PHYSICAL PROPERTIES AND CORRELATION BETWEEN NIRS SPECTRUM OF 'KHAO DAWK MALI 105' PADDY RICE

Abstract

Thailand is one of the main rice exporters in the world. The Thai rice cultivar known ‘Khao Dawk Mali 105’, also known internationally as Jasmine rice. The quality of Jasmine rice is important and must be determined prior to distribution or export. The non-destructive methods that assure accurate results are the alternative to time consuming conventional methods. One alternative method, and the most widely used, is near infrared spectroscopy (NIRS). This study focused on the use of paddy rice spectrum to develop models for prediction of physical properties of brown rice. Entire paddy rice samples were scanned with a near infrared spectrophotometer. Reflectance spectra from 1400-2400 nm were recorded, the spectra were then subjected to spectral analysis and model developed by using JMP software version 10. A partial least squares (PLS) model was developed and provided R2 values ranging from 0.39 to 0.79. The preceding analysis suggested that it was possible to develop simple models by PLS from the NIRS spectra for predicting physical properties of brown rice excepted for head rice yield of brown rice (HRYB). It was obvious that whiteness of brown rice (WB), translucency of brown rice (TB) and hardness of brown rice (HB) could be predicted and were found adequate for rough screening aiming at the approximate predictions.