316 / 350
Table 13.
Method Comparison Results for Yogurt at 60 Hours.
1
SD
SD
(S
r
)
(S
r
)
1
<10
<0
<10
<0
2
<10
<0
<10
<0
3
<10
<0
<10
<0
4
<10
<0
<10
<0
5
<10
<0
<10
<0
1 2.8 x10
2
2.4472
2.6 x10
2
2.415
2 2.0 x10
2
2.301
3.2 x 10
2
2.5051
3 2.8 x10
2
2.4472
3.0 x1 0
2
2.4771
4 3.0 x 10
2
2.4771
3.2 x 10
2
2.5051
5 3.6 x 10
2
2.5563
3.4 x 10
2
2.5315
1 2.8 x10
3
3.4472
2.4 x10
3
3.3802
2 2.4 x10
3
3.3802
3.6 x10
3
3.5563
3 2.8 x10
3
3.4472
2.6 x10
3
3.415
4 2.6 x10
3
3.415
3.4 x10
3
3.5315
5 2.6 x10
3
3.415
2.4 x10
3
3.3802
1 2.0 x 10
4
4.301
2.2 x 10
4
4.3424
2 1.6 x 10
4
4.2041
1.6 x 10
4
4.2041
3 2.0 x 10
4
4.301
2.2 x 10
4
4.3424
4 1.6 x 10
4
4.2041
1.4 x 10
4
4.1461
5 1.3 x 10
4
4.1139
1.6 x 10
4
4.2041
High
4.2248 0.0787
4.2478 0.0895 0.6776
Medium
3.4209 0.0279
3.4526 0.085 0.4633
NA
Low
2.4458 0.0942
2.4868 0.0445 0.3973
Uninoculated
-
-
-
Level
Sample
3M RYM Petrifilm
ISO / FDA BAM
-
p-value
Ct/g LOG MEAN
Ct/g LOG MEAN
2
3
Sour Cream 48 and 60 hours
4
No statistically significant difference was observed between 2 of the 3 levels analyzed between the two
5
methods. The p-values calculated at a 95% confidence level for the low and medium levels were 0.8528
6
and 0.3007. The 3M RYM method had a higher repeatability value than the ISO and FDA BAM methods
7
for the low and medium levels, with S
r
values, respectively, of 0.0681 and 0.0733 for the low level and
8
0.3970 and 0.4310 for the medium level. The t-test indicated a significant difference between the 3M
9
RYM method and the ISO and FDA BAM methods on the high level with a p-value of 0.0457. The means
10
were 2.9943 for the 3M RYM method and 3.1259 for the ISO and FDA BAM methods. For the high level
11
the ISO and FDA BAM had higher repeatability values compared to the RYM method, with S
r
values,
12
respectively, of 0.0367 and 0.1050. Detailed results are presented in Table 14.
13
14
15
20
AOAC Research Institute
Expert Review Panel Use Only
OMAMAN-16D/ PTM Report
ERP Use Only - December 2014