• Biochemical and Functional Relationships in Cheese.

      Guinee, Timothy P.; Fox, P.F.; Fenney, E.P; Mullins, C.; Corcoran, M.O.; Mulholland, E.; Auty, Mark (Teagasc, 2001-01-01)
      Cheese is used extensively in cooking applications, mainly because of its flavour and heat-induced functionality, which is a composite of different attributes such as softening, flow and stretch. The functional attributes of cooked cheese generally have a major impact on the quality of foods in which cheese is included as an ingredient, e.g. pizza pie. Owing to its importance in cookery applications, numerous studies have been undertaken on the effects of different factors on the age-related changes in the functionality of cooked cheese, especially Mozzarella, and to a lesser extent, Cheddar and processed cheese. These studies have shown that the functionality of natural cheese is dynamic, with the different functional attributes undergoing marked changes during ripening, and, for a given cheese variety, the desired functional attributes are optimum within a specific time frame during maturation. The time at which the cheese becomes functional and the width of the window - and hence the functional shelf-life, are affected by the extent of chemical changes, including the increase in proteolysis and the ratio of bound to free moisture. The main aims of this project were to investigate the effects of the following on the age-related changes in heat-related functional attributes (e.g. stretchability, fluidity) of cheese: * fat reduction, * the degree of fat emulsification, * the pH and calcium content and their interaction, * the correlation between proteolysis and functional attributes, especially attributes other than flowability, e.g. rheological properties of raw cheese, stretchability of heated cheese, and * the age-related changes in the functionality of cheeses other than Mozzarella, e.g. analogue pizza cheese and Emmental. At the outset of this project, comparatively little information was available on the effects of the above parameters on the age-related changes in heatinduced functional attributes (e.g. stretchability, fluidity) of cheese, especially for varieties other than Mozzarella.
    • 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.
    • Coffee-Stability of Agglomerated Whole Milk Powder and other Dairy Creamer Emulsions

      Kelly, Philip M.; Oldfield, D.J.; Teehan, C.M. (Teagasc, 1999-02-01)
      The objectives of this project were: (a) to investigate the circumstances that cause milk powders and creamers to fail when added to coffee based beverages; (b) to evaluate the role of processing variables in relation to their thermostabilising effects on milk during drying of coffee whiteners; and (c) to determine the role of emulsion formation on the stability of imitation creamers.
    • Commercial systems for ultra-rapid chilling of lamb

      Redmond, Grainne; McGeehin, Brian; Henchion, Maeve; Sheridan, James J.; Troy, Declan J.; Cowan, Cathal; Butler, Francis (Teagasc, 2001-08)
      The overall objective was to devise a rapid chilling system for the Irish lamb processing industry. The objective of the first trial was to assess the effect of ultra-rapid chilling in air at - 4ºC, -10ºC and -20ºC and subsequent ageing on the appearance and tenderness of lamb carcasses. The objective of the next trial was to investigate the effect of carcass splitting, which produces faster chilling rates and reduces skeletal constraint of muscles, on the tenderness of rapidly and conventionally chilled lamb. The next task was to compare the effects of immersion chilling and conventional air chilling on meat tenderness and evaporative weight loss in lamb carcasses. The next task was to assess the level of interest in industry. This required costings of the process and a survey of several lamb processors focusing on their perceptions of rapid chilling in general, its advantages and disadvantages, and the implications of adopting the new system. The final objective was to introduce the ultra-rapid chilling process to industry via a factory trial. Lambs were ultra-rapidly chilled and then exported to France for assessment.
    • The competitiveness of the Irish food processing industry

      Pitts, Eamonn; O'Connell, Larry; McCarthy, B. (Teagasc, 2001-07)
      Ways of measuring industrial competitiveness are discussed and an analysis of the competitiveness of the food sector as a whole and of three sub-sectors are presented. The techniques employed were Revealed Comparative Advantage and the Porter Diamond.
    • Contamination of Beef Carcasses during Hide Removal and use of a Test Bacterial Decontamination System on Beef Hide

      McEvoy, John M.; Doherty, Alice M.; Sheridan, James J.; McGuire, Liam (Teagasc, 2000-12)
      In Ireland, the Abattoirs Act, 1988 (Veterinary Examination) (Amendment), 1998 (S.I. No. 6, 1998) empowers the ante mortem veterinary inspector to reject animals for slaughter or require slaughter under special conditions, based on the level of visible hide contamination. Special conditions for slaughter include reduced line speed, increased space between animals and increased use of workstation hygiene facilities. Since their introduction in Ireland, cattle regulations have become more stringent and at present, both category 4 and 5 animals are rejected. However, a procedure for shaving accumulated hardened faeces (faecal clods) from category 4 and 5 animals has been introduced into most abattoirs, enabling them to reach the cleanliness standard. The potential risk of pathogens surviving in faecal clods on the hide of animals at slaughter is not known. This study examined: 1. The relationship between livestock cleanliness categories and the amount of contamination on the resultant carcasses. 2. The difference in bacterial contamination on carcasses from category 4 animals dressed without increased use of workstation hygiene facilities and those dressed with increased use of hygiene facilities. 3. The survival of E. coli O157:H7 in faecal clods
    • Control and detection of food-borne pathogens

