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von Oesen T, Schrader K, Clawin-Rädecker I, Martin D, Treblin M, Hoffmann W, Bode K, Zink R, Rohn S, Fritsche J. Physicochemical and Sensory Characterization of Whey Protein-Enriched Semihard Cheese. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:5898-5911. [PMID: 38459945 DOI: 10.1021/acs.jafc.3c08731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/11/2024]
Abstract
In view of potential future changes of German food legislation with regard to cheese product quality parameters, this study aimed to evaluate the quality of whey protein-enriched semihard cheese (WPEC). Model WPEC was produced in a pilot plant and on an industrial scale by adding defined amounts of high-heat (HH) milk to the cheese milk and comprehensively analyzed during cheese processing. The dry matter, total protein, pure protein, fat, and sodium chloride content of six-week ripened cheese samples were not significantly different (p < 0.05) when the technologically necessary heating of the curd was adapted to the amount of HH milk. However, the ripening, firmness, and melting behavior of WPEC was different compared to cheese without HH milk. During ripening, no formation of whey protein peptides was observed, but differences in the amount of some bitter peptides deriving from the casein fraction were found. Sensory data suggested a slightly more bitter taste perception by the panelists for the WPEC. Further technological adjustments are recommended to obtain marketable WPEC.
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Affiliation(s)
- Tobias von Oesen
- Department of Safety and Quality of Milk and Fish Products, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Hermann-Weigmann-Straße 1, Kiel 24103, Germany
| | - Katrin Schrader
- Department of Safety and Quality of Milk and Fish Products, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Hermann-Weigmann-Straße 1, Kiel 24103, Germany
| | - Ingrid Clawin-Rädecker
- Department of Safety and Quality of Milk and Fish Products, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Hermann-Weigmann-Straße 1, Kiel 24103, Germany
| | - Dierk Martin
- Department of Safety and Quality of Milk and Fish Products, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Hermann-Weigmann-Straße 1, Kiel 24103, Germany
| | - Mascha Treblin
- Institute of Food Chemistry, Hamburg School of Food Science, University of Hamburg, Grindelallee 117, Hamburg 20146, Germany
| | - Wolfgang Hoffmann
- Department of Safety and Quality of Milk and Fish Products, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Hermann-Weigmann-Straße 1, Kiel 24103, Germany
| | - Katja Bode
- Center of Expertise Research & Technology (CoE-R&T), DMK Group (Deutsches Milchkontor GmbH), Flughafenallee 17, Bremen 28199, Germany
| | - Ralf Zink
- Center of Expertise Research & Technology (CoE-R&T), DMK Group (Deutsches Milchkontor GmbH), Flughafenallee 17, Bremen 28199, Germany
| | - Sascha Rohn
- Department of Food Chemistry and Analysis, Institute of Food Technology and Food Chemistry, Technische Universität Berlin, TIB 4/3 1, Gustav-Meyer-Allee 25, Berlin 13355, Germany
| | - Jan Fritsche
- Department of Safety and Quality of Milk and Fish Products, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Hermann-Weigmann-Straße 1, Kiel 24103, Germany
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Roberge H, Moreau P, Couallier E, Abellan P. Lipids and Proteins Differentiation in Membrane Fouling Using Heavy Metal Staining and Electron Microscopy at Cryogenic Temperatures. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:2090-2098. [PMID: 37966971 DOI: 10.1093/micmic/ozad114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/08/2023] [Accepted: 09/24/2023] [Indexed: 11/17/2023]
Abstract
The detailed characterization of fouling in membranes is essential to understand any observed improvement or reduction on filtration performance. Electron microscopy allows detailed structural characterization, and its combination with labeling techniques, using electron-dense probes, typically allows for the differentiation of biomolecules. Developing specific protocols that allow for differentiation of biomolecules in membrane fouling by electron microscopy is a major challenge due to both as follows: the necessity to preserve the native state of fouled membranes upon real filtration conditions as well as the inability of the electron-dense probes to penetrate the membranes once they have been fouled. In this study, we present the development of a heavy metal staining technique for identification and differentiation of biomolecules in membrane fouling, which is compatible with cryofixation methods. A general contrast enhancement of biomolecules and fouling is achieved. Our observations indicate a strong interaction between biomolecules: A tendency of proteins, both in solution as well as in the fouling, to surround the lipids is observed. Using transmission electron microscopy and scanning electron microscopy at cryogenic conditions, cryo-SEM, in combination with energy-dispersive X-ray spectroscopy, the spatial distribution of proteins and lipids within fouling is shown and the role of proteins in fouling discussed.
