淀粉的红外光谱及其二维相关红外光谱的分析鉴定

旨在采用傅里叶变换红外光谱(FTIR)、去卷积光谱、二阶导数光谱以及二维相关红外光谱，区分鉴别3种淀粉样品。对原始光谱1200~900cm-1波数段进行傅里叶去卷积处理，计算能反映淀粉分子有序程度的1050/1020cm-1峰强度比值；对其指纹区(1700~800cm-1)做二阶导数处理。结果红外光谱显示3种淀粉原始光谱吸收峰非常相似，仅在吸收峰强度和峰位上有微小差异。发现3种淀粉颗粒有序结构的相对含量由多到少排序依次为莲藕淀粉、马铃薯淀粉、红薯淀粉。另外，3种淀粉样品在1607~1487cm-1波数段以及1468、1187、1055、931cm-1波数处二阶导数谱差异明显。并且，由3种淀粉样品的2D-IR光谱得知：在1150~1500cm-1以及860~1200cm-1波段内，不同淀粉光谱自动峰位置和强度显著不同。应用红外光谱、去卷积光谱、二阶导数光谱以及二维相关红外光谱技术不仅可以提供淀粉的分子振动信息，还可以对不同的淀粉进行很好的区分。因此红外光谱法对于分类鉴别不同种类的淀粉是一种快速、准确、有效的方法。

Starch Discrimination with Fourier Transform Infrared Spectroscopy(FTIR) and Two-dimensional Correlation Infrared Spectroscopy (2D-IR)

The objective of the present study was to discriminate three kinds of starch by fourier transform infrared spectroscopy(FTIR), deconvolution infrared spectroscopy, second derivative infrared spectroscopy and two-dimensional correlation infrared spectroscopy (2D-IR). The FTIR spectra of starch in the region of 1200- 900 cm- 1 were applied to deconvolution analysis; the peak ratios of 1050/1020 cm- 1 were calculated to analyze the starch ordered structure, the higher the ratios, the more contents of the ordered structure. The infrared spectra in the range of 1800- 700 cm- 1 were selected to perform second derivative infrared spectroscopy analysis. The results showed that the infrared spectra were similar on the whole; the ordered structure from high to low was lotus root starch, potato starch and sweet potato starch; the obvious differences in positions, shapes and absorption intensities of peaks of second derivative infrared spectroscopy were observed in the range of 1607-1487 cm-1, and in the wave number of 1468, 1187, 1055, 931 cm-1. 2D-IR spectroscopy showed that the automatic spectrum peak positions and intensities of three different starch were significantly different in the range of 1150-1500 cm- 1 and 860-1200 cm- 1. The results showed that the macroscopical finger print characters of FTIR and 2D-IR spectra could not only prove the information of main chemical constituents in starch, but also compare the components differences among the similar samples. In conclusion, the multistep IR macro-finger print method were rapid, effective, visual and accurate for starch research.