Detection of Crude Protein, Crude Starch, and Amylose for Rice by Hyperspectral Reflectance

ABSTRACT

The contents of crude protein, crude starch, and amylose are three important indices to evaluate the nutrition and taste quality of rice. Studying the characteristics of crude protein, crude starch, and amylose of rice may provide a basis for monitoring rice quality by remote sensing. Different varieties and qualities of rice samples were selected through testing. The crude protein, crude starch, and amylose were extracted from rice. The hyperspectral reflectances of samples were measured for their crude protein, crude starch, and amylose as well as mixture with crude protein and crude starch by an Analytical Spectral Device FieldSpec Pro FR. The hyperspectral characteristics and their correlation with the contents of crude protein, crude starch, and amylose were analyzed. The results showed that the hyperspectral reflectance of crude protein was different from that of crude starch and amylose. Furthermore, the positions of peak and valley in the spectral curve of the mixture appeared “red shift” or “blue shift.” Nevertheless the contents (%) of crude protein, crude starch, and amylose in rice flour were significantly correlated to the absorbing area from 2020 to 2235 nm. The identified factors show a feasible method for monitoring rice quality by remote sensing.

KEYWORDS:

• amylose
• crude protein
• crude starch
• rice
• spectral matching

ACKNOWLEDGMENT

Financial support comes from the National Natural Science Foundation of China program under Grant No. 10664001, 41061039, and 11164004; the Hi-Tech Research and Development Program (863) of China (2007AA10Z205); and the Graduate Innovation Fund of Guizhou Province (200713).