Chapter 8
Applications of Visible Spectroscopy and Color
Measurements in the Assessments of Carotenoid Levels
in Foods
Paula Mapelli-Brahm, Francisco J. Rodrı ´guez-Pulido, Carla M. Stinco,
Francisco J. Heredia, and Antonio J. Mele ´ ndez-Martı ´nez
Abstract
The color of the food can be evaluated visually or instrumentally. The instrumental measurement allows to
measure the color objectively and can be carried out by different techniques, most of them fast, cheap, and
simple. Carotenoids are responsible for the color of many plants and foods. The measurement of color can
be an effective tool to determine indirectly the concentration of carotenoids in plants and foods. In this
chapter, we describe both traditional and recent methodologies for color measurement.
Key words Spectrophotometry, Spectroradiometry, Digital image analysis (DIA), Tristimulus colorimetry, Transmission, Reflection
1 Introduction
1.1 Color Definition
According to Wyszecki and Stiles [1] color could be defined as a
mental response to the stimulus that a visible radiation produces on
the retina, which is transmitted to the brain by the optical nerve. In
other words, color is that aspect of visual perception by which an
observer may detect differences between two structure-free fields of
views of the same size and shape, such as may be caused by differences in the spectral composition of the radiant energy concerned
in the observation. The perception of color is a very complex
psychophysical phenomenon, related to aspects of different nature,
namely the physiology of vision, the psychology of the observer,
and the spectral radiant energy of a source of visible light.
In the human retina there are different kinds of photoreceptors.
On the one hand, the rods are sensitive to white and black. On the
other hand, there are cones of three different types, each of which is
selectively sensitive to light in an interval of wavelengths. The
Manuel Rodrı ´guez-Concepcio ´ n and Ralf Welsch (eds.), Plant and Food Carotenoids: Methods and Protocols,
Methods in Molecular Biology, vol. 2083, https://doi.org/10.1007/978-1-4939-9952-1_8,
© Springer Science+Business Media, LLC, part of Springer Nature 2020
103
Applications of Visible Spectroscopy and Color
Measurements in the Assessments of Carotenoid Levels
in Foods
Paula Mapelli-Brahm, Francisco J. Rodrı ´guez-Pulido, Carla M. Stinco,
Francisco J. Heredia, and Antonio J. Mele ´ ndez-Martı ´nez
Abstract
The color of the food can be evaluated visually or instrumentally. The instrumental measurement allows to
measure the color objectively and can be carried out by different techniques, most of them fast, cheap, and
simple. Carotenoids are responsible for the color of many plants and foods. The measurement of color can
be an effective tool to determine indirectly the concentration of carotenoids in plants and foods. In this
chapter, we describe both traditional and recent methodologies for color measurement.
Key words Spectrophotometry, Spectroradiometry, Digital image analysis (DIA), Tristimulus colorimetry, Transmission, Reflection
1 Introduction
1.1 Color Definition
According to Wyszecki and Stiles [1] color could be defined as a
mental response to the stimulus that a visible radiation produces on
the retina, which is transmitted to the brain by the optical nerve. In
other words, color is that aspect of visual perception by which an
observer may detect differences between two structure-free fields of
views of the same size and shape, such as may be caused by differences in the spectral composition of the radiant energy concerned
in the observation. The perception of color is a very complex
psychophysical phenomenon, related to aspects of different nature,
namely the physiology of vision, the psychology of the observer,
and the spectral radiant energy of a source of visible light.
In the human retina there are different kinds of photoreceptors.
On the one hand, the rods are sensitive to white and black. On the
other hand, there are cones of three different types, each of which is
selectively sensitive to light in an interval of wavelengths. The
Manuel Rodrı ´guez-Concepcio ´ n and Ralf Welsch (eds.), Plant and Food Carotenoids: Methods and Protocols,
Methods in Molecular Biology, vol. 2083, https://doi.org/10.1007/978-1-4939-9952-1_8,
© Springer Science+Business Media, LLC, part of Springer Nature 2020
103