• Second generation GM foods: perspectives on likely future acceptance by Irish consumers

      O'Connor, Elaine; Cowan, Cathal; Williams, Gwilym; O'Connell, John J.; Boland, Maurice; Downey, Gerard; Teagasc Walsh Fellowship Programme; Safefood; Safefood (Teagasc, 2005-07)
      Two hypothetical second-generation genetically-modified (GM) products, a yogurt and a dairy spread, were evaluated by consumers. Second-generation GM food products offer specific consumer benefits - in the case of this study, health benefits.
    • Second Generation GM Foods: Perspectives on Likely Future Acceptance by Irish Consumers

      O'Connor, Elaine; Cowan, Cathal; Williams, Gwilym; O'Connell, John J.; Boland, Maurice; Downey, Gerard (Teagasc, 01/07/2005)
      Two hypothetical second-generation genetically-modified (GM) products, a yogurt and a dairy spread, were evaluated by consumers. Second-generation GM food products offer specific consumer benefits - in the case of this study, health benefits.
    • Significance of Lactobacilli in Cheddar Cheese

      Cogan, Tim; Beresford, Tom; Drinan, Finbarr; Palles, Tony; Fitzsimons, Nora (Teagasc, 1998-09-01)
      The objectives of this project were to isolate and identify the non-starter lactobacilli in mature Cheddar cheese, identify strains which impart mature flavours to cheese and determine their role in developing cheese flavour. The main conclusions were as follows: Based on an analysis of 18 mature Cheddar cheeses, selected from 7 commercial manufacturers, non-starter lactic acid bacteria typically numbered, as expected, 106-108 per gram and were dominated (97 percent) by Lactobacillus paracasei. Although a small number of strains (typically 1 to 4) was found in each cheese there was considerable strain diversity in cheeses within as well as between manufacturing plants. When selected strains were investigated for survival and flavour enhancement when added (as starter adjuncts) with the normal starter cultures in Cheddar cheese manufacture, it was found that they remained dominant for up to 3 months of ripening. Commercial grading of these cheeses at 3 and 6 months confirmed that the added strains did modify flavour development and one (DPC 4103), in particular, had a beneficial effect. It was confirmed that two selected strains of non-starter lactobacilli were capable of metabolising citrate under the conditions of Cheddar cheese ripening and, consequently, if present in sufficient numbers, would influence flavour development. The work was greatly facilitated by the successful and novel adaptation of a modern rapid molecular technique (RAPD) for species and strain classification. In summary these studies found that one species of lactobacilli (Lb. paracasei) was the dominant non-starter lactic acid bacteria in mature Cheddar cheese. Although a wide variety of strains were identified, only a few were found in any particular cheese, suggesting their likely role in cheese flavour diversity even within the same manufacturing plant. This suggests the potential for flavour control or enhancement through the selective and controlled use of non-starter lactic acid bacteria. Preliminary investigations of the metabolism of those organisms supports this view and a follow-up study now in progress should provide greater clarity on this matter.
    • Spread of brain and spinal cord material during beef slaughter

      Daly, Dyan J.; Prendergast, Deirdre M.; Sheridan, James J. (Teagasc, 2002-04)
      Emboli of brain tissue in the lungs have been reported in cases following severe head injury (McMillan 1956) and birth trauma in people (Hauck e t al 1990) and in cattle following stunning (Bauer 1996; Garland 1996). This has important implications for food safety if the brain tissue of stunned cattle is infected with the prion responsible for bovine spongiform encephalopathy (BSE), (Prusiner 1991). BSE emerged following changes in the rendering process in the early 1980s which allowed the aetiologic agent to survive, contaminate protein feed supplement and infect cattle (Brown e t al. 2001). Within a short period of time after the first case of BSE, concerns were expressed regarding the transmission of BSE to humans and the likelihood of infection from consumption of beef and beef products. This has become increasingly significant with the discovery of the link between BSE in cattle and variant Creutzfeldt-Jakob disease (vCJD) in man (Bruce e t al 1997).
    • Status Report on Acrylamide in Potato Products

