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Food Protection Trends
Abstracts - January 2006
Evaluation of Hand Mixing
of Ground Beef and Poultry Samples as an Alternative to Stomaching for the Detection of Salmonella
Virginia/West Virginia Dairy
Practices Survey
Understanding and Controlling Microbiological Contamination of Beverage Dispensers in University Foodservice Operations
Evaluation of Hand Mixing
of Ground Beef and Poultry
Samples as an Alternative to
Stomaching for the Detection
of Salmonella
Neelam Narang-1* and William C. Cray, Jr.-2
1-1Eastern Regional Research Center, Microbial Food Safety Research Unit, Agricultural Research Service, United
States Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA
2-2Food Safety and Inspection
Service, Eastern Laboratory, United States Department of Agriculture, 950 College Station Road, Athens, GA 30605,
USA
SUMMARY
This study compared hand mixing with pummeling in a Stomacher for preparing raw ground beef and
poultry samples for the detection of Salmonella. A total of 800 ground beef samples, and 400 each of ground
chicken and turkey, were analyzed. Ten Salmonella isolates were studied in ground beef and five each in
ground chicken and turkey. Each package of raw ground meat was divided into eight (25 g each) samples. Six
of these samples were inoculated (0.04–0.25 CFU/g) with one of the ten Salmonella isolates; three of the six
samples were hand mixed briefly until clumps were dispersed, whereas the other three were pummeled in a
Stomacher for two minutes. The remaining two samples served as uninoculated controls. The samples were
processed for detection and identification of Salmonella according to methods described in the Food Safety
and Inspection Service (FSIS) Microbiological Laboratory guidebook. Statistical analysis, using analysis of
variance and student’s t-test, showed no significant (P < 0.05) difference in CFU/ml and MPN/g between the
two treatments for any of the ground beef and turkey samples inoculated with Salmonella. In ground chicken
samples, there appeared to be no consistent sample handling effect across the five isolates studied; when
tested as a group, no treatment effect was seen in the detection of Salmonella. The results show that all of the
Salmonella isolates tested could be detected by both treatment methods in the three meat matrices.
Virginia/West Virginia Dairy
Practices Survey
K. E. Matek-1,4*, E. Hovingh-2, C. E. Smith-3, K. Waterman-4, C. R. Hackney-1, and S. S. Sumner-4
1-West Virginia University, Human Nutrition and Foods Program, Morgantown, WV 26506, USA
2-The Pennsylvania State University, Department of Veterinary Science, University Park, PA 16802, USA
3-West Virginia State University, Department of Political Science, Institute, WV 25112, USA
4-Virginia Tech, Department of Food Science and Technology, Blacksburg, VA 24061, USA
SUMMARY
A survey of dairy farmers in Virginia and West Virginia evaluated
standard dairy farm practices to determine what producers perceive
to be important economic and production issues. The survey covered
milk quality and safety, and farm security. Most dairies reported somatic
cell counts below 500,000 SCC/ml, which is well within the legal limit.
However, respondents did not support decreasing the legal limit to
400,000 SCC/ml. Most producers (59%) checked milk for abnormalities
before milking and 49% treated more than half of detected clinical
mastitis cases with antibiotic therapy. Antibiotic residue testing was
conducted on all cows prior to addition to the bulk tank by 44% of
the respondents, whereas 29% reported that they never check.
Antibiotic-treated cull animals were most often handled responsibly
prior to selling, and the majority of respondents (52%) would not
change their cull animal practices if a financial penalty was established
for animals condemned at slaughter. Farm security protocols designed
to minimize the possibility of bioterrorism were rarely in place. Most
survey respondents (54%) were not willing to adopt a voluntary thirdparty
quality assurance program comprised of written disease
treatment protocols, training for all workers, treatment records, and
on-farm bulk tank antibiotic residue testing.
Understanding and Controlling
Microbiological Contamination
of Beverage Dispensers in University
Foodservice Operations
Chithra Lakshmanan and Donald W. Schaffner
Food Risk Analysis Initiative, Rutgers University, 65 Dudley Road,
New Brunswick, NJ 08901-8520, USA
SUMMARY
We have previously observed that beverage dispenser tips often
contain high total microbial counts and are among the most
contaminated surfaces found in foodservice establishments. The
objective of this research was to determine the cause of these high
microbial populations and find a practical solution to the problem.
Experiments were conducted on beverage dispensers in use in
university dining halls as well as on an identical but new beverage
dispenser located in our laboratory. Orange juice was dispensed
through the various dispensers and total plate counts from the
dispenser tips were measured at appropriate time intervals. Sanitizing
solutions containing 100 and 200 ppm chlorine were used on beverage
dispensers in dining halls, and subsequent microbial counts were
observed throughout the following day.
Microbial counts tended to be highest immediately after a
beverage had been dispensed and then declined gradually over time.
Microbial counts from the new laboratory-based dispenser were
initially low, but increased over time. Sections of the inside of the
dispenser tip were observed with a fluorescent microscope, and
results suggested the formation of biofilms. High microbial counts
obtained by swabbing the inside of the dispenser tips were also
consistent with the presence of biofilms. Sanitizing with a 200-ppm
chlorine solution resulted in a greater reduction in microbial counts
than with a 100-ppm solution. These results suggest that using a higher
concentration of sanitizer may help reduce microbial counts on
beverage dispenser tips. |
