statistical methodologies in confectionery w. peñaloza and a. bousbaine
DESCRIPTION
Statistical Methodologies in Confectionery W. Peñaloza and A. Bousbaine Nestlé Research Center, P.O. Box 44, 1000 Lausanne 26, Switzerland. Background & Objectives. Business trend for low fat and reduced calorie to bring guilt free indulgence to consumers. Project objectives. - PowerPoint PPT PresentationTRANSCRIPT
6/11-06-2011
Statistical Methodologies in Confectionery
W. Peñaloza and A. Bousbaine
Nestlé Research Center, P.O. Box 44, 1000 Lausanne 26, Switzerland
2
Project objectives
• Evaluate the microbiological safety and stability of confectionery products
• Provide guidance for microbiological challenge testing for the development of similar products
Business trend for low fat and reduced calorie to bring guilt free indulgence to consumers
Background & Objectives
3
Aw 0.8Aw 0.3
What do we know
• Praline concept & technology developed at NRC (P. Rousset) with industrial potential
• Industrial feasibility (Darryl Barwick)
Background & Objectives
4
Production
Thorough understanding of product stability against fungal growth (mycotoxins/spoilage)
Challenge testing
(at conditions as close as possible to industrial
production)
End of shelf life
Shelf life of product & conditions
Background & Objectives
5
What needs to be defined for the challenge testing
• Recipe (“canada”) – polishing & approval
• Product format/presentation praline, moulded or enrobed
• Storage e.g. refrigerated, ambient, warm?
( likely industrial production)
Major impact for planning:
Water migration kinetics
Challenge testing (Experimental design)
Background & Objectives
6
Experimental Design
Generic Design
Other Parameters
• Format: Bâton and Perforated
• Cocktail: None, Safety and Spoilage
• Storage Temperature: Refrigerated (10 °C), Ambient (22°C) and Warm (32 °C)
Run No Sorbate (%) aW1 0 0.762 0 0.843 0.2 0.764 0.2 0.845 0.1 0.8
7
Cocktails
• None: no inoculation, but natural contamination (air, raw materials, clean equipment surfaces, …)
• Safety: micotoxigenic moulds (aflatoxines, ochratoxins, …)
• Spoilage: moulds found in production line, storage tests,contaminated raw materials, inadequate hygenein the production line, …
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Measurements
Response
Visual Mould Growth
Codification
• 0: No growth seen even under the stereomicroscope
• 1: Incipient Mycelium growth normally detected after careful inspection and frequently under the stereomicroscope, detected by specialist
• 2: Mycelium growth clearly noticeable as white hairy areas by any consumer (not specialist)
• 3: Abundant mycelium growth and sporulation with or without change of colour
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Format: Bâton, Cocktail: NoneResults After 24 Weeks of Storage
10
Format: Bâton, Cocktail: SafetyResults After 24 Weeks of Storage
11
Format: Bâton, Cocktail: SpoilageResults After 24 Weeks of Storage
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Format: Perforated, Cocktail: NoneResults After 24 Weeks of Storage
13
Format: Perforated, Cocktail: Safety Results After 24 Weeks of Storage
14
Format: Perforated, Cocktail: SpoilageResults After 24 Weeks of Storage
15
Format: Bâton & Perforated, Cocktail: Spoilage
Results After 24 Weeks of Storage
16
I Index
Response
Let be the categories defined to characterize the degreeof visual moulds, where
Let k be the number of replicates for each combinationFormula-Format-Cocktail-Storage Temperature.
For each combination Formula-Format-Cocktail-Storage, let be the number of samples with a degree of visual moulds
It follows that
niwi ...,,1
nwww ...0 21
ix
iw
kxn
ii
1
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I Index
An index I can be defined as follows:
Properties of the I index
Situation 1 then
Situation 2 then
n
n
iii
wk
xwI
1
0..., 321 nxxxkx 011 nwk
xwI
kxandxxx nn 0... 121 1n
n
n
nn
wk
wk
wk
xwI
18
I Index
Statement
Proof
1. By definition, it is clear that
2. We have to show that
We have
Since
It follows that because
10 I
0I
1I
n
n
iii
n
n
iii
kwxwkw
xwI
1
1 11
nni
n
iinnni
n
iin
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iii wxkxwkwxwxwkwxw )(
1
1
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121 ...
n
iinn xkxkxxx
0)(1
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in
n
iini
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ii xkwwkwxw 0)( ni kww
19
Weights
Visible mould growth (spoilage)
1
3
noticed by expert
Storage time
stationary phase
lag phase
exponential phase
2noticed by consumer
Completely mouldy
high aw
low aw
20
Weights
Time
Growth
0
10
Germination
Specialist
Consumer
Abundant
7.5
2.5
Initial Inoculation
Growing
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Modelling
Response
I index
Modelling
A model relating the I index to the 2 parameters Sorbate and aW isestablished for each combination Format-Cocktail-Storage Temperature.
