• Vangl2 disruption alters the biomechanics of late spinal neurulation leading to spina bifida in mouse embryos

      Galea, Gabriel L.; Nychyk, Oleksandr; Mole, Matteo A.; Moulding, Dale; Savery, Dawn; Nikolopoulou, Evanthia; Henderson, Deborah J.; Greene, Nicholas D. E.; Copp, Andrew J. (The Company of Biologists, 2018-03-12)
      Human mutations in the planar cell polarity component VANGL2 are associated with the neural tube defect spina bifida. Homozygous Vangl2 mutation in mice prevents initiation of neural tube closure, precluding analysis of its subsequent roles in neurulation. Spinal neurulation involves rostral-to-caudal ‘zippering’ until completion of closure is imminent, when a caudal-to-rostral closure point, ‘Closure 5’, arises at the caudal-most extremity of the posterior neuropore (PNP). Here, we used Grhl3Cre to delete Vangl2 in the surface ectoderm (SE) throughout neurulation and in an increasing proportion of PNP neuroepithelial cells at late neurulation stages. This deletion impaired PNP closure after the ∼25-somite stage and resulted in caudal spina bifida in 67% of Grhl3Cre/+Vangl2Fl/Fl embryos. In the dorsal SE, Vangl2 deletion diminished rostrocaudal cell body orientation, but not directional polarisation of cell divisions. In the PNP, Vangl2 disruption diminished mediolateral polarisation of apical neuroepithelial F-actin profiles and resulted in eversion of the caudal PNP. This eversion prevented elevation of the caudal PNP neural folds, which in control embryos is associated with formation of Closure 5 around the 25-somite stage. Closure 5 formation in control embryos is associated with a reduction in mechanical stress withstood at the main zippering point, as inferred from the magnitude of neural fold separation following zippering point laser ablation. This stress accommodation did not happen in Vangl2-disrupted embryos. Thus, disruption of Vangl2-dependent planar-polarised processes in the PNP neuroepithelium and SE preclude zippering point biomechanical accommodation associated with Closure 5 formation at the completion of PNP closure.
    • Variation in the quality of meat from Irish steers at the time of slaughter.

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

      Troy, Declan J.; Joseph, Robin; European Union; AIR-CT94-1881 (Teagasc, 2001-07)
      Very fast chilling (VFC) of beef reduces the temperature to -1ºC after 5 hours post mortem throughout its mass. The process has many potential benefits (Joseph,1996) including the production of tender meat and greater process efficiency in the meat plant.
    • Virulence Gene Sequencing Highlights Similarities and Differences in Sequences in Listeria monocytogenes Serotype 1/2a and 4b Strains of Clinical and Food Origin From 3 Different Geographic Locations

      Poimenidou, Sofia V.; Dalmasso, Marion; Papadimitriou, Konstantinos; Fox, Edward M.; Skandamis, Panagiotis N.; Jordan, Kieran; European Union; 265877 (Frontiers, 2018-06-05)
      The prfA-virulence gene cluster (pVGC) is the main pathogenicity island in Listeria monocytogenes, comprising the prfA, plcA, hly, mpl, actA, and plcB genes. In this study, the pVGC of 36 L. monocytogenes isolates with respect to different serotypes (1/2a or 4b), geographical origin (Australia, Greece or Ireland) and isolation source (food-associated or clinical) was characterized. The most conserved genes were prfA and hly, with the lowest nucleotide diversity (π) among all genes (P < 0.05), and the lowest number of alleles, substitutions and non-synonymous substitutions for prfA. Conversely, the most diverse gene was actA, which presented the highest number of alleles (n = 20) and showed the highest nucleotide diversity. Grouping by serotype had a significantly lower π value (P < 0.0001) compared to isolation source or geographical origin, suggesting a distinct and well-defined unit compared to other groupings. Among all tested genes, only hly and mpl were those with lower nucleotide diversity in 1/2a serotype than 4b serotype, reflecting a high within-1/2a serotype divergence compared to 4b serotype. Geographical divergence was noted with respect to the hly gene, where serotype 4b Irish strains were distinct from Greek and Australian strains. Australian strains showed less diversity in plcB and mpl relative to Irish or Greek strains. Notable differences regarding sequence mutations were identified between food-associated and clinical isolates in prfA, actA, and plcB sequences. Overall, these results indicate that virulence genes follow different evolutionary pathways, which are affected by a strain's origin and serotype and may influence virulence and/or epidemiological dominance of certain subgroups.
    • Virulence Gene Sequencing Highlights Similarities and Differences in Sequences in Listeria monocytogenes Serotype 1/2a and 4b Strains of Clinical and Food Origin From 3 Different Geographic Locations

