The aim of the Food Chemistry & Technology Department is to help food processors maintain competitive advantage and secure premium markets. Our Dairy research focuses on cheese, infant formula and dairy based ingredients; Meat research, focusing on quality, whole chain management and recovering value from meat processing streams; Cereal research focusing on product quality and innovation in the bakery industry

Recent Submissions

  • Stabilising effect of α-lactalbumin on concentrated infant milk formula emulsions heat treated pre- or post-homogenisation

    Buggy, Aoife K.; McManus, Jenifer J.; Brodkorb, Andre; McCarthy, Noel; Fenelon, Mark A. (Springer, 2016-11-22)
    Protein type and/or heat treatment pre- or post-homogenisation can affect the physical stability of infant formulations during manufacture. Previous research has described the use of α-lactalbumin addition in infant formulae, but has not demonstrated the effect of heating pre- or post-emulsion formulation during processing. The objective of this study was to evaluate the effect of both of these parameters. Three batches of model 1st-stage infant formula containing differing whey protein ratios (60:40 whey: casein with α-lactalbumin content 12, 30 or 48% of total protein) were prepared. Each batch was split; one half receiving heat treatment pre-homogenisation and the second half homogenised and then heat treated. Emulsion stability was determined by size exclusion chromatography, SDS-PAGE, particle size and viscosity measurements. There was a significant (P < 0.05) reduction in the formation of large soluble aggregates upon increasing α-lac concentration in emulsions heat treated either before or after homogenisation. Heat treatment of formulations post-homogenisation resulted in a higher (P < 0.05) D.v09 within the particle size distribution; increasing α-lactalbumin concentration to 30 or 48% significantly (P < 0.05) reduced the D.v09 within the particle size distribution in these emulsions. The viscosity of concentrates (55 % total solids) containing the 12% α-lactalbumin, heat treated post-homogenisation, was significantly greater (P < 0.05) than the equivalent emulsion heat treated pre-homogenisation; increasing the α-lactalbumin concentration to 30 or 48% significantly (P < 0.05) reduced viscosity. When the α-lactalbumin content was increased to 48% as a percentage of the total protein, heating before or after emulsion formation had no effect on concentrate viscosity. The findings demonstrate the importance of thermal denaturation/aggregation of whey proteins (and in particular, the ratio of α-lactalbumin to β-lactoglobulin) prior to homogenisation of infant formula emulsions.
  • Simulated gastrointestinal digestion of nisin and interaction between nisin and bile

    Gough, Ronan; O'Connor, Paula M.; Rea, Mary C.; Gomez-Sal, Beatriz; Miao, Song; Hill, Colin; Brodkorb, Andre (Elsevier, 2017-08-14)
    Nisin, an antimicrobial peptide showing activity against many Gram positive bacteria, is widely used as a food preservative. The simulated gastrointestinal digestion of nisin (variant A) was studied using the in vitro INFOGEST digestion method. Following oral, gastric and small intestinal digestion, there was no intact nisin in the system and the nisin was primarily digested by pancreatin. After digestion, six nisin fragments (1–11, 1–12, 1–20, 1–21, 1–29 and 1–32) were identified by reversed phase high performance liquid chromatography and mass spectroscopy and four of these nisin fragments (1–20, 1–21, 1–29 and 1–32) demonstrated low antibacterial activity against Lactococcus lactis HP in agar diffusion activity assays. Additionally, it was observed that bile salts form a complex with nisin. This was examined by atomic force microscopy, turbidity and dynamic light scattering, which showed that this interaction resulted in significantly larger bile salt micelles. The presence of bile salts at physiological levels significantly altered the relative amounts of the nisin fragments 1–12, 1–20 and 1–29 produced during an in vitro digestion. This study highlights the importance of including bile in simulated digestions of antimicrobial peptides in order to obtain a more accurate simulation of the in vivo digestion products and their activity.
  • Isolation and characterisation of κ-casein/whey protein particles from heated milk protein concentrate and role of κ-casein in whey protein aggregation

