Food Science Commons^™

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 …

An Investigation Of The Sensory Properties Of Legumes As Influenced By Irish Consumer's Knowledge And Acceptance., Anne O'Leary, Therese G. Cadden, Ivano Caprioli

Conference papers

The health benefits related to legume consumption are many and varied, however the acceptability of this nutritive food has received very little attention.

The aim of this research is to investigate consumer knowledge of the health benefits associated with regular consumption of legumes and to explore consumer acceptability of legumes.

The study highlights how recipe formulation, consumption patterns, health behaviour and sensory properties all intertwine to shape an individuals acceptance of legumes.

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 …

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 …

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 …

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 …

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.

Inhibition Of Adhesion Of Streptococcus Mutans To Hydroxylapatite By Commercial Dairy Powders And Individual Milk Proteins, Rachel Halpin, Maeve O'Connor, Dolores O'Riordan, Michael O'Sullivan, Damien Brady

Articles

The aim of this study was to investigate the inhibitory effect of various dairy powders and milk constituents on the adhesion of a clinical isolate of Streptococcus mutans to hydroxylapatite (HA), an analogue of tooth enamel. Adhesion of a microorganism to a cell surface such as epithelial cells or tooth enamel is considered to be the first step in pathogenesis. Inhibiting this process may have therapeutic effects in vivo. The adherence assays were performed by incubating S. mutans with HA in the presence of each test material for 45 min, followed by centrifugal separation of the HA. Unbound bacteria were …

Design And Synthesis Of Carbohydrate Based Derivatives As Antimicrobial Compounds, Aoife Smith

Doctoral

Investigations into the design of analogues of GlcNAc-Ins, the substrate for the enzyme GlcNAc-Ins deacetylase (mshB), a therapeutic target on the pathway to mycothiol biosynthesis in Mycobacterium tuberculosis are described. Initial studies directed towards the design of a substrate analogue were based on the 3-D structure and a proposed mechanism of action of mshB (deduced by Dr. Andrew McCarthy, EMBL). The compounds were designed with the aim to produce an analogue which could better mimic the natural substrate for mshB (GlcNAc-Ins) for crystallisation and mechanistic studies to further improve the knowledge of this enzyme. A series of fatty acid ester …

Assessing The Effect Of Product Variability On The Management Of The Quality Of Mushrooms (Agaricus Bisporus), Catherine Barry-Ryan, Jesus Maria Frias, Leixuri Aguirre, Helen Grogan

Articles

To study the shelf-life of mushrooms, over 25 batches were subjected to three storage temperatures (T) (5, 15 and 25 ◦ C) and three storage relative humidity (RH) levels (70, 80 and 90%). The effect of T and the RH on the kinetics of quality attributes of the batches was studied by measuring water activity, turgor, colour (L, a* and b* in the Hunter Scale) and weight loss of three different tissues (cap, gills and stipe) of the mushroom. Linear mixed effect models, comprising polynomial models to describe quality kinetics and allowing for batch-to-batch and inside-batch nested variabilitystructure, were built. …

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 …

Recent Applications Of Chemical Imaging To Pharmaceutical Process Monitoring And Quality Control, A. A. Gowen, Colm O'Donnell, Patrick J. Cullen, S. Bell

Articles

Chemical Imaging (CI) is an emerging platform technology that integrates conventional imaging and spectroscopy to attain both spatial and spectral information from an object. Vibrational spectroscopic methods, such as Near Infrared (NIR) and Raman spectroscopy, combined with imaging are particularly useful for analysis of biological/pharmaceutical forms. The rapid, non-destructive and non-invasive features of CI mark its potential suitability as a process analytical tool for the pharmaceutical industry, for both process monitoring and quality control in the many stages of drug production. This paper provides an overview of CI principles, instrumentation and analysis. Recent applications of Raman and NIR-CI to pharmaceutical …

The Feasibility Of Producing Vacuum-Packed Fermented Vegetable Products., Antoni Llovera

Masters

The average intake of vegetables in Ireland falls below the recommendations of Bord Glas and FSAI. Carrots are the third most consumed vegetable in Ireland and they are an excellent source of vitamins A and B as well as phytochemicals. Lactic acid bacteria (LAB) are well-known in food for their benefits such as improvement of the nutritional value of food and improvement of the digestion of lactose. Vegetable consumption could be enhanced by promoting a novel snack fermented carrot product that would provide the healthy benefits of vegetables coupled with the benefits of the probiotic lactic acid bacteria. Two varieties …

Use Of Neutral Electrolysed Water (Ew) For Quality Maintenance And Shelf-Life Extension Of Minimally Processed Lettuce, Daniel Rico, Ana Belen Martin-Diana, Catherine Barry-Ryan, Jesus Maria Frias, Gary Henehan, José Barat

