Relations between composition and viscosity of cow's milk

1959 ◽  
Vol 26 (2) ◽  
pp. 182-189 ◽  
Author(s):  
C. P. Cox ◽  
Zena D. Hosking ◽  
L. N. Posener
Keyword(s):  
Effective Viscosity ◽  
Raw Milk ◽  
Cow’S Milk ◽  
Cow's Milk ◽  
Viscosity Measurements

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.

Evaluation of Spectrophotometric and Fluorometric Methods for Alkaline Phosphatase Activity Determination in Ewe's Milk

2000 ◽  
Vol 63 (9) ◽  
pp. 1258-1261 ◽  
Author(s):  
M. F. SCINTU ◽  
E. DAGA ◽  
A. LEDDA
Keyword(s):  
Alkaline Phosphatase ◽  
Standard Deviation ◽  
Raw Milk ◽  
Cow’S Milk ◽  
Official Method ◽  
Cow's Milk ◽  
Alp Activity ◽  
Relative Standard ◽  
Ewe's Milk ◽  
European Method

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).

scholarly journals Evaluation of the Physicochemical Quality of Raw Bovine and Goat Milk Marketed in the Steppic Region of Djelfa (Algeria)

2019 ◽  
Vol 76 (1) ◽  
pp. 55
Author(s):  
Mourad HAMIROUNE ◽  
Sounia DAHMANI ◽  
Zineb KASMI ◽  
Abdelhamid FOUGHALIA ◽  
Mahmoud DJEMAL
Keyword(s):  
Freezing Point ◽  
Bovine Milk ◽  
Goat Milk ◽  
Raw Milk ◽  
Cow’S Milk ◽  
Physicochemical Quality ◽  
Cow's Milk ◽  
Goat’S Milk ◽  
Disciplinary Procedures ◽  
Goat's Milk

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.

Assessment of the Colorimetric and Fluorometric Assays for Alkaline Phosphatase Activity in Cow's, Goat's, and Sheep's Milk

2008 ◽  
Vol 71 (9) ◽  
pp. 1884-1888 ◽  
Author(s):  
V. KLOTZ ◽  
ART HILL ◽  
K. WARRINER ◽  
M. GRIFFITHS ◽  
J. ODUMERU
Keyword(s):  
Alkaline Phosphatase ◽  
Colorimetric Assay ◽  
Residual Activity ◽  
Raw Milk ◽  
The United States ◽  
Cow’S Milk ◽  
Human Pathogens ◽  
Cow's Milk ◽  
Limit Of Quantitation ◽  
Time Required

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.

scholarly journals Direct Inhibition of the Allergic Effector Response by Raw Cow’s Milk—An Extensive In Vitro Assessment

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 ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Cell Activation ◽  
Allergic Diseases ◽  
Raw Milk ◽  
Mast Cell Activation ◽  
Cow’S Milk ◽  
Cow's Milk ◽  
Ige Mediated ◽  
Raw Cow’S Milk

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.

scholarly journals Study of the effect of high-frequency acoustic cavitation on the quality of raw milk and dairy products based on it

2019 ◽  
Vol 81 (3) ◽  
pp. 145-150
Author(s):  
K. A. Kanina ◽  
O. N. Krasulya ◽  
N. A. Zhizhin ◽  
E. S. Semenova
Keyword(s):  
High Frequency ◽  
Dairy Products ◽  
Raw Materials ◽  
Acoustic Cavitation ◽  
Raw Milk ◽  
Raw Material ◽  
Coliform Bacteria ◽  
Cow’S Milk ◽  
Cow's Milk

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.

scholarly journals Suppression of Food Allergic Symptoms by Raw Cow’s Milk in Mice is Retained after Skimming but Abolished after Heating the Milk—A Promising Contribution of Alkaline Phosphatase

Nutrients ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1499 ◽  
Author(s):  
Suzanne Abbring ◽  
Joseph Thomas Ryan ◽  
Mara A.P. Diks ◽  
Gert Hols ◽  
Johan Garssen ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Protective Effect ◽  
Raw Milk ◽  
Fat Content ◽  
Cow’S Milk ◽  
Protective Effects ◽  
Pasteurized Milk ◽  
Cow's Milk ◽  
Allergic Symptoms ◽  
Raw Cow’S Milk

