scholarly journals Freezing point of raw and heat-treated goat milk

2008 ◽  
Vol 52 (No. 11) ◽  
pp. 394-398 ◽  
Author(s):  
B. Janštová ◽  
M. Dračková ◽  
P. Navrátilová ◽  
L. Hadra ◽  
L. Vorlová
Keyword(s):  
Freezing Point ◽  
Goat Milk ◽  
Raw Milk ◽  
Average Increase ◽  
Heat Treated ◽  
The Mean ◽  
Bulk Tank

The freezing point (FP) was established in 48 bulk tank samples of raw and 48 samples of pasteurized goat milk that were collected in the course of lactation. Alongside, non-fat solids (NFS) content was monitored. Milk freezing point measurements were carried out using the thermistor cryoscope method in compliance with the standard CTS 570538 (1998). The mean freezing point of raw milk was found to be in an interval of –0.5513 ± 0.0046°C, variation ranged from –0.5466°C to –0.5567°C, with higher values in the spring months and a drop at the end of lactation. FP corresponded to the NFS content. The average freezing point of goat milk heat-treated on the farm to the temperature of 72°C over a period of 20 s was –0.5488 ± 0.0046°C, pasteurisation brought an average increase in FP by 0.0025°C.

scholarly journals Impact of Heat Treatment on the Freezing Points of Cow and Goat Milk

2009 ◽  
Vol 78 (4) ◽  
pp. 679-684
Author(s):  
Bohumíra Janštová ◽  
Pavlína Navrátilová ◽  
Michaela Dračková ◽  
Hana Přidalová ◽  
Lenka Vorlová
Keyword(s):  
Heat Treatment ◽  
Freezing Point ◽  
Goat Milk ◽  
Treatment Temperature ◽  
Raw Material ◽  
Cow Milk ◽  
Heat Treated ◽  
Bulk Tank ◽  
The Individual ◽  
The Impact

The aim of this study was to monitor the impact of heat treatment variables on the freezing point of cow and goat milk. The freezing point (FP) was established in 30 bulk tank samples of goat milk and in 30 bulk tank samples of cow milk which were subject to laboratory heat treatment at temperatures of 72 °C (A), 85 °C (B), 95 °C (C), with the same exposition times of 20 s. Freezing point measurements of raw and heat-treated milk were carried out in compliance with the Standard CTS 57 0538 by a thermistor cryoscope. The FP of raw cow milk increased with heat treatment from the initial values of -0.5252 ± 0.0114 °C (O) by 0.0023 °C (A), 0.0034 °C (B) and 0.0051°C (C). Changes in FP values of goat milk were detected, from its initial value of –0.5530 ± 0.0086 °C there was an increase in the FP depending on the mode of heat treatment due to pasteurization by an average of 0.0028 °C (A), 0.0036 °C (B) and 0.0054 °C (C). The dynamics of the changes were similar both in goat and cow milk. Freezing point values in cow and goat milk differed (P ⪬ 0.01) when compared to the freezing point of untreated milk after the individual interventions as well as when compared between each other. An increase in the heat treatment temperature of cow and goat milk causes an increase in the freezing point (a shift towards zero). These results can be used in practice for checking the raw material in dairy industry.

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.

scholarly journals Proteolytic and lipolytic potential of Pseudomonas spp. from goat and bovine raw milk

2018 ◽  
Vol 38 (8) ◽  
pp. 1577-1583 ◽  
Author(s):  
José C. Ribeiro Júnior ◽  
Pedro I. Teider Junior ◽  
André L.M. Oliveira ◽  
Edson A. Rios ◽  
Ronaldo Tamanini ◽  
...  
Keyword(s):  
Bovine Milk ◽  
Goat Milk ◽  
Raw Milk ◽  
Species Level ◽  
Cow Milk ◽  
Production Potential ◽  
Gram Negative ◽  
Pseudomonas Spp ◽  
Milk Samples ◽  
The Mean

ABSTRACT: Pseudomonas, the main genus of gram-negative microorganisms isolated from milk, is psychrotrophic, biofilm-forming, and thermo-resistant deteriorating enzyme producers. The aim of this study was to quantify Pseudomonas spp. in goat’s and cow’s milk produced in the Paraná state, Brazil, to evaluate the deteriorating activity of the isolates at mesophilic and psychrotrophic conditions and to identify, at the species level, the isolates with alkaline metalloprotease (aprX gene) production potential. Microbiological, biochemical and molecular methods were used for isolating, confirming and identifying of isolates. The mean counts were 1.6 (±6.3)x104 and 0.89(±3)x102 CFU/mL for goat and bovine milk samples, respectively, immediately after milking. Of the Pseudomonas colonies isolated from goat milk (n=60), 91.7% showed proteolytic potential when incubated at 35°C/48 h and 80% at 7°C/10 days, and lipolytic potential was observed in 95% of the isolates incubated in mesophilic and 78.3% at refrigeration conditions. From the isolates of bovine milk (n=20), 35% showed proteolytic activity only when incubated at 35°C/48 h, and lipolytic potential was observed in 25% of the isolates incubated at 7°C/10d and 35°C/48h. It was observed that 83.3% and 25% of the isolates genetically confirmed as Pseudomonas spp. of goat and bovine milk showed the potential for alkaline metalloprotease production, with the species P. azotoformans, P. koreensis, P. gessardii, P. monteilii and P. lurida being the most frequent in goat milk and P. aeruginosa the only species identified in cow milk.

