91. A Statistical Examination of the Interrelationship and Variability of Plate Count, Presumptive Coliform Content and Keeping Quality of Raw Milk

1935 ◽  
Vol 6 (1) ◽  
pp. 26-48 ◽  
Author(s):  
H. Barkworth
Keyword(s):  
Standard Deviation ◽  
Raw Milk ◽  
The Other ◽  
Plate Count ◽  
One Stage ◽  
Hygienic Quality ◽  
Keeping Quality ◽  
Quality Of Milk ◽  
The Relationship

The writer seeks to establish the interrelationship and variability of the three tests used for gauging the hygienic quality of milk, plate count, coliform content and keeping quality. Keeping quality is denned, and after discussing previous work and source of material, and noting the technique followed, the method of classification is described. Plate count and coliform content are treated logarithmically. Treatment of keeping-quality results presents especial difficulties, and the test is described in detail to disclose these, and reasons given for tabulating by half-days. The relationship between plate count and keeping quality is linear, but non-linearity occurs in those relationships which concern coliform content. This is because the first group “absent from 1 ml.” is not truly a definite class, but contains samples of superior quality. It is shown that an increase of one “stage” of coliform contamination reduces the average keeping quality as much as an increase of 0–54 in the logarithm of the plate count (approximately seven times). Variability of each term is discussed. The standard deviation of keeping quality is of the order of 1 half-day, that of logarithm of plate count is 0·77 and that of logarithm of coliform content in excess of unity. These variabilities are too great to permit of reasonable forecast of one term from the other two.

Impedance Measurement as an Alternative to the Plate Count Method for Estimating the Total Count of Bacteria in Raw Milk

1987 ◽  
Vol 50 (8) ◽  
pp. 665-668 ◽  
Author(s):  
F. F. J. NIEUWENHOF ◽  
J. D. HOOLWERF
Keyword(s):  
Standard Deviation ◽  
Microbiological Quality ◽  
Impedance Measurement ◽  
Raw Milk ◽  
Plate Count ◽  
Impedance Method ◽  
Count Method ◽  
Plate Counts ◽  
Plate Count Method

An improved impedance method is described with a good standard deviation of repeatability (sm = 0.05 log unit) and a fair standard deviation of the estimate of the plate count from the detection time [(sy)x = 0.33 log unit]. Compared with the standard deviation of repeatability of the plate count method (0.07 log unit), the standard deviation of repeatability of the impedance method described is a significant improvement. The impedimetric experiments were done with a Bactometer M123. The detection times as measured by this instrument were compared with the plate counts at 30°C for samples of raw refrigerated farm milk. With this technique a good indication of the microbiological quality of raw milk can be obtained within 15 h.

Keeping quality and raw-milk grading: I. Dye tests as measures of the keeping quality of milk

1950 ◽  
Vol 17 (2) ◽  
pp. 159-191 ◽  
Author(s):  
A. T. R. Mattick ◽  
A. Rowlands ◽  
H. Barkworth ◽  
Zena Hosking ◽  
O. Kempthorne
Keyword(s):  
Raw Milk ◽  
Keeping Quality ◽  
Quality Of Milk

The experiments analysed in this series of papers were undertaken as the result of a discussion on methods of measuring the keeping quality of milk, at a Conference of Advisory Bacteriologists of the Ministry of Agriculture and Fisheries.Owing to the disturbance and difficulty following the outbreak of war and the dislocation of handling and distribution, a serious decline in the keeping quality of raw-milk supplies was threatened.

204. The methylene blue reduction test and the keeping quality of milk

1938 ◽  
Vol 9 (3) ◽  
pp. 351-355 ◽  
Author(s):  
C. H. Chalmers
Keyword(s):  
Methylene Blue ◽  
Considerable Importance ◽  
Poor Correlation ◽  
Reduction Test ◽  
Methylene Blue Reduction ◽  
Keeping Quality ◽  
Different Temperatures ◽  
Quality Of Milk ◽  
The Relationship

The keeping quality of milk is a factor which is of considerable importance from the commercial aspect, yet the relationship which exists between the keeping quality and the bacteriological standards as laid down in the Milk Special Designations Order, 1936, has not been fully explored. Wilson compared the keeping quality at 17·5°C. of samples of mixed morning and evening milk with the reduction times at different temperatures and found, in each case, a relatively poor correlation. Since the samples consisted of mixed morning and evening milk it is not possible to state the age of the milk when the tests were commenced. Much of the Tuberculin Tested milk sold in the Provinces is bottled on the farm, and consequently the milk produced in the morning is bottled separately from that produced in the evening.

scholarly journals Data supporting the quality of sheep milk for processing

2001 ◽  
pp. 67-73
Author(s):  
József Csanádi ◽  
András Jávor ◽  
József Fenyvessy
Keyword(s):  
Raw Milk ◽  
Medium Size ◽  
Lactation Period ◽  
Slow Cooling ◽  
Physiological Factors ◽  
Hygienic Quality ◽  
Ewe's Milk ◽  
Quality Of Milk ◽  
Long Storage