      Poimenidou, Sofia V.; Dalmasso, Marion; Papadimitriou, Konstantinos; Fox, Edward M.; Skandamis, Panagiotis N.; Jordan, Kieran; European Union; 265877 (Frontiers, 2018-06-05)
      The prfA-virulence gene cluster (pVGC) is the main pathogenicity island in Listeria monocytogenes, comprising the prfA, plcA, hly, mpl, actA, and plcB genes. In this study, the pVGC of 36 L. monocytogenes isolates with respect to different serotypes (1/2a or 4b), geographical origin (Australia, Greece or Ireland) and isolation source (food-associated or clinical) was characterized. The most conserved genes were prfA and hly, with the lowest nucleotide diversity (π) among all genes (P < 0.05), and the lowest number of alleles, substitutions and non-synonymous substitutions for prfA. Conversely, the most diverse gene was actA, which presented the highest number of alleles (n = 20) and showed the highest nucleotide diversity. Grouping by serotype had a significantly lower π value (P < 0.0001) compared to isolation source or geographical origin, suggesting a distinct and well-defined unit compared to other groupings. Among all tested genes, only hly and mpl were those with lower nucleotide diversity in 1/2a serotype than 4b serotype, reflecting a high within-1/2a serotype divergence compared to 4b serotype. Geographical divergence was noted with respect to the hly gene, where serotype 4b Irish strains were distinct from Greek and Australian strains. Australian strains showed less diversity in plcB and mpl relative to Irish or Greek strains. Notable differences regarding sequence mutations were identified between food-associated and clinical isolates in prfA, actA, and plcB sequences. Overall, these results indicate that virulence genes follow different evolutionary pathways, which are affected by a strain's origin and serotype and may influence virulence and/or epidemiological dominance of certain subgroups.
    • The virulence of E. coli 0157:H7 isolated from Irish sheep and pigs to humans

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

      Achata, Eva M.; Oliveira, Marcia; Esquerre, Carlos A.; Tiwari, Brijesh K; O'Donnell, Colm P.; Irish Department of Agriculture, Food & the Marine; 13/FM/508 (Elsevier BV, 2020-06)
      There is a need to develop a rapid technique to provide real time information on the microbial load of meat along the supply chain. Hyperspectral imaging (HSI) is a rapid, non-destructive technique well suited to food analysis applications. In this study, HSI in both the visible and near infrared spectral ranges, and chemometrics were studied for prediction of the bacterial growth on beef Longissimus dorsi muscle (LD) under simulated normal (4 °C) and abuse (10 °C) storage conditions. Total viable count (TVC) prediction models were developed using partial least squares regression (PLS-R), spectral pre-treatments, band selection and data fusion methods. The best TVC prediction models developed for storage at 4 (RMSEp 0.58 log CFU/g, RPDp 4.13, R2p 0.96), 10 °C (RMSEp 0.97 log CFU/g, RPDp 3.28, R2p 0.94) or at either 4 or 10 °C (RMSEp 0.89 log CFU/g, RPDp 2.27, R2p 0.86) were developed using high-level data fusion of both spectral regions. The use of appropriate spectral pre-treatments and band selection methods was key for robust model development. This study demonstrated the potential of HSI and chemometrics for real time monitoring to predict microbial growth on LD along the meat supply chain.
    • Water sorption and hydration in spray-dried milk protein powders: Selected physicochemical properties