      Brunton, Nigel; Gormley, Ronan T.; Murray, Brendan (Teagasc, 2005-01-01)
      Acrylamide is a toxin that can potentially occur in high concentrations in heated starchy foods especially potato products such as crisps and french fries. In model systems isotopic substitution studies have demonstrated that acrylamide is formed via the Maillard type reaction between the amino acid aspargine and a carbonyl source such as the reducing sugars glucose and fructose. Levels of acrylamide in cooked potato products are primarily influenced by the levels of reducing sugars in the product and this in turn is influenced by storage time, temperature and variety of potato used. During cooking acrylamide formation begins to occur at temperatures above 100°C and increases up to temperatures of 220°C but decreases thereafter due to thermal degradation of the compound. Risk assessment studies on acrylamide intakes have been conducted in a number of countries and mg/kg body weight daily intakes have been estimated to be between 0.2-0.8. Adequate analytical techniques exist for quantification of acrylamide in potato and are mainly based around liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) and gas chromatography mass spectrometry (GC-MS) techniques
    • Stimulation of Propionic Acid Bacteria by Lactic Acid Bacteria in Cheese.

      Condon, S.; Cogan, Tim; Piveteau, P.; O'Callaghan, Jim; Lyons, B. (Teagasc, 2001-06-01)
      In the manufacture of Swiss-type cheese two successive fermentations occur. During manufacture, lactic acid bacteria (LAB), particularly Streptococcus thermophilus, Lactobacillus helveticus and Lb. delbrueckii subsp. lactis, convert lactose to lactate while, during ripening, propionic acid bacteria (PAB) convert lactate to propionic acid, acetic acid and carbon dioxide (CO2). CO2 is responsible for eye formation and propionic acid results in the typical nutty flavour of Swiss-type cheese. There have been a few reports of interactions between a small number of LAB and PAB but the compounds involved have not been identified. A better understanding of this phenomenon is necessary to select strains of PAB for cheesemaking and improve the quality of hard cheeses. Cheese cannot be used for such a study because of its complexity and the length of time it is ripened. Hence, a simple whey-based model developed by Piveteau et al (1995) was successfully used to study the interactions between LAB and PAB. In this procedure, the LAB were grown overnight in milk and the whey was collected by centrifugation. After neutralisation and filter-sterilisation, the growth of strains of PAB in this whey and in a control whey produced from the same milk by acidification with lactic acid were compared. The objectives of this study were to refine the model of Piveteau et al (1995) to study the interactions between LAB and PAB and to determine the nature of the stimulant(s) produced by the LAB. * Thirty-two combinations of different commercial strains of PAB and LAB were evaluated in a modified whey model. None showed any inhibition and all showed some degree of stimulation but the extent of the stimulation depended on the particular pair of PAB and LAB used. * An inhibitor of PAB was found in milk, which prevented the growth of PAB from low (105 cfu/ml) but not from high inocula (107 cfu/ml). The inhibitor was heat stable (to autoclaving for 15 min), of low molecular mass and could be removed by pre-growth of some but not all starter LAB in milk. * Growth of P. freudenreichii DPC 3801 in control whey was stimulated by peptone, tryptone, casein hydrolysed by the crude proteinase of Lb. helveticus DPC 4571 and by pre-growth of the lactobacillus in milk, but not by vitamins (riboflavin, thiamine, PABA, Ca panthothenate, biotin and nicotinic acid) or minerals (MgSO4, MnCl2, CoCl2 and CuSO4). * Growth of Lb. helveticus DPC 4571 in milk resulted in significant increases in peptide and amino acid production but the amino acids produced did not stimulate the growth of the PAB. Based on these results it was concluded that the stimulation was due to production of peptides by the LAB from casein. * The whey model developed by Piveteau et al (1995) to study the interactions between PAB and LAB was shown to be reproducible. Adjustment of the pH of the whey to 5.4 rather than 6.0, incubation at 24ºC rather than 30ºC and addition of 1% NaCl, to simulate cheese ripening conditions allowed growth of all the PAB tested. * Several chromatographic procedures, including ion-exchange, gel permeation and reverse-phase, high-pressure liquid chromatography failed to categorically identify the peptide(s) responsible for the stimulation of the PAB. In some of these chromatographic systems,the stimulatory activity was shown to be present in several peaks implying that different peptides were involved.
    • A study of cryptosporidium parvum in beef

