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B
ird
et al
.:
J
ournal of
AOAC I
nternational
V
ol
.
99, N
o
.
3, 2016
There were no statistically significant differences between the
3M Petrifilm RAC Plate and FDABAM methods as determined
by the 95% CI of the differences of means at any of the three
contamination levels.
Pasteurized Skim Milk
Pasteurized skim milk test portions were evaluated at a
low, medium, and high contamination level for the presence
of naturally occurring aerobic bacteria. Fifteen laboratories
participated in the analysis of this matrix, with 13 laboratories
submitting data.
For the SMEDP high contamination level, one outlier
laboratory was identified by the Cochran’s tests for outliers.
However, no evidence of physical cause or suspicion of cause
was noted and it was determined that the data would be included
in the statistical analysis.
There were no statistically significant differences between the
3M Petrifilm RAC Plate and SMEDP methods as determined
by the 95% CI of the differences of means at any of the three
contamination levels.
Instant NFDM
Instant NFDM test portions were evaluated at a low, medium,
and high contamination level for the presence of naturally
occurring aerobic bacteria. Fifteen laboratories participated in
the analysis of this matrix, with 15 laboratories submitting data.
For the 3M Petrifilm RAC Plate low contamination level
and for the SMEDP medium contamination level, one outlier
laboratory was identified by the Cochran’s tests for outliers.
Figure 4. Youden plots for 3M Petrifilm RAC Plate and SMEDP results for instant NFDM.
Figure 5. Youden plot for combined mean 3M Petrifilm RAC Plate and FDA BAM results for raw easy-peel shrimp evaluated at 32°C.