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KOI: Cocoa processing and chocolate production - 2013 Filled chocolates/pralines Migration fat blooom 10/09/2012 Ir. Claudia Delbaere
KOI: Cocoa processing and chocolate production - 2013
Filled chocolates/pralines Migration fat blooom
10/09/2012
Ir. Claudia Delbaere
KOI: Cocoa processing and chocolate production - 2013
Praline production
KOI: Cocoa processing and chocolate production - 2013
Praline production
Chocolate
Most prone to fat bloom: • Dark chocolate • Milk chocolate
Filling
Most prone to fat bloom: • Nut based fillings (e.g. hazelnut based fillings) • Fat based fillings
KOI: Cocoa processing and chocolate production - 2013
Praline production
Chocolate Filling
Tempering
Creation of an
adequate amount
of cocoa butter bV
crystals
Moulding
- Traditional moulding
- Enrobing
- Frozen cone / cold stamping
- One-shot
Cooling
Further crystal
development and
creation of a fat
crystal network
Storage
How to delay
fat bloom
development?
KOI: Cocoa processing and chocolate production - 2013
Praline production
Traditional moulding
Mould preheating – chocolate shell – vibration – cooling – filling – cooling – chocolate base – cooling - demoulding
Source: Barry Callebaut
KOI: Cocoa processing and chocolate production - 2013
Praline production
Enrobing
Filling preparation – cooling – enrobing with chocolate
Source: Barry Callebaut
KOI: Cocoa processing and chocolate production - 2013
Praline production
Cold stamping (frozen cone)
Source: Bühler
KOI: Cocoa processing and chocolate production - 2013
Praline production
One-shot
Source: Bühler
Shell mass
Filling mass
KOI: Cocoa processing and chocolate production - 2013
Praline production
Example of an industrial production line
1) Mould checking and (automatic) changing section 2) Mould pre-heating by warm air 3) Shell depositing and vibration 4) Short cut for solid production 5) Shell forming and shell cooling 6) Center filling 7) Center cooling 8) Backing-off 9) Final cooling 10) Demoulding on to band or plate and
end product discharge 11) Electric plant control
2
5
3
6
8
1
4
11
7
10
9
Source: Bühler
KOI: Cocoa processing and chocolate production - 2013
Migration fat bloom
KOI: Cocoa processing and chocolate production - 2013
Introduction
Fat bloom
Loss of initial gloss
Formation of white-greyish haze
Fat crystals on the surface → Diffraction of light
James and Smith (2009)
KOI: Cocoa processing and chocolate production - 2013
Introduction
Polymorphic fat bloom
Plain chocolate: cocoa butter crystal polymorphism (βV → βVI)
Van Malssen et al. (1999)
Liquid
α
βV
βVI
γ
b’
direct crystallization (during cooling)
melting
recrystallization
Well-tempered
Fat bloom
KOI: Cocoa processing and chocolate production - 2013
Introduction
Migration fat bloom
Composed chocolate products: migration of liquid foreign lipids (e.g. from the filling, nut, biscuit) into the chocolate
Fat bloom = quality problem n° 1 in filled chocolate industry o Shelf life reduction
o Hampering export
o Consumer rejection
Less research compared to plain chocolate bloom → In contrast with current higher industrial relevance !
• European chocolate manufacturing
market:
> 2.000 companies
> 200.000 people
> 43 billion Euro annual turnover
> 3 billion Euro export
• Large proportion of SMEs (> 90%)
KOI: Cocoa processing and chocolate production - 2013
Introduction
≠ Sugar bloom
Caused by condensation (colder → warmer)
Solubilization and recrystallization of sugar @ chocolate surface
Storage in frigde
KOI: Cocoa processing and chocolate production - 2013
Oil migration
Chocolate products with fat-based fillings, nuts, …
Driving force: D(TAG)
Smith et al. 2007
KOI: Cocoa processing and chocolate production - 2013
Oil migration
Mechanisms:
o Diffusion
o Capillary forces
Crucial role of chocolate microstructure!
