Search

The Fourier transform infrared (FTIR) spectroscopic method with attenuated total reflectance (ATR) was used for predicting the alcoholic strength, the methanol, acetaldehyde and fusel alcohols content of grape-derived spirits. FTIR-ATR spectrum in the mid-IR region (4000-400 cm -1 ) was used for the quantitative estimation by applying partial least square (PLS) regression models and the results were correlated with those obtained from reference methods. In the developed method, a cross-validation with 50% of the samples was used for PLS analysis along with a validation test set with 50% of the remaining samples. Good correlation models with a great accuracy were obtained for methanol (r 2 = 99.4; RPD = 12.8), alcoholic strength (r 2 = 97.2; RPD = 6.0), acetaldehyde (r 2 = 98.2; RPD = 7.5) and fusel alcohols (r 2 from 97.4 to 94.1; RPD from 6.2 to 4.1). These results corroborate the hypothesis that FTIR-ATR is a useful technique for the quality control of grape-derived spirits, whose practical application may improve the efficiency and quickness of the current laboratory analysis. The authors thank the technical support of Amélia Soares, Deolinda Mota and Otília Cerveira and the support of Centro de Estudos Florestais, a research unit funded by FCT (PEst-OE/AGR/ UI0239-2014) and Instituto de Ciências Agrárias e Ambientais Mediterrânicas, a research unit funded by FCT (PEst-OE/AGR/ UI0115/2014). The authors also thank to Centro de Biotecnologia de Plantas da Beira Interior for the FTIR-ATR equipment and software OPUS availability. info:eu-repo/semantics/publishedVersion

This study aimed to evaluate the potential of FT-Raman spectroscopy in the prediction of the chemical composition of Lavandula spp. monofloral honey. Partial Least Squares (PLS) regression models were performed for the quantitative estimation and the results were correlated with those obtained using reference methods. Good calibration models were obtained for electrical conductivity, ash, total acidity, pH, reducing sugars, hydroxymethylfurfural (HMF), proline, diastase index, apparent sucrose, total flavonoids content and total phenol content. On the other hand, the model was less accurate for pH determination. The calibration models had high r 2 (ranging between 92.8% and 99.9%), high residual prediction deviation - RPD (ranging between 4.2 and 26.8) and low root mean square errors. These results confirm the hypothesis that FT-Raman is a useful technique for the quality control and chemical properties’ evaluation of Lavandula spp honey. Its application may allow improving the efficiency, speed and cost of the current laboratory analysis. Acknowledgements: CEF is a research unit funded by Fundação para a Ciência e a Tecnologia I.P. (FCT), Portugal (UID/AGR/00239/2013). Centre of Molecular and Environmental Biology is a research unit funded by FCT, UID/BIA/04050/2013 (POCI-01–0145-FEDER-007569) and by the ERDF through the COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI). info:eu-repo/semantics/publishedVersion

The variation of wood density and mechanical properties with site, tree and within tree (longitudinal and radial) were studied for blackwood (Acacia melanoxylon R. Br.) grown in four sites in Portugal. Twenty trees were randomly selected (40 cm dbh class, 33–51 years of age), sampled at three stem height levels (5%, 35% and 65% of tree height) and three radial positions (10%, 50% and 90% of radius). They were further tested for air-dry density at 12% moisture content, bending strength (MOR), modulus of elasticity (MOE) and compression strength parallel to grain (CS), using ISO standards. The overall mean properties of blackwood were: 654 kg m−3 density, 139 N mm−2 MOR, 141 × 102 N mm−2 MOE and 61 N mm−2 CS. Site was not a significant source of variation for all wood properties. The variation between individual trees was the most important. Within the tree, the radial variation was highly significant for all traits, while the longitudinal variation was only significant for density. The correlation of density with the mechanical properties was moderate. Blackwood showed potential for being an alternative species to supply the industry with valuable hardwood timber. The significant differences found between the trees demonstrate the possibility of selection and improvement for increased wood quality.

