scholarly journals A Comparison of Different Methodologies for the Measurement of Extracellular Vesicles and Milk-derived Particles in Raw Milk from Cows

2016 ◽  
Vol 11 ◽  
pp. BMI.S38438
Author(s):  
Geoff Pollott ◽  
Amanda Brito ◽  
Christopher Gardiner ◽  
Charlotte Lawson

Cow's milk is economically important to the agricultural industry with the nutritive value of milk being routinely measured. This does not give full insight into normal mammary tissue turnover during the course of lactation, which could be important for both an understanding of milk production and animal welfare. We have previously demonstrated that submicron particles, including extracellular vesicles (EVs), can be measured in unprocessed cow's milk by flow cytometry and that they correlate with stage of lactation. A number of different techniques are available to measure EVs and other milk-derived particles. The purpose of this study was to compare two different methodologies and the value of fluorescent staining for the phospholipid phosphatidylserine (PS), which is exposed on the surface of EVs (but not other milk-derived particles). We used two different flow cytometers and nanotracker analysis to detect milk-derived particles in whole and skimmed milk samples. Our findings indicate significant correlation, after staining for PS, suggesting potential for larger multicenter studies in the future.

2000 ◽  
Vol 63 (9) ◽  
pp. 1258-1261 ◽  
Author(s):  
M. F. SCINTU ◽  
E. DAGA ◽  
A. LEDDA

The alkaline phosphatase (ALP) activity test has been used since 1935 to assess the effectiveness of pasteurization. Different analytical methods exist for detecting ALP in milk. Unfortunately, there is little information about ALP activity in ewe's milk. The aim of this study was to assess and compare the official European method (spectrophotometric method) and the Fluorophos method (fluorometric method) regarding their use in ewe's milk. Bulk ewe's milk samples were taken from a flock and from three different dairies. A portion of the original sample was pasteurized at 63°C for 30 min in a circulating bath; another portion was heated to and kept at 95°C for about 2 min, and 0.1% (vol/vol) of raw milk was added. The samples obtained were analyzed in duplicate using the spectrophotometric and fluorometric methods. The relation between ALP activity determined by the two methods was characterized by the following equation: Y = 1.34 + 0.0039X (where Y = ALP in μg of phenol per ml of milk and X = ALP in mU/liter; R2 = 91.5%). Precision parameters (repeatability [r], standard deviation of repeatability [sr], and relative standard deviation of repeatability [RSDr]) for both methods were calculated. The values of RSDr for the Fluorophos method were 4.30 for pasteurized milk and 2.96 for 0.1% raw milk, close to the value indicated by Rocco in whole cow's milk (RSDr = 4.4). The repeatability for the official method (r = 2.16) was close to that indicated for whole cow's milk (r = 2).


1954 ◽  
Vol 21 (1) ◽  
pp. 50-54 ◽  
Author(s):  
W. G. Whittlestone

An examination of the fat-globule size distribution pattern has been made throughout the lactation for one quarter of one cow, samples being taken at different stages in the milking process using a normal milking machine with sampling device attached.


Author(s):  
Mourad HAMIROUNE ◽  
Sounia DAHMANI ◽  
Zineb KASMI ◽  
Abdelhamid FOUGHALIA ◽  
Mahmoud DJEMAL

This research was conducted to study the key physicochemical parameters of samples of raw bovine and goat milk collected in the steppic region of Djelfa. One hundred and six samples of raw milk were collected from April 2018 to May 2018, at points of sale and analyzed. The results showed that cow’s milk had 3.66±0.89% fat, 11.4±1.56% solid not fat, 4.35±0.61% protein, 6.35±0.89% lactose and a density of 1.0360±0.0056 with a freezing point of -0.380±0.053 °C. While goat’s milk had 3.43±0.65% fat, 10.2±0.92% solid not fat, 3.88±0.36% protein, 5.66±0.52% lactose and a density of 1.0317±0.0035 with a freezing point of -0.348±0.044 °C. This proves that cow’s milk has a slightly higher physicochemical quality than goat’s milk. In addition, the present study showed that 100% raw goat milk is wet against 97.1% raw bovine milk. This indicates the presence of cases of fraud requiring disciplinary procedures. Moreover, in the majority of the cases, the storage temperatures of the milk far exceed the values recommended by the Algerian standards (+6°C). It is necessary to establish a program of control and popularization of all the actors of the sector in order to improve the quality and the quantity of raw milk produced.