      Duffy, Geraldine; McEvoy, John M.; Moriarty, Elaine M.; Sheridan, James J.; European Union; QLK1 CT 1999 00775 (Teagasc, 2003-07)
      There is increasing concern that foods, particularly those of animal origin, may play a role in the transmission of C ryptosporidium parvum to humans. Studies were undertaken to examine the risk posed by C . parvum in the beef chain.
    • A study on the use of chilling as a critical control point in a beef HACCP plan

      Kinsella, Kathleen; Sheridan, James J.; Rowe, T.; Downey, Gerard; National Development Plan (NDP) (Teagasc, 01/02/2006)
      Investigations were undertaken to establish the critical limits for use of chilling in a Hazard Analysis Critical Control Point (HACCP) system for beef. Information was obtained on the influence of chilling on the survival of bacteria, including the pathogen Salmonella Typhimurium DT104, attached to beef carcass surfaces. In general, a chilling regime could not be identified that gave consistent and meaningful reductions in surface bacterial counts while not seriously compromising the quality of the carcasses in terms of excessive amounts of weight loss. The study concluded that chilling was not a satisfactory process for use as a critical control point (CCP) in beef chilling and could not be recommended to the Irish beef industry for inclusion in a HACCP plan.
    • A study on the use of chilling as a critical control point in a beef HACCP plan.

      Kinsella, Kathleen; Sheridan, James J.; Rowe, T. (Teagasc, 2006-02)
      Investigations were undertaken to establish the critical limits for use of chilling in a Hazard Analysis Critical Control Point (HACCP) system for beef. Information was obtained on the influence of chilling on the survival of bacteria, including the pathogen Salmonella Typhimurium DT104, attached to beef carcass surfaces. In general, a chilling regime could not be identified that gave consistent and meaningful reductions in surface bacterial counts while not seriously compromising the quality of the carcasses in terms of excessive amounts of weight loss. The study concluded that chilling was not a satisfactory process for use as a critical control point (CCP) in beef chilling and could not be recommended to the Irish beef industry for inclusion in a HACCP plan.
    • Supercritical fluid extraction of veterinary drug residues from meat

      O'Keeffe, Mandy J.; O'Keeffe, Michael; Department of Agriculture, Food and the Marine, Ireland (Teagasc, 1999-10)
      Extraction is a key step in the analysis of food samples for residues of veterinary drugs. Over the last ten years there has been increasing interest in alternatives to the use of organic solvents for sample extraction. The development of supercritical fluid extraction (SFE) for the determination of residues in meat provides alternative methods, which may be automated and which have attractive properties such as avoidance of organic solvents and increased speed of extraction. This project is a jointly-funded United States Department of Agriculture and Department of Agriculture and Food activity with the objective of developing robust SFE procedures suitable for the quantitative recovery of ß-agonists (illegal growth promoters) from animal tissue. Fundamental aspects of SFE in its application to residue analysis are also addressed.
    • Surface decontamination of meat using thermal processes

      McCann, Máiréad; Sheridan, James J.; Downey, Gerard; European Union (Teagasc, 01/02/2007)
      This study investigated the effectiveness of a novel heat apparatus for decontamination of meat surfaces inoculated with important foodborne pathogens using either steam or dry air.
    • Surface decontamination of meat using thermal processes

      McCann, Máiréad; Sheridan, James J.; Downey, Gerard (Teagasc, 2007-02)
      This study investigated the effectiveness of a novel heat apparatus for decontamination of meat surfaces inoculated with important foodborne pathogens using either steam or dry air.
    • The survival of added escherichia coli O157:H7 in natural mineral water and its products and the development of a rapid method for enumeration of the heterotrophic bacteria in natural mineral water

