Near infrared spectroscopy: Irstea radiates good energy

Scanning an apple using this ordinary technique reveals its detailed composition – water, starch and sugar content – and what's more, instantly and without ever touching the apple! This technique is known as near infrared spectroscopy and is based on the interaction of light with the product. This interaction produces spectra and reveals light absorption levels in relation to wavelength linked to the physical and chemical structure of the object of study.

This strategic data is used by the agriculture and agri-food industries to evaluate the taste or ripeness of fruits, assess carbon levels in the soil and sort recyclable waste. For over 20 years, the Montpellier scientific community has been one of the most active in France in the field and one Irstea team [1] in particular has stood out.

Two awards for Irstea

Jean-Michel Roger © IrsteaIn 2008, Véronique Bellon-Maurel, team leader and currently Director of Irstea's Environmental Technologies Department, received the Tomas Hirschfeld award for her contribution to the study of near infrared spectroscopy (applied to the quality of agri-food products). Eight years later, the award has been given to another Irstea researcher, Jean-Michel Roger, specialized in chemometrics (spectrum analysis). He joined the team in 1998, specifically participating in the design of portable or online spectrometers, which required the development of a particular chemometric method now widely used in waste sorting. He is also vice-president of the French association HelioSPIR, a scientific near infrared spectroscopy network.

Double success for a small scientific team (made up of only 8 people)! "Sure, the prize has been awarded to an individual, but it recognizes the laboratory's accomplishments above all else," highlights the 2016 winner. "It isn’t the first time that a team has won the prize twice, but this double win is unprecedented because it has rewarded the same team for two different skills!" It is true that they have been focusing on measuring the composition of product, objects and environments (spectrometry) as much as on processing the spectra (chemometrics) and optics for spectrometry – new optical systems used to improve signal quality and thus to characterize physical and chemical properties. "We’ll be back in 10 years with a 3rd prize for the team!" predicts Roger.

What's next in terms of challenges? The research carried out by Roger and his colleagues link to problems with precision agriculture, agro-ecology and waste processing. "We are interested in environments that are difficult to measure, whether this involves plants, soil, waste or agricultural products. Measuring the composition of sludge from wastewater treatment plants is much harder than measuring an apple; it’s a much larger scale, and made up of unknown, foreign elements!"

Vocabulary

  • Near infrared spectroscopy: a powerful technique that quickly analyzes the composition of organic products
  • Spectrometry: a technique used to measure product composition, environments, objects etc. This method consists of projecting light – sunlight or a lamp – on an object, and then analyzing the light that comes out, making it possible to find out the composition of an object, product or environment.
  • Chemometrics: mathematical spectrum (curve) analysis originating from various sensors in order to transform the measurements into useful information.

The International Near Infrared Spectroscopy Committee will be giving the award this summer at the award ceremony, which will take place during an international conference held every 2 years in Pennsylvania [2].

For further information


[1] COMIC team (Optical Sensors for Complex Environments)