributed random effects. The common model parameters obtained (cleavage constant (0.0395±0.0062 s−1), degradation constant (0.556±0.112 s−1), cleavage energy of activation (469±23 kJ mol−1) and degradation energy of activation …
Calcium For Extending The Shelf Life Of Fresh Whole And Minimally Processed Fruits And Vegetables, Ana Belen Martin-Diana, Daniel Rico, Jesus Maria Frias, J. Barat, Gary Henehan
Calcium For Extending The Shelf Life Of Fresh Whole And Minimally Processed Fruits And Vegetables, Ana Belen Martin-Diana, Daniel Rico, Jesus Maria Frias, J. Barat, Gary Henehan
Articles
The preservation of quality of fresh products is relevant for the industry due to its economic impact. This paper presents a comprehensive review of the use of different sources of calcium to preserve fresh fruits and vegetables in order to extend the shelf life and enhance the nutritional value. Emphasis is on discussing about the best sources of calcium, concentration, temperature and method of application, suitability of the commodities; and some hints for the cost/benefit analysis are presented.