Discrimination of native wood charcoal by infrared spectroscopy

Brazil is one of the largest producers and consumers of charcoal in the world. About 50% of its charcoal comes from native forests, with a large part coming from unsustainable operations. The anatomic identification of charcoal is subjective; an instrumental technique would facilitate the monitoring of forests. This study aimed to verify the feasibility of using medium and near infrared reflectance spectroscopy to discriminate native (ipê) from plantation charcoals (eucalyptus). Principal Components Analysis, followed by Discriminant Factorial Analysis formed two different groups indicated by Mahalanobis distances of 40.6 and 80.3 for near and mid infrared, respectively. Validation of the model showed 100% efficacy. (Résumé d'auteur

Carotenoids in Cassava Roots

Vitamin A deficiency (VAD) is a preventable tragedy that affects millions of people, particularly in sub-Saharan Africa. A large proportion of these people rely on diets based on cassava as a source of calories. During the last two decades, significant efforts have been made to identify sources of germplasm with high pro-vitamin A carotenoids (pVAC) and then use them to develop cultivars with a nutritional goal of 15 μg g−1 of β-carotene (fresh weight basis) and good agronomic performance. The protocols for sampling roots and quantifying carotenoids have been improved. Recently, NIR predictions began to be used. Retention of carotenoids after different root processing methods has been measured. Bioavailability studies suggest high conversion rates. Genetic modification has also been achieved with mixed results. Carotenogenesis genes have been characterized and their activity in roots measured

High-throughput phenotyping and improvements in breeding cassava for increased carotenoids in the roots

Past research developed reliable equations to base selections for high β-carotene on near-infrared spectroscopy (NIR) predictions (100 genotypes d−1) rather than with high-performance liquid chromatography (HPLC) (<10 samples d−1). During recent harvest, CIAT made selections based on NIR predictions for the first time. This innovation produced valuable information that will help other cassava (Manihot esculenta Crantz) breeding programs. A total of 284 samples were analyzed with NIR and HPLC for total β-carotene (TBC) and by the oven method for dry matter content (DMC). Results indicated that NIR reliably predicted TBC and DMC. In addition, 232 genotypes grown in preliminary yield trials (PYTs) were harvested at 8.5 and 10.5 mo after planting (one plant per genotype and age) and root quality traits analyzed (by NIR only). Repeatability of results at the two ages was excellent, suggesting reliable results from NIR. In contrast to previous reports, age of the plant did not influence carotenoids content in the roots. The availability of a high-throughput NIR protocol allowed comparing results (for the first time) from seedling and cloned plants from the same genotype. Results showed very little relationship for DMC between seedling and cloned plants (R2 = 0.09). There was a much better association for TBC (R2 = 0.48) between seedling and cloned plants. It is postulated that variation in the environmental conditions when seedling and cloned plants (from the same genotype) may be responsible for these weak associations. Important changes in selection strategies have been implemented to overcome problems related to a lengthy harvesting season. (Résumé d'auteur

Fast determination of the resin and rubber content in Parthenium argentatum biomass using near infrared spectroscopy

Guayule (Parthenium argentatum), a plant native of semi-arid regions of northern Mexico and southern Texas, United States, is an under-used source of hypoallergenic latex, a solution to the serious latex allergy IgE problem worldwide. This study aimed to develop near infrared spectroscopy (NIRS) calibrations to assess resin and rubber contents in guayule plants. For achieving this goal a reference method (ASE; accelerated solvent extraction) was selected and optimized among three alternatives also including Soxhlet and Polytron. First resin (lipids, terpenes) was extracted with acetone from ground biomass at 40 °C, and then rubber was extracted with hexane from left solid at 120 °C. A set of 215 samples of guayule biomass (stems and branches) was collected from plants in two experimental fields located in France and in Spain and was analyzed for moisture, rubber and resin contents using the two solvent selected ASE methods. Near infrared spectra were recorded for all samples. Two thirds of the samples were randomly selected for calibration, the remaining being used for validation. For each constituent, calibration equations were developed using modified partial least squares regression. The equation performances were evaluated using the performance to deviation ratio (RPDp) and parameters, obtained by comparison of the validation set NIR predictions and corresponding laboratory values. Moisture content (RPDp = 6.91; ) calibration enabled accurate determination of these traits. NIR models for hexane extract (rubber content) (RPDp = 4.59; ) and acetone extract (resin content) (RPDp = 4.87; ) were highly efficient and enabled accurate characterization of guayule biomass. On the other hand, this analysis showed that both laboratory tools, coupled with multivariate analytical techniques, could be used to differentiate the samples and accurately predict the chemical composition of this disparate set of agricultural biomass samples. This study demonstrated the ability of NIRS analysis for high throughput determination of resin and rubber contents in guayule biomass