    Gaspard, Sophie J.; Auty, Mark A.E.; Kelly, Alan L.; O'Mahony, James A.; Brodkorb, Andre (Elsevier, 2017-06-12)
    Milk protein concentrate (79% protein) reconstituted at 13.5% (w/v) protein was heated (90 °C, 25 min, pH 7.2) with or without added calcium chloride. After fractionation of the casein and whey protein aggregates by fast protein liquid chromatography, the heat stability (90 °C, up to 1 h) of the fractions (0.25%, w/v, protein) was assessed. The heat-induced aggregates were composed of whey protein and casein, in whey protein:casein ratios ranging from 1:0.5 to 1:9. The heat stability was positively correlated with the casein concentration in the samples. The samples containing the highest proportion of caseins were the most heat-stable, and close to 100% (w/w) of the aggregates were recovered post-heat treatment in the supernatant of such samples (centrifugation for 30 min at 10,000 × g). κ-Casein appeared to act as a chaperone controlling the aggregation of whey proteins, and this effect was stronger in the presence of αS- and β-casein.
  • A Simple Method for the Purification of Nisin

    Gough, Ronan; Gomez-Sala, Beatriz; O'Connor, Paula M.; Rea, Mary C.; Miao, Song; Hill, Colin; Brodkorb, Andre (Springer, 2017-05-29)
    Nisin, an antimicrobial peptide showing activity against a broad range of Gram-positive bacteria, is widely used as a food preservative and has potential as a therapeutic for a range of infectious diseases. Here, we present a simple purification method, based on a salting-out approach, which can produce a powder containing ∼33% nisin, from a nisin-producing culture in a whey permeate-based medium. This process removes over 99% of the lactic acid, NaCl, lactose and non-nisin proteins from the cell-free culture supernatant. The approach can also enrich a commonly used commercial nisin preparation over 30-fold to a purity of ∼58%. These are higher purities than comparable published methods. The simplicity of this approach facilitates its use in research and also its scale-up.
  • Future Protein Supply and Demand: Strategies and Factors Influencing a Sustainable Equilibrium

    Henchion, Maeve; Hayes, Maria; Mullen, Anne Maria; Fenelon, Mark; Tiwari, Brijesh (MDPI, 2017-07-20)
    A growing global population, combined with factors such as changing socio-demographics, will place increased pressure on the world’s resources to provide not only more but also different types of food. Increased demand for animal-based protein in particular is expected to have a negative environmental impact, generating greenhouse gas emissions, requiring more water and more land. Addressing this “perfect storm” will necessitate more sustainable production of existing sources of protein as well as alternative sources for direct human consumption. This paper outlines some potential demand scenarios and provides an overview of selected existing and novel protein sources in terms of their potential to sustainably deliver protein for the future, considering drivers and challenges relating to nutritional, environmental, and technological and market/consumer domains. It concludes that different factors influence the potential of existing and novel sources. Existing protein sources are primarily hindered by their negative environmental impacts with some concerns around health. However, they offer social and economic benefits, and have a high level of consumer acceptance. Furthermore, recent research emphasizes the role of livestock as part of the solution to greenhouse gas emissions, and indicates that animal-based protein has an important role as part of a sustainable diet and as a contributor to food security. Novel proteins require the development of new value chains, and attention to issues such as production costs, food safety, scalability and consumer acceptance. Furthermore, positive environmental impacts cannot be assumed with novel protein sources and care must be taken to ensure that comparisons between novel and existing protein sources are valid. Greater alignment of political forces, and the involvement of wider stakeholders in a governance role, as well as development/commercialization role, is required to address both sources of protein and ensure food security.
  • Effect of pulse flours on the physiochemical characteristics and sensory acceptance of baked crackers

    Millar, Kim A.; Barry-Ryan, Catherine; Burke, Roisin; Hussey, Karen; McCarthy, Sinead; Gallagher, Eimear (Wiley, 2017-03-29)
    Pulse flours offer nutritional alternatives to wheat flour in the production of baked snacks due to their high protein and fibre levels and low glycaemic index. In this study, broad-bean (Vicia faba), yellow-pea and green-pea (Pisum sativum) flours were each blended with wheat flour at 40% in the formulation of chemically leavened crackers. The effects of flour type and baking time on the physiochemical properties, sensory acceptability, nutritional composition and antioxidant activity of the crackers were observed in comparison with 100% wheat crackers. Broad-bean crackers had the highest protein content and antioxidant activity (13 g per 100 g DM and 38.8 mgAAE per 100 g DM, respectively). Yellow-pea crackers had the highest fibre content (12 g per 100 g DM). Physical dimensions and colour attributes were significantly affected by pulse-flour substitution. Yellow-pea and broad-bean crackers were significantly preferred by consumers compared to the control, demonstrating the potential application of these flours to improve the eating quality and nutritional profile of crackers.
  • Selective enrichment of dairy phospholipids in a buttermilk substrate through investigation of enzymatic hydrolysis of milk proteins in conjunction with ultrafiltration

