• 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.
    • Upgrading the cold chain for consumer food products

      Gormley, Ronan T.; Brennan, Martine H.; Butler, Francis (Teagasc, 2000-12)
      The prepared consumer foods sector in Ireland is undergoing sustained dynamic growth. Products that are distributed chilled or frozen require a cold chain and there is potential to increase product quality by optimising the cold chain. This potential prompted the current study.
    • Use of Bacteriocins to Improve Cheese Quality and Safety

      Ross, R Paul; Hill, Colin; Ryan, Maire; Cunniffe, Alan; McAuliffe, Olivia; Murray, Deirdre; O'Keefe, Triona; Rea, Mary C. (Teagasc, 1998-09-01)
      The objectives of this project were to generate, characterise and exploit a range of novel bacteriocin producing starter cultures to improve both the safety and the quality of fermented dairy foods. The main conclusions were as follows: Lacticin 3147 is a broad spectrum bacteriocin which inhibits a wide range of Gram-positive bacteria including lactobacilli, clostridia and Listeria. The bacteriocin has been purified by chromatographic procedures and has been shown to be composed of two peptides, both of which are required for biological activity. The mechanism of action of lacticin 3147 has been elucidated. The entire plasmid encoding lacticin 3147 has been sequenced and the bacteriocin in distinct from any previously characterised lactococcal bacteriocin. The Food Grade introduction of the bacteriocin genes into cheese starters was carried out. Lacticin 3147 producing starters have been used to control the pathogen Listeria monocytogenes on the surface of mould ripened cheese. Lacticin 3147 producing starters have been used to control the non-starter lactic acid bacteria complement in Cheddar cheese during the ripening process. A novel starter system using a bacteriocin (lactococcin)- producing adjunct has been designed which gives increased cell lysis during Cheddar cheese manufacture while ensuring that efficient acid production is not compromised. In summary these studies have found that naturally occurring antimicrobials such as bacteriocins have a wide range of applications in the food industry for improving both the quality and safety of fermented dairy products.
    • The use of Cold Setting Whey Proteins to enhance the Gelation Properties of Foods.

      Keogh, Kieran; O'Kennedy, Brendan; Twomey, Myra (Teagasc, 1999-06-01)
      The main objective of this project was to produce dried, denatured, whey protein-based powders, which on reconstitution in food formulations show an increased ability to bind water in the presence of added salts, especially in the ambient temperature range. To achieve this, a number of secondary objectives were set to observe the behaviour of the whey protein system. These included the effects of salt on increases in viscosity during the heating process, the requirement for pH adjustment during processing and the ability of the pre-treated whey protein to interact with fat. The main conclusions were as follows: * It was shown that, compared to a commercial 75% whey protein concentrate, a preheated whey protein ingredient (cold-setting whey protein) improved the consistency of surimi and a cold-set dessert system. * For cold-setting applications, the whey proteins need to withstand heating without gel formation. For example, as the protein concentration was increased, the salt concentration had to be decreased and pH increased to prevent the initiation of gelling during processing. When the salt concentration was increased, a lower heat treatment was needed to prevent viscosity increase. However, lower heat treatment resulted in a lower degree of protein unfolding and weaker cold-set gels. This example implies that only certain whey sources are suitable starting materials for cold-set applications. * Model oil-in-water emulsions were studied using whey proteins pre-treated at different homogenisation and heating conditions to evaluate the potential of cold-setting whey proteins in yoghurt, mayonnaise and sauces. It was found that with these pretreatments, emulsion viscosity increases were observed at very low whey protein concentration (< 1%), when salt was added after emulsion formation, indicating that cold-set whey proteins are much more effective gelling agents than normal whey protein ingredients. For this reason, they have potential in acidified dairy products such as yoghurt. * Pre-heated whey protein dispersions are also capable of binding and stabilising calcium phosphate. This property can be exploited in the stabilisation of calcium-fortified milkbased beverages. * The commercial production of cold-setting whey protein ingredients will depend on the ability to retain whey protein solubility during processing. A number of mechanisms exist to achieve this but, in all cases, very exact control of the process is required. * Because low salt levels prevent the aggregation and gelling of denatured whey proteins, whey protein isolate is an ideal starting material for the production of these ingredients, but due to the high cost, de-mineralised whey was chosen instead as the starting material. Careful consideration has also to be given to the processing equipment and the economics involved. * The development of whey protein ingredients especially for cold-set end uses is a product specific exercise. General guidelines were developed in the current work, but further work with industry partners will be necessary before commercial success is achieved.
    • Using ultrasound to measure beef tenderness and fat content

      Allen, Paul; Dwyer, Catherine; Mullen, Anne Maria; Buckin, Vitaly; Smyth, Cormac; Morrissey, Siobhan (Teagasc, 2001-04)
      A new acoustical technique was developed for the quantitative analysis of the texture and composition of meat and meat products. This new approach exploits the fact that the acoustical velocity and attenuation of waves propagated through meat are affected by its mechanical properties, thus allowing characterisation in terms of its composition and eating quality. The method is based on a new high-resolution ultrasonic resonator. This technique is rapid and uses small samples. Procedures for the acoustical analysis of meat were developed and the results were correlated with taste panel and shear force measurements of meat tenderness.
    • Variation in the quality of meat from Irish steers at the time of slaughter.