Raw cow’s milk was previously shown to suppress allergic symptoms in a murine model for food allergy. In the present study, we investigated the contribution of fat content and heat-sensitive milk components to this allergy-protective effect. In addition, we determined the potency of alkaline phosphatase (ALP), a heat-sensitive raw milk component, to affect the allergic response. C3H/HeOuJ mice were treated with raw milk, pasteurized milk, skimmed raw milk, pasteurized milk spiked with ALP, or phosphate-buffered saline for eight days prior to sensitization and challenge with ovalbumin (OVA). Effects of these milk types on the allergic response were subsequently assessed. Similar to raw milk, skimmed raw milk suppressed food allergic symptoms, demonstrated by a reduced acute allergic skin response and low levels of OVA-specific IgE and Th2-related cytokines. This protective effect was accompanied by an induction of CD103+CD11b+ dendritic cells and TGF-β-producing regulatory T cells in the mesenteric lymph nodes. Pasteurized milk was not protective but adding ALP restored the allergy-protective effect. Not the fat content, but the heat-sensitive components are responsible for the allergy-protective effects of raw cow’s milk. Adding ALP to heat-treated milk might be an interesting alternative to raw cow’s milk consumption, as spiking pasteurized milk with ALP restored the protective effects.

Longitudinal Analysis of the Microbiological Quality of Raw Cow's Milk Samples Collected from Three Small Family Dairy Farms in Mexico Over a 2-Year Period

2019 ◽  
Vol 82 (12) ◽  
pp. 2194-2200 ◽  
Author(s):  
DIANA RIOS-MUÑIZ ◽  
JORGE F. CERNA-CORTES ◽  
CATALINA LOPEZ-SAUCEDO ◽  
ERIKA ANGELES-MORALES ◽  
MIRIAM BOBADILLA-del VALLE ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Microbiological Quality ◽  
Dairy Farms ◽  
Raw Milk ◽  
Cow’S Milk ◽  
Cow's Milk ◽  
E Coli ◽  
Milk Samples ◽  
Three Samples ◽  
Raw Cow’S Milk

ABSTRACT In Mexico, the total milk production that family dairy farms (FDF) contribute is ca. 35%, but this milk is not evaluated for microbiological quality. Forty percent of the milk and dairy products consumed by Mexicans is unpasteurized. In total, 24 raw cow's milk samples from three FDF (one sample per each season from each FDF for two sequent years) were characterized for the presence of food quality indicator organisms, Staphylococcus aureus, Salmonella enterica, Listeria monocytogenes, and Mycobacterium spp., by standard procedures. Escherichia coli presence was also evaluated by a direct count method and diarrheagenic E. coli (DEC) by molecular methods. On the basis of Mexican guidelines for raw milk entering production, 42% of samples exceeded the aerobic mesophilic bacteria limits. A total of 83% raw milk samples were positive for total coliforms, 54% for fecal coliforms, and 46% for E. coli. Forty-three E. coli isolates were selected and characterized for the presence of 11 DEC loci; of theses, 40 isolates were negative for all DEC loci, and 3 isolates, all collected from the same sample, were Shiga toxin 2 (stx2) positive and O157 antigen negative, and one stx2 isolate was resistant to 6 of the 16 antibiotics tested. None of the 24 raw milk samples were positive for Salmonella enterica, L. monocytogenes, or staphylococcal enterotoxin. S. aureus was isolated from nine samples, of which only three samples harbored resistant isolates. From three samples, four nontuberculous mycobacterial isolates were recovered (Mycobacteroides chelonae, Mycobacteroides porcinum, and two Mycobacteroides abscessus). All four isolates produced biofilm and had sliding motility, and three isolates (M. porcinum and two M. abscessus) were resistant to the two antibiotics tested (clarithromycin and linezolid). FDF provide raw milk to a large proportion of the Mexican population, but its consumption could be harmful to health, emphasizing the need to implement national microbiological quality guidelines for raw milk intended for direct human consumption. HIGHLIGHTS

Enumeration and Confirmation of Aeromonas hydrophila, Aeromonas caviae, and Aeromonas sobria Isolated from Raw Milk and Other Milk Products in Northern Greece

1999 ◽  
Vol 62 (5) ◽  
pp. 463-466 ◽  
Author(s):  
DIMITRIOS S. MELAS ◽  
DEMETRIOS K. PAPAGEORGIOU ◽  
ANTONIOS I. MANTIS
Keyword(s):  
Raw Milk ◽  
Cow’S Milk ◽  
Aeromonas Species ◽  
Northern Greece ◽  
Cow's Milk ◽  
Milk Samples ◽  
Aeromonas Sobria ◽  
Aeromonas Caviae ◽  
Feta Cheese ◽  
Ewe's Milk

