Desenvolvimento de metodologias analiticas utilizando espectroscopia visivel e infravermelho proximo

AUTOR(ES)
DATA DE PUBLICAÇÃO

1999

RESUMO

This work describes the development of analytical methodologies using visible and near infrared spectroscopy. In the visible range a new method for determination of color index of sugars (ICUMSA) produced for exportation was developed. Secondarily, a multi- channel spectrophotometer was constructed employing a diode array detector EGG-Reticon - RL 1024. The spectral range of the instrument was determined to be from 414.6 to 652.7 nm. The equipment was employed to obtain the diffuse reflectance measurements aiming the determination of the sugar color index. A good correlation (R = 0.93) was observed between the measurements taken at 420 nm and the results obtained by the conventional method. A near infrared (NIR) spectrophotometer with a acousto-optical tunable filter was employed with the objective of the simultaneous determination of the total acidity and total dissolved solids in concentrate orange juice. Measurements of the total acidity and total dissolved solids were made for more than 1000 samples supplied by CITROSUCO S.A. The results obtained in the spectral range 1500-1900 nm were modeled by Partial Least Square algorithm (PLS) and SEP (Standard Error of Prediction) values of 0.18 and 0.21 were obtained for total acidity and total dissolved solids, respectively. The results were considered suitable for quality control of concentrate orange juice. The developed methodology can be adapted to be used in-line aiming the control of those parameters in the orange industry.

ASSUNTO(S)

espectroscopia visivel espectroscopia de infravermelho

ACESSO AO ARTIGO

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