Discrimination of Grain Seeds of Natural Aging by Two-Dimensional Infrared Spectroscopy

Seed aging affects seed vigor and the quality of seeds as food. In this paper, barley, wheat, rice, corn and sorghum seeds of different storage years were discriminated by Fourier transform infrared (FT-IR) spectroscopy combined with second derivative infrared (SD-IR) spectroscopy and two-dimensional correlation infrared (2D-IR) spectroscopy. The results showed that several peak intensity ratios in the original spectra were different. In addition, the SD-IR spectra showed differences concerned with peak shape and intensity particularly in the range of 1 800 similar to 800 cm(-1). Besides, the 2D-IR spectra showed that the number and intensities of auto-peaks and cross-peaks have clear differences in the range of 1 350 similar to 1 800 cm(-1) for barley, and in the range of 860 similar to 1 690 cm(-1) for wheat, rice, corn and sorghum. It is demonstrated that FT-IR and 2D-IR spectroscopy could be used to discriminate grain seeds of different storage years rapidly and effectively.