红外光谱技术在淀粉粒有序结构分析中的应用
- 格式:pdf
- 大小:1.22 MB
- 文档页数:9
作物学报 ACTA AGRONOMICA SINICA 2012, 38(3): 505-513 http://www.chinacrops.org/zwxb/ ISSN 0496-3490; CODEN TSHPA9 E-mail: xbzw@chinajournal.net.cn
本研究由国家自然科学基金项目(31071342)和江苏省作物学优势学科项目资助。 * 通讯作者(Corresponding authors): 刘巧泉, E-mail: qqliu@yzu.edu.cn; 韦存虚, E-mail: cxwei@yzu.edu.cn Received(收稿日期): 2011-08-22; Accepted(接受日期): 2011-12-15; Published online(网络出版日期): 2012-01-04. URL: http://www.cnki.net/kcms/detail/11.1809.S.20120104.1649.009.html
DOI: 10.3724/SP.J.1006.2012.00505
红外光谱技术在淀粉粒有序结构分析中的应用
满建民1 蔡灿辉1 严秋香2 胡茂志2 刘巧泉1,* 韦存虚1,*
1 扬州大学教育部植物功能基因组学重点实验室 / 江苏省作物遗传生理重点实验室, 江苏扬州 225009; 2 扬州大学测试中心, 江苏扬州 225009
摘 要: 傅里叶变换红外光谱技术(FTIR)可用于研究淀粉粒的有序结构, 包括透射模式和衰减全反射模式2种。本文
探讨不同去卷积设置条件对FTIR波谱的影响, 并分析FTIR在淀粉粒有序结构分析中的应用。研究结果表明, 不同
去卷积设置对FTIR波谱和相关峰强度影响较大, 以半峰宽19 cm-1和增强因子1.9的设置对FTIR原始波谱去卷积,
获得的结果较好。天然淀粉晶体类型不同, 其FTIR波谱有差异, 表现在马铃薯和山药淀粉的衰减全反射FTIR波谱
相似, 与水稻淀粉明显不同; 水稻和马铃薯淀粉透射FTIR波谱相似, 与山药淀粉明显不同。淀粉中的水分含量影响
衰减全反射FTIR波谱, 当水分含量超过60%时, 对波谱分析结果基本没有影响。酸水解优先降解淀粉粒无定形区的
结构成分, 提高淀粉粒的有序度。淀粉葡糖苷酶水解淀粉对淀粉粒外部区域的有序度影响不大, 但明显提高整个淀粉
粒的有序度。不同品质稻米淀粉的衰减全反射FTIR波谱相似。上述研究结果为应用FTIR分析淀粉粒有序结构提供
重要的参考作用。
关键词: 傅里叶变换红外光谱; 淀粉粒; 有序结构; 波谱去卷积
Applications of Infrared Spectroscopy in the Analysis of Ordered Structure of
Starch Grain
MAN Jian-Min1, CAI Can-Hui1, YAN Qiu-Xiang2, HU Mao-Zhi2, LIU Qiao-Quan1,*, and WEI Cun-Xu1,*
1 Key Laboratories of Plant Functional Genomics of the Ministry of Education and Crop Genetics and Physiology of the Jiangsu Province, Yangzhou University, Yangzhou 225009, China; 2 Testing Center, Yangzhou University, Yangzhou 225009, China
Abstract: Fourier transform infrared spectroscopy (FTIR) is used to study the ordered structure of starch grain, which has two modes: transmittance and attenuated total reflectance (ATR). In this paper, the different deconvolution parameters of spectra were applied to compare their effects on FTIR spectra in studying the ordered structure of starch grain. The results indicated that the different deconvolution parameters had significant effects on FTIR spectra and the intensities of relative peaks. The peak half-width of 19 cm-1 and the resolution enhancement factor of 1.9 were ideal deconvolution parameters of spectra to obtain the better results. Native starches had A, B, and C three types of crystalline, their FTIR spectra showed some differences. Potato and Chinese yam starches had similar ATR-FTIR spectra, which were different from that of rice starch. However, rice and potato starches had similar transmittance-FTIR spectra, which were different from that of Chinese yam starch. The water content of sam-ple affected the spectra of ATR-FTIR, but this effect was not detected when water content exceeded 60%. The ATR-FTIR spectra showed that the hydrolysis of amorphous structure in starch grain was faster than that of ordered structure during acid treatment. The ordered degree of structure in starch grain increased with increasing time of acid hydrolysis. The amyloglucosidase hydrolysis had no significant effect on the ordered degree of structure at the outside of starch grain by the ATR-FTIR spectra, but the ordered degree of structure of whole starch grain significantly increased with enzyme hydrolysis according to the transmittance-FTIR spectra. The amylose content is an important physicochemical property in determining the starch quality. Rice starches with dif-ferent amylose contents showed the similar ATR-FTIR spectra. These results would be very useful for the application of FTIR to the analysis of ordered structure of starch grain. Keywords: Fourier transform infrared spectroscopy; Starch grain; Ordered structure; Deconvolution of spectrum 506 作 物 学 报 第38卷
淀粉是植物主要的能量贮藏物质, 也是重要的
食品来源和工业原料。植物淀粉以半晶态的颗粒形
式存在于自然界, 包含结晶区和无定形区2种结构
成分, 主要由直链淀粉和支链淀粉组成[1]。淀粉分子
中的直链淀粉和支链淀粉中的短链部分形成了双螺
旋结构, 又称为短程有序结构(short-range ordered
structure), 这些双螺旋分子链通过分子间的相互作
用力以一定的空间点阵在淀粉颗粒的某些区域形成
不同的多晶形, 即晶体, 又称为长程有序结构(long-
range ordered structure)[1-2]。依据粉末X-射线衍射波
谱, 可将淀粉结晶结构分为A-型、B-型和C-型3种
类型, 其中A-型晶体主要存在于禾谷类作物种子中,
B-型晶体主要存在于植物块茎中和高直链作物种子
中, C-型晶体由A-型晶体和B-型晶体共同组成, 主
要存在于豆类作物种子和薯蓣类根状茎中[2]。
目前研究淀粉粒有序结构主要采用偏光显微镜
技术(polarized light microscopy, PLM)、粉末X-射线
衍射技术(X-ray powder diffraction, XRD)、13C CP/
MAS固体核磁共振技术(cross-polarization magic-angle spinning nuclear magnetic resonance, 13C CP/MAS NMR)和傅里叶变换红外光谱技术(Fourier transform in-
frared spectroscopy, FTIR)[2-5]。PLM主要用于淀粉
粒晶体结构存在有无的定性分析[3]。XRD检测淀粉
分子的长程有序结构(即晶体), 虽然可用于淀粉粒
晶体类型的定性分析, 但在定量计算淀粉等多晶体
系的结晶度方面存在一定的困难[2]。13C CP/MAS
NMR测定淀粉分子的短程有序, 能够研究淀粉粒
的晶体类型和计算淀粉的结晶度和双螺旋含量, 但
仪器较昂贵, 测试样品用时较长, 结晶度和双螺旋
含量定量计算也非常复杂[4]。FTIR对淀粉结晶、分
子链的构象及螺旋结构的改变十分敏感, 用于淀粉
粒短程有序结构的研究[5]。与XRD和13C CP/MAS
NMR相比, FTIR测试所需样品量极少(10 mg)、操
作快速简单(2~3 min)、灵敏度高, 在国外已广泛用
于淀粉粒有序结构的分析[5-7], 但在国内这方面的