4 Notes
1. The illuminant D65 and the 10
Standard Observer are recommended for food color measurements.
2. For spectrophotometric measurements it is necessary to centrifuge and filter the samples for removing suspended particles.
3. For spectrophotometric measurements the method for the
measurement should be previously created to cover the entire
visible spectrum (380–770 nm) at constant intervals
(Δλ ¼ 2 nm).
4. If the samples are very dark, it is necessary to use cuvettes with
smaller path length for spectrophotometric measurements.
5. For spectrophotometric measurements and for the spectroradiometric measurements of liquid samples the cuvettes used to
make the blank measurements should be the same as those used
to make the measurements of the samples.
6. For the spectroradiometric measurements the method for the
measurement should be previously created. The following
parameters should be defined: Integration time; signal level;
averages (the spectroradiometer should be set to take at least
three consecutive measurements of each sample); resampled
from 380 to 780 nm (to cover the entire visible spectrum);
Top100 aperture (If 10 mm path length-cuvettes are used, the
opening of the top 100 should be adjusted to blende 3).
Anyway, this depends on the distance between sample and
Top100 probe.
7. System geometry of the spectroradiometer:
The zoom, to which the probe was attached, was held at a
fixed distance of 50 cm in a straight line from the sample or the
blank. Incident illumination: 45
.
8. The potential of the digital image analysis system is very high.
However, small deviations in color measurements have been
observed in the blue zone of the CIELAB color space. Notwithstanding, these hues are not common in foods, and even
less so in foods where carotenoids are to be evaluated.
9. In the digital image analysis, in rare occasions and when pressing the button that acquires an image, the equipment gives
error in the focus. This is because there is no sharp-edged
object just below the camera. This is usually solved by slightly
moving the sample in the tray inside the booth and recapturing
the image.
10. You may want to process the image with software other than
the one DigiEye incorporates. In fact, it is common to use
automatic tools programmed under Matlab or Python. In
114
Paula Mapelli-Brahm et al.
1. The illuminant D65 and the 10
Standard Observer are recommended for food color measurements.
2. For spectrophotometric measurements it is necessary to centrifuge and filter the samples for removing suspended particles.
3. For spectrophotometric measurements the method for the
measurement should be previously created to cover the entire
visible spectrum (380–770 nm) at constant intervals
(Δλ ¼ 2 nm).
4. If the samples are very dark, it is necessary to use cuvettes with
smaller path length for spectrophotometric measurements.
5. For spectrophotometric measurements and for the spectroradiometric measurements of liquid samples the cuvettes used to
make the blank measurements should be the same as those used
to make the measurements of the samples.
6. For the spectroradiometric measurements the method for the
measurement should be previously created. The following
parameters should be defined: Integration time; signal level;
averages (the spectroradiometer should be set to take at least
three consecutive measurements of each sample); resampled
from 380 to 780 nm (to cover the entire visible spectrum);
Top100 aperture (If 10 mm path length-cuvettes are used, the
opening of the top 100 should be adjusted to blende 3).
Anyway, this depends on the distance between sample and
Top100 probe.
7. System geometry of the spectroradiometer:
The zoom, to which the probe was attached, was held at a
fixed distance of 50 cm in a straight line from the sample or the
blank. Incident illumination: 45
.
8. The potential of the digital image analysis system is very high.
However, small deviations in color measurements have been
observed in the blue zone of the CIELAB color space. Notwithstanding, these hues are not common in foods, and even
less so in foods where carotenoids are to be evaluated.
9. In the digital image analysis, in rare occasions and when pressing the button that acquires an image, the equipment gives
error in the focus. This is because there is no sharp-edged
object just below the camera. This is usually solved by slightly
moving the sample in the tray inside the booth and recapturing
the image.
10. You may want to process the image with software other than
the one DigiEye incorporates. In fact, it is common to use
automatic tools programmed under Matlab or Python. In
114
Paula Mapelli-Brahm et al.