Download Sensory Analysis Course 2013/14

Difference in threshold detection
of graininess in chocolate:
machine vs. human
Sara De Pelsmaeker, Juliette S. Behra,
Joachim Schouteten, Xavier Gellynck
Source of Inspiration
4th European Conference on Sensory and Consumer Research:
A Sense of Quality
Keynote Presentation:
Sensory scientists in the food industry: Nice to have or must have?
Kepa Barcenas, R&D Director - Confections & Mints at Wrigley
Time
Added Value
Money
Saving or profit
Preferred
Product
Speed to
market
Scientific contribution
•Sensory scientists speak in terms of preferred product,
significant higher liking, intention to eat, discrimination
and describing products,…
•Industry speaks in terms of added value, investment
versus profit, putting real numbers on the graphs,…
 Finding GAPS
Where is the gap?
Chocolate is a suspension of sugar and cocoa particles in
a continuous fat phase.
Mixing
Refining
Conching
Tempering
Moulding
Packaging
Below a critical size particles are not
perceived by humans beings.
Literature: between 25 and 35 µm
gritty perception
Objective of the research:
Find the maximum size of particles
that cannot be perceived by
human beings
Methodology
Chocolate production
Instrumental analysis
 Particle Size Distribution
(PSD)
 Texture
 Differential Scanning
Calorimeter (DSC)
Sensory analysis
 Trained panel
- 3-AFC test
- Ranking test
 Quantitative Descriptive
analysis (QDA)
Sensory analysis
 Consumer panel
Instrumental analysis
- Particle Size Distribution (PSD)
D4,3 (µm)
Dv,90 (µm)
Mean
SD
Mean
SD
30 RC
13.83
0.14
34.09
0.05
30 CC
13.10
0.29
32.85
0.75
30 TC
13.42
0.45
32.94
1.13
40 RC
18.16
0.29
43.46
1.33
40 CC
15.67
0.66
39.04
1.57
40 TC
16.14
0.23
39.24
0.85
50 RC
23.9
1.59
63.49
3.63
50 CC
22.7
1.4
60.48
3.06
50 TC
22.48
0.65
59.79
1.5
• Expected Dv,90 of 50 µm 
60µm
• Conching decreases Dv,90
•
Three chocolates are
significanly different
SD: Standard Deviation; 30, 40, 50: expected Dv,90;
RC: Refined Chocolate; CC: Conched Chocolate; TC: Tempered Chocolate
Instrumental analysis
- Particle Size Distribution (PSD)
8
7
6
Volume %
5
30µm
4
40µm
3
50µm
2
1
0
0.01
0.1
1
10
Particle diameters (µm)
100
1000
Instrumental analysis
- Texture
Chocolate
Maximum load (N)
30 µm
40 µm
60 µm
Mean
18.39
17.18
17.07
SD
0.37
0.94
0.34
No significant difference
- DSC measurement
No significant difference in melting behaviour
between the three chocolates
Instrumental analysis
- Texture
Chocolate
Maximum load (N)
30 µm
40 µm
60 µm
Mean
18.39
17.18
17.07
SD
0.37
0.94
0.34
No significant difference
- DSC measurement
No significant difference in melting behaviour
between the three chocolates
- Ranking test
50
40
30
20
10
0
0
Percentage of panelists (%)
- 3-AFC
Percentage of panelists
(%)
Sensory analysis
1
2
Number of right answers
3
100
90
80
70
60
30 µm
50
40
40 µm
30
20
60 µm
10
0
1st
2nd
Ranking order
3rd
Sensory analysis
- Quantitative Descriptive Analysis
Snap
Residuals
9
8
7
6
5
4
3
2
1
Hardness
40 µm
60 µm
Film
Sweetness
Graininess
Bitterness
Sensory analysis
- Acceptance test
40
35
Percentage of respondants (%)
30
25
20
30 µm
40 µm
15
60 µm
10
5
0
like
extremely
like very
much
like
moderatly
like slightly neither like
nor dislike
Evaluation scale
dislike
slightly
dislike
moderatly
dislike very
much
dislike
extremely
Sensory analysis
- Graininess
70
65
60
Percentage of respondents (%)
55
50
45
40
35
30 µm
30
40 µm
25
60 µm
20
15
10
5
0
too much grainy
too grainy
just right
Evaluation scale
not grainy enough
really not grainy
enough
Sensory analysis
- Ranking
100.0
90.0
Percentage of respondants (%)
80.0
70.0
60.0
30 µm
50.0
40 µm
40.0
60 µm
30.0
20.0
10.0
0.0
1st
2nd
Ranking order of the samples
3rd
Thank you for your attention!
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