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Affiliation(s)
- Hélène Roberge
- Nantes Université, CNRS, Institut des Matériaux de Nantes Jean Rouxel, IMN, 2 rue de la Houssinère, 44000 Nantes, France
- Laboratoire de Génie des Procédés, Nantes Université, CNRS, ONIRIS, Environnement et Agroalimentaire, 37 boulevard de l'université, GEPEA, 44600 Saint-Nazaire, France
| | - Philippe Moreau
- Nantes Université, CNRS, Institut des Matériaux de Nantes Jean Rouxel, IMN, 2 rue de la Houssinère, 44000 Nantes, France
| | - Estelle Couallier
- Laboratoire de Génie des Procédés, Nantes Université, CNRS, ONIRIS, Environnement et Agroalimentaire, 37 boulevard de l'université, GEPEA, 44600 Saint-Nazaire, France
| | - Patricia Abellan
- Nantes Université, CNRS, Institut des Matériaux de Nantes Jean Rouxel, IMN, 2 rue de la Houssinère, 44000 Nantes, France
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Chemical Fixation, Immunofluorescence, and Immunogold Labeling of Electron Microscopical Sections. Methods Mol Biol 2019. [PMID: 31148030 DOI: 10.1007/978-1-4939-9469-4_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Knowledge about the spatiotemporal distribution patterns of proteins and other molecules of the cell is essential for understanding their function. A widely used technique is immunolabeling which uses specific antibodies to reveal the distribution of molecular components at various structural levels. Immunofluorescence gives an overview about the distribution of molecules at the level of the fluorescence or confocal laser scanning microscope. Electron microscopy offers the highest resolution of morphological techniques and is thus an indispensable tool for the analysis of molecule distribution patterns at the subcellular level. In this chapter we describe selected routine methods for immunofluorescence and for labeling ultrathin sections of resin-embedded material with antibodies conjugated to colloidal gold, including protocols for chemical fixation, embedding, and sectioning.
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Abstract
Knowledge about the spatio-temporal distribution patterns of proteins and other molecules of the cell is essential for understanding their function. A widely used technique is immunolabeling which uses specific antibodies to reveal the distribution of molecular components at various structural levels. Electron microscopy offers the highest resolution of morphological techniques and is thus an indispensable tool for the analysis of molecule distribution patterns at the subcellular level. In this chapter we describe a routine method for labeling ultrathin sections of resin-embedded material with antibodies conjugated to colloidal gold.
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Sarraf CE, Harris AB, McCulloch AD, Eastwood M. Heart valve and arterial tissue engineering. Cell Prolif 2003; 36:241-54. [PMID: 14521518 PMCID: PMC6496809 DOI: 10.1046/j.1365-2184.2003.00281.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2003] [Accepted: 08/06/2003] [Indexed: 11/20/2022] Open
Abstract
In the industrialized world, cardiovascular disease alone is responsible for almost half of all deaths. Many of the conditions can be treated successfully with surgery, often using transplantation techniques; however, autologous vessels or human-donated organs are in short supply. Tissue engineering aims to create specific, matching grafts by growing cells on appropriate matrices, but there are many steps between the research laboratory and the operating theatre. Neo-tissues must be effective, durable, non-thrombogenic and non-immunogenic. Scaffolds should be bio-compatible, porous (to allow cell/cell communication) and amenable to surgery. In the early days of cardiovascular tissue engineering, autologous or allogenic cells were grown on inert matrices, but patency and thrombogenicity of grafts were disappointing. The current ethos is toward appropriate cell types grown in (most often) a polymeric matrix that degrades at a rate compatible with the cells' production of their own extracellular matrical proteins, thus gradually replacing the graft with a living counterpart. The geometry is crucial. Computer models have been made of valves, and these are used as three-dimensional patterns for mass-production of implant scaffolds. Vessel walls have integral connective tissue architecture, and application of physiological level mechanical forces conditions bio-engineered components to align in precise orientation. This article reviews the concepts involved and successes achieved to date.
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Affiliation(s)
- C E Sarraf
- Centre for Tissue Engineering Research, Department of Biomedical Sciences, University of Westminster, London, UK.
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