• Development of HACCP analysis systems for beef slaughter

      Doherty, Alice M.; McEvoy, John M.; Sheridan, James J.; McGuire, Liam; O'Sullivan, Marian; Department of Agriculture, Food and the Marine, Ireland (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.
    • Development of Organic Breads and Confectionery

      Gallagher, Eimear; Keehan, Denise; Butler, Francis; Downey, Gerard (Teagasc, 01/07/2005)
      In recent years, concern for the environment and consumer dissatisfaction with conventional food has led to growing interest in organic farming and food. The demand has also been fuelled by highly-publicised food scares. Food safety and genetic modification issues have led some consumers to opt for organic food as a safer alternative. Recently, there has been a significant increase in the number of launches of organic bakery products in Ireland. As a result, there is an increased need to identify suitable organic bakery ingredients for use in bread and confectionery formulations. However, only a limited number of scientific studies on the physical, chemical and functional properties of organic flours and ingredients exist. The effects of commonly-used ingredients in baking, i.e. organic improvers and fats, on the baking characteristics of organic products have not yet been reported and little is known about the influence of approved additives that may be beneficial to organic baking. Arising from these gaps in the knowledge base on the use of organic flours and ingredients, the objective of this study was to evaluate the chemical, rheological and baking characteristics of white, wholemeal and confectionery organic flours and to assess the baking potential of organic bakery ingredients, in particular improvers, fats and additives. Ingredients and baked goods were compared to non-organic controls.
    • Development of organic breads and confectionery

      Gallagher, Eimear; Keehan, Denise; Butler, Francis (Teagasc, 2005-07)
      Recently, there has been a significant increase in the number of launches of organic bakery products in Ireland. As a result, there is an increased need to identify suitable organic bakery ingredients for use in bread and confectionery formulations. However, only a limited number of scientific studies on the physical, chemical and functional properties of organic flours and ingredients exist. The effects of commonly-used ingredients in baking, i.e. organic improvers and fats, on the baking characteristics of organic products have not yet been reported and little is known about the influence of approved additives that may be beneficial to organic baking. Arising from these gaps in the knowledge base on the use of organic flours and ingredients, the objective of this study was to evaluate the chemical, rheological and baking characteristics of white, wholemeal and confectionery organic flours and to assess the baking potential of organic bakery ingredients, in particular improvers, fats and additives. Ingredients and baked goods were compared to non-organic controls.
    • Development of Technologies for Separation and Functional Improvement of Individual Milk Protein Fractions

      Stanton, Catherine; Fitzgerald, Richard J.; Donnelly, W.J.; O'Connor, Paula M. (Teagasc, 1999-02-01)
      Milk proteins can be hydrolysed (i.e. fragmented) using proteolytic enzymes to give enhanced functional and nutritional properties. There is an increasing demand for hydrolysed protein ingredients with specific properties for nutrition of individuals with specialised dietary requirements including infants, the critically ill, the immuno-compromised and athletes. Such hydrolysed proteins can be specifically designed to provide distinctive tailor-made solutions to meet customer needs in these areas. This project explored the technologies for the production of two types of hydrolysates i.e. acid-soluble and glutamine-rich. Acid-soluble protein hydrolysates have potential in the fortification of acidic beverages, including soft drinks. Glutamine-rich hydrolysates are suggested as an optimal glutamine source for administration during periods of stress, such as recovery from strenuous exercise, or from surgery. Casein was selected as the protein for development of acid-soluble product and cereal protein for the glutamine-rich product. The main conclusions were as follows: A number of protein hydrolysate products with value added properties and the processes required for their manufacture have been developed and are available for uptake by the food industry. Laboratory investigations identified conditions for the generation of two casein hydrolysates with desirable functional properties. Scale-up conditions for the manufacture of these hydrolysates in the pilot plant were successfully developed. Both hydrolystates were 100% soluble at pH 4.6, exhibited clarity in solution at low pH in clear soft drinks and in caramelised beverages and were stable in solution over a wide temperature range (from 4 to 30ºC) for extended periods. Solutions containing these hydrolysates exhibited no foaming properties and had acceptable sensory properties, being considered as weakly bitter compared to unsupplemented solutions. These performance characteristics make the acid-soluble hydrolysates useful supplements for caramelised beverages, such as colas, and clear soft drinks. Six glutamine-enriched peptide products were produced at laboratory scale using two commercially available enzyme preparations. These products had desirable characteristics such as increased levels of peptide bound glutamine, low free amino acid and free pyroglutamate levels. Pilot plant processes were developed for manufacture of the two glutamine-rich hydrolysates with most suitable compositional properties and these were fully characterised chemically. The manufacturing process was modified to enable industrial scale batches (5,000 litres) to be produced.
    • Development of value-added beef products

