|
|
|
|
|
|
|
Publication no. C-2004-0420-01R
| VIEW
ARTICLE
A Comparative Study of Fourier Transform Raman and NIR Spectroscopic Methods
for Assessment of Protein and Apparent Amylose in Rice.
Miryeong Sohn (1,2), David S. Himmelsbach (1), and Franklin E. Barton, II (1).
(1) USDA-Agricultural Research Service, Richard B. Russell Agricultural Research
Center, P.O. Box 5677, Athens, GA 30605. (2) Corresponding author. Phone: (706)
546-3374. Fax: (706) 546-3607. E-mail: <msohn@qaru.ars.usda.gov> Cereal Chem.
81(4):429-433. Accepted January 13, 2004. This article is in the public domain
and not copyrightable. It may be freely reprinted with customary crediting of
the source. American Association of Cereal Chemists, Inc., 2004.
Fourier-transform Raman (FT-Raman) spectroscopy and near-infrared (NIR)
reflectance spectroscopy were used to compare calibration models for determining
rice cooking quality parameters such as apparent amylose and protein. Samples
from two seasons were used in each calibration set. The laboratory values ranged
from 4.89 to 12.48% for protein and from 0.2 to 25.7% for amylose. The data for
both FT-Raman and NIR were preprocessed with orthogonal signal correction (OSC)
for standardization. For both spectroscopic methods, five models were optimized
by partial least squares regression (PLSR) and by Martens’ uncertainty
regression (MUR), including no processing, smoothing, normalization, first
derivative (D1), and second derivative (D2). Based solely on standard error of
cross-validation (SECV), the FT-Raman method was superior to the NIR method for
protein. For amylose, the FT-Raman and NIR methods resulted in similar
calibration statistics with a high precision, with the FT-Raman requiring fewer
factors. The best FT-Raman models were generated from OSC preprocessing with MUR
for protein (SECV 0.15%, five factors) and from OSC without MUR for amylose
(SECV 0.70%, seven factors). The best NIR models were obtained with D2 transform
of OSC spectra for protein (SECV 0.22%, four factors) and with OSC spectra for
amylose (SECV 0.57%, 11 factors).
|
|
|
|
|
|
|
