• The microbiological safety and quality of foods processed by the "sous vide" system as a method of commercial catering

      Bolton, Declan J. (Teagasc, Ballsbridge, Dublin 4, 1998-08)
      The objective of this project was to improve the quality and safety of sous vide foods by investigating the responses of the food-poisoning microorganisms to the processing and storage conditions used in this technology. The major food poisoning bacteria of concern in sous vide foods are strains of Clostridium botulinum, Bacillus cereus, verotoxigenic Escherichia coli O157:H7 (VTEC), Salmonella spp., Listeria monocytogenes and Yersinia enterocolitica.
    • Extending the shelf life of fresh sliced mushrooms

      Brennan, Martine H.; Gormley, Ronan T. (Teagasc, 1998-08)
      The Irish mushroom industry is expanding rapidly as is the demand for sliced mushrooms. To increase the competitiveness of Irish mushrooms for export their shelf life should be extended to compensate for the time lost in transit. The aim of this project was to extend the shelf life of sliced mushrooms by 50 % using novel processing treatments and / or packaging. A method was established to assess the effects of different treatments on mushroom quality. This method was followed using solutions of citric acid, hydrogen peroxide, EDTA, nisin, diacetyl, vitamin E, ascorbic acid, rosemary extracts and sodium metabisulphite.
    • Relating starch properties to boiled potato texture

      Gormley, Ronan T. (Teagasc, Ballsbridge, Dublin 4, 1998-08)
      Basic information on starch properties may help to explain the different textural characteristics of potato cultivars, and also their suitability for different forms of processing. The study involved tests on both raw potatoes, and on starch separated from potatoes, and embraced three main activities: (i) to relate boiled-potato texture with the other test variables; (ii) to develop a rapid crush-test for assessing cooked-potato texture; (iii) to study the effect of chilling and freezing on the development of resistant starch (RS) in boiled potatoes.
    • Control and detection of food-borne pathogens

      Duffy, Geraldine; Cloak, Orla; Sheridan, James J. (Teagasc, Ballsbridge, Dublin 4, 1998-08)
      The objective of this study was to develop rapid methods for the detection of bacteria from food.
    • The ultra-rapid chilling of lamb carcasses

      McGeehin, Brian; Sheridan, James J. (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.
    • Development of HACCP analysis systems for beef slaughter

      Doherty, Alice M.; McEvoy, John M.; Sheridan, James J.; McGuire, Liam; O'Sullivan, Marian (Teagasc, Ballsbridge, Dublin 4, 1999-01)
      The aim of this study was to establish the types and levels of bacterial contamination on beef carcasses slaughtered under commercial conditions. This information is necessary as baseline data for the implementation of a Hazard Analysis Critical Control Point (HACCP) plan in a meat factory. Samples were taken over a twelve month period from five carcass sites representing the fore and hind quarters of the carcass. These included the hock, bung, inside round, cranial back and brisket. The carcasses were sampled at different stages of dressing namely legging, hide removal, evisceration, carcass splitting, carcass washing and chilling (24 h later). Four meat cuts (inside round, outside round, chuck roll (cranial back) and brisket) were also sampled after boning. Counts were enumerated for the following groups of bacteria: total bacterial counts (25°C and 4°C); pseudomonad counts (25°C and 4°C); E nterobacteriaceae counts; E scherichia coli O157:H7 and L isteria spp.
    • Wheat flour properties and end product quality

      Dwyer, Elizabeth; O'Halloran, Grainne R. (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.
    • Escherichia coli 0157:H7: implications for HACCP on the farm and in the abattoir

      Bolton, Declan J.; Byrne, Catriona; Sheridan, James J.; Riordan, Denise C. (Teagasc, 1999-01)
      Experiments were designed to assess the risks associated with Escherichia coli O157:H7 on the farm, through the abattoir and into the butcher shop. Data was also generated for application in model building and the reliability of pathogen models for predicting pathogen growth in different foods was examined.
    • Enhancing the tenderness of beef

      Troy, Declan J. (Teagasc, 1999-02)
      This project investigated various methods which had potential to increase beef tenderness and was also aimed at elucidating the biochemical mechanism underlying the improved tenderness.
    • Up-grading of low value meats and by-products for use in consumer foods

