Utilization of spectral signatures of food for
daily use
Henning Schulte,
Gunnar Brink,
Robin Gruna,
Reinhard Herzog,
Heinrich Grüger
Kapitel/Beitrag aus dem Buch: Längle, T et al. 2015. OCM 2015 – 2nd International Conference on Optical Characterization of Materials, March 18th – 19th, 2015, Karlsruhe, Germany : Conference Proceedings.
The analysis of spectral signatures of materials is an established technology in biochemistry and analytical chemistry.
This includes the identification of different materials and some
of their ingredients. A common method used is optical spectroscopy. Optical spectroscopy refers to the visible effects caused
by the interaction of matter with electromagnetic radiation. Because each element has its own specific energy reflection within
different wavelengths, the identification of materials or material
families is generally possible. With respect to the availability of
sensors, the greatest opportunity for the broad use of this technology is expected in the wavelength of NIR. Given the complexity of reliable identification and verification of spectral signatures
of a product, the three aspects that must be minimally considered are as follows: the product itself, the necessary sensors, and
the evaluation of the obtained data. Special attention must be
paid to the measurement itself, the reflection of the material, and
the calibration of the measurement arrangement. There is information available about organic and inorganic products and their
spectral reflection within near infrared (NIR). Within our focus
of research, existing information related to food is mostly about
products and their quality, especially, microbial spoilage, freshness, and ripening. Meat, fruits, and dairy are the most analyzed
products in this wavelength region. The quantity of sugar, carbohydrates, and fat is essential for the investigations related to
nutrients in a product.
The major trend in the area of sensors (for optical spectroscopic
measurements) is the miniaturization and integration of functions, separating out expensive assembly needs. On the other hand, there is a need for increasing performance. Resolution and
wavelength have to match the applied chemometric models with
an acceptable signal-to-noise ratio. The availability of new, better,
and cheaper spectral sensors will directly influence the market
of automated sorting technology. The current focus is on simple
and standardized solutions that use sensor technology within the
wavelength of visible light. Chinese manufacturers, especially,
play an increasingly important role in this development.
To gain all this new scientific knowledge, a broad, sophisticated
community of scientists with their institutes is necessary. All of
them are connected via a global virtual science network. A key
question is an understanding of the primary drivers and the outlook for a future infrastructure. Besides spectral information, one
way to gain additional information about products is to combine
them, e.g., with volume knowledge