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Imaging technology:
what can it tell you about
your product?
Martin Whitworth
Campden BRI Day 2017
Imaging applications
• Online process control
– Machine vision
– Product inspection
– Sorting
• Product characterisation
– Documentation and
specification of appearance
– Revealing the invisible
– Image analysis: colour, size,
shape, structure etc.
Food appearance
• Colour
• Size, shape
• Gloss, texture,
uniformity
Calibrated colour
imaging • Calibrated: Suitable for
colour measurement
• Consistent: Documentation
of trial product appearance
• Accurate reproduction:
Reference charts
Application for specifications
Case study • Retailer and poultry suppliers visited with
example products.
• Limits agreed for visual characteristics.
• Campden BRI produced charts using accurate
images of the agreed product examples.
Foreign body identification Multi-laminate film
50 μm
PE Al PE PET
Layers identified by
FT-IR spectroscopy
200 μm
Metal
fleck on
sugar Identified as
copper by X-
ray spectrum
Human
hair
Rabbit
hair/fur
Particle size and shape • Several methods available
• Dynamic image analysis
– Grain, seeds, ground
materials, powders,
particles in liquid
suspension...
– Size and shape
Dynamic image analysis
Laser diffraction
Dynamic light scattering
ESZT
Sieving
1μm 1mm 1nm
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
De
nsity d
istr
ibu
tio
n q
0*
1 2 3 4 5 6 7 8 9 10
Width / mm
Width
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
De
nsity d
istr
ibu
tio
n q
0*
1 2 3 4 5 6 7 8 9 10
Length / mm
Length
Thermal imaging
• Development and
validation of cooking and
reheating instructions
• Instructions validated for
a range of typical ovens.
• Enables hot and cold
spots to be identified
– To ensure product is
cooked throughout
– To avoid excessive
temperatures for
packaging
Microwave heating of product in
plastic pot without stirring
20
40
60
°C 78°C
NIR hyperspectral imaging • Mapping of composition
• Rapid (a few seconds)
• Also suitable for online use
0 min 1 min 4 min 7 min 14 min Frying
time
Example: Fat in chips
Chocolate bars • NIR absorbance
bands provide
information on
composition
• Differences
apparent
• Quantitative
measurements
possible with
calibration.
Moisture (OH)
Crystalline sucrose
Fat (CH2)
Low High
Chocolate
Biscuit Structure
revealed
Moisture distribution
• Effect of baking
• Storage trials for migration over shelf life
Biscuit baking
Dough
Moisture (%)
Biscuit
Bread staling
Fresh Stale
Product structure • C-Cell instrument for bread
quality assessment
• Developed at Campden BRI
Control: Chorleywood process
Radical process
C-Cell contrast:
0.7895 ± 0.005 0.832 ± 0.008
Case study:
Radical bread process • Softer, finer
structure
• C-Cell data used
in support of
patent claims
Structure formation during
baking • X-ray CT scanning
• Oven placed inside
scanner
Structure during baking
Fruit
cakes
Muffins
Croissants
Control +DATEM +Lipase
Case study: Lipid ingredients • Improve bread volume and structure.
• Tested hypothesis for clients about the stages
at which they affect the structure.
X-ray micro CT • High resolution, non-destructive 3D imaging
X-ray micro CT
Barley malt
Cake
Plastic
bottle
cap
Chocolate - with aerated filling
0.0
0.2
0.4
0.6
0.8
1.0
0 1 2 3
Vo
lum
e (
%)
Diameter (mm)
Bubble size
distribution
1.2 1.7
2.3
3.9 Porosity
(%)
Total: 9.1
Imaging technology: what can
it tell you about your product?
• Documentation and specification of
appearance (calibrated colour imaging)
• Particle size and shape
• Foreign body identification (microscopy)
• Temperature uniformity (thermal imaging)
• Mapping composition (NIR, FTIR, X-ray)
• Structure measurement (X-ray micro-CT)
