Lipid and protein composition of a membrane-rich fraction of butter oil

1979 ◽  
Vol 46 (3) ◽  
pp. 511-521 ◽  
Author(s):  
Mary McCarthy ◽  
Denis R. Headon
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Bovine Milk ◽  
Skim Milk ◽  
Protein Composition ◽  
Fatty Acid Analysis ◽  
Protein Ratio ◽  
Butter Oil ◽  
Ethanolamine Phosphatidyl ◽  
Whole Milk ◽  
Phospholipid Classes

SummaryLipid and aqueous extracts of bovine milk and 5 fractions prepared from bovine milk, including a membrane-rich fraction (MRF) isolated during butter oil production, were analysed for neutral lipid, phospholipid, protein and glycoprotein. The MRF showed an 8·5-fold enrichment in the phospholipid: protein ratio compared to whole milk. The percentage distribution of the 3 major phospholipid classes, phosphatidyl ethanolamine, phosphatidyl choline and sphingomyelin was 30, 36, 31 % respectively, the values of which differ slightly from those of whole milk. Fatty acid analysis of the major neutral and phospholipid classes indicated a predominance of palmitate, stearate and oleate. SDS polyacrylamide-gel electrophoresis in polyacrylamide gradients indicated that the percentage protein having a mol. wt in excess of 75000 increased by a factor of 2 in the MRF when compared to milk. Glycoprotein profiles of the MRF and its precursor cream differ significantly from the patterns evident in whole milk and skim-milk.

scholarly journals Rapid Determination of Ampicillin in Bovine Milk by Liquid Chromatography with Fluorescence Detection

1997 ◽  
Vol 80 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Catharina Y W Ang ◽  
Luo Wenhong
Keyword(s):  
Fluorescence Detection ◽  
Rapid Determination ◽  
Bovine Milk ◽  
Skim Milk ◽  
Reversed Phase ◽  
Coefficients Of Variation ◽  
Whole Milk ◽  
Liquid Chromatographic ◽  
Clear Supernatant

Abstract A rapid and sensitive liquid chromatographic (LC) method was developed for the determination of am- picillin residues in raw bovine milk, processed skim milk, and pasteurized, homogenized whole milk with vitamin D. Milk samples were deprote- inized with trichloroacetic acid (TCA) and acetonitrile. After centrifugation, the clear supernatant was reacted with formaldehyde and TCA under heat. The major fluorescent derivative of ampicillin was then determined by reversed-phase LC with fluorescence detection. Average recoveries of ampicillin fortified at 5,10, and 20 ppb (ng/mL) were all >85% with coefficients of variation <10%. Limits of detection ranged from 0.31 to 0.51 ppb and limits of quantitation, from 0.66 to 1.2 ppb. After appropriate validation, this method should be suitable for rapid analysis of milk for ampicillin residues at the tolerance level of 10 ppb.

Interactions between the bovine milk fat globule membrane and skim milk components on heating whole milk

1992 ◽  
Vol 59 (2) ◽  
pp. 187-195 ◽  
Author(s):  
Avis V. Houlihan ◽  
Philippa A. Goddard ◽  
Stephen M. Nottingham ◽  
Barry J. Kitchen ◽  
Colin J. Masters
Keyword(s):  
Milk Fat ◽  
Bovine Milk ◽  
Skim Milk ◽  
Milk Proteins ◽  
Raw Milk ◽  
Membrane Lipid ◽  
Milk Fat Globule Membrane ◽  
Whole Milk ◽  
Milk Fat Globule ◽  
Fat Globule

SummaryHeating raw milk at 80 °C for 2·5–20 min was found to result in compositional changes in the milk fat globule membrane (MFGM). The yield of protein material increased with the duration of heating, owing to incorporation of skim milk proteins, predominantly β-lactoglobulin, into the membrane. Lipid components of the MFGM were also affected, with losses of triacylglycerols on heating.

The effect of heat treatment and skimming on precipitate formation in caprine and bovine milks

2014 ◽  
Vol 82 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Zorana N Miloradovic ◽  
Nemanja V Kljajevic ◽  
Snezana T Jovanovic ◽  
Tanja R Vucic ◽  
Ognjen D Macej
Keyword(s):  
Heat Treatment ◽  
Centrifugal Force ◽  
Colloidal Stability ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Bovine Milk ◽  
Protein Composition ◽  
Heat Stability ◽  
Protein Loss ◽  
Caprine Milk