      Duffy, Geraldine; Cloak, Orla; Sheridan, James J.; Department of Agriculture, Food and the Marine, Ireland (Teagasc, Ballsbridge, Dublin 4, 1998-08)
      The objective of this study was to develop rapid methods for the detection of bacteria from food.
    • Control of Blown Pack Spoilage in Vacuum Packaged Meat

      Bolton, Declan J.; Moschonas, Galatios; Sheridan, James J.; Downey, Gerard; National Development Plan (Teagasc, 01/10/2009)
      Blown pack spoilage (BPS) represents a significant commercial loss to Irish meat processors. This research discovered that the organisms causing BPS are ubiquitous in the abattoir environment, making eradication very difficult. The risk of BPS is best managed through a process of regular treatment of plant and equipment with a sporicidal agent such as peroxyacetic acid, good hygiene to minimise carcass contamination and removal of the heat shrinkage stage during vacuum packaging as this activates the spores and reduces the time to spoilage.
    • Control of Cheese Microflora using Bacteriocins.

      Ross, R Paul; Hill, Colin; O'Keeffe, T.; McAuliffe, Olivia; Ryan, Maire; O'Connor, Paula M.; Freyne, T. (Teagasc, 2001-08-01)
      Bacteriocins are proteins, produced by some bacteria which are capable of inhibiting other bacteria. The overall aim of this project was the development and exploitation of bacteriocins such as Lacticin 3147 (produced by a food-grade microorganism), as biological tools to control the microflora of foods. Lacticin 3147-producing strains were evaluated for their ability to improve the microbial quality of a variety of dairy products and in particular, Cheddar cheese. The manipulation of cheese flora using bacteriocins should offer manufacturers greater control in the consistency and quality of the final product, in addition to improving its safety. In concert with these studies, Lacticin 3147 was studied in detail at the molecular level resulting in its biochemical and genetic analysis. These studies have demonstrated the complexity and uniqueness of this potent antimicrobial.
    • Control of escherichia coli 0157:H7 in beefburgers

      Bolton, Declan J.; Byrne, Catriona; Catarame, Terese; Sheridan, James J. (Teagasc, 2001-04)
      The inactivation of E. coli O157:H7 by heating, freezing, pulsed electric field, sodium lactate, lactic acid and citric acid, alone or in combination was investigated. The industrial process for beefburger manufacture did not significantly reduce E.coli O157:H7 numbers regardless of the burger recipe and method of tempering used. Fast freezing of the burgers (to -18°C in 30 minutes as opposed to 36 hours), pulsed electric field, sodium lactate, lactic acid and citric acid, individually and in combination, did not significantly reduce E. coli O157:H7 numbers when applied at different stages throughout the beef burger manufacturing process. Beefburger safety is therefore reliant on proper storage, handling and thermal processing in the domestic or catering kitchen. The lethal effect of thermal processing may be enhanced by the addition of sodium lactate to the burger during mixing. These results are presented and discussed.
    • Current food safety priorities : report on the European Union risk analysis information network (EU - RAIN)

      Maunsell, Bláithín; Bolton, Declan J.; Downey, Gerard (Teagasc, 2006-04)
      An estimated 10 to 30% of the population in industrialised countries suffers food-borne illness annually, resulting in an unacceptable social (human suffering) and economic (health care and lost working days) cost. Risk analysis, a proactive preventative approach to food safety, was the focus of the European Union Risk Analysis Information Network (EU-RAIN) concerted action project. Funded by the European Commission, this project commenced in March 2003 and concluded in February 2006.
    • Dairy Ingredients for Chocolate and Confectionery Products.

      Keogh, M.K.; Twomey, Myra; O'Kennedy, Brendan; Auty, Mark; Kennedy, R.; O'Keeffe, James; Kelleher, Colin T (Teagasc, 2001-05-01)
      High free-fat, spray-dried powders were successfully produced at a lower fat content (40% rather than 56%) using ultrafiltration. Chocolates made from these powders had improved flow properties and superior quality. The stability, viscosity and firmness of toffees were improved by optimising the casein, whey protein and lactose levels of skim milk powders used in their manufacture.
    • Dairy Ingredients for the Baking Industry.

