Abstract
Protein content and protein composition are considered very important factors in influencing the cooking and processing characteristics of rice. In the present study, the possibility of using near infrared reflectance spectroscopy (NIRS) to measure the protein composition (prolamin, globulin and glutelin) of rice flour was examined. The NIR spectra (1100-2500 nm) of a total of 119 rice flour samples with different protein compositions and particle sizes were acquired with a NIR spectrometer. Prediction accuracy of protein content was subsequently examined, revealing a similar accuracy (standard error of prediction (SEP) of 0.22%) to previous studies. NIR calibration models for determining protein composition were also examined using the partial least square (PLS) regression method. The best models were generated using multiplicative scatter correction-pretreated spectra, giving SEP of 0.18%, 0.06% and 0.25% for prolamin, globulin and glutelin, respectively. The findings show that NIR spectroscopy has the potential to serve as a rapid method for predicting the protein composition of rice flour.