A total of 138 raw cow's and 57 raw ewe's milk samples; 80 pasteurized cow's milk samples; 39 Anthotyros cheese, 36 Manouri cheese, and 23 Feta cheese samples; and 15 rice pudding samples were examined for the presence and any countable population of Aeromonas species. Twenty-two (15.9%) of the 138 cow's milk samples analyzed were contaminated with A. hydrophila. In 13 of these samples, populations of 3.0 × 102 to 5.0 × 103 CFU/ml were counted in starch ampicillin agar (SAA). Eighteen cow's milk samples (13.0%) were contaminated with A. caviae, and in eight of these samples, populations of 2.0 × 102 to 3.0 × 103 CFU/ml were counted in SAA. Five cow's milk samples (3.6%) were contaminated with A. sobria, and in two of these samples, populations of 2.5 × 103 and 5.0 × 103 CFU/ml were counted in SAA. Eleven cow's milk samples (7.9%) were contaminated with other Aeromonas spp. not classified. Eight (14.0%) of the 57 ewe's milk samples analyzed were contaminated with A. hydrophila. In these samples, populations of 5.0 × 102 to 5.0 × 103 CFU/ml were counted in SAA. Six ewe's milk samples (10.5%) were contaminated with A. caviae, and populations of 1.5 × 102 to 1.0 × 103 CFU/ml were counted in SAA. Two ewe's milk samples (3.5%) were contaminated with A. sobria, and populations counted in SAA were 5.0 × 102 and 1.0 × 103 CFU/ml. Four samples (7.0%) were contaminated with other Aeromonas spp. not classified. A. hydrophila was recovered in 4 (10.2%) and 3 (8.3%) of the Anthotyros and Manouri cheese samples analyzed, respectively, but no countable populations were noted in SAA. None of the pasteurized milk, Feta cheese, and rice pudding samples yielded Aeromonas spp. The results of this work indicate that motile Aeromonas are common in raw milk in Greece. Also, the presence of A. hydrophila in the whey cheeses Anthotyros and Manouri indicates that postprocessing contaminations of these products with motile Aeromonas may occur during production.

A survey on the occurrence of aflatoxin M1 in raw milk samples in Bafq and Bahabad, Iran

2021 ◽  
Author(s):  
Vahid Safavizadeh ◽  
Mozhgan Mojkar
Keyword(s):  
Aspergillus Parasiticus ◽  
Raw Milk ◽  
National Standard ◽  
Aflatoxin M1 ◽  
Cow’S Milk ◽  
Elisa Method ◽  
Cow's Milk ◽  
Milk Samples ◽  
The City

Aflatoxins are a group of mycotoxins mostly produced by the fungi called Aspergillus flavus, Aspergillus parasiticus, and Aspergillus nomium. Aflatoxin M1 (AFM1) is the major metabolite of aflatoxin B1 and is a hepatotoxic and carcinogenic toxin. The aim of this study was to determine the level of contamination of cow's milk with aflatoxin M1 in Bafq and Bahabad. For this study, samples of raw cow's milk were collected randomly from milk collection centers around the city of Bafq and Bahabad from March to April. The determination of aflatoxin M1 levels was based on the ELISA method. Contamination was observed in 100% of milk samples. According to the results of the study, the rate of contamination with aflatoxin M1 in 43.3% of milk samples was above the acceptable level (50 ng/L) in Iranian national standard. It is concluded that further monitoring of milk production should be carried out in the spring and winter seasons.

scholarly journals Isolation and Molecular Identification and Antimicrobial Susceptibility of Providencia spp. from Raw Cow’s Milk in Baghdad, Iraq

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Nagham Mohammed Ayyal Al‐Gburi
Keyword(s):  
Antimicrobial Susceptibility ◽  
Raw Milk ◽  
Diffusion Method ◽  
Cow’S Milk ◽  
Biochemical Tests ◽  
Street Vendors ◽  
Cow's Milk ◽  
Milk Samples ◽  
Biolog Gn ◽  
Raw Cow’S Milk

A total of sixty raw milk samples were collected from (street vendors and shops) from Baghdad city, Iraq. The samples were inoculated into peptone water and, then, subcultured onto McConkey agar and Blood agar. Identification of isolates was confirmed by microscopic examination, cultural characteristic, biochemical tests, Vitek (VITEK®2 system), and Biolog GN substrate reactions followed by 16S rRNA and specific genes sequencing. Of 60 raw cow’s milk samples, Providencia spp. were identified only in 4 samples (6.67%) and P. rettgeri was the most common, 2/4 (50%), followed by P. stuartii and P. vermicola, 1/4 (25%) . Antimicrobial susceptibility tests were conducted against ten antibiotics by the disc diffusion method. All Providencia isolates showed multidrug resistance (MDR), and the absolute resistant was 100% to tetracycline, erythromycin, and doxycycline and 50% against ampicillin\sulbactam and amoxicillin/clavulanic acid. They were highly susceptible (100%) to trimethoprim, imipenem, and chloramphenicol. These findings indicate that milk might be contaminated with Providencia spp. leading to transmission to humans causing poisoning, diarrhea, and other infections. This is the first study of isolated Providencia spp. from raw cow’s milk.

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