      Keogh, M.K.; Neville, Denis P.; Stanton, Catherine; Auty, Mark; Kennedy, R.; Arendt, Elke (Teagasc, 2001-08-01)
      Shortenings (baking fats), microencapsulated using dairy ingredients and milk protein hydrolysates, were produced for testing in a variety of baked products. The powders were evaluated for their functionality as powdered baking fats, as potential replacers of synthetic emulsifiers, as ingredients capable of improving baking performance or as potential health-enhancing ingredients. These studies provide the technology for the dairy industry to enter the specialised food ingredients sector with a siftable, non-greasy, free-flowing powdered fat for the baking industry.
    • Dairy Ingredients in Chocolate

      Keogh, M.K.; O'Kennedy, Brendan; Twomey, Myra; O'Brien, Nora M.; Kennedy, B.; Gorry, C. (Teagasc, 1998-09-01)
      The main objective was to assess and control the contribution of various ingredient components to chocolate behaviour and to optimise ingredients for specific chocolate applications. A key aim, therefore, was to understand the role of composition and particle structure and to produce spray dried powders with a functionality in chocolate as close as possible to roller dried powders. By demonstrating how the powder properties affect chocolate, it should be possible to control the functional properties of the powders to meet any powder or chocolate specification. Novel powder compositions indicated by this work should also be useful to chocolate makers. The ability to make chocolate under test conditions and to assess the role of milk powders or other ingredients has been put in place for the first time in Ireland. Previous knowledge of milk seasonality and of powder technology has provided a basis for understanding variations in milk powder functionality in chocolate. Spray dried powders with mean free fat values of 50 to 94%, particle sizes of 30 to 65 mm and vacuole volumes of 0.0 to 3.9 ml/100g were produced from milks of varying composition but under the same processing conditions. Advances were made in analysing powder structure through microscopy, particle size and occluded air measurement. Valuable new information has been generated on the changes in free fat, solid fat content, particle size and occluded air in powders. Explanations were provided for the first time for the complex effects of these properties on chocolate viscosity and yield value. This information will also make a positive contribution to other projects in the milk powder area. Good contacts have been established with multinational manufacturers and with producers of milk powder for chocolate.
    • Developing sous vide/freezing systems for ready-meal components

      Tansey, Fergal; Gormley, Ronan T.; Carbonell, Serge; Oliveira, Jorge; Bourke, Paula; O'Beirne, David; Department of Agriculture, Food and the Marine (Teagasc, 2005-04)
      Sous vide cooking involves sealing raw or par-cooked food in a vacuumised laminated plastic pouch or container, cooking by controlled heating, rapid chilling and then re-heating for consumption. The chilled storage period is up to 21 days at 0 to 3oC. The recommended thermal process for sous vide products is 90oC for 10min or its time-temperature equivalent. Concerns about the safety of sous vide products, mainly due to the potential for temperature abuse in the chill chain, has prevented the widespread use of this technology. The role of the current project, therefore, was to investigate sous vide cooking followed by freezing, as a safe alternative to sous vide/chilling for 10 ready-meal components i.e. carbohydrates (potatoes, pasta, rice), vegetables (carrots, broccoli) and muscle foods (salmon, cod, chicken, beef and lamb).
    • Developing Sous Vide/Freezing Systems for Ready-Meal omponents

      Tansey, Fergal; Gormley, Ronan T.; Carbonell, Serge; Oliveira, Jorge; Bourke, Paula; O'Beirne, David (Teagasc, 01/04/2005)
      Sous vide cooking involves sealing raw or par-cooked food in a vacuumised laminated plastic pouch or container, cooking by controlled heating, rapid chilling and then re-heating for consumption. The chilled storage period is up to 21 days at 0 to 3oC. The recommended thermal process for sous vide products is 90oC for 10min or its time-temperature equivalent. Concerns about the safety of sous vide products, mainly due to the potential for temperature abuse in the chill chain, has prevented the widespread use of this technology. The role of the current project, therefore, was to investigate sous vide cooking followed by freezing, as a safe alternative to sous vide/chilling for 10 ready-meal components i.e. carbohydrates (potatoes, pasta, rice), vegetables (carrots, broccoli) and muscle foods (salmon, cod, chicken, beef and lamb).
    • Development and Application of Strategies to Generate Bacteriophage Resistant Strains for Use in Milk Fermentation Processes

