Liu Zhenfang, Huang Min, Zhu Qibing, Qin Jianwei, Kim Moon S
Key Laboratory of Advanced Process Control for Light Industry (Ministry of Education), Jiangnan University, Wuxi, 214122, China.
Key Laboratory of Advanced Process Control for Light Industry (Ministry of Education), Jiangnan University, Wuxi, 214122, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2022 Jul 5;275:121154. doi: 10.1016/j.saa.2022.121154. Epub 2022 Mar 15.
Raman spectroscopy attempts to reflect food quality by characterizing molecular vibration and rotation. However, the blocking of optical signals by packaging materials and the interference of the optical signal generated by the packaging itself make the detection of internal food quality without destroying packaging highly difficult. In this regard, this paper proposes a novel packaged food internal signal separation based on spatially offset Raman spectroscopy (SORS) coupled with improved fast independent component analysis (FastICA). Firstly, the Raman scattering image of the packaged food with offset laser incident point was obtained. Then, the movable quadratic mean of information entropy was used to select the observation feature region of the image. Thirdly, the main independents decomposed by the optimized FastICA method were identified by spectral attenuation characteristics of the SORS peak signal. Finally, the non-negativity of the separated signal was ensured by baseline recognition and correction. The effectiveness of this method was verified by refactoring the similarity between the signal and the reference signal by testing three different packaging and four internal materials under standard experimental conditions. The applicability of the method was proved by the internal signal separation of three packaged foods on sale. The experimental results indicate that the proposed method can separate the Raman signal of packaged food and can be used as a pretreatment method and auxiliary analysis means for the detection of packaged food.
拉曼光谱法试图通过表征分子振动和转动来反映食品质量。然而，包装材料对光信号的阻挡以及包装本身产生的光信号干扰使得在不破坏包装的情况下检测食品内部质量极具难度。对此，本文提出一种基于空间偏移拉曼光谱法（SORS）并结合改进的快速独立成分分析（FastICA）的新型包装食品内部信号分离方法。首先，获取激光入射点偏移的包装食品的拉曼散射图像。然后，利用信息熵的移动二次均值来选择图像的观测特征区域。第三，通过SORS峰值信号的光谱衰减特性识别经优化的FastICA方法分解出的主要独立成分。最后，通过基线识别和校正确保分离信号的非负性。在标准实验条件下，通过测试三种不同包装和四种内部材料，重构信号与参考信号之间的相似度，验证了该方法的有效性。通过对三种市售包装食品进行内部信号分离，证明了该方法的适用性。实验结果表明，所提出的方法能够分离包装食品的拉曼信号，可作为包装食品检测的预处理方法和辅助分析手段。