The aim of this work is to develop a tool to predict some pulp properties e.g., pulp yield, Kappa number, ISO brightness (ISO 2470:2008), fiber length and fiber width, using the sapwood and heartwood proportion in the raw-material. For this purpose, Acacia melanoxylon trees were collected from four sites in Portugal. Percentage of sapwood and heartwood, area and the stem eccentricity (in N-S and E-W directions) were measured on transversal stem sections of A. melanoxylon R. Br. The relative position of the samples with respect to the total tree height was also considered as an input variable. Different configurations were tested until the maximum correlation coefficient was achieved. A classical mathematical technique (multiple linear regression) and machine learning methods (classification and regression trees, multi-layer perceptron and support vector machines) were tested. Classification and regression trees (CART) was the most accurate model for the prediction of pulp ISO brightness (R = 0.85). The other parameters could be predicted with fair results (R = 0.64–0.75) by CART. Hence, the proportion of heartwood and sapwood is a relevant parameter for pulping and pulp properties, and should be taken as a quality trait when assessing a pulpwood resource. info:eu-repo/semantics/acceptedVersion

Bee pollen contains almost all nutrients required by the human organism as well as diverse health-promoting substances. However, its composition and nutritional value greatly depend on the botanical origin. As such, it is important to develop a rapid and non-expensive methodology that allows studying its characteristics, making labelling more objective and easier. The FTIR-ATR technique was used to predict some nutritional parameters in 126 bee pollen samples. FTIR-ATR spectrum obtained in the region between 4000 and 400 cm -1 with PLS Regression models were used to correlate spectral information with the data obtained using reference methods. In this first approach with pollen samples, good correlation models with appropriate accuracy were obtained for the evaluated parameters with r 2 varying from 74.8 to 97% and residual prediction deviation between 2.0 and 5.8. These results suggest that FTIR-ATR may be a useful technique for assessing bee pollen’s composition. Centro de Estudos Florestais is a research unit funded by FCT (PEst-OE/AGR/UI0239-2014). Centre of Molecular and Environmental Biology is a research unit funded by FCT, UID/ BIA/04050/2013 (POCI-01-0145-FEDER-007569) and by the ERDF through the COMPETE2020 – Programa Operacional Competitividade e Internacionalizac¸a˜o (POCI). info:eu-repo/semantics/publishedVersion

Wood basic density is one of the most important wood quality properties and one of the simplest to assess but it is too time consuming to be really useful for the screening of populations or for improvement programmes where large numbers of samples need to be assessed. Although the usefulness of near infrared (NIR) spectroscopy to assess wood properties, including wood density, is well established only a few of the published models are suitable for screening. The NIR-based partial least squares regression models obtained in this study can be used for screening the basic density of the Portuguese blackwood [ Acacia melanoxylon (R. Br.)] population with standard errors of cross-validation of only 11 kg m−3 and values for the residual prediction deviation well above the 2.5 limit. It was also concluded that at least 45 samples for calibration and a further 16 samples for validation are necessary to obtain acceptable models for screening. Even using a very small number of spectra per disc, accurate estimates of wood basic density were obtained.

Submitted by Maria Eduarda Pereira Rodrigues (erodrigues@ipcb.pt) on 2016-02-18T12:18:20Z No. of bitstreams: 1 BioRes_11_1_1892_GarciaGonzalo_SMPSGA_Prediction_Softwood_Paper_Props_Density_Regression_8080.pdf: 885317 bytes, checksum: a53ab4c4bcb7710090b598a213c3ce5f (MD5) Approved for entry into archive by Maria Eduarda Pereira Rodrigues (erodrigues@ipcb.pt) on 2016-02-18T16:00:29Z (GMT) No. of bitstreams: 1 BioRes_11_1_1892_GarciaGonzalo_SMPSGA_Prediction_Softwood_Paper_Props_Density_Regression_8080.pdf: 885317 bytes, checksum: a53ab4c4bcb7710090b598a213c3ce5f (MD5) Made available in DSpace on 2016-02-18T16:00:40Z (GMT). No. of bitstreams: 1 BioRes_11_1_1892_GarciaGonzalo_SMPSGA_Prediction_Softwood_Paper_Props_Density_Regression_8080.pdf: 885317 bytes, checksum: a53ab4c4bcb7710090b598a213c3ce5f (MD5) Previous issue date: 2016