      Desmond, Eoin; Troy, Declan J.; Kenny, Tony; McDonagh, Ciara; Ward, Patrick (Teagasc, 2001-05)
      This work investigated technologies to improve the functionality of beef, particularly low-value beef to increase its versatility for the development of value-added restructured and emulsion type beef products. More specifically the project objectives were (1) to increase the functionality of beef; (2) to develop innovative beef products; (3) to increase the use of low-value carcass cuts as a functional ingredient in beef products. The research was carried out in three stages: solubilisation of connective tissue components of beef using organic acids, application of proteases to beef model systems to increase functionality, and physical disruption of connective tissue in beef by mechanical treatments such as needle and blade tenderising, tumbling and massaging.
    • Effect of Milk Composition on the Quality of Fresh Fermented Dairy Products

      Wilkinson, M.G.; Guinee, Timothy P.; Fenelon, Mark A. (Teagasc, 2000-09-01)
      The rheology of yogurts or fresh fermented products generally describes and measures the texture of the product and includes such terms as viscosity and firmness of the gel while syneresis refers to the tendency of the yogurt to whey-off during storage. The importance of rheology and susceptibility to syneresis of fermented milk products is that they both have major impacts on consumer perceptions of the final product quality. Indeed, variation in the quality of yogurt products can lead the consumer to experience either an over-thin watery or an over-thick stodgy texture or a product which has a high level of free whey. It is obvious that the seasonal milk supply in Ireland compounds the particular difficulties associated with achieving a consistency in the quality of yogurts or other fresh fermented products. Importantly, both the rheology and syneresis of yogurts are markedly influenced by milk composition, processing treatments and the addition of hydrocolloids. Therefore, this project was undertaken so as to develop a laboratory fermented milks model system which allows the evaluation of the effects of variation of milk components, individually or in combination, on the rheological and syneretic properties of fermented milk products such as yogurt. In particular, the effects of varying total protein, casein-to-whey protein ratio, and fat content were studied as these variations reflect both the differences in milk composition due to lactational/seasonal effects and those due to process variations such as milk heat treatment.
    • The Effect of Nutrition on the Flavour of Strawberries Grown Under Protection.

      MacNaeidhe, F. S. (Teagasc, 2001-07-01)
      The superior flavour of strawberries grown in the brown earth soils in Ireland compared with those grown on podsolics derived from calcium rich chalk has been recognised by UK wholesalers for some time. The strawberry variety Elsanta is the most common variety grown in both regions and it is reasonable to conclude that environmental factors especially soil type are mainly responsible for the superior flavour of strawberries grown on brown earth soils. The differences in soil pH, calcium and potassium concentrations were used as the main basis in drafting a research project investigating the effect of nutrition on the flavour of strawberries. A research project on the effect of nutrition on the flavour of strawberries under protection was undertaken at Clonroche in 1997.
    • The Effects of Processing and Ripening on the Quality of Pizza Cheese