      Moloney, Aidan P; Mullen, Anne Maria; Maher, S.C.; Buckley, D.J.; Kerry, Joseph P. (Teagasc, 01/01/2004)
      There is no information on the variation in quality, in particular tenderness, that exists in Irish Beef nor is there information on the variation that would remain if optimum practices were imposed at all stages of the beef production chain. Evaluation of the success of measures to improve beef consistency requires information on existing variation and the minimum variation achievable.The objectives of this project were (i) to establish the variation that exists in the quality of meat from Irish cattle, (ii) to quantify the minimum variation in meat quality that can be achieved in a practical beef production system, (iii) to determine the effects and mechanisms of additional sources of variation. The conclusions from this project are: • The M. longissimus dorsi (loin) was found to be more variable than the M. semimembranosus (topside) for most quality attributes examined (tenderness, sarcomere length and pH). The scale of variation within the loin was similar to that reported by the other research groups within the EU and US. Heifers were more variable than steers for most attributes, while there was no consistent classification effect on the variability of meat quality attributes. • Tenderness was equally variable in meat from genetically similar steers, managed similarly, compared to commercial steers randomly selected from a factory lairage but matched for weight and grade.This was likely a result of both groups being crossbred beef cattle of similar age, fat score, carcass weight and managed identically post-mortem. However, variation in tenderness of both groups was less than that observed in a survey of commercial throughput (experiment 1). This decrease is attributed to better pre-and-post-slaughter handling practices. • The data suggest that selection of sires (within a breed) with better than average conformation has no deleterious effect on the eating quality of beef of their progeny.A more comprehensive comparison of sires within a breed and between breeds is required to confirm the generality of this conclusion. • In a comparison of genotypes, gender and slaughter weights, there was no evidence that variation around the mean value for tenderness differed between breeds or liveweights after 14 days ageing. Bulls were more variable than steers for some quality traits but the variation in tenderness was similar for bulls and steers after 14 days ageing. • While optimising the management of animals during the pre and post-slaughter period reduced variation in tenderness, some residual variation remained. A large percentage of the residual variation in tenderness (Warner Bratzler shear force) after 2 and 7 days post-mortem was explained by proteolysis (breakdown of myofibrillar proteins).Variation in tenderness (Warner Bratzler shear force) after 2 days post-mortem was largely explained by phosphates (energy) and proteolysis, while sensory tenderness was largely explained by phosphates and glycolytic potential. • Further work is required to reduce residual variation in Irish beef and to determine the causes of this variation.
    • Very fast chilling in beef

      Troy, Declan J.; Joseph, Robin; European Union; AIR-CT94-1881 (Teagasc, 2001-07)
      Very fast chilling (VFC) of beef reduces the temperature to -1ºC after 5 hours post mortem throughout its mass. The process has many potential benefits (Joseph,1996) including the production of tender meat and greater process efficiency in the meat plant.
    • The virulence of E. coli 0157:H7 isolated from Irish sheep and pigs to humans

      Lenahan, Mary; Sheridan, James J.; O'Brien, Stephen (Teagasc, 2008-02)
      Investigations were carried out at five sheep and five pig export abattoirs situated in the Republic of Ireland to determine the prevalence of E. coli O157:H7 in these animals at slaughter. This is the first study for the presence of E. coli O157:H7 on sheep and pigs to be carried out in Ireland. Faeces and pre- and post-chill carcass swabs were collected from pigs over a one year period between January and December 2004. Samples were collected from sheep over a 13-month period between February 2005 and February 2006. The pig study recovered E. coli O157:H7 from 0.24 % (n=4) of 1680 porcine samples while the sheep study isolated the pathogen from 2.1 % (n=33) of 1600 ovine samples. PCR analysis of E. coli O157:H7 isolates determined that they carried the virulence genes vt1, vt2, eaeA and hlyA typically associated with clinical illness in humans. The results presented indicate that Irish sheep and pigs are reservoirs for E. coli O157:H7 which may be potentially harmful to humans.
    • Wheat flour properties and end product quality

      Dwyer, Elizabeth; O'Halloran, Grainne R.; Department of Agriculture, Food and the Marine (Teagasc, 1999-01)
      For pizza production, the flour quality values identified for the wheat cultivars, Promessa, Quintus (spring), and Soissons (winter) should be used as guidelines in selecting new cultivars and in the development of flour specifications. Similarly for biscuit production, compositional and rheological data for the cultivars, Riband,Woodstock (soft-milling) and Brigadier (hardmilling) should be used for identifying biscuit flours. The rheological properties of dough (as measured by the alveograph, extensograph and farinograph) did not relate to the baking quality for some wheat cultivars. However the rheological properties of the gel protein prepared from these flours explained their baking quality. The very high elastic moduli of these gels explained the basis of shrinkage of pizza bases produced from Baldus and Lavett flours and biscuits produced from Ritmo flour.