Although the volume of ingredients in ewe’s milk is substantially higher than in cow’s milk, its hygienic quality is lower. The weak quality of raw ewe’s milk limits the possibilities of processing and results in bad quality products. In our investigation we analysed the state of ewe’s milk processing at a typical medium size dairy firm. We investigated the collection, the amount and the quality of milk and the level of ingredients in milk throughout the purchasing period (lactation period).The purchasing of ewe’s milk was limited to 5 months (from April to September). Although meat (lamb) provides the major source of income to sheep breeders the extension of the period of ewe’s milk production can be beneficial to shepherds and dairy firms. The amount of ewe’s milk ingredients found corresponded to published findings. However, the hygienic quality of ewe’s milk was varied greatly in the different milk samples and these deviations meant bad quality on average. Physiological factors, the circumstances of sheep breeding and milking, the slow cooling of the milk, the little amount of daily milk and the long storage before transportation to the dairy firm together cause poor hygienic quality. The main problem is the long storage time of milk, but our results raise the question of reconsidering the quality classes. Investigating the effect of the hygienic quality of raw milk on product quality, we can get correct data that can be really authoritative.

QUALITY ASSESSMENT OF RAW MILK IN KOSOVO

2018 ◽  
Vol 28 (4) ◽  
pp. 1305-1309
Author(s):  
Emine Uka ◽  
Nexhdet Shala ◽  
Arsim Elshani
Keyword(s):  
Negative Impact ◽  
Raw Milk ◽  
The Other ◽  
Human Consumption ◽  
Monitoring Point ◽  
Milk Processing ◽  
Milk Samples ◽  
Fresh Milk ◽  
Quality Of Milk

Since milk is one of the most consumable products of human consumption and in Kosovo, it is one of the most prosperous agriculture branches and the continued support to farmers from the Ministry of Agriculture, European Commission and USID, through which we will offer knowledge about the quality of this milk. Quality milk production is the ultimate goal and goal of any milk producer and processor. On the other hand, the low quality of milk has a negative impact on all segments of the dairy industry, especially in the fresh milk processing segment.Our work provides testing of raw milk samples taken by farmers who send milk to milk collection points and dairies in order to determine the quality of your milk. As a monitoring point we have received the Vita dairy and Aldi dairy in the period January 2017 - October 2018, and we have presented a comparison of their results.

SOME OBSERVATIONS ON THE BACTERIOLOGICAL KEEPING QUALITY OF MILK PROCESSED BY HIGH TEMPERATURES WITH A 0.6 SECOND HOLDING TIME1 2

1963 ◽  
Vol 26 (10) ◽  
pp. 332-336 ◽  
Author(s):  
D. A. Evans ◽  
Eleanor L. Lachman ◽  
Warren Litsky
Keyword(s):  
Heat Treatment ◽  
Raw Milk ◽  
Plate Heat Exchanger ◽  
Plate Heat ◽  
Milk Samples ◽  
Whole Milk ◽  
Keeping Quality ◽  
Quality Of Milk ◽  
Sterilized Milk

Summary Raw milk was processed through a commercial sized plate heat exchanger at temperatures of 160 F through 260 F with a 0.6 sec hold. Milk samples were collected at increments of 10 F during processing and analyzed for psychrophilic, mesophilic and thermophilic counts initially and at weekly intervals thereafter. All samples were held at 40 F after processing. Results indicated that temperatures of processing at 160 F and 170 F were not sufficient to impart acceptable keeping qualities to whole milk held at 40 F for a period of one week. By comparison, processing temperatures of 180 F through 210 F with 0.6 sec hold appeared to impart to whole milk keeping qualities which were approximately comparable to those observed in milk pasteurized according to present standards. When heat treatment in the range of 220 F through 260 F were used, it was indicated that bacteriological keeping quality of the milk was improved to an extent far beyond that experienced with present day commercial pasteurization. There appeared to be somewhat of a tendency for higher count raw milk related to the level of population in the processed product although the magnitude of this relationship was not clearly defined in all cases. It was evident that this process did not produce “commercially sterilized” milk at the processing temperatures and holding time used.

317. The resazurin and methylene-blue tests as a measure of the keeping quality of milk

1945 ◽  
Vol 14 (1-2) ◽  
pp. 21-27 ◽  
Author(s):  
E. B. Anderson ◽  
G. S. Wilson
Keyword(s):  
Methylene Blue ◽  
Correlation Coefficients ◽  
Raw Milk ◽  
Accurate Estimate ◽  
Human Consumption ◽  
Methylene Blue Reduction ◽  
Keeping Quality ◽  
Methylene Blue Test ◽  
Quality Of Milk