      Kenny, Tony; Desmond, Eoin; Ward, Patrick (Teagasc, 1999-02)
      Animal offals can be divided into (1) edible offals and by-products including fats, blood, and low-grade trimmings such as poultry skin and pork hock meat; (2) extracts from edible offals for use as ingredients in food products; (3) inedible offals; (4) hides and skins; (5) raw materials for extraction of pharmaceuticals or chemicals; (6) raw materials for sundry by-products.
    • Methods for veterinary drug residue analysis in food

      O'Keeffe, Michael (Teagasc, 1999-02)
      A comprehensive capability to test for residues of veterinary drugs is an important support for the Irish food industry. There is a requirement for food manufacturers to demonstrate the compliance of their products with stringent customer specifications. In addition, legislative requirements are becoming more exacting both in terms of the range of substances covered and the lower residue levels to which test systems must measure.
    • New technologies in the manufacture of low fat meat products

      Allen, Paul; Dreeling, Niamh; Desmond, Eoin; Hughes, Eimear; Mullen, Anne Maria; Troy, Declan J. (Teagasc, 1999-02)
      The objective of this project was to provide a sound scientific basis for the development of low fat meat products. The emphasis was placed on identifying the barriers to producing high quality, low fat meat products and providing a knowledge base for manufacturers to overcome these, rather than actually developing new products. Each partner had specific tasks and worked with traditional products of their country. A wide range of products was thereby studied including comminuted, emulsion, cured and dried fermented, so that the results are widely applicable.
    • Biochemical and physical indicators of beef quality

      Troy, Declan J. (Teagasc, 1999-03)
      Beef of a consistent quality is required by the meat industry in order to maintain and expand markets. Measurement of beef quality is difficult at factory level. Measurements to indicate the final eating quality are not well developed yet. This project examined novel approaches to this problem using biochemical and physical methods. The Biochemical indicators of beef quality examined included: pH , Protease activity as a potential indicator of meat tenderness, Cathepsin B and cathepsin B&L activities in relation to beef ageing, Relationship between cathepsin B and cathepsin B&L activity and WBSF values, Protein fragments as an indication of beef tenderness and Myofibrillar proteins. The Physical indicators of beef quality examined included: Post-mortem changes in muscle electrical properties and their relationship to meat quality attributes, Near infrared reflectance spectra as indicators of beef quality, Shear force as an indicator of tenderness.
    • Protein-bound veterinary drug residues in food

      O'Keeffe, Michael; Horne, Elizabeth; Cadogan, Aodhmar; Coyle, Tiernan (Teagasc, 1999-03)
      Bound residues of veterinary drugs have been recognised as an important aspect of food safety particularly (a) where such residues may persist for long periods after withdrawal of the drug treatment and (b) where the bound residues may be released, during digestion of edible tissues, in biologically active forms. Residues bound to proteins are not extractable by the conventional solvent extraction procedures for residue determination. Procedures for the release of bound residues from proteins, identification of their chemical structure, and determination of the amount of bound residues in edible tissues are required.
    • Near infra-red spectroscopy in the food industry: a tool for quality management

      Downey, Gerard (Teagasc, 1999-03)
      Near infrared (NIR) spectroscopy is a rapid, non-destructive analytical technique which has been used in the food and agriculture industries for almost 20 years. Ireland was one of the first countries in the world to adopt this method for national trading purposes and the grain trade has used it for off-farm and in-process analysis since 1981. However, other sectors have been slower to realise its potential and as part of a process of demonstrating the role which it may play in monitoring quality in a range of food industry applications, a programme of research and development has been on-going within Teagasc and its predecessor An Foras Talúntais.
    • Development of a novel bulk packaging system for retail cuts of meat