    Barry, Kate M.; Dinan, Timothy G.; Kelly, Philip M. (Elsevier, 2017-02-04)
    Extensive enzymatic hydrolysis of milk proteins in reconstituted buttermilk powder was combined with ultrafiltration to generate a phospholipid (PL) enriched fraction with maximum permeation of hydrolysed peptides. Buttermilk, naturally high in PLs, is the ideal substrate for enrichment of these bio- and techno-functionally active compounds. A 7.8 fold increase in PL was achieved in the 50 kDa retentate; 6.16 ± 0.02% total PL compared with 0.79 ± 0.01% in the starting substrate, an increase considerably greater than previously reported. Total lipid content (% dry matter) increased 6.3 fold in the retentate, 43.43 ± 0.61%, from the starting substrate, 6.84 ± 0.17%. This combined strategic approach enabled maximum enrichment of PLs with no transmission of lipid material into the permeate, 0.09 ± 0.02% total lipid, and non-detectable levels of PLs recovered in the permeate, 0.00 ± 0.01% total PL.
  • Alternative uses for co-products: Harnessing the potential of valuable compounds from meat processing chains

    Mullen, Anne Maria; Alvarez Garcia, Carlos; Zeugolis, Dimitrios; Henchion, Maeve; O'Neill, Eileen; Drummond, Liana (Elsevier, 2017-05-03)
    Opportunities for exploiting the inherent value of protein-rich meat processing co-products, in the context of increased global demand for protein and for sustainable processing systems, are discussed. While direct consumption maybe the most profitable route for some, this approach is influenced greatly by local and cultural traditions. A more profitable and sustainable approach may be found in recognizing this readily available and under-utilised resource can provide high value components, such as proteins, with targeted high value functionality of relevance to a variety of sectors. Applications in food & beverages, petfood biomedical and nutrition arenas are discussed. Utilization of the raw material in its entirety is a necessary underlying principle in this approach to help maintain minimum waste generation. Understanding consumer attitudes to these products, in particular when used in food or beverage systems, is critical in optimizing commercialization strategies.
  • Dairy food structures influence the rates of nutrient digestion through different in vitro gastric behaviour

    Mulet-Cabero, Ana-Isabel; Rigby, Neil M.; Brodkorb, Andre; Mackie, Alan (Elsevier, 2016-12-31)
    The purpose of this study was to investigate in vitro the extent to which specific food structures alter gastric behaviour and could therefore impact on nutrient delivery and digestion in the small intestine. Results obtained from a specifically developed gastric digestion model, were compared to results from a previous human study on the same foods. The semi-dynamic model could simulate the main gastric dynamics including gradual acidification, lipolysis, proteolysis and emptying. Two dairy-based foods with the same caloric content but different structure were studied. The semi-solid meal comprised a mixture of cheese and yogurt and the liquid meal was an oil in water emulsion stabilised by milk proteins. Our findings showed similar gastric behaviour to that seen previously in vivo. Gastric behaviour was affected by the initial structure with creaming and sedimentation observed in the case of liquid and semi-solid samples, respectively. Lipid and protein digestion profiles showed clear differences in the amount of nutrients reaching the simulated small intestine and, consequently, the likely bioaccessibility after digestion. The semi-solid sample generated higher nutrient released into the small intestine at an early stage of digestion whereas nutrient accessibility from liquid sample was delayed due to the formation of a cream layer in the gastric phase. This shows the strong effect of the matrix on gastric behaviour, proteolysis and lipolysis, which explains the differences in physiological responses seen previously with these systems in terms of fullness and satiety.
  • Detection and characterisation of Complement protein activity in bovine milk by bactericidal sequestration assay