scholarly journals Freezing point of heat-treated drinking milk in the Czech Republic

2011 ◽  
Vol 24 (No. 4) ◽  
pp. 156-163 ◽  
Author(s):  
P. Navrátilová ◽  
B. Janštová ◽  
P. Glossová ◽  
L. Vorlová
Keyword(s):  
Freezing Point ◽  
Current System ◽  
Raw Milk ◽  
Mean Value ◽  
The Czech Republic ◽  
Uht Milk ◽  
Limit Value ◽  
Heat Treated ◽  
One Year ◽  
Drinking Milk

In theCzechRepublic, the freezing point of milk is presently used as a quality indicator of cows’ raw milk as well as of heat-treated drinking milk, and its limit value is ≤ –0.520°C. Of the total of 295 drinking milk samples examined over a period of one year, 145 were samples of pasteurised milk and 150 were samples of UHT milk. In compliance with the Czech State Standard57 05 38, the freezing point was determined by a thermistor cryoscope. The measured mean value of the freezing point of the heat-treated drinking milk was –0.515°C ± 0.0078. A total of 207 (70.2%) samples of the heat-treated drinking milk, i.e. 93 (64.1%) samples of pasteurised and 114 (76%) samples of UHT milk, were found above the maximum limit value. The unsatisfactory results of the monitoring of the freezing point of drinking milk emphasise the need for a reassessment of the current system of the milk quality evaluation with respect to this quality index.  

scholarly journals The freezing point of raw and heat treated sheep milk and its variation during lactation

2013 ◽  
Vol 82 (2) ◽  
pp. 187-190
Author(s):  
Bohumíra Janštová ◽  
Pavlína Navrátilová ◽  
Michaela Králová ◽  
Lenka Vorlová
Keyword(s):  
Freezing Point ◽  
Chemical Properties ◽  
Raw Milk ◽  
Important Indicator ◽  
Pasteurized Milk ◽  
Milk Samples ◽  
Sheep Milk ◽  
Physico Chemical ◽  
Heat Treated ◽  
Time Specific

The freezing point of milk is an important indicator of the adulteration of the milk with water, but heat treatment may also affect its value. The aim of this study was determine freezing point of raw and heat treated sheep milk and its variation during lactation. The freezing point was determined in 42 bulk tank raw sheep milk samples and 42 pasteurized milk samples collected during lactation of sheep at one ecofarm in Moravian Walachia (Valašsko in the Czech Republic). The freezing point was determined in accordance with the standard ČSN 57 0538 using a thermistor cryoscope. The average freezing point of raw milk was -0.617 ± 0.052 °C, with a range from -0.560 to -0.875 °C. The freezing point was lower in the first months of lactation and increased at the end of lactation. The freezing point correlated (r = 0.8967) with the content of total non-fat solids. The average freezing point of sheep milk pasteurized at 65 °C for 30 min was -0.614 ± 0.053 °C, with a range from -0.564 to -0.702 °C. The median of freezing point differences between raw and pasteurized milk was 0.004 °C. Our study extends data about physico-chemical properties of sheep milk and registers for the first time specific changes in the freezing point value of sheep milk by heating.

Effect of Extended Storage on Microbiological Quality, Somatic Cell Count, and Composition of Raw Goat Milk on a Farm

2007 ◽  
Vol 70 (5) ◽  
pp. 1281-1285 ◽  
Author(s):  
S. S. ZENG ◽  
S. S. CHEN ◽  
B. BAH ◽  
K. TESFAI
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Microbiological Quality ◽  
Goat Milk ◽  
Psychrotrophic Bacteria ◽  
The Mean ◽  
Bulk Tank