      Kerr, Marie; Fitzgerald, Margaret; Sheridan, James J. (Teagasc, 2000-12)
      The consumption of natural mineral water is rapidly growing and outpacing all other beverages on a global scale. In Europe, bottled water already has a bigger market share than carbonated soft drinks. Yet there is only a limited availability of information on the microbiological safety and quality of bottled natural mineral waters sold within the European Community. As natural mineral water does not receive any bacteriocidal treatment prior to bottling, the risk of pathogen contamination is a public health concern. Pathogen contamination may occur as a result of over exploitation of natural mineral water resources i.e. over abstraction by commercial bottling companies may lead to disturbance of the water table causing contaminated surface water to be drawn down into ground water supplies (Green and Green 1994). Such contamination was implicated in an outbreak of cholera associated with the consumption of bottled natural mineral water in Portugal in 1974 (Blake et al. 1977). The transport and dissemination of E. coli and enterococci in a limestone aquifer had been demonstrated by Personné et al. (1998), confirmation that E. coli can survive the transitory period from the surface to underground water supplies, thus raising the question of E. coli O157:H7 with its low infective dose < 10 cells (Willshaw et al. 1994 and Tilden et al. 1996) surviving the transitory period from surface to a natural mineral water aquifer.
    • Technologies for detecting PSE in pork

      Mullen, Anne Maria; McDonagh, Ciara; Troy, Declan J. (Teagasc, 2003-02)
      The ability of a single, on-line measurement to predict the quality status of an entire muscle or even of a whole carcass was investigated. Variation between pork muscles for on-line measurements of pH, conductivity and colour was evaluated. Intermuscular variation was detected at 24h p ostmortem with higher pH and conductivity values in the topside (M. s emimembranosus) than the striploin (M . longissimus thoracis et lumborum). Correlations showed that a relationship exists between the muscles (r = 0.46-0.88, p<0.05) at 45min and 3h p ostmortem. The location within the topside or the striploin at which the measurements were taken did not influence the result. Shackling did not introduce a significant variation between sides for pH, conductivity and colour values up to 24h p ostmortem, showing measurements could be taken on either side of the carcass.
    • Technology transfer of research results (The 2xtra project)

      McDonagh, Ciara; Byrne, Briege; Troy, Declan J.; Mullen, Anne Maria; Downey, Gerard; European Commission; European Union (Teagasc, 2008-02)
      The 2XTRA project (Technology Transfer Research Results Atlantic Area) was carried out with the aim of promoting economic activity based on research results and technologies developed within universities, research and technology institutes and companies in the European Atlantic Area. This collaborative work was carried out by a strong partnership of 13 entities across this region and included universities, research and technology institutes, private consultants and TBC (technology-based company) incubators. The specific goals of the project were: ● The exchange of information and experiences on technology transfer (TT) with a view to assisting project partners directly and feeding into their regional innovation systems. ● The promotion of new technology-based companies by drawing on collective experiences and developing methodologies relating to - identification and evaluation of business ideas - production of business plans, and - support of early stage companies internationalising. ● The creation of an Atlantic Area Network to support and promote technology-based companies (TBCs) and the technology transfer process. These objectives were achieved through defined activities carried out in three separate stages of this project.
    • A test bacterial decontamination system for meat products

      Ward, Oonagh C.; Logue, Catherine M.; Sheridan, James J.; European Union; FAIR CT 1027 (Teagasc, 2000-12)
      A pilot scale apparatus was designed to allow meat samples to be treated with steam at sub-atmospheric pressures and correspondingly reduced temperatures. Experiments were carried out to determine the effectiveness of sub-atmospheric steam decontamination in eliminating bacteria on the surface of fresh beef. This type of treatment can have special advantages in that steam can be produced at temperatures well below 100ºC. This means that the heat advantages of steam as a decontaminating agent can potentially be obtained at lower temperatures.
    • Texture of fruit and vegetable components of ready meals

      Downey, Gerard (Teagasc, 2000-12)
      Vegetable and fruit purées are important parts of prepared ready-meals. Further expansion of this food sector will depend among other things on improved and consistent product quality. Innovative organoleptic properties in ready-meal components will assist in product diversification and the growth of market share.
    • Tracking of Salmonella through the Pork Slaughter Process