Caprine and bovine milks have a similar overall gross composition, but vary considerably in the ratios of their casein components. These differences in colloidal casein micelles could affect directly or indirectly the heat stability of caprine and bovine milks at their natural pH. In the present work, the differences in colloidal stability of caprine and bovine milk have been studied by analysing the effect of heat treatment and skimming on precipitation of proteins. Raw and heated milk samples (70 °C/5 min, 80°C/5 min and 90°C/5 min) were centrifuged at 600, 2000, and 4500 g. The amount of precipitate formed after skimming was measured and the protein composition of both precipitates and supernatants analysed using the SDS-PAGE (sodium dodecyl sulphate polyacrylamide gel electrophoresis) and densitometry. In caprine milk, the heat treatment prior to skimming had a statistically significant effect on protein precipitation. Centrifugal force had a statistically significant effect on amount of precipitate for both milks, but the amount was 2 to 4 times higher for caprine milk. When defatting the milk for electrophoresis, a centrifugal force of 600 g appeared to be the most appropriate, in order to avoid protein loss and a possible error in the interpretation of results. Results of this study could also serve as the basis for further investigations on adjusting the skimming conditions for caprine milk in industrial dairy processing environment.

Denaturation of selected bioactive whey proteins during pasteurization and their ability to modulate milk immunogenicity

2020 ◽  
pp. 1-4
Author(s):  
Dimuthu Bogahawaththa ◽  
Todor Vasiljevic
Keyword(s):  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Polyacrylamide Gel Electrophoresis ◽  
Whey Proteins ◽  
Sodium Dodecyl ◽  
Bovine Milk ◽  
Skim Milk ◽  
Peripheral Blood Mononuclear ◽  
High Temperature Short Time

Abstract This research communication relates to the hypothesis that the consumption of raw or unprocessed cow's milk contributes to lowered prevalence of allergies. Thermal pasteurization of bovine milk can result in denaturation of minor whey proteins and loss of their bioactivity. Denaturation of bovine serum albumin (BSA), immunoglobulin G (IgG) and lactoferrin (LF) in skim milk was studied under different temperature (72, 75 or 78°C) and time (0–300 s) combinations. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) results revealed that denaturation of all 3 proteins occurred at 72°C and progressed with increase in temperature and holding time. About 59% of LF and 12% of IgG denatured under high-temperature short-time (72°C/ 15 s) pasteurization, while BSA was least impacted. To assess modulation of milk immunogenicity, secretion of selected T helper (Th)-type cytokines by human peripheral blood mononuclear cells (PBMCs) was studied in vitro in response to different concentrations of BSA (0.4–1.0 mg/ml) and IgG (0.8–1.6 mg/ml) in unheated skim milk. Addition of IgG at 1.6 mg/ml induced a prominent Th1-skewed cytokine profile that may not trigger a Th2-skewed allergic reaction. BSA did not appear to modulate milk immunogenicity to any significant extent.

Qualitative and quantitative determination of proteolysis in mastitic milks

1982 ◽  
Vol 49 (4) ◽  
pp. 587-596 ◽  
Author(s):  
Olivier de Rham ◽  
Anthony T. Andrews
Keyword(s):  
Proteolytic Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Skim Milk ◽  
Considerable Proportion ◽  
Freezing And Thawing ◽  
Protein Fragments ◽  
Whole Milk ◽  
Proteinase A ◽  
Mastitic Milk ◽  
Induced Changes

SUMMARYProteolytic activity in mastitic skim-milk was often 5–10 fold higher than in normal milk, its level being related to somatic cell count but not precisely correlated with it. In milks with the highest levels of activity plasmin accounted for about one third of the total proteinase. A further third was sedimented with the micellar fraction together with the plasmin, but unlike plasmin, was not inhibited by addition of soyabean trypsin inhibitor (SBTI). The final third remained in the serum phase.Polyacrylamide gel electrophoresis (PAGE) showed that αsl- and β-caseins were degraded at about the same overall rate. The plasmin produced the usual readily identified fragments from β-casein, but incubation of mastitic milk also produced changes in patterns in the γ-casein region differing from plasmin-induced changes which were also apparent when the micellar fraction was incubated. As they were inhibited by SBTI, a second trypsin-like enzyme in addition to plasmin may also have been present. Other proteinase(s) not inhibited by SBTI was also associated with casein micelles and produced at least 3 characteristic protein fragments seen on PAGE. The serum phase proteinase(s) was likewise not inhibited by SBTI, and did not produce any well-defined electrophoretic bands, suggesting a rather non-specific breakdown of caseins. After separation of mastitic whole milk, a considerable proportion of the proteolytic activity was found in the cream phase. The proportion was enhanced by freezing and thawing, and the enzyme appeared to be identical to the SBTI-resistant micellar proteinase.Because of the considerable proteolysis likely to occur under the time and temperature conditions involved, our results may provide some explanation for the problems encountered in cheesemaking with mastitic milks (e.g. yield losses, poor curd strength and off-flavour development).

