Heat stability of DFMs
Trial on heat stability
Purpose
To test the pelleting capabilities of DFM´s sold in the market place
To reassure CFU recovery from ”production to trough”
Material & Methods
Commercial samples representing 5 different bacteria were
analyzed
Feed production was carried out at independent institute
under highly controlled environment 1)
Feeds were analyzed pre- and post pelleting by an
independent lab 2)
1)
2)
Technological Institute, Kolding, Denmark (2007)
2) LUFA-ITL-GmbH – AGROLAB LABORGRUPPE, Germany
Trial on heat stability
Material & Methods
Commercial samples representing 5 different
microorganisms were analyzed
Feed production was carried out at independent institute
under highly controlled environment 1)
Feeds were analyzed pre- and post pelleting by an
independent lab 2)
1)
2)
Technological Institute, Kolding, Denmark (2007)
LUFA Lab organization, Kiel, Germany
Trial on heat stability
Material & Methods
Dietary composition of the diets
Wheat
Barley
SBM
Fishmeal
Skim milk/whey powder
Premix
Trial on heat stability
Material & Methods
Mixing
60g of a DFM was included in a premix and mixed in a
compulsory mixer for 10 min
The premix was added into 150kg piglet feed at an inclusion
of 5% and mixed in a horizontal mixer for 10 min
Pelleting
Conditioner
Feeder
Press
Cooling
Total heat exposure: 85 °C for 15 sec.
Trial on heat stability
Material & Methods
Cleaning procedures
The equipment was vacuum cleaned between treatments.
Sampling
4 sub-samples (500g each) were sampled within the 1½ min. feeds
were pelleted and cooled down immediately
Standardization
Samples were standardized twice on a large riffler followed by a
final division on a small riffler into 2 representative samples of 1
kg each.
Trial on heat stability
Material & Methods
Bacteria selected in test.
Lactobacillus farciminis
Pediococcus acidilactici
Enterococcus faecium
Sacharomyces cerevisae
Bacillus subtilis, Bacillus licheniformis
Trial on heat stability
Sample ID
Calculated
CFU/g
Meal feed
CFU/g
Pelleted feed
CFU/g
Recovery of
viable cells, %
Negative control
Total aerobic
NA
2,6E+06
3,6E+04
1
L. farciminis
NA
3,1E+04
<10
<1
P. acidilactici
4,0E+06
3,6E+06
2,7E+04
1
E faecium
4,0E+06
8,5E+06
1,5E+06
18
S. cerevisae
8,0E+06
8,0E+06
2,7E+04
<1
B. Licheniformis &
B. subtilis
1,3E+06
1,2E+06
1,2E+06
100
Trial on heat stability
Bacteria
DFM´s in the market place
L. farciminis
Biacton
P. acidilactici
Bactocell
E faecium
Cylactin, Fecinor, Oralin, Bonvital, Provita, Biomin IMB52
S. cerevisae
Levucell, Biosaf, Biosprint, Yea-Sacc
B. Licheniformis &
B. subtilis
BioPlus 2B
Underlined DFM´s were tested
Mathematic “tricks” to report on product stability
Some producers report CFU counts as log values when recovery is calculated.
What is the impact of that ?
CFU
log (CFU)
Expected
Analyzed
Expected
Analyzed
5 E+09
8 E+06
9.698
6.903
Recovery
0.16%
Recovery
71 %
Note: 5E+09 = 5.0 x 109
ABRACADABRA --- Good recovery on LAB and yeast !!!!
Sample ID
Recovery of
viable cells, %
real count
Meal feed
Log CFU/g
Pelleted feed
Log CFU/g
Recovery of
viable cells, %
Log count
Negative control
Total aerobic
1
6,414
4,556
71
L. farciminis
<1
4,491
1
22
P. acidilactici
1
6,556
4,431
68
E faecium
18
6,929
6,176
89
S. cerevisae
<1
6,903
4,431
64
B. Licheniformis &
B. subtilis
100
6,079
6,079
100
The lower the recovery the higher impact on log transformation !!
Trial on heat stability
Summary & Conclusions
Independent study is showing that
Spore forming bacteria are heat stable
BioPlus 2B is proven heat stable
LAB are sensitive to heat exposure
Yeasts are sensitive to heat exposure
Watch out for the way stability is reported
”magic” (log transformation) is sometimes applied