Dairy goat herds in the United States generally are small, widely scattered, and distant from processing facilities. Unlike the situation for cow milk, it is not cost-effective to collect goat milk everyday or every other day. In some areas, goat milk is collected only once each week, which is in violation of regulations specified in the Pasteurized Milk Ordinance for grade A milk. This study was conducted to determine the effect of up to 7 days of refrigerated bulk tank storage on composition, somatic cell count (SCC), pH, and microbiological quality of goat milk. Duplicate farm bulk tank samples were taken daily after the morning milking for seven consecutive days each month during the lactation season. Samples were analyzed immediately for all variables except free fatty acids. There were no significant changes (P > 0.05) detected in milk fat, protein, lactose, nonfat solids, SCC, or pH during extended storage, although significant effects of stage of lactation (P < 0.05) were observed. The mean standard plate count (SPC) increased to 1.8 × 105 CFU/ml after 6 days of storage, exceeding the grade A limit (i.e., 1.0 × 105 CFU/ml). The mean psychrotrophic bacteria count increased steadily to 1.5 × 104 CFU/ml after 6 days of storage, whereas the mean coliform count was approximately 500 CFU/ml for the first 3 days and less than 2,500 CFU/ml throughout the 7 days of storage. No significant changes (P > 0.05) in the concentrations of free fatty acids, except for butyric and caprylic acids, were observed during milk storage. When stored under refrigerated and sanitary conditions, goat milk in farm bulk tanks met the grade A criteria for both SPC and SCC during 5 days of storage but was of low quality thereafter because of the growth of psychrotrophic bacteria.

scholarly journals Bacteriological Quality of Raw Ovine Milk from Different Sheep Farms

Animals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1163
Author(s):  
Andualem Tonamo ◽  
István Komlósi ◽  
László Varga ◽  
Levente Czeglédi ◽  
Ferenc Peles
Keyword(s):  
Raw Milk ◽  
Early Morning ◽  
Housing Conditions ◽  
Bulk Tank Milk ◽  
Bacterial Counts ◽  
Bacteriological Quality ◽  
Microbiological Laboratory ◽  
The Mean ◽  
Bulk Tank

The primary purpose of this research was to examine the bacteriological properties of raw ovine milk produced by Merino, Tsigai, Dorper, Lacaune, and British Milk Sheep flocks on four sheep farms located in the eastern part of Hungary. In addition to individual raw milk (IRM) and bulk tank milk (BTM) samples, the udder surface (US) of ewes was also tested for bacteriological quality. A total of 77 US, 77 IRM, and 10 BTM samples were collected in the early morning during regular milking sessions. The samples, kept cooled at temperatures below 4 °C, were delivered to the microbiological laboratory and were examined immediately. The relatively low numbers of bacteria in both US and IRM samples reflected good housing conditions of ewes kept on the four farms studied. However, BTM samples had up to 3.5–4.0 log10 CFU/mL higher mean bacterial counts than their IRM counterparts, and the mean levels of bacteria in BTM on two farms even exceeded the regulatory limit of 6.18 log10 CFU/mL. Further studies need to be performed to clarify this issue.

Survey of Ontario Bulk Tank Raw Milk for Food-Borne Pathogens

1997 ◽  
Vol 60 (11) ◽  
pp. 1341-1346 ◽  
Author(s):  
MARINA L. STEELE ◽  
W. BRUCE McNAB ◽  
CASE POPPE ◽  
MANSEL W. GRIFFITHS ◽  
SHU CHEN ◽  
...  
Keyword(s):  
Disease Outbreaks ◽  
Raw Milk ◽  
Plate Count ◽  
Salmonella Spp ◽  
Food Borne Pathogens ◽  
Unpasteurized Milk ◽  
Food Borne ◽  
The Mean ◽  
Bulk Tank ◽  
Campylobacter Spp

Raw (unpasteurized) milk can be a source of food-borne pathogens. Raw milk consumption results in sporadic disease outbreaks. Pasteurization is designed to destroy all bacterial pathogens common to raw milk, excluding spore-forming bacteria and possibly Mycobacterium paratuberculosis, but some people continue to drink raw milk, believing it to be safe. Current methods for assessing the bacteriological quality of raw milk, such as aerobic plate counts, are not usually designed to detect specific pathogens. The objective of this study was to estimate the proportion of pick-ups (loads of raw milk from a single farm bulk tank) from Ontario farm bulk tanks that contained Listeria monocytogenes. Salmonella spp., Campylobacter spp., and/or verotoxigenic Escherichia coli (VTEC). Samples from 1,720 pick-ups of raw milk were tested for the presence of these pathogens, and 47 L. monocytogenes, three Salmonella spp., eight Campylobacter spp., and 15 VTEC isolates were detected, representing 2.73, 0.17, 0.47, and 0.87% of milk samples, respectively. Estimates of the proportion of theoretical tanker truck loads of pooled raw milk contaminated with pathogens ranged from a low of 0.51 % of tankers containing raw milk from 3 bulk tanks being contaminated with Salmonella spp. to a high of 34.41 % of tankers containing raw milk from 10 bulk tanks being contaminated with at least one of the pathogens. Associations between the presence of pathogens and raw milk sample characteristics were investigated. The mean somatic cell count was higher among VTEC- or L. monocytogenes-positive samples, and the mean aerobic plate count was found to be higher among L. monocytogenes-positive samples. These results confirm the presence of bacterial food pathogens in raw milk and emphasize the importance of continued diligence in the application of hygiene programs within dairies and the separation of raw milk from pasteurized milk and milk products.