The contour plots of the established models are given in the next slides.
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Results After 24 Weeks of Storage
0 0.004 0.008 0.012 0.016 0.02 0.024 0.028 0.032 0.036 above
Index: Contour Plots
Format: Bâton, Cocktail: None, Storage Temperature: 22 °C
Sorbate (%)
aW
0.76
0.78
0.80
0.82
0.84
0.00 0.04 0.08 0.12 0.16 0.20
23
Results After 24 Weeks of Storage
0 0.012 0.024 0.036 0.048 0.06 0.072 0.084 0.096 0.108 above
Index: Contour Plots
Format: Bâton, Cocktail: Safety, Storage Temperature: 22°C
Sorbate (%)
aW
0.76
0.78
0.80
0.82
0.84
0.00 0.04 0.08 0.12 0.16 0.20
24
Results After 24 Weeks of Storage
0 0.09 0.18 0.27 0.36 0.45 0.54 0.63 0.72 0.81 0.9 above
Index: Contour Plots
Foramt: Bâton, Cocktail: Spoilage, Storage Temperature: 22 °C
Sorbate (%)
aW
0.76
0.78
0.80
0.82
0.84
0.00 0.04 0.08 0.12 0.16 0.20
25
Results After 24 Weeks of Storage
0 0.034 0.068 0.102 0.136 0.17 0.204 0.238 0.272 0.306 above
Index: Contour Plots
Format: Perforated, Cocktail: None, Storage Temperature: 22 °C
Sorbate (%)
aW
0.76
0.78
0.80
0.82
0.84
0.00 0.04 0.08 0.12 0.16 0.20
26
Results After 24 Weeks of Storage
0 0.04 0.08 0.12 0.16 0.2 0.24 0.28 0.32 0.36 above
Index: Contour Plots
Format: Perforated, Cocktail: Safety, Storage Temperature: 22 °C
Sorbate (%)
aW
0.76
0.78
0.80
0.82
0.84
0.00 0.04 0.08 0.12 0.16 0.20
27
Results After 24 Weeks of Storage
0 0.09 0.18 0.27 0.36 0.45 0.54 0.63 0.72 0.81 0.9 above
Index: Contour Plots
Format: Perforated, Cocktail: Spoilage, Storage Temperature: 22 °C
Sorbate (%)
aW
0.76
0.78
0.80
0.82
0.84
0.00 0.04 0.08 0.12 0.16 0.20
28
Results After 24 Weeks of Storage
0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 above
Index: Contour Plots
Format: Bâton & Perforated, Cocktail: None, Storage Temperature: 22 °C
Sorbate (%)
aW
0.76
0.78
0.80
0.82
0.84
0.00 0.04 0.08 0.12 0.16 0.20
29
Results After 24 Weeks of Storage
0 0.03 0.06 0.09 0.12 0.15 0.18 0.21 0.24 0.27 above
Index: Contour Plots
Format: Bâton & Perforated, Cocktail: Safety, Storage Temperature: 22 °C
Sorbate (%)
aW
0.76
0.78
0.80
0.82
0.84
0.00 0.04 0.08 0.12 0.16 0.20
30
Results After 24 Weeks of Storage
0 0.09 0.18 0.27 0.36 0.45 0.54 0.63 0.72 0.81 0.9 above
Index: Contout Plots
Format: Bâton & Perforated, Cocktail: Spoilage, Storage Temperature: 22 °C
Sorbate (%)
aW
0.76
0.78
0.80
0.82
0.84
0.00 0.04 0.08 0.12 0.16 0.20
31
Conclusions
After 24 weeks of storage, visual mould growth appears mainly when thecocktail is spoilage and when the storage temperature is ambient.Visual mould growth is seen on the combinations No 2 and 4.Visual mould growth is more pronounced when the samples are perforated.Combination No 2 does not contain Sorbate and has an aW of 0.84.Combination No 4 contains 0.2% Sorbate and has an aW of 0.84.
The results show that:
• aW plays an essential role• Sorbate plays also a role, but less pronounced• Storage temperature plays also a role. Ambient temperature increases the degree of visual mould growth.• Format plays as well a role. Perforation increases the degree of visual mould growth.
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The established I index characterizes very well the degree of visual moulds,and allows a very easy and understandable way of communicating theresults.
From the modelling using the I index, it appears that:
1. Cocktails: None and Safety
• aW is the key parameter, and this parameter should be as low as possible.• Sorbate plays a slight role. It helps a little bit.
2. Cocktail: Spoilage
• aW is the key parameter, and it should be kept at its lowest value.• Sorbate plays a negligible role. It brings more or less nothing!
The effect of Format is also highlighted in the modelling results.
Conclusions
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The authors wish to thank all the people involved in the whole project, inparticular:
- V. Meunier- P. Rousset- A. Rytz
Acknowlegements
34