Description
Maritime pine (Pinus pinaster) tapping was developed through the vast areas of the south of France, whose, the largest forest is in Landes de Gascogne, a single-species forest massif with more than 1.3 million hectares of maritime pine (Rosa, Soares and Tomé, 2018). Mari-time pine (Pinus pinaster) tapping was undergo at a large scale until 1970. Then, industrial production has disappeared due its low competitiveness at an international level. The objec-tive is to promote tapping in this area by providing to companies a rapid and non-destructive analysis tool to enable them to determine the quality of tinned resin directly in the forest field. Indeed, after the tree was tapped, the collected resin can be distilled, in the laboratory, into two substances: turpentine, composed of monoterpenes, and rosin, mainly composed of diterpenes, also called resinic acids.
Researches were focused on a miniaturized spectrometer (molecular sensor SCiO ™) devel-oped by Consumer Physics. This lightweight spectrometer (about 35 grams) covers a spec-tral range between 780 and 1110 nm. It allows observation of electronic transitions, harmon-ics and combination bands of the molecules present in the resin. The studied quality include chemical proportion (rate of turpentine) and composition (α-pinene, β-pinene, δ-3-carene, ɣ-terpinene, dehydroacetic acid, levopimaric acid, abietic acid, neoabietic acid). Parameters were correlated to the spectra in order to build predictive models using Partial Least Squares (Wold, Sjöström and Eriksson, 2001), Independent Component Analysis (Gustafsson, 2005) and Least Squares-Support Vector Machines (Chauchard et al., 2004) regressions methods.
Computed models gave good results regarding almost of all the parameters. Although the study is still underway to try to improve the predictive models, results of this exploratory study are promising and confirming that handheld NIR spectrometer could be a good alter-native for screening quality parameters of pine resin directly in the field.
| Consider for full paper in JNIRS | Yes, please |
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