THE MICROFLORA OF RAW BULK TANK MILK

1966 ◽  
Vol 12 (3) ◽  
pp. 429-432 ◽  
Author(s):  
H. Jackson ◽  
L. F. L. Clegg
Keyword(s):  
Colony Count ◽  
Plate Count ◽  
Staining Reaction ◽  
Dominant Group ◽  
Standard Plate Count ◽  
Plate Count Agar ◽  
Gram Staining ◽  
Lactose Fermentation ◽  
Standard Plate ◽  
Bulk Tank

Milk samples from 141 farms were plated on standard plate count agar and the colony count determined after incubation for 48 hours at 32 °C. Twenty colonies were picked at random from plates containing between 30 and 300 colonies. The isolates were inoculated into litmus milk and subsequently characterized on the basis of shape, Gram-staining reaction, catalase production, lactose fermentation, and the ability to form spores.Certain general trends in the flora were observed. In milk of a colony count less than 2 × 104 per ml, micrococci were the dominant group of organisms, and as the colony count of the milk increased the percentage of micrococci decreased and the percentage of Gram-negative rods and streptococci usually increased. In spite of these general trends a study of the flora of individual samples showed that quite marked variations did occur.

Effect of Delayed Heading on Some Quality Attributes of Penaeus Shrimp1

1979 ◽  
Vol 42 (5) ◽  
pp. 407-409 ◽  
Author(s):  
R. J. ALVAREZ ◽  
J. A. KOBURGER
Keyword(s):  
Panel Data ◽  
Storage Period ◽  
Plate Count ◽  
Sensory Panel ◽  
Bacterial Populations ◽  
Standard Plate Count ◽  
Plate Count Agar ◽  
Pseudomonas Species ◽  
Standard Plate ◽  
Plate Counts

To determine the effect of delayed heading on shrimp quality, shrimp were stored on ice with and without heads for 10 days. Some shrimp were delay-headed after 5 days and returned to ice for the remainder of the storage period. Microbiological studies were conducted at 0, 5 and 10 days of storage. Total aerobic plate counts were done using Standard Plate Count agar with an added 0.5% NaCl. Incubation was at 20 C for 5 days. Analyses indicated similar counts on shrimp tails stored with or without heads and those delayed-headed. Counts ranged from 2.4 × 106 bacteria/gram at 0 day to 1.6 × 109 bacteria/gram on the 10th day. Identification of the flora present revealed that the same major groups of organisms predominated on shrimp tails subjected to the different storage treatments and the head did not alter development of the usual flora. Flavobacterium, Pseudomonas, Planococcus, Moraxella and the Vibrio/Aeromonas group were the major genera encountered. A shift in bacterial populations was observed during storage. Flavobacterium species predominated during the first 5 days of storage; however, after the fifth day Pseudomonas species predominated. Sensory panel data revealed no differences in acceptability between shrimp tails stored with or without heads and those delay-headed.

THE QUALITY OF RAW MILK FROM SELECTED OHIO MARKETS.

1966 ◽  
Vol 29 (4) ◽  
pp. 118-121 ◽  
Author(s):  
S. P. Ohri ◽  
W. L. Slatter
Keyword(s):  
Raw Milk ◽  
Plate Count ◽  
High Count ◽  
Coliform Count ◽  
Standard Plate Count ◽  
Milk Samples ◽  
Bacteriological Method ◽  
Standard Plate ◽  
Bulk Tank

Summary An 8-month survey of the bacteriological quality of bulk tank produced fluid milk supplies for four major markets in Ohio, was made utilizing the Standard Plate Count (SPC), the preliminary incubation count (PI), the thermoduric (pasteurized milk) count, and the coliform count. In terms of maximum standards of 200,000 and 100,000 organisms/ml, the SPC would have eliminated 13% and 20% of the milk samples, respectively. A SPC of 50,000/ml, a PI count of 200,000/ml, a thermoduric count of 500/ml, and a coliform count of 100/ml would have eliminated 37%, 34%, 40%, and 40%, respectively, of the samples but not all of the samples eliminated by one test were eliminated by another test. All of the tests employed showed a seasonal trend especially in the high count categories but the trend was less noticeable in the results of the preliminary incubation count. A combination of two of the methods was superior to any single bacteriological method employed in detecting unsatisfactory milk. Of the tests used, the combination of the thermoduric count (500/ml) and the coliform count (100/ml) was the most effective in the detection of unsatisfactory milk samples.

