摘要
以松原粮食集团提供不同年份的玉米储备粮为实验样品,采用三级显微拉曼光谱检测仪对不同状态下的玉米单籽粒进行光谱采集,并结合密度泛函理论(DFT)得到分子光谱,研究其内部成分随时间变化的规律。通过DFT理论优化分子结构和分析,将求得分子中每个键对应的振动频率与实际测得的玉米籽粒拉曼光谱进行对比,完成部分峰位指认;对不同储存年份的玉米籽粒外表面拉曼光谱进行了测量,对原始光谱进行预处理后分别在476、1006、1156、1459、1519、1597和1633 cm^(-1)这几处发现了较强的拉曼峰,表征着玉米淀粉、叶黄素、木质素的存在;对不同年份玉米籽粒纵切面的拉曼光谱进行测量,将此部分光谱归一化处理后得到了对应峰位的相对峰强与相对峰面积。通过比较发现除在表面得到的拉曼峰外,在850~1450 cm^(-1)附近处还发现了新的拉曼峰。其中位于475、863、944、1260、1338和1378 cm^(-1)几处表征淀粉含量的拉曼峰峰强、峰面积、半高宽(FWHM)值随储存年份的增加产生了或增加或减少的现象,表明其物质组成、成分含量、分子结构均发生了不同改变,基本与玉米淀粉老化的机理一致。其中在1080和1130 cm^(-1)拉曼峰在三个不同年份玉米纵切面拉曼光谱中的变化差距较大:1080 cm^(-1)的拉曼峰只存在于2018年、2019年储存的玉米光谱中,1192 cm^(-1)处的拉曼峰只存在于2020年份的玉米光谱中,且峰强、Full Width at the half of the maximum(FWHM)值有不同程度的变化,可能表示淀粉内某种糖类物质之间的相互转换,可作为鉴定不同年份玉米样品的特征峰。对叶黄素含量相关峰位的物理参数进行了比较,并将其中的峰强、峰面积值与年份做线型拟合分析,拟合程度较好,相关系数均达到了0.9以上,表明叶黄素含量随储存时间延长呈线性下降的趋势。通过与理论计算得到的叶黄素光谱对比分析,发现叶
In this study,Songyuan Grain Group Storage's corn grain reserves from various years were used as samples,and a three-stage micro Raman spectrometer was used to gather the spectra of individual grains of corn from multiple conditions.The regularity of its internal components changes over time was investigated using the molecular spectra produced by Density Functional Theory(DFT).The DFT theory optimised the chemical structure,and the vibration frequency associated with each molecule's bond was analyzed.The partial peak location was then determined by comparing the vibration frequency to the Raman spectra of corn grains as measured in practice.Strong Raman peaks were discovered in the original spectra after pretreatment at 476,1006,1156,1459,1519,1597,and 1633 cm^(-1).It indicated the presence of lignin,lutein,and corn starch.Measurements were made of the Raman spectra of longitudinal corn sections from various years.After spectral normalisation,the relative peak intensities and areas of all peak sites were determined.In addition to the surface-based Raman peaks,fresh Raman peaks in the 850~1450 cm^(-1) range had also been discovered.With more storage years,distinct changes occur in the starch content's Raman intensity,peak area,and FWHM at 475,863,944,1260,1338,and 1378 cm^(-1).It demonstrates how its molecular structure,substance,and makeup have distinctly altered.This modification essentially fits the corn starch aging process.The Raman peaks at 1080 and 1130 cm^(-1) revealed a significant variation in the vertical section Raman spectra of maize across three years.While the Raman peak at 1192 cm^(-1) only occurs in the spectrum of maize stored in 2020,the peak strength and FWHM value varies to variable degrees,the Raman peak at 1080 cm^(-1) is only present in the spectrum of corn stored in 2018 and 2019.It suggests that the reciprocal conversion of specific carbohydrate compounds in starch can be utilized as a distinctive peak to distinguish between corn samples from various years.The peak strength and peak area
作者
黄纪翀
宋少忠
刘春宇
徐立君
陈安亮
鹿鸣
郭雯静
苗壮
李长明
谭勇
刘哲
HUANG Ji-chong;SONG Shao-zhong;LIU Chun-yu;XU Li-Jun;CHEN An-liang;LU Ming;GUO Wen-jing;MIAO Zhuang;LI Chang-ming;TAN Yong;LIU Zhe(Jilin Province Key Laboratory of Spectral Detection Science and Techno logy,School of Physics,Changchun University of Science and Technology,Changchun 130022,China;School of Information Engineering,Jilin Normal University of Engineering and Technology,Changchun 130052,China;School of Biology and Agricultural Engineering,Jilin University,Changchun 130015,China)
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2024年第8期2166-2173,共8页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金青年科学基金项目(32102034)
吉林省科技厅中央引导地方科技发展资金项目(YDZJ202201ZYTS510)
吉林省自然科学基金项目(2020122348JC)
吉林省发改委创新能力建设项目(2020C019-6)资助。
关键词
拉曼光谱
密度泛函理论
玉米储备粮
成分分析
Raman spectroscopy
Density functional theory
Corn grains
Componential analysis
