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Table 2014.2. Interlaboratory study results of 3M Petrifilm RYM vs. the FDA BAM and ISO 21527 methods for Raw Almonds
3M Petrifilm RYM Method
FDA BAM/ISO 21527 Methods
a
p-value
d
Difference
of Means
e
Reverse
Transformed
Mean
Difference
f
Matrix
Lot
N
b
Mean
c
s
r
s
R
Lot
N
b
Mean
c
s
r
s
R
Raw
Almonds
25
o
C
48 hours
Control
12(0)
<
1.00
-
-
Control
12(0)
<
1.00
-
-
-
-
-
Low
14(0)
1.45
0.17
g
0.26
Low
14(0)
1.55
0.19
0.34
0.4165
0.10
-7.30
Medium 14(1)
2.12
0.26
0.39
Medium 14(0)
2.21
0.20
0.24
0.3322
0.09
-30.36
High
14(2)
3.00
0.18
0.49
High
14(1)
3.08
0.12
0.31
0.2833
0.08
-202.26
Raw
Almonds
25
o
C
60 hours
Control
12(0)
<
1.00
-
-
Control
12(0)
<
1.00
-
-
-
-
-
Low
14(0)
1.53
0.23
0.28
Low
14(0)
1.55
0.19
0.34
0.8391
0.02
-1.60
Medium 14(0)
2.20
0.21
0.27
Medium 14(0)
2.21
0.20
0.24
0.7789
0.01
-3.69
High
14(2)
3.04
0.18
0.41
High
14(1)
3.08
0.12
0.31
0.5418
0.04
-105.79
Raw
Almonds
28
o
C
48 hours
Control
12(0)
<
1.00
-
-
Control
12(0)
<
1.00
-
-
-
-
-
Low
14(0)
1.58
0.16
g
0.21
Low
14(0)
1.55
0.19
0.34
0.7381
0.03
2.54
Medium 14(0)
2.17
0.17
g
0.29
Medium 14(0)
2.21
0.20
0.24
0.6139
0.04
-11.73
High
14(2)
3.01
0.17
0.45
High
14(1)
3.08
0.12
0.31
0.3904
0.07
-178.97
Raw
Almonds
28
o
C
60 hours
Control
12(0)
<
1.00
-
-
Control
12(0)
<
1.00
-
-
-
-
-
Low
14(0)
1.60
0.17
g
0.20
Low
14(0)
1.55
0.19
0.34
0.5474
0.05
4.33
Medium 14(0)
2.21
0.17
g
0.23
Medium 14(0)
2.21
0.20
0.24
0.9483
0.00
0.00
High
14(2)
3.03
0.18
0.42
High
14(1)
3.08
0.12
0.31
0.4687
0.05
-130.75
a
Samples were analyzed by a harmonized FDA BAM Chapter 18 and
ISO 21527 methods using 0.1% peptone as the sample diluent
b
Number of laboratories that reported complete results. Outliers are
presented in parentheses.
c
Log
10
yeast and mold CFU/g.
d
Significant difference (p<0.05)
e
A mean difference absolute value of greater than 0.5 indicates a statistical
significant difference between methods
f
Results presented as CFU/g
g
Results indicate that the candidate method is more repeatable then the
reference methodss
r
– Repeatability; s
R
– Reproducibility;
1
2
3
Candidates for 2016 Method of the Year
97