Lipases in bovine milk and the relationship between the lipoprotein lipase and tributyrate hydrolysing activities in cream and skim-milk

1975 ◽  
Vol 42 (2) ◽  
pp. 255-266 ◽  
Author(s):  
H. B. Castberg ◽  
T. Egelrud ◽  
P. Solberg ◽  
T. Olivecrona
Keyword(s):  
Affinity Chromatography ◽  
Lipoprotein Lipase ◽  
Enzyme Activities ◽  
Marked Decrease ◽  
Uv Light ◽  
Bovine Milk ◽  
Skim Milk ◽  
Total Inhibition ◽  
Whole Milk ◽  
The Relationship

SummaryThe lipoprotein lipase and tributyrate hydrolysing activities were found to be similarly distributed in the fractions obtained when whole milk was separated into skim-milk and cream, and when the cream was washed and freed from lipid. These enzyme activities in skim-milks and in extracts of lipid-free cream could not be separated by affinity chromatography on heparin-Sepharose. The enzymes were inactivated to the same degree when incubated at 37°C in the presence of 1·5 M-NaCl, pH 8·5, and both showed the same marked decrease in stability at 4°C in 1·5 M-NaCl, when the pH was changed from 8·3 to 9·0. Irradiation of skim-milk with UV-light caused the same decrease in both lipoprotein lipase and tributyrate hydrolysing activities. An antiserum against a highly purified skim-milk lipoprotein lipase caused total inhibition of the lipoprotein lipase and tributyrate hydrolysing activities in skim-milk and in extracts of lipid-free cream. It is suggested that in bovine milk there is only one major lipase and that it is identical to lipoprotein lipase.

Cariogenicity of a Milk-Based Drink Used as a Dietary Supplement for Older Adults Using a Root Caries Experimental Model

2018 ◽  
Vol 53 (1) ◽  
pp. 76-83 ◽  
Author(s):  
Ramiro J. Castro ◽  
Rodrigo A. Giacaman ◽  
Rodrigo A. Arthur ◽  
Marisa Maltz
Keyword(s):  
Older Adults ◽  
Bovine Milk ◽  
Skim Milk ◽  
Positive Control ◽  
Fat Content ◽  
Root Caries ◽  
Bacterial Counts ◽  
Whole Milk ◽  
Caries Model ◽  
Mineral Loss

The aim of this study was to evaluate the cariogenicity of a milk-based drink intended for older adults that was used as part of a governmental initiative in Chile to improve their nutritional conditions. This drink contains a high concentration of sugars, which can contribute to root caries development. To test this hypothesis, an experimental biofilm/caries model was used. Dentin slabs were used to grow biofilms of Streptococcus mutans UA159. Slabs/biofilms were exposed 3× per day to bovine milk with different fat content, the milk-based drink, and the milk-based drink supplemented with 10 g of sucrose added per serving. Slabs exposed to 10% sucrose or 0.9% NaCl were used as positive and negative controls, respectively. Biofilms were analyzed for bacterial counts and acidogenicity. Dentin demineralization was estimated by the loss of surface microhardness and integrated mineral loss. Results were compared by analysis of variance and Tukey’s test. The milk-based drink showed higher acidogenicity than milk with its entire (whole) or reduced total fat content (skim). The milk-based drink supplemented with ­sucrose had similar acidogenicity as the 10% sucrose positive control (p = 0.506). Whole milk exposure elicited lower bacterial counts than the positive control, the milk-based drink, and the milk-based drink supplemented with sucrose (p = 0.002; 0.006 and 0.014 respectively). Although skim milk induced higher demineralization than whole milk, both milk types produced lower demineralization than the milk-based drink. Regarding integrated mineral loss, demineralization induced by the milk-based drink and the milk-based drink supplemented with sucrose was similar to that induced by the positive control and skim milk (p > 0.05). Sugar-containing milk-based drinks used as dietary supplements for older adults may be highly cariogenic and could represent a potential risk for root caries.

scholarly journals Non-Coding RNA in Raw and Commercially Processed Milk and Putative Targets Related to Growth and Immune-Response

2020 ◽  
Author(s):  
S. Shome ◽  
R. Jernigan ◽  
D. Beitz ◽  
S. Clark ◽  
E. Testroet
Keyword(s):  
Immune Response ◽  
Bos Taurus ◽  
Bovine Milk ◽  
Skim Milk ◽  
Putative Gene ◽  
Non Coding Rna ◽  
Heat Treated ◽  
Whole Milk ◽  
Dairy Plant ◽  
Processing Steps