A total of 910 maritime pine (Pinus pinaster Aiton) wood discs, belonging to a genetic trial of 80 families with 11–12 trees per family, were used in this study. A near infrared (NIR) partial least squares regression (PLSR) model for the prediction of Kappa number of Pinus pinaster Aiton pulps obtained from samples pulped under identical conditions was calculated. Very good correlations between NIR spectra of maritime pine pulps and Kappa numbers in the range from 58 to 100 were obtained. Besides the raw spectra, spectra pre-processed with ten methods were used for PLS analysis (cross validation with 57 samples), showing that even after test set validation (with 34 samples) no model decision could be made due to almost identical statistics. The final evaluation that proved the predictive power of the models by predicting pulps with unknown Kappa numbers allowed choosing a model according to a minimal number of outliers found during this process. The minimum–maximum normalized spectra in the wave number range from 6,110 to 5,440 cm−1 used for the calculation gave the best model with a root mean square error of prediction of 2.3 units of Kappa number, a coefficient of determination of 95.9%, and one PLS component. The percentage of outliers during evaluation was 0.9%.

In this paper, the morphological properties of fiber length (weighted in length) and of fiber width of unbleached Kraft pulp of Acacia melanoxylon were determined using TECHPAP Morfi® equipment (Techpap SAS, Grenoble, France), and were used in the calibration development of Near Infrared (NIR) partial least squares regression (PLS-R) models based on the spectral data obtained for the wood. It is the first time that fiber length and width of pulp were predicted with NIR spectral data of the initial woodmeal, with high accuracy and precision, and with ratios of performance to deviation (RPD) fulfilling the requirements for screening in breeding programs. The selected models for fiber length and fiber width used the second derivative and first derivative + multiplicative scatter correction (2ndDer and 1stDer + MSC) pre-processed spectra, respectively, in the wavenumber ranges from 7506 to 5440 cm−1. The statistical parameters of cross-validation (RMSECV (root mean square error of cross-validation) of 0.009 mm and 0.39 μm) and validation (RMSEP (root mean square error of prediction) of 0.007 mm and 0.36 μm) with RPDTS (ratios of performance to deviation of test set) values of 3.9 and 3.3, respectively, confirmed that the models are robust and well qualified for prediction. This modeling approach shows a high potential to be used for tree breeding and improvement programs, providing a rapid screening for desired fiber morphological properties of pulp prediction. info:eu-repo/semantics/publishedVersion

Aim of the study: The ability of NIR spectroscopy for predicting the ISO brightness was studied on unbleached Kraft pulps of Acacia melanoxylon R. Br.Area of study: Sites covering littoral north, mid interior north and centre interior of Portugal.Materials and methods: The samples were Kraft pulped in standard identical conditions targeted to a kappa number of 15. A Near Infrared (NIR) partial least squares regression (PLSR) model was developed for the ISO brightness prediction using 75 pulp samples with a variation range of 18.9 to 47.9 %.Main results: Very good correlations between NIR spectra and ISO brightness were obtained. Ten methods were used for PLS analysis (cross validation with 48 samples), and a test set validation was made with 27 samples. The 1stDer pre-processed spectra coupling two wavenumber ranges from 9404 to 7498 cm-1 and 4605 to 4243 cm-1 allowed the best model with a root mean square error of ISO brightness prediction of 0.5 % (RMSEP), a r2 of 99.5 % with a RPD of 14.7.Research highlights: According to AACC Method 39-00, the present model is sufficiently accurate to be used for process control (RPD ≥ 8).Key words: Acacia melanoxylon; unbleached Kraft pulps; ISO Brightness; NIR; RPD.

