scholarly journals Comparative Structural and Compositional Analyses of Cow, Buffalo, Goat and Sheep Cream

Foods ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2643
Author(s):  
Valeria D. Felice ◽  
Rebecca A. Owens ◽  
Deirdre Kennedy ◽  
Sean A. Hogan ◽  
Jonathan A. Lane
Keyword(s):  
Milk Fat ◽  
Antigen Processing ◽  
Laser Scanning ◽  
Saturated Fatty Acids ◽  
Buffalo Milk ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Milk Formula ◽  
Fat Globules ◽  
Milk Fat Globules

Factors affecting milk and milk fraction composition, such as cream, are poorly understood, with most research and human health application associated with cow cream. In this study, proteomic and lipidomic analyses were performed on cow, goat, sheep and Bubalus bubalis (from now on referred to as buffalo), bulk milk cream samples. Confocal laser scanning microscopy was used to determine the composition, including protein, lipid and their glycoconjugates, and the structure of the milk fat globules. BLAST2GO was used to annotate functional indicators of cream protein. Functional annotation of protein highlighted a broad level of similarity between species. However, investigation of specific biological process terms revealed distinct differences in antigen processing and presentation, activation, and production of molecular mediators of the immune response. Lipid analyses revealed that saturated fatty acids were lowest in sheep cream and similar in the cream of the other species. Palmitic acid was highest in cow and lowest in sheep cream. Cow and sheep milk fat globules were associated with thick patches of protein on the surface, while buffalo and goat milk fat globules were associated with larger areas of aggregated protein and significant surface adsorbed protein, respectively. This study highlights the differences between cow, goat, sheep, and buffalo milk cream, which can be used to support their potential application in functional foods such as infant milk formula.

scholarly journals MICROSCOPY TECHNIQUES ARE EFFECTIVE TOOLS FOR IMPLEMENTING STUDIES IN DAIRY SCIENCE AND TECHNOLOGY

2018 ◽  
Author(s):  
Paolo D'Incecco ◽  
Luisa Pellegrino
Keyword(s):  
Protein Interactions ◽  
Milk Fat ◽  
Laser Scanning ◽  
Biological Membrane ◽  
Immunogold Labelling ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Storage Lipids ◽  
Fat Globules ◽  
Microscopy Techniques

Milk is a complex system where lipids, proteins, sugars and salts are present in different phases, and thus shows a characteristic behaviour during either technological treatments or storage. Lipids are organized as globules, small drops of triglycerides surrounded by a biological membrane that ensures stability of their emulsion. Casein is the main milk protein and is organized as micelles containing salts and strongly hydrated. This last feature has an important effect on the micelle stability. Furthermore, micelle stability is ensured by glycosylated k-casein fragments. Interaction between fat globules and casein micelles are likely to occur since ~1010 globules e 1014 micelles are present in 1 mL of milk and their reactive surface is approximately 0.07 and 4 m2 respectively. Different milk processes, i.e. mechanic or thermal, are responsible for interactions which may vary in number and chemical nature. Microscopy techniques represent an indispensable tool to study milk microstructure during milk processing or even on finished products upon storage. Confocal laser scanning microscopy, through specific probes, is suitable to study phenomena of coalescence among fat globules and fat-protein interactions in fluid milk, gel (clotted milk) or cheese. Transmission electron microscopy and immunogold labelling are used to more deeply investigate either milk components ultrastructure or specific interactions established between the milk fat globule membrane and the casein fractions. Food products are matrices where a multidisciplinary approach is necessary for their study, and microscopy certainly plays a key role.

Thermal effects on IgM-milk fat globule-mediated agglutination

2018 ◽  
Vol 86 (1) ◽  
pp. 108-113 ◽  
Author(s):  
Steffen F. Hansen ◽  
Lotte B. Larsen ◽  
Lars Wiking
Keyword(s):  
Milk Fat ◽  
Storage Temperature ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Immunoglobulin M ◽  
Laser Scanning Microscopy ◽  
Fat Globules ◽  
Milk Fat Globules ◽  
Milk Fat Globule ◽  
Fat Globule

AbstractThe process of agglutination causes firm cream layers in bovine milk, and a functioning agglutination mechanism is paramount to the quality of non-homogenized milks. The phenomenon is not well-described, but it is believed to occur due to interactions between immunoglobulins (Ig) and milk fat globules. For the first time, this paper demonstrates how the process of agglutination can be visualized using confocal laser scanning microscopy, rhodamine red and a fluoresceinisothiocynat-conjugated immunoglobulin M antibody. The method was used to illustrate the effect on agglutination of storage temperature and pasteurization temperature. Storage at 5 °C resulted in clearly visible agglutination which, however, was markedly reduced at 15 °C. Increasing storage temperature to 20 or 37 °C cancelled any detectable interaction between IgM and milk fat globules, whereby the occurrence of cold agglutination was documented. Increasing 20 s pasteurization temperatures from 69 °C to 71 °C and further to 73 °C lead to progressively higher inactivation of IgM and, hence, reduction of agglutination. Furthermore, 2-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis showed that changes in storage temperature caused a redistribution of Ig-related proteins in milk fat globule membrane isolates. Poly-immunoglobulin G receptor was present in milk fat globule preparations stored at cold (4 °C) conditions, but absent at storage at higher temperature (25 °C). The findings provide valuable knowledge to dairy producers of non-homogenized milk in deciding the right pasteurization temperature to retain the crucial agglutination mechanism.

scholarly journals Buffalo milk fat globules and their biological membrane: in situ structural investigations