scholarly journals БАКТЕРІАЛЬНЕ ЗАБРУДНЕННЯ МОЛОКА ЗА РІЗНИХ ТЕМПЕРАТУР І ТЕРМІНІВ ЗБЕРІГАННЯ

2016 ◽  
Vol 18 (3(70)) ◽  
pp. 108-112
Author(s):  
N.M. Zazharska
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Bacterial Contamination ◽  
Freezing Point ◽  
Goat Milk ◽  
Rapid Cooling ◽  
Milk Samples ◽  
Different Temperatures ◽  
Bulk Tank

Research was conducted in the laboratory LILCO, Surgères, France. For the first experiment, 24 samples of cooled bulk tank goat milk were selected be transported within 2 – 3 hours at different temperatures. Then all samples were stored day at 4 °C. The indicators of bacterial contamination, fat, protein, freezing point, somatic cell count, urea were similar for different temperatures of transporting milk samples. Noted the big somatic cell count (> 2000 thousand / ml) at low bacterial contamination (19,6 × 103 CFU/mL) of goat milk. Samples of milk can be delivered to the laboratory for 2–3 hours at a temperature of 2, 10 or 20 °C if the milk immediately after milking cooled and stored in a tank at 4 °C.10 samples of cow's milk (non–cooled – 3 hours after milking, cooled – after a day) were also examined. Bacterial contamination of milk which has been cooled and being stored one day at 4 °C was in 4.6 times less (P < 0.01) than non–cooled milk, analyzed in 3 hours after milking. This proves that bacterial contamination of milk in Ukraine accordance with European requirements (up to 100 thousand. CFU/ml) is possible only when rapid cooling of milk after milking to 4 оС and storing it in the cooling tank. 

scholarly journals Differences of some indicators of raw milk properties and especially mineral composition between small ruminants as compared to cows in the Czech Republic

2008 ◽  
Vol 56 (5) ◽  
pp. 51-56 ◽  
Author(s):  
Oto Hanuš ◽  
Marcela Vyletělová ◽  
Václava Genčurová ◽  
Irena Hulová ◽  
Hana Landová
Keyword(s):  
Czech Republic ◽  
Freezing Point ◽  
Small Ruminants ◽  
Goat Milk ◽  
Raw Milk ◽  
Milk Composition ◽  
Cow Milk ◽  
The Czech Republic ◽  
Positive Effects ◽  
True Protein

Sheep and goat farming is returning back into the Czech Republic (CR) because of positive effects of alternative milk consumption on human health. Especially the elements Ca and Mg are important for nutrition. Paper presents the comparison of mineral milk composition of goats (White short–haired–W, n = 60), sheep (Tsigai–C, n = 60) and cows (Holstein–H, n = 36; Czech Fleckvieh–B, n = 93). Cow milk results were considered as reference. The herds were kept at altitude 260 m (H), 360 m (B), and 572 m above sea level (W, C) with total precipitation 449, 700 and 1200 mm per year and mean air temperatures 9.6, 7.0 and 3.7 °C. Bulk milk samples (4–8 animals in sample) from the first two thirds of the lactation and the winter and summer season were investigated. Goat milk freezing point differed from other species (P < 0.001), −0.6048 for C < −0.5544 W < −0.5320 H < −0.5221 °C for B. Cow milk Ca values were comparable to former results although milk yield (MY) was higher. Along lower MY the Ca was higher (1299.6 > 1172.0 mg . kg−1; P < 0.001) in B than H, similar trend was in Mg (122.0 > 107.4 mg . kg−1; P<0.001). Differences (P > 0.05) between species were in Ni and also mostly in Cu. Iodine results differed between species but not between cow breeds (P < 0.001; 462.8 H and 434.9 B > 126.0 W and 164.2 μg . l−1 C). It could be explainable by using of I disinfection at teat treatment in cows and absence of treatment in small ruminants. Macroelements were mostly highest (Ca, P, Na, Mg) in sheep milk, with exception of K. Phosphorus values (950.1 H, 1016.9 B, 1042.6 W and 1596.7 mg . kg−1 C) in species were linked with crude or true protein and casein values. Small ruminant milk could be good source of minerals for human nutrition, especially in the case of Ca and Mg of sheep and goat milk.

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