COMPARISON OF PLATE LOOP AND AGAR PLATE METHODS FOR BACTERIOLOGICAL EXAMINATION OF MANUFACTURING GRADE RAW MILK1,2

1967 ◽  
Vol 30 (4) ◽  
pp. 112-115 ◽  
Author(s):  
Sita Ramayya Tatini ◽  
Roger Dabbah ◽  
J. C. Olson
Keyword(s):  
Agar Plate ◽  
Bacterial Count ◽  
Raw Milk ◽  
Substantial Improvement ◽  
Plate Count ◽  
Bacteriological Examination ◽  
Standard Plate Count ◽  
Milk Samples ◽  
Standard Plate ◽  
Bulk Tank

Summary Plate loop counts and standard plate counts on each of several manufacturing grade raw milk samples (handled in cans or in farm bulk tanks) have been compared. On the average, the plate loop count (PLC) was lower than the standard plate count (SPC) regardless of the type of handling of milk on the farm, can or bulk tank. Agreement between the SPC and PLC seemed to depend upon the bacterial-count levels present in milk. Statistical analyses indicated significant differences, at 1% level of probability, between the average bacterial count by SPC and PLC methods regardless of count level (≤100,000/ml or >100,000/ml) in case of can milk samples. On the other hand, in case of farm bulk tank milk samples, no significant differences, at the 1% level of probability, between the average bacterial count by SPC and PLC methods were obtained, when the counts were equal to or less than 100,000 per ml; when the counts exceeded 100,000 per ml, significant differences were present. Since the bacterial counts of manufacturing grade raw milk samples are likely to exceed 100,000/ml, the data presented in this investigation indicate that, until the bacteriological quality of manufacturing grade milk supplies undergoes substantial improvement, the PLC method does not appear to be a suitable substitute for the SPC method for routine bacteriological examination of such milk supplies.

Temperature Equilibration Times of Plate Count Agar and a Comparison of 50 Versus 45 C for Recovery of Raw-Milk Bacteria1

1975 ◽  
Vol 38 (6) ◽  
pp. 319-322 ◽  
Author(s):  
C. N. HUHTANEN ◽  
A. R. BRAZIS ◽  
W. L. ARLEDGE ◽  
C. B. DONNELLY ◽  
R. E. GINN ◽  
...  
Keyword(s):  
Raw Milk ◽  
Plate Count ◽  
Equilibration Time ◽  
Standard Methods ◽  
Standard Plate Count ◽  
Milk Samples ◽  
Plate Count Agar ◽  
Standard Plate ◽  
Time Required ◽  
Tempering Time

Sixty raw milk samples were plated using “Standard Methods” agar tempered to 45 or 50 ± 1 C. The standard plate count was significantly lower with the agar at 50 C. Tempering time (to 44–46 C) of a flask of agar in a water bath was about 5–10 min longer than that of a comparable flask of water. Time required to reach the desired temperature depended upon the volume of agar in the flasks, the number of flasks, and the volume of the water in the bath. Up to an hour of equilibration time may be necessary for newly autoclaved agar to reach the recommended temperature (44–46 C). Insufficient tempering time might cause an excessively high plating agar temperature which might cause a reduction in bacterial counts, especially of a heat sensitive psychrotrophic bacterium.

MICROBIAL COUNTS OF INDIVIDUAL PRODUCER AND COMMINGLED GRADE A RAW MILK1

1973 ◽  
Vol 36 (3) ◽  
pp. 146-151 ◽  
Author(s):  
H. E. Randolph ◽  
B. K. Chakraborty ◽  
Otto Hampton ◽  
D. L. Bogart
Keyword(s):  
Statistical Significance ◽  
Correlation Coefficients ◽  
Raw Milk ◽  
Microbial Populations ◽  
Plate Count ◽  
Microbial Counts ◽  
Standard Plate Count ◽  
Standard Plate ◽  
Bulk Tank ◽  
Highly Correlated

Microbial populations of Grade A raw milk samples from 105 individual producers and 74 bulk tank trucks (commingled) were enumerated by Standard Plate Count (SPC), psychrotrophic count (PBC), coliform count (CC), laboratory pasteurized count (LPC), thermophilic count (TBC), yeast and mold count (Y&M), and special penicillin (PEN) and crystal violet tetrazolium (CVT) agar count procedures. In addition, microbial populations were determined by the SPC, PBC, PEN, and CVT procedures after preliminary incubation (PI) of samples. Initial mean counts obtained on individual producer samples were generally lower than those for commingled samples. However, producer samples had higher mean counts after PI. Growth ratios were lower for commingled than for individual producer samples indicating slower growth during PI. Results obtained by the PBC, PEN, and CVT procedures were similar when viewed as correlation coefficients, distribution of samples according to microbial counts, mean counts, and growth ratios during PI. Before PI, the correlation between these three tests was poor and lacked statistical significance when the PBC was <50,000/ml. After PI, the tests were highly correlated (P<0.01) and the r values ranged from 0.8 to 0.9 for samples with PBC levels above 108/ml.

scholarly journals Multiregional Evaluation of the SimPlate Heterotrophic Plate Count Method Compared to the Standard Plate Count Agar Pour Plate Method in Water