Galdamez et al. 2009
D = diffusivity e = void fraction t = tortuosity
→ Deff ~ structure
KOI: Cocoa processing and chocolate production - 2013
Oil migration
Methods to study oil migration: example
TAG composition → HPLC-analysis
1
10 C
F
Minutes
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
mV
olts
0
200
400
600
800
1000
1200
1400
1600
1800
2000
mV
olts
0
200
400
600
800
1000
1200
1400
1600
1800
2000
6.3
16
29
23
0.0
07
13
.32
9
24
62
6
0.0
59
16
.17
9
19
66
78
0.4
75
17
.14
9
48
61
0.0
12
19
.25
4
13
73
60
5
3.3
15
20
.35
5
70
10
4
0.1
69
21
.51
0
36
62
0
0.0
88
22
.45
4
82
95
79
5
20
.02
2
23
.61
0
74
04
62
1.7
87
24
.42
0
12
53
13
0.3
02 24
.80
8
33
59
63
2
8.1
09
26
.50
8
29
65
42
0.7
16
27
.72
5
16
65
64
62
40
.20
1
29
.25
6
20
36
8
0.0
49
30
.56
0
10
15
41
80
24
.50
8
32
.06
8
10
42
0
0.0
25
33
.13
5
44
55
2
0.1
08
34
.71
8
66
49
0.0
16
35
.07
1
78
08
0.0
19
35
.57
8
53
08
0.0
13
Detector 1
2TW18H1L2.dat
2TW18H1L2-Rep2.dat
Retention Time
Area
Area Percent
Minutes
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
mV
olts
0
200
400
600
800
1000
1200
1400
1600
1800
2000
mV
olts
0
200
400
600
800
1000
1200
1400
1600
1800
2000
1.2
2
40
70
0.0
10
6.4
3
10
26
4
0.0
25
6.9
1
35
66
6
0.0
87
7.2
5
80
33
0.0
20
7.5
0
56
86
0.0
14
8.8
6
35
68
4
0.0
87
9.2
7
71
97
0.0
18
9.6
0
27
58
5
0.0
68
10
.20
63
60
0.0
16
12
.10
85
39
0.0
21
16
.84
84
62
0.0
21
19
.91
50
46
3
0.1
24
21
.01
88
85
0.0
22
22
.10
83
24
9
0.2
04
23
.10
29
34
21
0.7
18
24
.24
15
24
75
0.3
73
25
.04
23
14
79
0.5
67
25
.41
47
50
31
3
11
.62
8
27
.09
21
48
92
0.5
26
28
.26
21
92
73
20
53
.67
7
29
.76
30
52
7
0.0
75
31
.06
12
69
00
17
31
.06
4
32
.59
20
58
7
0.0
50
33
.72
63
58
1
0.1
56
34
.98
27
98
2
0.0
68
35
.24
23
85
9
0.0
58
35
.69
60
27
9
0.1
48
35
.90
28
53
1
0.0
70
36
.14
35
36
8
0.0
87
Detector 1
3T2L2W1.dat
3T2L2W1-Rep2.dat
Retention Time
Area
Area Percent
POP
POS
SOS
OOO
LOO
KOI: Cocoa processing and chocolate production - 2013
Oil migration
Methods to study oil migration: example
TAG composition → HPLC-analysis
0
5
10
15
20
25
30
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34
Are
a O
OO
(%
)
WeeksNumber of weeks
00
0 (
%)
KOI: Cocoa processing and chocolate production - 2013
Migration fat bloom
Mechanism
Ziegleder, 2006
KOI: Cocoa processing and chocolate production - 2013
Migration fat bloom
Methods to study visual fat bloom
Image analysis
Scanning electron microscopy
Trained panel
KOI: Cocoa processing and chocolate production - 2013
Migration fat bloom
Methods to study bV – bVI transition
X-ray diffraction
Timms, 2003
KOI: Cocoa processing and chocolate production - 2013
How to prevent migration fat bloom?
Composition
o Fillings: the higher the liquid oil content, the higher the risk of fat bloom
o If cocoa butter and filling fats are not compatible: softening effect
o Addition of anti-blooming agents to chocolate and/or filling
Processing conditions
o Tempering
o Shell thickness
o Moulding technology
o Cooling
Storage conditions
o Storage temperature of 15-18°C is recommended
o Avoid fluctuating temperatures
KOI: Cocoa processing and chocolate production - 2013
How to prevent migration fat bloom?
Thermal treatments: storage at low tempatures
Depypere et al. (2009)
Cold storage after production decreased oil migration and fat bloom development in filled
chocolates.
The results suggest a crystallization effect during cold storage, leading to permanent microstructural
changes.
KOI: Cocoa processing and chocolate production - 2013
How to prevent migration fat bloom?
Thermal treatments: storage at high tempatures
30 min/30°C
2 hrs/30°C
12 months at 20°C
Reference
KOI: Cocoa processing and chocolate production - 2013
Thanks for your attention!
Laboratory of Food Technology and Engineering (FTE) – UGent Cacaolab
Ghent University, Belgium
++32(0)92646198 ++32(0)92646218
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