2000 ◽  
Vol 25 ◽  
pp. 165-168
Author(s):  
B.A. Slaghuis ◽  
G.H. Klungel

AbstractThe freezing point of bovine milk is known to vary between narrow limits. However, some variation is possible, because of the osmotic relationship between blood and milk. The extent of variation in freezing points of cow's milk was studied. For one year, freezing points were determined in individual milk samples from a high producing herd. Differences (P<0.05) were found between evening and morning milk yield and freezing points. A ‘lactation curve’ for freezing points was fitted and showed some similarity with milk yield curves. Stage of lactation explained part of the variation of freezing points of cow's milk.


2008 ◽  
Vol 71 (9) ◽  
pp. 1884-1888 ◽  
Author(s):  
V. KLOTZ ◽  
ART HILL ◽  
K. WARRINER ◽  
M. GRIFFITHS ◽  
J. ODUMERU

Raw milk is a well-established vehicle for the carriage of human pathogens, and many regulatory bodies have consequently mandated compulsory pasteurization as a food safety intervention. The residual activity of alkaline phosphatase (ALP) has historically been used to verify the adequacy of pasteurization of cow's milk. However, there is uncertainty on how the current ALP standards and methods of analysis can be applied to sheep's and goat's milk, which naturally contain different levels of the enzyme than that found in cow's milk. The official ALP methods applied in Canada (colorimetric assay; MFO-3) and in the United States (Fluorophos) were assessed for their ability to detect enzyme activity in raw and pasteurized milk derived from cows, sheep, and goats. The detection limit and the limit of quantitation were 0.8 and 2.02 μg/ml phenol, respectively, for the MFO-3 method and 43 and 85 mU/liter, respectively, for the Fluorophos method. The average ALP levels in raw goat's, cow's, and sheep's milk were 165, 1,562, and 3,512 μg/ml phenol, respectively. Raw milk detection limits, which correspond to raw milk phosphatase levels, were 0.051, 0.485, and 0.023% in cow's, goat's, and sheep's milk, respectively, for the MFO-3 method and 0.007, 0.070, and 0.004%, respectively, for the Fluorophos method. Although both methods can be used for ALP determination in cow's, goat's, and sheep's milk, the Fluorophos assay was superior to the colorimetric MFO-3 method based on sensitivity and time required to complete the analysis.


Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1258
Author(s):  
Suzanne Abbring ◽  
Bart R. J. Blokhuis ◽  
Julie L. Miltenburg ◽  
Kiri G. J. Romano Olmedo ◽  
Johan Garssen ◽  
...  

The mechanisms underlying the allergy-protective effects of raw cow’s milk are poorly understood. The current focus is mainly on the modulation of T cell responses. In the present study, we investigated whether raw cow’s milk can also directly inhibit mast cells, the key effector cells in IgE-mediated allergic responses. Primary murine bone marrow-derived mast cells (BMMC) and peritoneal mast cells (PMC), were incubated with raw milk, heated raw milk, or shop milk, prior to IgE-mediated activation. The effects on mast cell activation and underlying signaling events were assessed. Raw milk was furthermore fractionated based on molecular size and obtained fractions were tested for their capacity to reduce IgE-mediated mast cell activation. Coincubation of BMMC and PMC with raw milk prior to activation reduced β-hexosaminidase release and IL-6 and IL-13 production, while heated raw milk or shop milk had no effect. The reduced mast cell activation coincided with a reduced intracellular calcium influx. In addition, SYK and ERK phosphorylation levels, both downstream signaling events of the FcεRI, were lower in raw milk-treated BMMC compared to control BMMC, although differences did not reach full significance. Raw milk-treated BMMC furthermore retained membrane-bound IgE expression after allergen stimulation. Raw milk fractionation showed that the heat-sensitive raw milk components responsible for the reduced mast cell activation are likely to have a molecular weight of > 37 kDa. The present study demonstrates that raw cow’s milk can also directly affect mast cell activation. These results extend the current knowledge on mechanisms via which raw cow’s milk prevents allergic diseases, which is crucial for the development of new, microbiologically safe, nutritional strategies to reduce allergic diseases.