2015 ◽  
Vol 67 ◽  
pp. 35-43 ◽  
Author(s):  
Hanh T.H. Nguyen ◽  
Lydia Ong ◽  
Eric Beaucher ◽  
Marie-Noëlle Madec ◽  
Sandra E. Kentish ◽  
...  
Keyword(s):  
Milk Fat ◽  
Biological Membrane ◽  
Buffalo Milk ◽  
Structural Investigations ◽  
Fat Globules ◽  
Milk Fat Globules

scholarly journals Bovine Herpesvirus 1 UL49.5 Protein Inhibits the Transporter Associated with Antigen Processing despite Complex Formation with Glycoprotein M

2006 ◽  
Vol 80 (12) ◽  
pp. 5822-5832 ◽  
Author(s):  
Andrea D. Lipińska ◽  
Danijela Koppers-Lalic ◽  
Michał Rychłowski ◽  
Pieter Admiraal ◽  
Frans A. M. Rijsewijk ◽  
...  
Keyword(s):  
Antigen Processing ◽  
Laser Scanning ◽  
Bovine Herpesvirus ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Bovine Herpesvirus 1 ◽  
Infected Cells ◽  
Herpesvirus 1 ◽  
Golgi Network ◽  
Peptide Translocation

ABSTRACT Bovine herpesvirus 1 (BHV-1) interferes with peptide translocation by the transporter associated with antigen processing (TAP). Recently, the UL49.5 gene product of BHV-1 was identified as the protein responsible for the observed inhibition of TAP. In BHV-1-infected cells and virions, the UL49.5 protein forms a complex with glycoprotein M (gM). Hence, it was investigated whether UL49.5 can combine the interactions with gM and the TAP complex. In cell lines constitutively expressing both UL49.5 and gM, UL49.5 appears to be required for functional processing of gM. Immunofluorescence-confocal laser scanning microscopy demonstrated that both proteins are interdependent for their redistribution from the endoplasmic reticulum to the trans-Golgi network. Remarkably, expression of cloned gM results in the abrogation of the UL49.5-mediated inhibition of TAP and prevents the degradation of the transporter. However, in BHV-1-infected cells, differences in UL49.5 and gM expression kinetics were seen to create a window of opportunity at the early stages of infection, during which time the UL49.5 protein can act on TAP without gM interference. Moreover, in later periods, non-gM-associated UL49.5 can be detected in addition to the UL49.5/gM complex. Thus, it has been deduced that different functions of UL49.5, editing of gM processing and inhibition of TAP, can be combined during BHV-1 infection.

3-D imaging of cells using a confocal laser scanning microscope and digital image processing

1988 ◽  
Vol 46 ◽  
pp. 96-97
Author(s):  
Thomas M. Jovin ◽  
Michel Robert-Nicoud ◽  
Donna J. Arndt-Jovin ◽  
Thorsten Schormann
Keyword(s):  
Laser Scanning ◽  
Confocal Laser Scanning Microscope ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Scanning Microscope ◽  
Laser Scanning Microscope ◽  
Biochemical Processes ◽  
Adjacent Structures

Light microscopic techniques for visualizing biomolecules and biochemical processes in situ have become indispensable in studies concerning the structural organization of supramolecular assemblies in cells and of processes during the cell cycle, transformation, differentiation, and development. Confocal laser scanning microscopy offers a number of advantages for the in situ localization and quantitation of fluorescence labeled targets and probes: (i) rejection of interfering signals emanating from out-of-focus and adjacent structures, allowing the “optical sectioning” of the specimen and 3-D reconstruction without time consuming deconvolution; (ii) increased spatial resolution; (iii) electronic control of contrast and magnification; (iv) simultanous imaging of the specimen by optical phenomena based on incident, scattered, emitted, and transmitted light; and (v) simultanous use of different fluorescent probes and types of detectors.We currently use a confocal laser scanning microscope CLSM (Zeiss, Oberkochen) equipped with 3-laser excitation (u.v - visible) and confocal optics in the fluorescence mode, as well as a computer-controlled X-Y-Z scanning stage with 0.1 μ resolution.

Vacuoles Induced in Mammalian Cells by Helicobacter Cytotoxin are Acidic Organelles

1990 ◽  
Vol 48 (3) ◽  
pp. 168-169
Author(s):  
M. H. Chestnut ◽  
C. E. Catrenich
Keyword(s):  
Acridine Orange ◽  
Mammalian Cells ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Ulcer Disease ◽  
Gastroduodenal Disease ◽  
H Pylori

Helicobacter pylori is a non-invasive, Gram-negative spiral bacterium first identified in 1983, and subsequently implicated in the pathogenesis of gastroduodenal disease including gastritis and peptic ulcer disease. Cytotoxic activity, manifested by intracytoplasmic vacuolation of mammalian cells in vitro, was identified in 55% of H. pylori strains examined. The vacuoles increase in number and size during extended incubation, resulting in vacuolar and cellular degeneration after 24 h to 48 h. Vacuolation of gastric epithelial cells is also observed in vivo during infection by H. pylori. A high molecular weight, heat labile protein is believed to be responsible for vacuolation and to significantly contribute to the development of gastroduodenal disease in humans. The mechanism by which the cytotoxin exerts its effect is unknown, as is the intracellular origin of the vacuolar membrane and contents. Acridine orange is a membrane-permeant weak base that initially accumulates in low-pH compartments. We have used acridine orange accumulation in conjunction with confocal laser scanning microscopy of toxin-treated cells to begin probing the nature and origin of these vacuoles.

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