Browsing Food Biosciences by Author "Croguennec, Thomas"
Complexes between linoleate and native or aggregated β-lactoglobulin: Interaction parameters and in vitro cytotoxic effect.Le Maux, Solene; Bouhallab, Said; Giblin, Linda; Brodkorb, Andre; Croguennec, Thomas; Department of Agriculture, Food and the Marine; Teagasc Walsh Fellowship Programme; Irish Research Council for Science, Engineering and Technology; 08/RD/TMFRC/650 (Elsevier, 2013-11)Iron is essential for human health, but it sometimes causes an unpleasant taste, rusty colour and a decrease in the stability of food products. Previously, we found that ethanol-treated yeast (ETY) cells could remove iron from wine and juice, and reduce the fishy aftertaste induced by iron in wine–seafood pairings. However, the mechanism of iron sorption by ETY cells is undefined; thus, there is no indicator that can be used to estimate the iron sorption capacity of these cells. In this study, we showed that cell wall components are not mainly associated with iron sorption by investigating ETY cells with the cell wall removed. Moreover, plasma membrane permeability was correlated with the iron sorbing capacity of the cells. Microscopic analysis showed that iron accumulated within ETY cells. Proteinase-treated ETY cells had no iron sorbing capacity. On the basis of these results, we conclude that intracellular proteins are involved in iron sorption by ETY cells.
β-lactoglobulin as a molecular carrier of linoleate: characterisation and effects on intestinal epithelial cells in vitroLe 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 uptakeLe 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