      Ross, R Paul; Fitzgerald, Gerald F; Coffey, Aidan; Coakley, M.; O'Sullivan, Daniel (Teagasc, 1999-02-01)
      The objectives of this project were firstly, the identification of natural phage resistance systems for exploitation, secondly, the development of methodologies to utilise these systems to improve the bacteriophage resistance of starter strains for use in milk fermentation processes, and thirdly, the actual application of these methodologies to improving starter strains. The main conclusions were as follows: Three new natural plasmid (DNA)-associated bacteriophage resistance systems were identified at Moorepark. The detailed genetic makeup of the phage resistance plasmid (pMRC01) was elucidated. Bacteriophages currently evolving in the industrial cheese-making environment were monitored to facilitate the judicious choice of phage resistance systems for use in commercial starter cultures which can more effectively target the documented problematic phage types. Two highly virulent phages targeting important cheese starters were identified in the industrial cheese-making environment. A reliable food-grade method to facilitate the transfer of phage resistance systems to cheese-making starter strains was developed. This is based on bacteriocin immunity-linked phage resistance. Phage resistant cheese starter cultures were developed through natural selection and by molecular manipulation using phage resistance plasmids. The phage resistance plasmid pMRC01 was introduced to 31 cheese starter strains.
    • Development and Evaluation of Caseins/Caseinates for use as Ingredients in Food Products

      Mehra, Raj; Walsh, Daniel; O'Kennedy, Brendan; Kelly, Philip M. (Teagasc, 1998-09-01)
      The overall objective of this project was to investigate the effects of key processing steps in the industrial production of acid casein on the characteristics and functionality of sodium caseinate with particular emphasis on analytical/functionality testing and seasonal/lactational effects on the original milk. The main conclusions were as follows: The most significant result indicates that drying and concentration after washing of the acid casein curd are responsible for alterations in the structure of casein, which result in sodium caseinates with different properties. This was confirmed in the case of two acid casein plants investigated which showed similar results even though using different washing and drying technologies. This difference due to the drying step may be further amplified depending upon whether commercial sodium caseinate is manufactured from acid casein in the dried or wet curd state. The analytical and functional testing methodology adapted in our laboratory proved effective in predicting the effects of processing steps on the functionality of sodium caseinate. In particular, the ability to detect the presence of aggregate formation was particularly important. The database generated subsequently helped an acid casein manufacturer in modifying its process(es) to manufacture experimental sodium caseinate for specific food end-uses. Progress was greatly facilitated by the collaboration of individual manufacturers in the sourcing of problem samples from previously manufactured codes, and facilitating access to process plant during production. In a commercial application of the database, confidential work was undertaken on behalf of a client. Experimentally-produced sodium caseinate ingredients were evaluated using our adapted functionality testing methods and based on the results, the company was able to modify its process(es) to produce sodium caseinates with functionality for specific food end-users. It was concluded that while processing parameters in the production of acid casein can have a significant effect on the functional behaviour of the resultant sodium caseinate, the ability to assess this change in functional behaviour, through relevant functional testing, was equally important.
    • The development and/or validation of novel intervention technologies to assure meat food safety

      Bolton, Declan J.; Byrne, Brian; Lyng, James G. (Teagasc, 2007-02)
      This project was undertaken to fill some of the knowledge gaps in meat food safety from farm to fork. The data provide the scientific basis for a clean sheep policy to reduce the impact of fleece as a source of microbial contamination on ovine carcasses at the beginning of the slaughter process. At the other end of the slaughter-line, a polyurethane sponge swabbing technology was developed for ovine and bovine carcass sampling as required in 2001/471/EC and the new European Commission Hygiene Regulations. At the processing stages, studies were undertaken to determine the most effective media for the recovery and culture of Cl. perfringens cells and spores; the results were then applied to thermal inactivation studies on these bacteria. Thermal resistance data were also obtained for Bacillus cereus and a radio frequency cook for meat products was validated in terms of the destruction of Cl. perfringens and B. cereus cells and spores. Finally, an aerobiology study investigated the effectiveness of a range on measures to prevent air acting as a vector for bacterial dispersion in a meat processing plant.
    • The Development and/or Validation of Novel Intervention Technologies to Assure Meat Food Safety

      Bolton, Declan J.; Byrne, Brian; Lyng, James G.; Downey, Gerard; Department of Agriculture, Food and the Marine, Ireland; Food Safety Authority of Ireland (Teagasc, 01/02/2007)
      This project was undertaken to fill some of the knowledge gaps in meat food safety from farm to fork. The data provide the scientific basis for a clean sheep policy to reduce the impact of fleece as a source of microbial contamination on ovine carcasses at the beginning of the slaughter process. At the other end of the slaughter-line, a polyurethane sponge swabbing technology was developed for ovine and bovine carcass sampling as required in 2001/471/EC and the new European Commission Hygiene Regulations. At the processing stages, studies were undertaken to determine the most effective media for the recovery and culture of Cl. perfringens cells and spores; the results were then applied to thermal inactivation studies on these bacteria. Thermal resistance data were also obtained for Bacillus cereus and a radio frequency cook for meat products was validated in terms of the destruction of Cl. perfringens and B. cereus cells and spores. Finally, an aerobiology study investigated the effectiveness of a range on measures to prevent air acting as a vector for bacterial dispersion in a meat processing plant.