      Guinee, Timothy P.; Mulholland, E.; Mullins, C.; Corcoran, M.O.; Auty, Mark (Teagasc, 1999-02-01)
      The main aims of this project were to quantify the changes in fuctionality during maturation of cheese and to develop an understanding of the factors which mediate the development of functionality. The approach to achieving these objectives involved the establishment of a suitable pilot plant production procedure for low moisture Mozzarella, developing and/or adapting existing methods for objective evaluation of the functional properties of pizza cheeses, and evaluating the effects of ripening and variations in cheesemaking conditions (e.g. pH at stretching) on the composition, yield and functionality of low moisture Mozzarella cheese. The main conclusions were as follows: The technology for developing low moisture Mozzarella cheeses, with different compositions and functionalities, via alteration of cheesemaking parameters, has been developed. A database has been established on the storage-related changes that occur in texture, proteolysis and functionality of low moisture Mozzarella cheeses of different compositions. In addition an extensive database on the compositional, biochemical, microstructural, rheological and/or functional properties of different commerical cheeses - low moisture Mozzarella, Cheddar and analogue pizza cheese, has been compiled. The functionality of low moisture Mozzarella changes markedly on storage/ripening at 4ºC. Initially, during the first 5-10 days of storage, the functionality of the baked cheese is poor but then improves on further storage as reflected by reductions in melt time and apparent viscosity (chewiness) and increases in stretchability and flowability. The changes in functionality are mediated by storage-related increases in pH, proteolysis, protein-bound water and free oil in the cheese. On prolonged storage (e.g. > 60 d at 4ºC), the cheese functionality becomes impaired as the shredded cheese develops an increased susceptibility to clumping/balling which makes it difficult to dispense the cheese onto the pizza pie and achieve a uniform surface distribution. Moreover, the baked cheese tends to exude excess free oil and loses its desired level of chewiness attaining a 'soupy' consistency. Novel methods were developed/adapted to objectively quantify functionality in the raw (susceptibility of shredded cheese to clump) and cooked (stretchability, chewiness, viscoelasticity) cheeses.
    • Effects of Seasonal Variation in Milk Composition on the Quality of Pizza Cheese

      Guinee, Timothy P.; O'Brien, Bernadette; Kelly, Paul M; Connolly, J.F. (Teagasc, 1999-02-01)
      The main aims of this study were to investigate the effects of diet and lactation stage on the composition and cheesemaking quality of milk produced under controlled conditions. The main conclusions were as follows: These studies clearly demonstrated that the Recommended Moorepark Milk Production System in conjunction with an objectively standardised cheesemaking process provides a model for year round production of quality Mozzarella cheese. Databases have been established on the effects of diet quantity and quality, and stage of lactation on the composition, processability and cheesemaking characteristics of milk from both Spring- and Autumn-calving herds. Increasing the daily herbage allowance from 16 to 24 kgs DM/cow/day during mid-lactation, resulted in increases in the level of milk casein and cheese yield but had little influence on cheese functionality. Similarily improving diet quality in mid-lactation by reducing the stocking density from 4.3 to 3.8 cows/ha combined with concentrate supplementation (3 kgs/cow/day) had the same effect. Using milk from a Spring-calving herd, produced according to the Recommended Moorepark Milk Production System, in conjunction with an objectively-standardised Mozzarella cheesemaking process, no major problems were encountered during the lactation period 170 - 273 days from calving. Extending the lactation period of the Spring-calving herd from ~ 273 to 286 days resulted in higher cheese moisture (by ~ 2%), softer cheese, and lower chewiness in the melted cheese. A sharp decline in both total protein, casein and lactose in the milk was observed during this period. However the blending of this milk with milk of an Autumn-calving herd overcame these cheesemaking problems. The yield of low moisture Mozzarella cheese (using milks from Spring- or Autumn-calved herds) was positively correlated with milk casein level. The yield of cheese from the Spring-calved herd increased concomitantly with increasing casein level to day 273 of lactation and decreased thereafter as the casein concentration declined. In these studies it was found that easy-to-use tests such as lactose level in the milk and rennet coagulation properties as determined by Formagraph were useful indicators of the suitability of milk for cheesemaking. The Recommended Moorepark Milk Production System, as applied in the late lactation period, was characterised by a high plane of nutrition and a drying-off strategy which ensured a minimum daily milk yield per cow of 9 kg. It resulted in milk of good cheesemaking quality - lactose > 4.25%, and casein > 2.6% and satisfactory rennet coagulation properties - curd firming rate of > 0.15 min ¯¹ curd firmness at 60 min of > 45mm - at the end of lactation.
    • Enhancement of pigmeat quality by altering pre-slaughter management