1959 ◽  
Vol 26 (2) ◽  
pp. 182-189 ◽  
Author(s):  
C. P. Cox ◽  
Zena D. Hosking ◽  
L. N. Posener

Theoretical and practical aspects of the apparent or effective viscosity of milk have been studied by many workers: see reviews by Scott Blair(1,2,3). Seidler & Elke(4), Cox(5), and others have considered the relations between observation temperature and viscosity measurements; Mohr & Oldenburg(6) and Puri & Gupta(7), for example, have investigated the effects of differences between individual viscometers. Other workers, including Puri & Gupta(7), Kobler(8) and Spöttel & Gneist(9), have examined the viscosity of whole raw milk after different times and temperatures of storage; and Weinlig(10), Trout & Weinstein(11) and Whitnah, Rutz & Fryer(12,13) have studied changes in viscosity values in connexion with various processes such as pasteurization and homogenization.


Author(s):  
K. A. Kanina ◽  
O. N. Krasulya ◽  
N. A. Zhizhin ◽  
E. S. Semenova

The article presents the results of studies obtained in the study of the quality of milk processed with the use of high-frequency acoustic cavitation and dairy products produced with its use. The research was carried out with the use of General scientific and special research methods in the laboratory of the Department of technology of storage and processing of animal products of the K. A. Timiryazev and in the accredited laboratory of technochemical control of the all-Russian research Institute of dairy industry. It is shown that the treatment of cow's milk-raw materials high-frequency ultrasonic vibrations (above 45 kHz), the generated electric ultrasonic device immersion type pulse impact ouzo "Activator-150", the number of bacteria of group of intestinal sticks (coliforms) decreased by almost 40%, which allows to make a conclusion about the appropriateness of the selected method of exposure for the destruction of microorganisms E. coli and coliform bacteria. Processed, using high-frequency acoustic cavitation, cow's milk was used for the production of brine cheese-cheese. It is shown that cheese cheese had a high nutritional value, which is due to the preservation of essential substances in the raw material (in particular, calcium, which in the production of cheese cheese precipitates if pasteurized milk is used), elastic consistency, safety of consumer characteristics - microbiological and physico-chemical.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Abderrahim Benmoussa ◽  
Idrissa Diallo ◽  
Mabrouka Salem ◽  
Sara Michel ◽  
Caroline Gilbert ◽  
...  

Abstract Extracellular vesicles (EVs) are involved in cell-to-cell communication and modulation of numerous physiological and pathological processes. EVs are found in large quantities in milk and contain several inflammation- and immunity-modulating proteins and microRNAs, through which they exert beneficial effects in several inflammatory disease models. Here, we investigated the effects of two EV subsets, concentrated from commercial cow’s milk, on a murine model of colitis induced with dextran sodium sulfate (DSS). P35K EVs, isolated by ultracentrifugation at 35,000 g, and P100K EVs, isolated at 100,000 g, were previously characterized and administered by gavage to healthy and DSS-treated mice. P35K EVs and, to a lesser extent, P100K EVs improved several outcomes associated to DSS-induced colitis, modulated the gut microbiota, restored intestinal impermeability and replenished mucin secretion. Also, P35K EVs modulated innate immunity, while P100K EVs decreased inflammation through the downregulation of colitis-associated microRNAs, especially miR-125b, associated with a higher expression of the NFκB inhibitor TNFAIP3 (A20). These results suggest that different milk EV subsets may improve colitis outcomes through different, and possibly complementary, mechanisms. Further unveiling of these mechanisms might offer new opportunities for improving the life of patients with colitis and be of importance for milk processing, infant milk formulation and general public health.


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