The pulping properties of cypress species are not known and the present paper aims to filling this gap. Namely, Cupressus lusitanica Mill., C. sempervirens L. and C. arizonica Greene have been submitted to kraft pulping and the pulp properties are compared with those of Pinus pinaster Aiton. and P. sylvestris Watereri as references. Schopper Riegler degree, density, Bekk’s smoothness, tensile index, tear index, burst index, stretch, dry zero-span strength, wet zero-span strength, brightness, opacity and light scattering coefficient have been tested. The pulp yields and delignification degrees of cypress woods were lower than those of the pine references. Fibre length, width and coarseness were statistically different between pines and cypress species and C. sempervirens pulps have corresponding data close to those of pine species. Cypress pulps can be refined much faster than pine pulps. The papers sheets of cypress fibres have, in general, lower mechanical performance than those of pine fibres. Papers from C. arizonica and C. lusitanica are similar and C. sempervirens has intermediate properties being between the other cypress and pine species. However, cypress fibres are relatively short, flexible and collapsible and can be refined with low energy demand, and thus could be incorporated into papers resulting in products with better light scattering and smoothness.

Wood density and pulp yield are key parameters in the evaluation of tree productivity and quality for pulping and their relationships are of high practical importance. The influence of wood density on pulp yield and other pulp quality parameters was investigated using Acacia melanoxylon and its natural variability as a case study. Twenty trees were harvested (five trees in each of four sites in Portugal), and wood discs taken at different height levels, from the base to the top of the tree, providing 100 wood samples, covering the natural variability of wood density ranging from 449 kg m−3 to 649 kg m−3. Under the same experimental conditions of kraft pulping, screened pulp yield ranged 47.0–58.2 %, Kappa number 10.9–18.4, ISO brightness 14.9–45.6, fibre length 0.660–0.940 mm and fibre width 16.2–22.9 μm. The pulp yield and Kappa number were not correlated with wood density. Higher pulp yields were associated with lower Kappa numbers and alkali consumption, suggesting the important role of chemical composition of wood on kraft cooking. The results confirm the high pulping potential of Acacia melanoxylon trees grown in Portugal and suggest the possibility of tree selection using both wood density and pulp yield.

Two models were developed to evaluate total volume under and over-bark of Blackwood (Acacia melanoxylon R. Br.) stand trees. By variance analysis regarding volume with and without bark it was confirmed that trees age is responsible for 48 to 50% of its volumetric behaviour. Considered the averages of those variables and regarding the three homogeneous groups of the studied sites, a single model type was used (v=β1dβ2hβ3) for estimating volumes. The critical errors are between 72 and 195 dm3 under-bark, and 82 and 212dm3 over-bark. The model that uses sites as dummy variables to the estimation of stand tree volumes is the same, and this method performs maximum expected errors with values of 155 dm3 (under-bark) and 169dm3 (over-bark), to mean maximum volumes of 1362 and 1459 dm3 respectively.The use of dummy variables is a more expedite and rapid modelling method, and its maximum expected errors perform lower values.Keywords: Blackwood; tree volume; modelling; ANOVA; dummy variables. ResumoDois métodos para estimar o volume em pé de árvores de Acacia melanoxylon em Portugal. Foram construídos dois modelos para estimar o volume sobre e sob casca de árvores em pé da acácia austrália (Acacia melanoxylon R. Br.). Por análise de variância do volume com e sem casca, foi confirmado que a idade das árvores é responsável por 48 a 50% do seu comportamento volumétrico. Consideradas as médias dessas variáveis e tendo em conta os três grupos homogêneos das “estações” estudadas, foi usado um único modelo tipo (v = β1dβ2hβ3) para estimar volumes. Os erros críticos situam-se entre 72 e 195 dm3 sobre casca, e 82 e 212 dm3 sob casca. O modelo que usa as “estações” como variáveis dummy para estimar volumes de árvores em pé é o mesmo e gera erros máximos esperados com valores de 155 dm3 (sob casca) e de 169 dm3 (sobre casca), para volumes máximos médios de 1362 e 1459 dm3, respectivamente. A utilização de variáveis dummy é um método de modelação rápido e mais expedito, e os seus valores de erros máximos esperados são inferiores.Palavras-chave: Austrália; volume de árvore; modelação; ANOVA; variáveis dummy.