      Lawlor, Peadar G; Lynch, P Brendan; Mullane, J.; Kerry, Joseph P.; Hogan, Sean A.; Allen, Paul (Teagasc, 25/10/2005)
      The studies presented in this report were conducted to investigate the effect of breed, slaughter weight, castration of male pigs and strategic feeding strategies on the performance of pigs to slaughter and on their carcass quality. The effect of breed, gender and feeding regimen on the performance of pigs and their carcass quality was examined in the first study (Section 3). From weaning to slaughter Landrace-sired pigs grew at a similar rate but had a better feed conversion efficiency compared with Duroc-sired pigs. Landrace-sired pigs also had a higher carcass lean and greater muscle depth than Duroc-sired pigs. Entire male pigs grew more efficiently, had lower lean content in their carcasses and had a reduced kill out yield when compared with gilts. The eye muscle depth was greater for gilts than entire males. Diluting the diet with grass-meal (GM) reduced growth rate, caused a deterioration in feed conversion efficiency, reduced back fat thickness, reduced eye muscle thickness and reduced kill out yield compared to the control feeding regimen of a cereal based diet. Compensatory growth was observed during a re-alimentation period following a period of diet dilution with grass-meal. However, where it did occur, in most cases it was only partial. Adding 5% rapeseed oil instead of lard to the finisher diet increased nitrogen utilization efficiency and phosphorous utilization efficiency. The effect of gender (boar, castrate, gilt) and slaughter weight (80 to 120kg) on pig performance, carcass quality, meat quality, and nitrogen excretion was investigated in the second study (Section 4). Boars grew faster than gilts and more efficiently than castrates or gilts. Castrates had a higher kill out yield than boars. Nitrogen excretion from castrates was similar to gilts which were both higher than that from boars. The processing value of carcasses from castrates may be higher than that of boars and gilts. In particular castrates had heavier loins and bellies than either boars or gilts. Carcasses from castrates and gilts had a higher temperature (recorded 24 hours post slaughter) than boars. However, pH24 was not affected by gender. The intramuscular fat content of the l. dorsi in castrates was higher than that of boars or gilts, however at 1.65% this was well below the level (2.0%) above which any noticeable sensory attributes might be detected. Feed intake increased with increasing slaughter weight and feed conversion efficiency deteriorated. N excretion also increased with each increment in weight. Carcass lean content increased up to 90kg live EOP 4939.doc 4 25/10/2005 weight then reached a plateau and declined after 110kg live weight. Heavier carcasses yielded more product for approximately the same slaughtering cost and the associated larger muscles could make it easier to use seam butchery techniques that result in lean, well-trimmed, attractive cuts and joints. The pH45 and pH24 were reduced with increasing slaughter weight and drip loss increased. Heavier pigs may be more prone to the development of PSE than lighter pigs as their carcass temperature remains higher for longer than that of lighter pigs.
    • Enhancement of the Nutritional Value and Eating Quality of Beef