      Maidannyk, Valentyn; McSweeney, David J.; Hogan, Sean; Miao, Song; Montgomery, Sharon; Auty, Mark A.E.; McCarthy, Noel; Department of Agriculture, Food and the Marine; 15-F-679 (Elsevier, 2020-08-22)
      Low and high protein dairy powders are prone to caking and sticking and can also be highly insoluble; with powder storage conditions an important factor responsible for such issues. The aim of this study focused on the bulk and surface properties of anhydrous and humidified spray-dried milk protein concentrate (MPC) powders (protein content ~40, 50, 60, 70 or 80%, w/w). Water sorption isotherms, polarized light and scanning electron micrographs showed crystallized lactose in low protein powders at high water activities. High protein systems demonstrated increased bulk diffusion coefficients compared to low protein systems. Glass transition temperatures, α-relaxation temperatures and structural strength significantly decreased with water uptake. CLSM measurements showed that humidified systems have slower real time water diffusion compared to anhydrous systems. Overall, the rate of water diffusion was higher for low protein powders but high protein powders absorbed higher levels of water under high humidity conditions.
    • Wheat flour properties and end product quality

      Dwyer, Elizabeth; O'Halloran, Grainne R.; Department of Agriculture, Food and the Marine (Teagasc, 1999-01)
      For pizza production, the flour quality values identified for the wheat cultivars, Promessa, Quintus (spring), and Soissons (winter) should be used as guidelines in selecting new cultivars and in the development of flour specifications. Similarly for biscuit production, compositional and rheological data for the cultivars, Riband,Woodstock (soft-milling) and Brigadier (hardmilling) should be used for identifying biscuit flours. The rheological properties of dough (as measured by the alveograph, extensograph and farinograph) did not relate to the baking quality for some wheat cultivars. However the rheological properties of the gel protein prepared from these flours explained their baking quality. The very high elastic moduli of these gels explained the basis of shrinkage of pizza bases produced from Baldus and Lavett flours and biscuits produced from Ritmo flour.
    • A Whey Fraction Rich in Immunoglobulin G Combined with Bifidobacterium longum subsp. infantis ATCC 15697 Exhibits Synergistic Effects against Campylobacter jejuni

      Quinn, Erinn M.; Kilcoyne, Michelle; Walsh, Dan; Joshi, Lokesh; Hickey, Rita M.; Teagasc Walsh Fellowship Programme (MDPI AG, 2020-06-29)
      Evidence that whey proteins and peptides have health benefits beyond basic infant nutrition has increased dramatically in recent years. Previously, we demonstrated that a whey-derived immunoglobulin G-enriched powder (IGEP) enhanced adhesion of Bifidobacterium longum subsp. infantis ATCC 15697 (B. infantis) to HT-29 cells. In this study, we investigated the synergistic effect of IGEP-treated B. infantis on preventing the attachment of highly invasive Campylobacter jejuni 81–176 (C. jejuni) to intestinal HT-29 cells. The combination decreased the adherence of C. jejuni to the HT-29 cells by an average of 48% compared to the control (non-IGEP-treated B. infantis). We also confirmed that treatment of IGEP with sodium metaperiodate, which disables the biological recognition of the conjugated oligosaccharides, reduced adhesion of B. infantis to the intestinal cells. Thus, glycosylation of the IGEP components may be important in enhancing B. infantis adhesion. Interestingly, an increased adhesion phenotype was not observed when B. infantis was treated with bovine serum-derived IgG, suggesting that bioactivity was unique to milk-derived immunoglobulin-rich powders. Notably, IGEP did not induce growth of B. infantis within a 24 hours incubation period, as demonstrated by growth curves and metabolite analysis. The current study provides insight into the functionality of bovine whey components and highlights their potential in positively impacting the development of a healthy microbiota.
    • Whey protein effects on energy balance link the intestinal mechanisms of energy absorption with adiposity and hypothalamic neuropeptide gene expression