1. During four periods equally spaced throughout the year raw milks coming from surrounding farms into the Buckingham receiving station were examined by (a) the 10 min. resazurin test, (b) the 1 hr. resazurin test, (c) the resazurin test in which the time to reach disk 1 was recorded, (d) the modified methylene-blue test, and (e) a keeping quality test based on taste and alcohol precipitation. Altogether, 2588 samples were examined.2. Table 2, in which the correlation coefficients are worked out between the results of the dye and the K.Q. tests, shows that there is little to choose between the methylene-blue test and the time to reach disk 1 in the resazurin test; but since an average of only 15 min. was saved by carrying out the resazurin test, there seems little advantage to be gained by the use of this test. Both of these tests are superior to the 10 min. and the 1 hr. resazurin tests.3. A comparison of Tables 5–7, in which the average K.Q. of the milks corresponding to different disk numbers or reduction times is recorded, shows that the methylene-blue test affords the best indication of the K.Q.4. A study of Table 3, setting out the relation between the 10 min. resazurin and the methylene-blue reduction tests, shows that 99% of milks giving a 0–½ reading in the resazurin test reduce methylene blue within 30 min. and 80 % of them within 10 min.; but that, of milks reducing methylene blue within 30 min., only 53% give a disk reading of 0–½ in the 10 min. resazurin test. If it is agreed that no raw milk on arrival at the creamery which reduces methylene blue within 30 min. and which has, according to Table 7, an average K.Q. of only about 5 hr. at the time of testing, is fit for human consumption, then it is clear that the present rejection standard in the 10 min. resazurin test passes nearly 50% of unsatisfactory milks.5. The data recorded in this paper all go to show that the best indirect index of the K.Q. of raw milk is afforded by the methylene-blue test as carried out by the method officially laid down by the Ministry of Health.6. On the other hand, if time is an overruling consideration, then a slightly less accurate estimate of the K.Q. of raw milk is afforded by the 1 hr. resazurin test. It must be pointed out, however, that the figures given in Table 6 suggest that below disk 2 there is some irregularity in the relation between the disk numbers and the K.Q. If the 1 hr. resazurin test should come into use for the routine grading of milk, a revision of the present tints at the lower end of the scale might prove desirable.

scholarly journals THE SIZE OF THE FARM AND ITS INFLUENCE AT CLEANLINESS OF THE COWS AND MILK HYGIENE

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
A. Marić ◽  
B. Važić ◽  
Maja Regoda ◽  
M. Erbez
Keyword(s):  
Dairy Cows ◽  
Somatic Cells ◽  
Raw Milk ◽  
Surrounding Area ◽  
Hygienic Quality ◽  
Number Of Microorganisms ◽  
Milk Hygiene ◽  
Physical Comfort ◽  
Quality Of Milk

For animals the sense of physical comfort is necessary (physical comfort). When animals feel physically comfortable, it means that every part of their bodies is in harmony with the surrounding area. Therefore, the farms are usually build in accordance with the number of cattle that will be hold in designed facilities, which provide a higher degree of cows cleanliness. Cleanliness of cows is important in order to produce hygienically clean milk and to achieve the cattle welfare of dairy cows too. Cleanliness of animals mostly depends on what kind of object they are placed in. Hygienically proper milk includes the number of microorganisms up to 100,000 / ml and the number of somatic cells to 400,000 / ml, which are regulated by the "Regulations on quality of fresh raw milk." For this research farms are divided into three groups according to the number of cows. The first group included the number of cows from 1 to 9, the second group included 10 to 19, and a third group 20 or more cows. The aim of this paper is to examine whether there is an influence of the size of farms (number of cows) on the subjective cow cleanliness and hygienic quality of milk.

143. The Comparative Values of the Plate Count and the Modified Methylene-Blue Reduction Test as Routine Methods for Grading Milk

1936 ◽  
Vol 7 (3) ◽  
pp. 258-270 ◽  
Author(s):  
A. A. Nichols ◽  
S. J. Edwards
Keyword(s):  
Methylene Blue ◽  
Marked Improvement ◽  
Plate Count ◽  
Reduction Test ◽  
The Past ◽  
Hygienic Quality ◽  
Methylene Blue Reduction ◽  
Quality Of Milk

During the past twenty years the plate count has been largely employed as a means of assessing the hygienic quality of milk. There is no doubt that for this purpose it has proved to be of great value, and the marked improvement which has taken place in the quality of the milk of many producers is largely attributable to its use.

scholarly journals Some Aspects of the Relationship Between the Quality of Sheep Milk and Dairy Products

2003 ◽  
pp. 12-15
Author(s):  
József Csanádi ◽  
Ottilia Baráné Herczegh ◽  
József Fenyvessy
Keyword(s):  
Raw Milk ◽  
Limit Values ◽  
Sheep Milk ◽  
Texture Parameters ◽  
Traditional Cheese ◽  
Negative Effect ◽  
Quality Of Milk ◽  
Quality Of Products ◽  
The Relationship

The correlation between the quality of raw milk and the quality of milk products is evident. In spite of this fact we can find only a few references contained exact data related sheep milk. In recent paper we investigated the effect of SCC of sheep milk on the cheese yield (semi hard traditional cheese) and certain texture parameters of yoghurt from sheep milk. We wanted to know the relevant limit values of these properties for dairy applications.In our opinion – in the case of the cheese yield – that the strong negative effect can be experienced when SCC is above 700.000-1 million/cm3.In the case of yoghurt from sheep milk the limit values of SCC can be 1 million/cm3 for Adhesivity and Whey draining and 500.000/cm3 for Hardness. Considering these limit values in the selection of milk become materialise the highest quality of products and the economical production.

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