      Moloney, Aidan P; Monahan, Frank J; Noci, F.; Murray, Brendan; Troy, Declan J. (Teagasc, 2004-01-01)
      Consumer interest in the nutritional aspects of health has increased interest in developing methods to manipulate the fatty acid composition of ruminant products. Ruminant meats such as beef and lamb are often criticised by nutritionists for having high amounts of saturated fatty acids (S) and low polyunsaturated fatty acids (P).The P:S ratio in beef is approximately 0.1, the ideal being about 0.4. This project is part of a larger EU-supported project entitled Healthy Beef (Enhancing the content of beneficial fatty acids in beef and improving meat quality for the consumer: QLRT-CT-2000-31423). The Teagasc contribution, which was a collaboration between Grange Research Centre and The National Food Centre, focussed on nutritional manipulation of beef cattle. In particular, on exploiting grazing and fishoil as tools to enhance the concentration of “healthy” fatty acids in beef. The conclusions were: • The beneficial effect of a grazed grass-based diet on the fatty acid composition of beef was confirmed • The scale of this beneficial effect is strongly dependent on the duration of grazing • The optimum concentration of beneficial fatty acids was not achieved suggesting that feeding management prior to grazing is important • Grazing influenced beef colour and drip-loss in a durationdependent manner • Animals finished off grass for 40 or 98 days produced meat that was tougher than that from animals finished on silage and concentrates or fed grass for the last 158 days. • Fish oil supplementation enhanced the concentration in beef, of fatty acids that are beneficial to human health • The linear response to increasing level of fish oil consumption indicates scope to further enhance the concentrations of beneficial fatty acids in beef Wilting of grass prior to ensiling did not impact negatively on the overall content of n-3P in muscle, but it increased the concentration of conjugated linoleic acid • Dietary inclusion of fish oil or wilting of grass prior to ensiling did not affect muscle appearance • Fish oil seemed to increase tenderness but only at the high level of inclusion. This merits further study • There was some evidence that wilting of grass prior to ensiling enhanced meat tenderness. This needs to be confirmed.
    • Enhancing the healthiness, shelf-life and flavour of Irish fresh packaged beef

      Moloney, Aidan P; Murray, Brendan; Troy, Declan J.; O'Grady, Michael; Kerry, Joseph P.; Downey, Gerard (Teagasc, 2007-02)
      Consumer concern about the nutritional aspects of health has heightened interest in developing methods for manipulation of the fatty acid composition of ruminant products. Ruminant meats such as beef and lamb are often criticised by nutritionists for having high amounts of saturated (S) fatty acids and low levels of polyunsaturated (P) fatty acids. The P:S ratio in beef is approximately 0.1, the ideal being about 0.4. However, an excessive increase in P concentration could predispose beef lipids to rancidity and loss of shelflife. Moreover, the colour of meat is an important influence on the purchase decision of the consumer. This report summarises the Teagasc contribution to a larger project supported under the Food Institutional Research Measure programme administrated by the Department of Agriculture and Food. The Teagasc contribution focused on enhancing the fatty acid composition of beef by nutritional manipulation of cattle using grazing and plant oils, the use of healthy - fatty acid enriched bovine tissue to make a processed beef product and the efficacy of dietary inclusion of tea catechins and rosemary to enhance the shelf-life of beef.
    • 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.
    • Enterococci in Food Fermentations: Functional and Safety Aspects

      Cogan, Tim; Rea, Mary C.; Drinan, Finbarr; Gelsomino, R. (Teagasc, 2001-04-01)
      Enterococci are natural residents of the human and animal gastrointestinal tracts; many species are also found in soil, plants and food. These organisms also form an important part of the microflora of many cheeses, especially those made in Southern Europe, where they can reach levels of 107 - 108 cfu/g. There is contradictory information on their role in flavour development in cheese with some studies showing that they have a positive effect and others a negative one. Enterococcus faecalis, Ec. faecium and Ec. durans are the important species found in cheese, though recent results from our laboratory show that Ec. casseliflavus may also be important (see below). Many of these species withstand pasteurisation. Their presence in food has been questioned because they are responsible for many nosocomial infections in hospitals. They are also promiscuous and easily transfer antibiotic resistance to other organisms and acquire resistance to vancomycin themselves. Cheddar cheese has a complex microflora and is conducive to growth of many bacteria, especially lactic acid bacteria. Enterococci are facultative anaerobes, which ferment lactose and can grow in high salt concentrations. Therefore, they should grow in cheese if they are present in the raw milk. Phenotypically they can be confused with starter lactococci. Traditionally, they are separated from lactococci by their ability to grow at 45°C and in 6.5% salt. However, these tests have serious drawbacks since some species of enterococci cannot grow at 45°C and some lactococci can grow at 45°C and in 6.5% salt. The effect of enterococci on flavour development in Cheddar cheese has not been studied to any great extent. The overall objectives of this collaborative project were to investigate the taxonomic relationships between food, veterinary and clinical isolates of enterococci, their virulence, their ability to produce toxins, their antibiotic resistance and their technological performance in cheesemaking. The specific objectives of the Moorepark team were to study the co-metabolism of citrate and sugar by enterococci, develop a DNA probe to distinguish between Enterococcus and Lactococcus and evaluate the contribution of enterococci to flavour development in Cheddar cheese.
    • Enzyme Modified Cheese Flavour Ingredients