Articles

Experiments were conducted to determine the effectiveness of different treatments based on the use of neutral electrolysed water (EW) on fresh-cut lettuce. EW was diluted to obtain different free chlorine concentrations (120, 60 and 12 ppm) and compared with standard washing treatment of 120 ppm chlorine solution. Shelf-life quality and safety markers were studied at the beginning and at the end of the 7-day storage at 4 ºC. The use of EW decreased the respiration rate of the samples which might be related with the observed reduction in microbial spoilage. The use of EW also increased the activity of a …

Antioxidant Activity Of Spice Extracts And Phenolics In Comparison To Synthetic Antioxidants, M. Hossain, N. Brunton, Catherine Barry-Ryan, Ana Belen Martin-Diana, M. Wilkinson

Articles

The antioxidant capacity of 30 spices used frequently in ready meals and a selection of key compounds from spices were investigated in the current study using ferric reducing antioxidant properties (FRAP), 2,2'-azinobis(3-ethylebenzothiaziline-6-sulfonate) (ABTS) and microsomal lipid peroxidation (MLP) assays. Antioxidant capacities of the spice extracts were compared to 5 popular synthetic antioxidants [buylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tert-butylated hydroquinone (TBHQ), propyl gallate (PG) and octyl gallate (OG)]. Results showed that clove extracts had the highest antioxidant capacity as measured by FRAP, ABTS and MLP assays. Extracts from garlic powder were the lowest ranked of all the spices examined. Synthetic …

Antibiotic Resistance In Foodborne Pathogens- A Cause For Concern?, Ciara Walsh, Seamus Fanning

Articles

The widespread use of antibiotics in food animal production systems has resulted in the emergence of antibiotic resistant zoonotic bacteria that can be transmitted to humans through the food chain. Infection with antibiotic resistant bacteria negatively impacts on public health, due to an increased incidence of treatment failure and severity of disease. Development of resistant bacteria in food animals can result from chromosomal mutations but is more commonly associated with the horizontal transfer of resistance determinants borne on mobile genetic elements. Food may represent a dynamic environment for the continuing transfer of antibiotic resistance determinants between bacteria. Current food preservation …

Transfer Of Ampicillin Resistance From S. Typhimurium Dt104 To E. Coli K12 In Food, Ciara Walsh, Geraldine Duffy, R. O'Mahoney, D. A. Mcdowell, Seamus Fanning

Articles

Aims:  To investigate the transfer of antibiotic resistance from a donor Salmonella Typhimurium DT104 strain to a recipient Escherichia coli K12 strain.

Methods and Results:  Mating experiments were conducted in broth, milk and ground meat (beef) at incubation temperatures of 4, 15, 25 and 37°C for 18 and 36 h. Ampicillin-resistance transfer was observed at similar frequencies in all transfer media at 25 and 37°C (10⁻⁴ to 10⁻⁵ log₁₀ CFU ml g⁻¹, transconjugants per recipient) for 18 h. At 15°C, transfer was observed in ground meat in the recipient strain (10⁻⁶, log_{10 …}

Combination Of Natural Variability Estimation With Real Time Measurement For Mushroom Shelf Life Assessment., Leixuri Aguirre

Doctoral

The shelf life of mushrooms (Agaricus bisporus) is affected by the natural variability of the produce which influences the perishable vegetable quality. One of the main causes of this variability is non-homogeneity in the product maturity at harvest, resulting in each vegetable batch being at a different stage of senescence. The present work aims to study a new approach to improve the assessment of the shelf life of mushrooms (Agaricus bisporus) taking into account this variability. The study of variability involved the: i) study of the shelf life, quality parameters and variability of the mushrooms and modelling these experimental laboratory …

Antioxidant And Antimicrobial Activity From Six Species Of Edible Irish Seaweeds, Sabrina Cox

Conference papers

No abstract provided.

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.

Relevance For Food Safety Of Applications Of Nanotechnology In The Food And Feed Industry, Iona Pratt, Catherine Adley, Gordon Chambers, Wayne Anderson

Articles

The application of nanotechnology in the food and feed industry offers many potential benefits for both consumers and manufacturers.The ultrafine dimensions of nanoparticles, and consequently their very large surface area, enable them to function more effectively than conventional macro-scale structures in many applications. Nanotechnology is however a relatively new area of science and the benefits and risks associated with its use in the food and feed industry are not fully understood at this time.This brings with it new challenges in ensuring the safety of food and feed that has been produced with the aid of nanotechnology. This report provides an …

Extending And Measuring The Quality Of Fresh-Cut Fruit And Vegetables: A Review, Catherine Barry-Ryan, Ana Belen Martin-Diana, Daniel Rico, J. Barat

Articles

The market sales of ready-to-use fresh vegetables have grown rapidly in recent decades as a result of changes in consumer attitudes, especially consumption of fresh-cut lettuce and carrot due to their use in prepared salads. Chlorine solutions have been widely used to sanitise fruit and vegetables in the fresh-cut industry. However, the association of chlorine with the possible formation of carcinogenic chlorinated compounds in water has called into question the use of chlorine in food processing. There is a real need to find alternatives for preservation of fresh-cut fruit and vegetables in order to improve the efficacy of washing treatments. …

