The assessment of amylose content using near infrared spectroscopy analysis of rice grain samples

Abstract

Nowadays there are several methods in assessing the traits of rice including destructive and non-destructive method. The objective of this study is to evaluate the amylose content (AC) on seven types of rice grain in Malaysian market by using the Near-Infrared (NIR) Spectroscopy. AC is one of the main criteria to determine the quality of cooked rice. The total sample is 210, which includes two types of brown rice and basmati rice respectively, and three types of milled white rice where each of them were divided into 30 samples per group. Spectrums from 210 samples were collected between the range 680nm and 1280 nm using a non-destructive, rapid, and economical method. Reflectance spectra was converted into absorbance spectra and the baseline shift effect in the absorbance spectra was removed using first and second order derivative coupled with a first and second order Savitzky-Golay smoothing filter. Next, the spectral data was processed and examined independently, by applying partial least square (PLS) analysis. Results show that NIR Spectroscopy helped to determine the amylose content based on the spectra at 878 nm, 979 nm, 989 nm, 1100 nm and 1210 nm. The prediction on amylose content in Malaysian rice by using NIR Spectroscopy needs to be further investigated on a large number of samples with different varieties, growing, cultivation methods and processing after harvesting.