masterThesis
Determinação de parâmetros (sólidos solúveis, pH e acidez titulável) em ameixas intactas usando espectroscopia no infravermelho próximo e seleção de comprimento de onda
Fecha
2013-05-17Registro en:
COSTA, Rosangela Câmara. Determinação de parâmetros (sólidos solúveis, pH e acidez titulável) em ameixas intactas usando espectroscopia no infravermelho próximo e seleção de comprimento de
onda. 2013. 117 f. Dissertação (Mestrado em Físico-Química; Química) - Universidade Federal do Rio Grande do Norte, Natal, 2013.
Autor
Costa, Rosangela Câmara
Resumen
The aim of this study was to evaluate the potential of near-infrared reflectance
spectroscopy (NIRS) as a rapid and non-destructive method to determine the soluble
solid content (SSC), pH and titratable acidity of intact plums. Samples of plum with a
total solids content ranging from 5.7 to 15%, pH from 2.72 to 3.84 and titratable acidity
from 0.88 a 3.6% were collected from supermarkets in Natal-Brazil, and NIR spectra
were acquired in the 714 2500 nm range. A comparison of several multivariate
calibration techniques with respect to several pre-processing data and variable selection
algorithms, such as interval Partial Least Squares (iPLS), genetic algorithm (GA),
successive projections algorithm (SPA) and ordered predictors selection (OPS), was
performed. Validation models for SSC, pH and titratable acidity had a coefficient of
correlation (R) of 0.95 0.90 and 0.80, as well as a root mean square error of prediction
(RMSEP) of 0.45ºBrix, 0.07 and 0.40%, respectively. From these results, it can be
concluded that NIR spectroscopy can be used as a non-destructive alternative for
measuring the SSC, pH and titratable acidity in plums