      Nilaweera, Kanishka; Cabrera-Rubio, Raul; Speakman, John R.; O'Connor, Paula M.; McAuliffe, Ann Marie; Guinane, Caitriona M.; Lawton, Elaine M.; Crispie, Fiona; Aguillera, Monica; Stanley, Maurice; et al. (American Physiological Society, 21/03/2017)
      We tested the hypothesis that dietary whey protein isolate (WPI) affects the intestinal mechanisms related to energy absorption and that the resulting energy deficit is compensated by changes in energy balance to support growth. C57BL/6 mice were provided a diet enriched with WPI with varied sucrose content, and the impact on energy balance-related parameters was investigated. As part of a high-sucrose diet, WPI reduced the hypothalamic expression of pro-opiomelanocortin gene expression and increased energy intake. The energy expenditure was unaffected, but epididymal weight was reduced, indicating an energy loss. Notably, there was a reduction in the ileum gene expression for amino acid transporter SLC6a19, glucose transporter 2, and fatty acid transporter 4. The composition of the gut microbiota also changed, where Firmicutes were reduced. The above changes indicated reduced energy absorption through the intestine. We propose that this mobilized energy in the adipose tissue and caused hypothalamic changes that increased energy intake, acting to counteract the energy deficit arising in the intestine. Lowering the sucrose content in the WPI diet increased energy expenditure. This further reduced epididymal weight and plasma leptin, whereupon hypothalamic ghrelin gene expression and the intestinal weight were both increased. These data suggest that when the intestine-adipose-hypothalamic pathway is subjected to an additional energy loss (now in the adipose tissue), compensatory changes attempt to assimilate more energy. Notably, WPI and sucrose content interact to enable the component mechanisms of this pathway.
    • Whey protein effects on energy balance link the intestinal mechanisms of energy absorption with adiposity and hypothalamic neuropeptide gene expression

      Nilaweera, Kanishka; Cabrera-Rubio, Raul; Speakman, John R.; O'Connor, Paula M.; McAuliffe, Ann Marie; Guinane, Caitriona M.; Lawton, Elaine M.; Crispie, Fiona; Aguillera, Monica; Stanley, Maurice; et al. (American Physiological Society, 19/06/2017)
      We tested the hypothesis that dietary whey protein isolate (WPI) affects the intestinal mechanisms related to energy absorption and that the resulting energy deficit is compensated by changes in energy balance to support growth. C57BL/6 mice were provided a diet enriched with WPI with varied sucrose content, and the impact on energy balance-related parameters was investigated. As part of a high-sucrose diet, WPI reduced the hypothalamic expression of pro-opiomelanocortin gene expression and increased energy intake. The energy expenditure was unaffected, but epididymal weight was reduced, indicating an energy loss. Notably, there was a reduction in the ileum gene expression for amino acid transporter SLC6a19, glucose transporter 2, and fatty acid transporter 4. The composition of the gut microbiota also changed, where Firmicutes were reduced. The above changes indicated reduced energy absorption through the intestine. We propose that this mobilized energy in the adipose tissue and caused hypothalamic changes that increased energy intake, acting to counteract the energy deficit arising in the intestine. Lowering the sucrose content in the WPI diet increased energy expenditure. This further reduced epididymal weight and plasma leptin, whereupon hypothalamic ghrelin gene expression and the intestinal weight were both increased. These data suggest that when the intestine-adipose-hypothalamic pathway is subjected to an additional energy loss (now in the adipose tissue), compensatory changes attempt to assimilate more energy. Notably, WPI and sucrose content interact to enable the component mechanisms of this pathway.
    • Whey protein isolate decreases murine stomach weight and intestinal length and alters the expression of Wnt signalling-associated genes

      McAllan, Liam; Speakman, John R.; Cryan, John F.; Nilaweera, Kanishka (Cambridge University Press, 13/01/2015)
      The present study examined the underlying mechanisms by which whey protein isolate (WPI) affects energy balance. C57BL/6J mice were fed a diet containing 10 % energy from fat, 70 % energy from carbohydrate (35 % energy from sucrose) and 20 % energy from casein or WPI for 15 weeks. Mice fed with WPI had reduced weight gain, cumulative energy intake and dark-phase VO2 compared with casein-fed mice (P< 0·05); however, WPI intake had no significant effects on body composition, meal size/number, water intake or RER. Plasma levels of insulin, TAG, leptin, glucose and glucagon-like peptide 1 remained unchanged. Notably, the intake of WPI reduced stomach weight and both length and weight of the small intestine (P< 0·05). WPI intake reduced the gastric expression of Wingless/int-1 5a (Wnt5a) (P< 0·01) and frizzled 4 (Fzd4) (P< 0·01), with no change in the expression of receptor tyrosine kinase-like orphan receptor 2 (Ror2) and LDL receptor-related protein 5 (Lrp5). In the ileum, WPI increased the mRNA expression of Wnt5a (P< 0·01) and caused a trend towards an increase in the expression of Fzd4 (P= 0·094), with no change in the expression of Ror2 and Lrp5. These genes were unresponsive in the duodenum. Among the nutrient-responsive genes, WPI specifically reduced ileal mRNA expression of peptide YY (P< 0·01) and fatty acid transporter protein 4 (P< 0·05), and decreased duodenal mRNA expression of the insulin receptor (P= 0·05), with a trend towards a decreased expression of Na–glucose co-transporter 1 (P= 0·07). The effects of WPI on gastrointestinal Wnt signalling may explain how this protein affects gastrointestinal structure and function and, in turn, energy intake and balance.
    • Whey protein isolate polydispersity affects enzymatic hydrolosis outcomes