      Prendergast, Deirdre M.; Duggan, Sharon J.; Duffy, Geraldine; Downey, Gerard; Safefood; National Development Plan 2007-2013 (Teagasc, 01/10/2009)
      To help address the problem of salmonellosis in the Republic of Ireland (RoI), a national Salmonella control programme was introduced in 1997 with a view to reducing the prevalence of Salmonella in pigs on the farm and on pig carcasses. The primary objective of this present study was to determine the correlation between the Salmonella serological and bacteriological status of pigs presented for slaughter and the Salmonella status of pork cuts following slaughter, dressing and chilling. Two additional studies investigated the prevalence and numbers of Salmonella spp. in the boning halls of four commercial pork abattoirs and at retail level in butcher shops and supermarkets in the RoI. The results indicated that categorisation of pig herds on the basis of a historical serological test for Salmonella was not a good predictor of the bacteriological Salmonella status of individual pigs at time of slaughter. However, it is acknowledged that serological testing does help in giving a rough estimate of the overall Salmonella status of a pig herd. There was a linear correlation between prevalence of Salmonella in caecal contents and on pork cuts at factory level; therefore, if the number of herds presented for slaughter with high levels of Salmonella (category 3) was reduced, there would be less potential for contamination of the lairage, equipment etc. and so less likelihood of Salmonella contamination on pork. The impact of crosscontamination during transport, lairage, processing and distribution cannot be ignored and measures to diminish this would significantly reduce the dissemination of Salmonella in the chain and the consequent risk posed. A key finding was the considerable variation in the incidence of Salmonella on different sampling days and in different slaughter plants.
    • The ultra-rapid chilling of lamb carcasses

      McGeehin, Brian; Sheridan, James J.; Department of Agriculture, Food and the Marine (Teagasc, 1999-01)
      The practice in Irish commercial abattoirs is to chill lamb carcasses for a period of approximately 16 hours at 2 - 4°C, at which stage the core temperature of the carcass has reached 7°C. Chilling in this manner is considered necessary because it is generally held that faster chilling leads to toughening of the meat. The objective of this work was to develop a continuous ultra-rapid chilling system for lambs which would reduce carcass chilling time without adversely affecting the quality of the meat.
    • Up-grading of low value meats and by-products for use in consumer foods.

      Kenny, Tony; Desmond, Eoin; Ward, Patrick (Teagasc, 1999-02-01)
      The investigation was concerned with the up-grading of: (i) connective tissue material in the form of beef membrane, pig rind and turkey skin; (ii) muscle material from low-value cuts and from offals such as beef heart; (iii) heart muscle, by extrusion processing; (i) An emulsified material from beef membrane and beef replaced up to 5% of lean meat in corn beef and up to 10% in beefburgers without impairing cooked yield and eating quality. A collagen emulsion paste (CEP) from pig rind replaced up to 5% of lean meat in ham prepared from diced meat, and between 2 and 5% in ham prepared from whole muscles without reduction in cooked yield, texture, appearance and eating quality. Turkey skin was minced, chopped and incorporated at 10, 15 and 20% levels in a mix with turkey leg meat, which was used to make battered and breaded re-formed steaklets. Steaks containing up to 20% of emulsified skin were similar to control samples in flavour, juiciness and overall acceptability. An antioxidant may be required to prevent rancidity during frozen storage. (ii) Yields of surimi-like material, prepared by water-extraction, sieving and centrifuging, were 16% from lean of topside of beef (used as control for comparison), 39% from beef heart, 17% from pork mechanically recovered meat, 11% from beef weasand and less than 5% from beef cheek meat. The beef heart surimi was studied for its gelation properties and for its performance as an ingredient replacing lean meat in frankfurters and in beefburgers at levels between 3 and 15%. In frankfurters the addition of the surimi reduced cook loss and increased tenderness. For overall eating quality the frankfurters with 7 or 10% of surimi were preferable, and those with 15% equal, to those with none. In beefburgers cook loss was decreased from 32 to 25% by the addition of 15% surimi. Other results were similar to those for frankfurters, showing that the surimi could be added at 10 to 15% level without impairing texture or flavour. (iii) Cold extrusion processing of beef heart muscle with the aim of increasing its functionality showed that gelation properties of the material were not improved by extrusion compared to bowl chopping; moreover, the extruded product had a strong odour and dark colour.