2000 ◽  
Vol 66 (1) ◽  
pp. 453-454 ◽  
Author(s):  
R. Wayne Jackson ◽  
Karen Osborne ◽  
Gary Barnes ◽  
Carol Jolliff ◽  
Dianna Zamani ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Water Samples ◽  
Plate Count ◽  
Heterotrophic Plate Count ◽  
Plate Method ◽  
Standard Plate Count ◽  
Plate Count Agar ◽  
Count Method ◽  
Standard Plate ◽  
Plate Count Method

ABSTRACT A new SimPlate heterotrophic plate count (HPC) method (IDEXX Laboratories, Westbrook, Maine) was compared with the pour plate method at 35°C for 48 h. Six laboratories tested a total of 632 water samples. The SimPlate HPC method was found to be equivalent to the pour plate method by regression analysis (r = 0.95;y = 0.99X + 0.06).

A New Medium for Determining the Total Plate Count in Food

1999 ◽  
Vol 62 (12) ◽  
pp. 1404-1410 ◽  
Author(s):  
C. F. SMITH ◽  
D. E. TOWNSEND
Keyword(s):  
Linear Regression Analysis ◽  
Alternative Methods ◽  
Plate Count ◽  
Most Probable Number ◽  
Suitable Alternative ◽  
Probable Number ◽  
Standard Plate Count ◽  
Plate Count Agar ◽  
Total Plate Count ◽  
Standard Plate

SimPlate for Total Plate Count–Color Indicator (TPC-CI, IDEXX Laboratories, Inc., Westbrook, Me.) is a new medium that incorporates the redox dye resazurin to detect and quantify bacteria in food. Enumeration is achieved by the most probable number method using a SimPlate device. Viable bacteria are detected in each well of the SimPlate device by the biochemical reduction of resazurin, which is blue, to the pink resorufin or the clear dihydroresorufin indicators. Results after 24 h of incubation for TPC-CI are highly correlated with standard plate count agar after 48 h of incubation. Correlation coefficients from studies conducted at five laboratories ranged from 0.94 to 0.98 in side-by-side comparisons against standard plate count agar. Four additional test sites, using alternative methods for determining the aerobic plate count in food, reported similar results in comparison studies (r = 0.91 to 0.97). The slopes from linear regression analysis at all sites ranged from 0.91 to 0.98, with y intercepts ranging from 0.11 to 0.84. Samples used for the validation of TPC-CI included raw food products (i.e., liver and grains), which may contain natural enzymes that interfere with enzyme-based detection methods. No interference was seen from the foods tested. These results suggest that TPC-CI is a suitable alternative to existing plate count methods and has reduced incubation time.

An Update Survey of Bulk Tank Milk Quality in Vermont

1991 ◽  
Vol 54 (7) ◽  
pp. 549-553 ◽  
Author(s):  
JOHN J. GOLDBERG ◽  
JOSEPH W. PANKEY ◽  
PEGGY A. DRECHSLER ◽  
PATRICIA A. MURDOUGH ◽  
DIANTHA B. HOWARD
Keyword(s):  
Somatic Cell ◽  
Research Laboratory ◽  
Somatic Cell Count ◽  
Geometric Mean ◽  
Arithmetic Mean ◽  
Plate Count ◽  
Bulk Tank Milk ◽  
Standard Plate Count ◽  
Standard Plate ◽  
Bulk Tank

Quality of Vermont bulk tank milk was first surveyed in 1985 as part of a statewide milk quality enhancement program. In a second survey conducted in 1990, bulk tank milk from 1,971 farms was sampled and tested for standard plate count, bacterial type and species distribution, and somatic cell count. Test results from 1,203 duplicate bulk tank milk samples were compared between five Vermont milk processors and the University of Vermont Quality Milk Research Laboratory. Arithmetic mean standard plate count conducted by processors was 2.3 × 104 CFU/ml in 1990 compared with 3.0 × 104 CFU/ml in 1985 (Geometric mean went from 1.3 × 104 CFU/ml in 1985 to 1.1 × 104 CFU/ml in 1990). Trypticase blood-esculin agar was used at the Quality Milk Research Laboratory to determine distribution of bacteria types and species. Comparison of results with a 1985 survey appeared to demonstrate a reduction in the percentage of farms with Streptococcus agalactiae from 47% to 32%. Frequency of other organisms increased with the majority being environmental organisms. Arithmetic mean total raw bacteria count on blood agar was 1.9 × 104 CFU/ml. Correlation between standard plate count and blood agar raw bacteria count was low. Arithmetic mean somatic cell count appeared to decline from 5.4 × 105 cells/ml in 1985 to 3.4 × 105 cells/ml in 1990 (Geometric mean went from 4.1 × 105 cells/ml in 1985 to 2.9 × 105 cells/ml in 1990). Correlation between somatic cell counts conducted by milk processors and the Quality Milk Research Laboratory was high.

Sign in / Sign up

Export Citation Format

Share Document