Near infrared spectroscopy applied to forest products identification and quality assesment

Source Agritrop Cirad (https://agritrop.cirad.fr/613027/)

International audience

anglais. Near infrared (NIR) spectroscopy is a widely used tool, in lab and field both, in the agricultural, food and pharmaceutical industries. It is used for quantitative evaluations (e.g. protein content, fatty acid content), but also for quality control by exploiting the spectral signature only. Advantages are low preparation of the samples before spectra aquisition, and fast spectral measurement. As a result, this tool enables high-throughput characterization, reducing of cost of analysis, which is its main success factor. In the field of wood, NIR spectroscopy has been studied for several decades, in particular for wood chemistry. It is used industrially in cooperage and pulp and paper production. Tropical woods have been concerned early too, in particular tropical pines and eucalyptus. The applications described in this presentation will illustrate, through a few examples, the potential uses of this tool. First of all, and because it's a topical issue in Madagascar, NIR spectroscopy is being studied to identify Rosewood and Ebony species based on wood spectra. Several presentations will be given during this conference. There are also studies on the identification of geographical origin. It could also be a tool for verifying the species used in wooden cultural objects. NIR spectroscopy is therefore useful for phenotyping large sample sets for chemical properties (extracts, lignin, cellulose) and also for certain physico-mechanical properties linked to chemistry (wood density, wood shrinkage, natural durability). In the frame of wood energy, applications exist to qualify charcoal quality (fixed carbon, volatile matter), charcoal yield predicted from wood spectra, most probably linked to water content, the calorific value of wood. Numerous applications have been published on non-timber forest products, such as the prediction of essential oil content in rosewood from wood spectra, the detection of chemical types from leaf spectra on Ravensara aromatica, and fraud control in adulteration studies.