    Maye, Susan; Stanton, Catherine; Fitzgerald, Gerald F.; Kelly, Philip M. (Cambridge University Press for the Institute of Food Research and the Hannah Research Institute, 2015-06-29)
    While the Complement protein system in human milk is well characterised, there is little information on its presence and activity in bovine milk. Complement forms part of the innate immune system, hence the importance of its contribution during milk ingestion to the overall defences of the neonate. A bactericidal sequestration assay, featuring a Complement sensitive strain, Escherichia coli 0111, originally used to characterise Complement activity in human milk was successfully applied to freshly drawn bovine milk samples, thus, providing an opportunity to compare Complement activities in both human and bovine milks. Although not identical in response, the levels of Complement activity in bovine milk were found to be closely comparable with that of human milk. Differential counts of Esch. coli 0111 after 2 h incubation were 6·20 and 6·06 log CFU/ml, for raw bovine and human milks, respectively – the lower value representing a stronger Complement response. Exposing bovine milk to a range of thermal treatments e.g. 42, 45, 65, 72, 85 or 95 °C for 10 min, progressively inhibited Complement activity by increasing temperature, thus confirming the heat labile nature of this immune protein system. Low level Complement activity was found, however, in 65 and 72 °C heat treated samples and in retailed pasteurised milk which highlights the outer limit to which high temperature, short time (HTST) industrial thermal processes should be applied if retention of activity is a priority. Concentration of Complement in the fat phase was evident following cream separation, and this was also reflected in the further loss of activity recorded in low fat variants of retailed pasteurised milk. Laboratory-based churning of the cream during simulated buttermaking generated an aqueous (buttermilk) phase with higher levels of Complement activity than the fat phase, thus pointing to a likely association with the milk fat globule membrane (MFGM) layer.
  • Second Generation GM Foods: Perspectives on Likely Future Acceptance by Irish Consumers

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

    Tansey, Fergal; Gormley, Ronan T.; Carbonell, Serge; Oliveira, Jorge; Bourke, Paula; O’Beirne, David (Teagasc, 2005-04-01)
    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).
  • The market potential for in-conversion organic products in Ireland

    Cowan, Cathal; Connolly, Liam; Howlett, Brendan; Meehan, Hilary; Ryan, Jane; Mahon, Denise; McIntyre, Bridin; Fanning, Martin; Downey, Gerard (Teagasc, 2005-08-01)
    This report deals with the market for and financial feasibility of converting from conventional to organic food production in Ireland. All members of the organic supply chain were included in the study i.e. farmers, intermediaries, retailers and consumers, to examine the potential of a market for conversion grade produce. Conversion products are those produced in the second year of the conversion phase from conventional to organic farming. Products do not attain full organic status until this is completed.
  • Comparative Proteomic Profiling of Divergent Phenotypes for Water Holding Capacity across the Post Mortem Ageing Period in Porcine Muscle Exudate

    Di Luca, Alessio; Hamill, Ruth M; Mullen, Anne Maria; Slavov, Nikolai; Giuliano, Elia (PLOS, 2016-03-07)
    Two dimensional Difference Gel Electrophoresis (2-D DIGE) and mass spectrometry were applied to investigate the changes in metabolic proteins that occur over a seven day (day 1, 3 and 7) post mortem ageing period in porcine centrifugal exudate from divergent meat quality phenotypes. The objectives of the research were to enhance our understanding of the phenotype (water holding capacity) and search for biomarkers of this economically significant pork quality attribute. Major changes in protein abundance across nine phenotype-by-time conditions were observed. Proteomic patterns were dominated by post mortem ageing timepoint. Using a machine learning algorithm (l1-regularized logistic regression), a model was derived with the ability to discriminate between high drip and low drip phenotypes using a subset of 25 proteins with an accuracy of 63%. Models discriminating between divergent phenotypes with accuracy of 72% and 73% were also derived comparing respectively, high drip plus intermediate phenotype (considered as one phenotype) versus low drip and comparing low drip plus intermediate phenotype (considered as one phenotype) versus high drip. In all comparisons, the general classes of discriminatory proteins identified include metabolic enzymes, stress response, transport and structural proteins. In this research we have enhanced our understanding of the protein related processes underpinning this phenotype and provided strong data to work toward development of protein biomarkers for water holding capacity.
  • Nitrofurans: Measuring Tissue-Bound Residues in Meat

    O’Keeffe, Michael; Conneely, Anne; Nugent, Audrey; Downey, Gerard (Teagasc, 2006-08-01)
    The aims of this project were to (a) develop a range of screening and confirmatory test methods that might be applied to effectively test for the illicit use of the prohibited nitrofuran antimicrobials,(b) study the persistence of nitrofuran antimicrobials as bound metabolite residues inedible tissues and (c) undertake a pan-European survey of the incidence of nitrofurans in retail pork.
  • Adding Value To Under utilised Fish Species

