Prediction of oil content in the mesocarp of fruit from the macauba palm using spectrometry1

Abstract

-In the present work a model was developed for the prediction of the oil content of the mesocarp of fruit from the macauba palm, using visible and near infrared spectrometry. Reference values were determined the by Soxhlet method. The model was calibrated using spectral data from the mesocarp of macauba fruit by partial least squares regression, considering nine latent variables. The results of the calibration series were consistent with those of the validation series, registering an The coefficient of determination between the reference method and the developed model, systematic error between the predicted values and the measured values and root mean square error, for calibration and validation with independent data, respectively, equal to 0.8223, -9.2-14 and 5.917 and 0.7760, 7.081 and -0.064. VIS-NIR spectroscopy is a viable tool in the evaluation of genotypes in breeding programs for the macauba palm.Key words: Acrocomia aculeata. Quantification of the oil. VIS-NIR model calibration. RESUMO -No presente trabalho, foi desenvolvido um modelo para a predição do teor de óleo do mesocarpo nos frutos de macaúba, usando a espectrometria do visível e infravermelho próximo. Os valores de referência foram determinados pelo método soxhlet. O modelo foi calibrado usando dados espectrais do mesocarpo dos frutos de macaúba pela regressão por mínimos quadrados parciais, considerando nove variáveis latentes. Os resultados da série da calibração foram consistentes com os da série da validação, registrando o coeficiente de determinação entre o método referencia e o modelo desenvolvido, erro sistemático entre os valores preditos e os valores mensurados e a raiz quadrada do erro médio quadrático entre o método referência e o modelo desenvolvido, de 0,8223, -9,2-14 e 5,917 e de 0,7760, -0,064 e 7,081, para a calibração e validação respectivamente. A espectrometria VIS-NIR é viável como ferramenta de avaliação de genótipos em programas do melhoramento de macaúba.Palavras-chave: Acrocomia aculeata. Quantificação do óleo. Calibração de modeloVIS-NIR.

Rapid determination of oil content in dried-ground oil palm mesocarp and kernel using near infrared spectroscopy

“…Sample variability including physical size and range of parameter value is the important aspect for NIR spectroscopy calibration. Matsimbe et al 27 and Blanco et al 28 reported that NIR spectroscopy is related to the sample physical state where non-homogeneous sample state potentially provides inconsistency of NIR spectra and prediction. Furthermore, in spectrometry, the variability of spectra is influenced by the physical effect of light and the state of the sample.…”

“…To counter the influence of moisture and particle size variations in this study, the samples were conditioned through drying and grinding in order to obtain more homogeneous samples with stable NIR spectra and a relatively large number (>1000) of samples were studied to develop good calibrations. 27 PCA analysis allowed discrimination between normal data population and outlier samples. Only 21 (2.07%) mesocarp and 8 (0.81%) kernel samples had GH > 3 and were defined as outlier samples.…”

Classification of Macaw Palm Fruits From Colorimetric Properties for Determining the Harvest Moment

“…Once the optical properties obtained on the surface of the palm tree fruits are used as an indicator of maturation, and the oil contents contained in the mesocarp of the fruits are directly associated to the point of physiological maturation. The different spectral responses can be used to estimate the amount of oil (Saeed et al, 2012, Matsimbe et al, 2015, Costa et al, 2017.…”

Determination of macaw fruit harvest period by biospeckle laser technique

“…Matsimbe et al (2015) used the spectroscopy of infrared and near infrared (VIS-NIR) applied to the macaw palm fruit mesocarp to estimate oil content. Although promising, these results still limit the measurement of the oil content without destroying the fruit, once the VIS-NIR models did not obtain significant results when applied directly in the epicarp.…”