      Wilkinson, M.G.; Kilcawley, Kieran N; Mulholland, E.; Department of Agriculture, Food and the Marine, Ireland (Teagasc, 01/09/2000)
      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.
    • 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.; European Union (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.
    • Establishment of Enabling Technology for Manufacture of Selected Types of Continental and Speciality Cheeses

      Wilkinson, M.G.; Sheehan, Jeremiah J.; Guinee, Timothy P.; Cogan, Tim (Teagasc, 1998-09-01)
      The objectives in the project were the development of the science and technology for speciality cheese manufacture, identification and overcoming of the technical constraints to the manufacture of soft speciality cheeses in Ireland and the development of Moorepark Technology Limited (MTL) pilot plant as an integrated, flexible pre-commercial manufacturing platform with which to evaluate the market for speciality cheese.
    • A European study on animal food & biomedical aspects of E.coli 0157:H7

      Duffy, Geraldine; Garvey, Patricia; Sheridan, James J.; European Union; CT98-3935 (Teagasc, 2002-02)
      Verocytotoxin producing Escherichia coli (VTEC) and, in particular, strains of serogroup O157, have emerged as significant pathogens causing a range of severe and potentially fatal illnesses. The European Union has recognised the threat posed by E coli O157:H7 and the need to devise control strategies based on an understanding of VTEC pathogenicity, transmission, survival and growth. It acknowledges the importance of informing farmers, veterinarians, food producers and health authorities so that each of these groups can act appropriately to reduce the overall hazards posed by these organisms. To contribute to the development and dissemination of effective control strategies, the European Commission funded this Concerted Action Project 1
    • An examination of the molecular mechanisms controlling the tissue accumulation of conjugated linoleic acid (CLA) in cattle

      Waters, Sinead M.; Hynes, A.C.; Killeen, Aideen P.; Moloney, Aidan P; Kenny, David A. (Teagasc, 01/12/2008)
      Long chain n-3 polyunsaturated fatty acids (n-3 PUFA) and conjugated linoleic acid (CLA) have demonstrable and potential human health benefits in terms of preventing cancer, diabetes, chronic inflammation, obesity and coronary heart disease. Supplementation of cattle diets with a blend of oils rich in n-3 PUFA and linoleic acid have a synergistic effect on the accumulation of ruminal and tissue concentrations of trans vaccenic acid (TVA), the main substrate for ?-9 desaturase which is responsible for de novo tissue synthesis of the cis 9, trans 11 isomer of CLA. This dietary strategy translates into increases in milk concentrations of CLA in dairy cows; however, concentrations in the muscle of beef animals have not always been increased. There is an apparent paradox in that n-3 PUFA supplementation enhances ruminal synthesis of trans-vaccenic acid (TVA), but then inhibits its conversion to CLA possibly through altering the activity of ?-9 desaturase. Recently, the promoter regions of the bovine ?- 9 desaturase gene has been isolated and analysed and has been shown to contain a conserved PUFA response region.
    • Extending the shelf life of fresh sliced mushrooms

      Brennan, Martine H.; Gormley, Ronan T.; Department of Agriculture, Food and the Marine (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.