      Allen, Paul; Doherty, Alice M.; Isdell, Emer (Teagasc, 1999-03)
      Meat colour is an important criterion in the appeal of meat to consumers at the point of sale. The bright red colour of fresh beef and lamb and the pinkish colour of fresh pork are due to the oxygenation of the myoglobin pigment when the meat is exposed to air. However, exposure to air over several days causes irreversible browning and rejection of the meat by consumers. The gaseous environment in which retail cuts are stored is therefore critical to ensure a good colour over the display life. Existing packaging systems do not have a sufficiently long storage life for the additional time required for exports from Ireland to the UK or continental Europe. The objective of this project was to develop a bulk packaging system for retail cuts that would have a sufficient shelf life to be used by the Irish industry to export retail ready cuts. In conclusion, a packaging system has been developed on a laboratory scale which is capable of extending the storage life of some beef cuts, lamb loin chops and pork loin chops. The display life of these after storage is comparable to fresh cuts. In order for this system to be commercialised it would have to be shown to work on a larger scale in a production environment.
    • The quality of under-utilised deep-water fish species

      Brennan, Martine H.; Gormley, Ronan T. (Teagasc, 1999-09)
      The quality of twenty-three frozen under-utilised fish species was examined. The species were spot samples of deep-water fish caught near the Rockall Trough by the Fisheries Research Centre. Their basic composition was 80.8 - 86.4% water, 9.8 - 25.2% protein, 0.18 - 16.2% lipid and 0.7 - 2.0% ash. Lead, cadmium and mercury concentrations were determined for six species and were much lower than the maximum levels set in 1992. Ammonia levels were unacceptably high in three shark species.
    • Development of a critical control step for E.coli 0157:H7 in pepperoni

      Duffy, Geraldine; Riordan, Denise C.; Sheridan, James J. (Teagasc, 1999-10)
      Verocytotoxin producing Escherichia coli (VTEC) and particularly strains of serogroup O157, have emerged as food poisoning pathogens which can cause a severe and potentially fatal illness. The symptoms of VTEC infection include haemorrhagic colitis with bloody diarrhoea and severe abdominal pain. The infection may lead to renal failure as a result of haemolytic uraemic syndrome. Because of the severity of the illness and the low infectious dose, this pathogen is classed as a serious food safety issue. It is recommended by the United States Department of Agriculture that the production process for ready to eat foods such as fermented meats (pepperoni, salami etc.) should be capable of addressing a worst case scenario ie. the production process should be able to yield a log105.0cfu /g (105 cfu/g) reduction in numbers of E. coli O157:H7 on the raw meat. The aim of this study was to develop an industrially viable critical control step(s) which could be implemented into the pepperoni production process.
    • Supercritical fluid extraction of veterinary drug residues from meat

      O'Keeffe, Mandy J.; O'Keeffe, Michael (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.
    • Enzyme Modified Cheese Flavour Ingredients

      Wilkinson, M.; Kilcawley, Kieran; Mulholland, E. (Teagasc, 2000-09-01)
      Enzyme-modified cheeses (EMCs) are defined as concentrated cheese flavours produced enzymatically from cheeses of various ages and are principally used as an ingredient in processed foods, where they provide a cost-effective alternative to natural cheese. They can be used as the sole source of cheese flavour to intensify an existing cheese taste, or to impart a specific cheese character to a more bland product. Their main applications are in processed cheese, analogue cheese, cheese spreads, snack foods, soups, sauces, biscuits, dips and pet foods. Their main advantages over other cheese flavour ingredients are: low production costs, consistency, high flavour intensity, diverse flavour range, extended shelf- life, low storage costs and increased functionality. EMCs are generated utilising the same flavour pathways that occur in natural cheese ripening i.e. proteolysis, lipolysis and glycolysis. They are not as easy to differentiate as natural cheeses, as they are characterised by flavour and aroma alone as texture is not a factor in EMC production. The relationship of the flavour of EMCs to the flavour of the corresponding natural cheese remains unclear. This is especially true for Cheddar EMC which is commercially available in a range of Cheddar flavours . Despite the fact that a wide range of commercial EMCs are available, there is very little detailed information available regarding their properties or the specific production processes used. The main objective of this research was to build a knowledge base on EMC products and to utilise this to develop a biotechnological process for the production of improved enzyme modified cheeses for use as flavour ingredients. The strategy was to establish quantitative relationships between the compositional, proteolytic and lipolytic parameters and the sensory characteristics of EMCs. This data would then be used to develop a predictive model for flavour development in EMC production and the subsequent generation of an optimised EMC process enabling the generation of a range of cheese flavours from single or multiple substrates.