      O'Loughlin, Ian B.; Murray, Brian A.; Brodkorb, Andre; Fitzgerald, Richard J.; Robinson, A. A.; Holton, T. A.; Kelly, Tom A.; Teagasc Walsh Fellowship Programme; Enterprise Ireland; CC/2008/0001/A. (Elsevier, 24/05/2013)
      The effects of heat-induced denaturation of whey protein isolate (WPI) on the enzymatic breakdown of α-La, caseinomacropeptide (CMP), β-Lg A and β-Lg B were observed as hydrolysis proceeded to a 5% degree of hydrolysis (DH) in both unheated and heat-treated (80 °C, 10 min) WPI dispersions (100 g L−1). Hydrolysis of denatured WPI favoured the generation of higher levels of free essential amino acids; lysine, phenylalanine and arginine compared to the unheated substrate. LC–MS/MS identified 23 distinct peptides which were identified in the denatured WPI hydrolysate – the majority of which were derived from β-Lg. The mapping of the detected regions in α-La, β-Lg, and CMP enabled specific cleavage points to be associated with certain serine endo-protease activities. The outcomes of the study emphasise how a combined approach of substrate heat pre-treatment and enzymology may be used to influence proteolysis with attendant opportunities for targeting unique peptide production and amino acid release
    • Whole genome sequence analysis; an improved technology that identifies underlying genotypic differences between closely related Listeria monocytogenes strains

      Fox, Edward M.; Casey, Aidan; Jordan, Kieran; Coffey, Aidan; Gahan, Cormac G.M.; McAuliffe, Olivia (Elsevier, 2017-07-08)
      As the new technology of whole genome sequencing (WGS) has been shown to have greater discriminatory power in differentiating strains than the much-used pulsed-field gel electrophoresis (PFGE), there is currently a transition from using PFGE to WGS for disease outbreak investigation. Therefore, there is a need for comparison of bacterial isolates using both PFGE and WGS. In this study, two pairs of L. monocytogenes strains with geographically diverse sources of isolation but which had indistinguishable or closely related PFGE profiles, were subjected to WGS analysis. Comparative analysis of their genomes showed that one pair of strains which had closely related PFGE profiles in fact differed significantly from one another in terms of their antibiotic and heavy metal stress resistance determinants, and mobile genetic elements. Therefore, this research demonstrated the ability of WGS analysis to differentiate very closely related strains and that WGS analysis represents the most effective tool available for subtyping L. monocytogenes isolates.
    • Whole-Genome Shotgun Sequence of Salmonella bongori, First Isolated in Northwestern Italy

      Romano, Angelo; Bellio, Alberto; Macori, Guerrino; Cotter, Paul D.; Manila Bianchi, Daniela; Gallina, Silvia; Decastelli, Lucia (American Society for Microbiology, 06/07/2017)
      This study describes the whole-genome shotgun sequence of Salmonella bongori 48:z35:–, originally isolated from a 1-year-old symptomatic patient in northwest Italy, a typically nonendemic area. The draft genome sequence contained 4.56 Mbp and the G+C content was 51.27%.
    • WO 2018/114971 A1 A method for producing beads

