DETERMINATION OF UNDRIED ROUGH RICE CONSTITUENT CONTENT USING NEAR-INFRARED TRANSMISSION SPECTROSCOPY

Abstract

Near-infrared transmission (NIRT) spectroscopy was used in an attempt to predict moisture content, proteincontent and amylose content from undried whole-grain rough rice spectra. One hundred-fifty undried rough rice sampleswere collected. Using partial least squares calibration models obtained from undried whole-grain rough rice spectra, thecoefficient of determination (r 2) and the standard error of prediction (SEP) of the validation set were r 2 = 0.96 andSEP = 0.70 for rough rice moisture content, r 2 = 0.70 and SEP = 0.24 for brown rice protein content, r 2 = 0.76 andSEP = 0.22 for milled rice protein content, and r 2 = 0.00 and SEP = 0.27 for milled rice amylose content. The results ofthe validation indicated that NIRT could be used to determine moisture content and protein content. Thus, NIRTtechnology may be used to classify undried rough rice into qualitative groups such as high protein content rice and lowprotein content rice upon arrival at a rice-drying facility after harvesting.