• Background Genetic selection for one trait can have an impact on other important traits for final use; thus, it is important to assess the correlation between traits.

Aim of the study: The aim of the study is to assess the variation of pith eccentricity, heartwood proportion, latewood percentage and basic wood density along the stem of 45-year-old A. melanoxylon trees collected in four sites of Portugal, and investigate the eventual relationship between these variables.Area of study: Sites covering littoral north, mid interior north and centre interior of Portugal.Materials and methods: Four sites and five trees per site were selected in the Acacia melanoxylon Portuguese forest.One wood sample at each of six height levels per tree was collected in order to evaluate its basic density, pith eccentricity, heartwood and latewood proportions.Main results: The high variability of the wood macroscopic properties among trees from the same site regarding to the variation of the corresponding average properties along the stem is a key characteristic of the experimental data.As a consequence, a multiple linear regression model tested was not able to properly explain the wood basic density variation of the 120 wood samples analysed. In spite of this, the following trends could be recognized: (i) excluding the base level, wood basic density moderately increased with tree level; (ii) latewood proportion followed similar behaviour; (iii) pith eccentricity was low; (iv) heartwood proportion decreased markedly with tree height, from 70% at the base to 7% at the top.Research highlights: The high basic density, the relatively low variability along the stem and the low pith eccentricity enable us to anticipate good performance as raw material for the wood industry.Key words: Acacia melanoxylon; basic density; earlywood; latewood; heartwood; sapwood; pith eccentricity.

Paper properties determine the product application potential and depend on the raw material, pulping conditions, and pulp refining. The aim of this study was to construct mathematical models that predict quantitative relations between the paper density and various mechanical and optical properties of the paper. A dataset of properties of paper handsheets produced with pulps of Acacia dealbata, Acacia melanoxylon, and Eucalyptus globulus beaten at 500, 2500, and 4500 revolutions was used. Unsupervised classification techniques were combined to assess the need to perform separated prediction models for each species, and multivariable regression techniques were used to establish such prediction models. It was possible to develop models with a high goodness of fit using paper density as the independent variable (or predictor) for all variables except tear index and zero-span tensile strength, both dry and wet. info:eu-repo/semantics/publishedVersion

A total of 120 Acacia melanoxylon R. Br. (Australian blackwood) stem discs, belonging to 20 trees from four sites in Portugal, were used in this study. The samples were kraft pulped under standard identical conditions targeted to a Kappa number of 15. A Near Infrared (NIR) partial least squares regression (PLSR) model was developed for the Kappa number prediction using 75 pulp samples with a narrow Kappa number variation range of 10 to 17. Very good correlations between NIR spectra of A. melanoxylon pulps and Kappa numbers were obtained. Besides the raw spectra, also pre-processed spectra with ten methods were used for PLS analysis (cross validation with 48 samples), and a test set validation was made with 27 samples. The first derivative spectra in the wavenumber range from 6110 to 5440 cm-1 yielded the best model with a root mean square error of prediction of 0.4 units of Kappa number, a coefficient of determination of 92.1%, and two PLS components, with the ratios of performance to deviation (RPD) of 3.6 and zero outliers. The obtained NIR-PLSR model for Kappa number determination is sufficiently accurate to be used in screening programs and in quality control.