      Brodkorb, Andre; Haque, Kamrul; Teagasc Agriculture and Food Development Authority (2020-10-19)
      The current invention relates to a method for producing beads. In particular, the current invention relates to a method for producing microbeads. The invention also relates to a microbead preparation produced by the method of the invention.
    • WS16.1 Clinical Outcomes of Real-World Kalydeco (CORK) study – Investigating the impact of CFTR potentiation on the intestinal microbiota, exocrine pancreatic function and intestinal inflammation prospectively over 12 months

      Deane, Jennifer; Ronan, N. J.; O'Callaghan, G. P.; Fouhy, Fiona; Rea, Mary; O'Sullivan, Orla; Hill, C. J.; Shanahan, F.; Ross, R Paul; McCarthy, M.; et al. (Elsevier, 2015-06-05)
      Objectives Ivacaftor is effective in the treatment of patients with CF and the G551D gating mutation. We present faecal analysis results of the CORK cohort, a single-centre, adult (n = 20), prospective, longitudinal study of G551D clinical responders (median follow-up 12 months), examining the gut microbiota, exocrine pancreatic function and intestinal inflammation on a 3 monthly basis after commencing treatment.
    • β-lactoglobulin as a molecular carrier of linoleate: characterisation and effects on intestinal epithelial cells in vitro

      Le Maux, Solene; Giblin, Linda; Croguennec, Thomas; Bouhallab, Said; Brodkorb, Andre; Department of Agriculture, Food and the Marine; Irish Research Council for Science, Engineering and Technology; Teagasc Walsh Fellowship Programme; 08/RD/TMFRC/650 (American Chemical Society, 27/08/2012)
      The dairy protein β-lactoglobulin (βlg) is known to bind hydrophobic ligands such as fatty acids. In the present work, we investigated the biological activity in vitro of linoleate once complexed to bovine βlg. Binding of linoleate (C18:2) to bovine βlg was achieved by heating at 60 °C for 30 min at pH 7.4, resulting in a linoleate/βlg molar binding stoichiometry of 1.1, 2.1, and 3.4. Two types of binding sites were determined by ITC titrations. Binding of linoleate induced the formation of covalent dimers and trimers of βlg. The LD50 on Caco-2 cells after 24 h was 58 μM linoleate. However, cell viability was unaffected when 200 μM linoleate was presented to the Caco-2 cells as part of the βlg complex. The Caco-2 cells did not increase mRNA transcript levels of long chain fatty acid transport genes, FATP4 and FABPpm, or increase levels of the cAMP signal, in response to the presence of 50 μM linoleate alone or as part of the βlg complex. Therefore, it is proposed that βlg can act as a molecular carrier and alter the bioaccessibility of linoleate/linoleic acid.
    • β-Lactoglobulin-linoleate complexes: In vitro digestion and the role of protein in fatty acids uptake

      Le Maux, Solene; Brodkorb, Andre; Croguennec, Thomas; Hennessy, Alan A.; Bouhallab, Said; Giblin, Linda; Department of Agriculture, Food and the Marine; Irish Research Council for Science, Engineering and Technology; Teagasc Walsh Fellowship Programme; 08/RD/TMFRC/650 (Elsevier Inc and American Dairy Science Association, 2013-07)
      The dairy protein β-lactoglobulin (BLG) is known to bind fatty acids such as the salt of the essential longchain fatty acid linoleic acid (cis,cis-9,12-octadecadienoic acid, n-6, 18:2). The aim of the current study was to investigate how bovine BLG-linoleate complexes, of various stoichiometry, affect the enzymatic digestion of BLG and the intracellular transport of linoleate into enterocyte-like monolayers. Duodenal and gastric digestions of the complexes indicated that BLG was hydrolyzed more rapidly when complexed with linoleate. Digested as well as undigested BLG-linoleate complexes reduced intracellular linoleate transport as compared with free linoleate. To investigate whether enteroendocrine cells perceive linoleate differently when part of a complex, the ability of linoleate to increase production or secretion of the enteroendocrine satiety hormone, cholecystokinin, was measured. Cholecystokinin mRNA levels were different when linoleate was presented to the cells alone or as part of a protein complex. In conclusion, understanding interactions between linoleate and BLG could help to formulate foods with targeted fatty acid bioaccessibility and, therefore, aid in the development of food matrices with optimal bioactive efficacy