    Fagan, John; Gormley, Ronan T.; Mitchell, Michelle; Downey, Gerard (Teagasc, 2006-02-01)
    Tightening fish quotas and supply shortages for conventional species are causing major difficulties for both fishermen and seafood processors. There is a need, therefore, to explore the potential of underutilised fish species both as fillets or portions and as added-value products. The current project at Ashtown Food Research Centre (AFRC) addressed this issue for a number of underutilised species via (a) sous vide processing (with savoury sauces),(b)marinating (salt- and sugar-based marinades) and (c) via a combination of freeze-chilling and modified atmosphere packaging (MAP).A range of physico-chemical and sensory tests was conducted on the products and their shelf-life status was also determined.
  • Food Authentication using Infrared Spectroscopic Methods

    Downey, Gerard; Kelly, J. Daniel (Teagasc, 2006-06-01)
    Confirmation of the authenticity of a food or food ingredient is an increasing challenge for food processors and regulatory authorities. This is especially the case when an added-value claim, such as one relating to geographic origin or a particular processing history, is made on the food label. Regulatory agencies are concerned with the prevention of economic fraud while the food processor needs confirmation of such claims in order to protect a brand, the image of which could be severely damaged should an adulterated ingredient make its way into the branded food product.To be of greatest value, any analytical tool deployed to confirm authenticity claims needs to be portable, easy to use, non-destructive and accurate. Infrared spectroscopy, near and mid-infrared, is a tool which has been demonstrated to possess these properties in a wide range of situations.While some applications in food authenticity have been reported, the work undertaken in this project was designed to explore their capabilities regarding a number of products and authenticity issues of particular interest to the Irish agri-food industry i.e. olive oil, honey, soft fruit purées and apple juice.
  • Development of Organic Breads and Confectionery

    Gallagher, Eimear; Keehan, Denise; Butler, Francis; Downey, Gerard (Teagasc, 2005-07-01)
    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.
  • Supply Chains Linking Food SMEs in Lagging Rural Regions in Ireland

    Henchion, Maeve; McIntyre, Bridin; Meredith, David; Downey, Gerard (Teagasc, 2005-04-01)
    This report reflects the Irish contribution to a 3-year EU-funded research project, SUPPLIERS, which was concerned with the development, innovation, competitiveness and sustainability of food SMEs in lagging rural regions(LRRs) of the EU and Poland. It summarises the results of the research conducted in Ireland, evaluates these findings and makes recommendations to benefit food SMEs located in Ireland’s LRRs. Two regions were selected for study in Ireland. These were the West, comprising counties Galway, Mayo and Roscommon, and the Northwest, comprising counties Donegal, Sligo and Leitrim. Both are classified as Objective 1 regions reflecting their predominantly rural character, economic disadvantage and relative remoteness from urban centres. Three food products were selected for detailed study in each region. Products selected in the West were mushrooms, farmed salmon and speciality foods and, in the Northwest, organic produce, farmed shellfish and prepared consumer foods. This product range encompassed a range of chains from local to international, integrated to fragmented, direct to indirect, providing a basis for comparison and evaluation of different chain structures. This summary report concentrates on the results of four surveys carried out over the course of the study. Producers, intermediaries, commercial customers and support institutions were surveyed.
  • Exploration of microwave dielectric and near infrared spectroscopy with multivariate data analysis for fat content determination in ground beef

    Zhao, Ming; Downey, Gerard; O'Donnell, Colm P. (Elsevier, 2016-03-19)
    This study investigated using microwave dielectric and near infrared (NIR) spectroscopy for the determination of fat content in ground beef samples (n=69) in a designed experiment. Multivariate data analysis (principal component analysis (PCA) and partial least squares (PLS) regression modelling) was used to explore the potential of these spectroscopic techniques over selected multiple frequency or wavelength ranges. Chemical reference data for fat and water content in ground beef were obtained using a nuclear magnetic resonance-based SMART Trac analyser. Best performace of PLS prediction models for fat content revealed a coefficient of determination in prediction (R²P) of 0.87 and a root mean square error of prediction (RMSEP) of 2.71% w/w for microwave spectroscopy; in a similar manner, R²P of 0.99 and RMSEP of 0.71% w/w were obtained for NIR spectroscopy. The influence of water content on fat content prediction by microwave spectroscopy was investigated by comparing the prediction performance of PLS regression models developed using a single Y-variable (PLS1; fat or water content) and using both Y-variables (PLS2; fat and water contents).

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