Abstract Background:Bovine milk contains extracellular vesicles (EVs) that play a role in cellular communication, acting in either an autocrine, paracrine, or an exocrine manner. The unique properties of the EVs protect the cargo against degradation. We profiled the ncRNAs (non-coding RNA) present in the EVs from five fluid dairy products - raw whole milk, heat-treated skim milk, homogenized heat-treated skim milk, pasteurized homogenized skim milk, and pasteurized heavy whipping cream (four replicates each) obtained at different processing steps from a commercial dairy plant. EVs and their cargo were extracted by using a validated commercial kit that has been shown to be efficient and specific for EVs. Because many ncRNAs and the ncRNAs of bovine are less well characterized that human but are generally highly conserved, both human and Bos taurus databases were probed for putative targets. Results:Thirty microRNAs (miRNAs), isolated from milk, with their corresponding 1546 putative gene targets have functions associated with immune response and growth and development, indicating the potential for these ncRNAs to beneficially support mammary health and growth for the cow as well as neonatal gut maturation. The most abundant miRNAs were miR-125, which is involved in host bacterial and viral immune response, and human homolog miR-718 in the regulation of p53, VEGF, and IGF signaling pathways, respectively. Sixty-two miRNAs were enriched and 121 miRNAs were diluted throughout all the milk samples when compared to raw whole milk. In addition, our study explored the putative roles of other ncRNAs which included 88 piRNAs (piwi-interacting RNA), 64 antisense RNAs, and 105 long-intergenic ncRNAs contained in the bovine exosomes. Conclusion:Together, the results indicate that bovine milk contains significant numbers of ncRNAs with putative regulatory targets associated with immune- and developmental-functions important for neonatal bovine health, and that processing significantly increases the abundance of these ncRNA species. It is worth noting, however, that these gene regulatory targets are putative, and, though not necessary, further evidence could be generated through experimental validation.

scholarly journals Non-coding RNA in raw and commercially processed milk and putative targets related to growth and immune-response

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
S. Shome ◽  
R. L. Jernigan ◽  
D. C. Beitz ◽  
S. Clark ◽  
E. D. Testroet
Keyword(s):  
Immune Response ◽  
Bovine Milk ◽  
Skim Milk ◽  
Statistical Testing ◽  
Human Homolog ◽  
Putative Gene ◽  
Milk Samples ◽  
Non Coding Rna ◽  
Heat Treated ◽  
Whole Milk

Abstract Background Bovine milk contains extracellular vesicles (EVs) that play a role in cellular communication, acting in either an autocrine, paracrine, or an exocrine manner. The unique properties of the EVs protect the cargo against degradation. We profiled the ncRNAs (non-coding RNA) present in the EVs from seven dairy products - raw whole milk, heat-treated skim milk, homogenized heat-treated skim milk, pasteurized homogenized skim milk, pasteurized heavy whipping cream, sweet cream buttermilk and cultured buttermilk with four replicates each, obtained at different processing steps from a commercial dairy plant. EVs and their cargo were extracted by using a validated commercial kit that has been shown to be efficient and specific for EVs. Further, to find the annotation of ncRNAs, we probed bovine and other organism repositories(such as miRBase, miRTarBase, Ensemble) to find homolog ncRNA annotation in case the annotations of ncRNA are not available in Bos Taurus database. Results Specifically, 30 microRNAs (miRNAs), were isolated throughout all the seven milk samples, which later when annotated with their corresponding 1546 putative gene targets have functions associated with immune response and growth and development. This indicates the potential for these ncRNAs to beneficially support mammary health and growth for the cow as well as neonatal gut maturation. The most abundant miRNAs were bta-miR-125a and human homolog miR-718 based on the abundance values of read count obtained from the milk samples.bta-miR-125a is involved in host bacterial and viral immune response, and human homolog miR-718 is involved in the regulation of p53, VEGF, and IGF signaling pathways, respectively. Sixty-two miRNAs were up-regulated and 121 miRNAs were down-regulated throughout all the milk samples when compared to raw whole milk. In addition, our study explored the putative roles of other ncRNAs which included 88 piRNAs (piwi-interacting RNA), 64 antisense RNAs, and 105 lincRNAs (long-intergenic ncRNAs) contained in the bovine exosomes. Conclusion Together, the results indicate that bovine milk contains significant numbers of ncRNAs with putative regulatory targets associated with immune- and developmental-functions important for neonatal bovine health, and that processing significantly affects the ncRNA expression values; but statistical testing of overall abundance(read counts) of all miRNA samples suggests abundance values aren’t much affected. This can be attributed to the breakage of exosomal vesicles during the processing stages. It is worth noting, however, that these gene regulatory targets are putative, and further evidence could be generated through experimental validation.

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