Novel Copper(Ii) And Silver(I) Complexes Incorporating Benzimidazole And Related Nitrogen Donor Ligands: Synthesis, Biomimetic, Anticancer And Antifungal Activities, Mark O'Connor

Doctoral

This project describes the synthesis and biomimetic/biological properties of sixty nine copper (II) and silver (I) complexes. The complexes were derived from reactions of four copper (II) carboxylate compounds along with copper(II) and silver(I) salts with various nitrogen donor ligands. Approximately sixty of the complexes are novel. X-ray crystal structures for five of the novel copper (II) complexes are reported. [Cu9salH)2 (1) [Cu2(asp)4(H2O)2].H2O (2) [Cu(dipsH)2(H2O) (3) and {Cu(msal)(H2))}n (4) were generated when copper (II) hydroxide was reacted with the relevant carboxylic acid. Complexes (1) – (4) reacted with simple benzimidazoles to yield twelve complexes with three of them being structurally …

Characterisation Of The Aldo Keto Reductase From Helicbacter Pylori., Denise Cornally

Doctoral

Aldo keto reductases reversibly reduce toxic aldehydes to their corresponding alcohol products. The aldo-keto reductase from Helicobacter pylori (HpAKR) was cloned and expressed in Escherichia coli as a His-tag fusion protein and purified using nickel chelate chromatography. The enzyme is a monomer with a molecular mass of approximately 39 kDa. It reduces a broad range of aldehyde substrates with a high catalytic efficiency and exhibits dual co-factor specificity for both NADH and NADPH. HpAKR can function over a broad pH range (pH 4-9) with a pH optimum of 5.5. Inhibition of AKR activity was observed with sodium valproate. Generation of …

The History Of Eggs In Irish Cuisine And Culture, Mairtin Mac Con Iomaire, Andrea Cully

Conference papers

Eggs have played an important role in the Irish culture. For centuries, eggs have done so much more than simply nourish the body; they have soaked up mythological and folk belief, and have been used to celebrate certain religious festivals. They were also an early form of income or means of barter, often contributing far more to the family income than the commonly used term ‘pin money’ suggests. Initiatives sponsored by successive governments and the rise in the co-operative movement led to improvements in the poultry and egg industry from the end of the nineteenth century to the 1960s when …

Time-Temperature And Relative Humidity Profiles Of Chilled And Frozen Foods In Retail Outlets Nationwide, And Evaluation Of Related Practices, Caroline Garvan

Masters

Temperature abuse combined with poor operational practices are the dominant factors in the mishandling of food products which can result in outbreaks of food borne disease. The objective of this work was to determine efficacy of temperature and relative humidity control using recorded data and to assess the food safety management systems in operation in retail outlets in the Republic of Ireland. This study also aims to examine food safety risk to consumers as a result of inadequate temperature control and poor food hygiene practices using microbial analysis and predictive modelling. External air temperature, core temperature and relative humidity of …

Development And Assessment Of A Rapid Method To Detect Escherichia Coli O26, O111 And O157 In Retail Minced Beef., Mary Murphy, Anne Carroll, Paul Whyte, Micheál O'Mahoney, Wayne Anderson, Eleanor Mcnamara, Seamus Fanning, Ciara Walsh

Articles

A molecular-based detection method was developed to detect Escherichia coli O26, O111 and O157 in minced (ground) beef samples. This method consists of an initial overnight enrichment in modified tryptone soya broth (mTSB) and novobiocin prior to DNA extraction and subsequent serogrouping using a triplex PCR. This method has a low limit of detection and results are available within 24 hours of receipt of samples. Once optimized, this rapid method was utilized to determine the prevalence of these E. coli serogroups in six hundred minced beef samples all of which were previously examined by immunomagnetic separation (IMS) and selective plating …

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.

Characteristics Of Cooked Chickpeas And Soybeans During Combined Microwave–Convective Hot Air Drying, Aoife Gowen, Nissreen Abu-Ghannam, Jesus Maria Frias, Jorge Oliveira

Articles

Moisture content, shrinkage, water activity (Aw), color and texture of cooked chickpeas and soybeans during convective, microwave and combined microwave–convective drying were studied. Combined drying was significantly (P < 0.05) faster than either convective or microwave drying, and resulted in less shrinkage of the dehydrated product. Rapid burning occurred when samples were dried below a Aw of 0.27 ± 0.07 for chickpeas (P < 0.05), and 0.13 ± 0.04 for soybeans (P < 0.05). Both chickpeas and soybeans displayed a transitional behavior in texture when dried to a Aw below 0.40 ± 0.10 (P < 0.05) for chickpeas, and below 0.63 ± 0.15 (P < 0.05) for soybeans, when samples became brittle. Shelf stable dehydrated chickpea and soybean products with low water activity (Aw = 0.35) and good visual quality could be obtained within 14 min of combination drying.

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 …