Xu Zheng, Zhu Shichen, Wang Wenjie, Liu Shulai, Zhou Xuxia, Dai Wangli, Ding Yuting
College of Food Science and Technology, Zhejiang University of Technology, Hangzhou, China.
Key Laboratory of Marine Fishery Resources Exploitment & Utilization of Zhejiang Province, Hangzhou, China.
J Sci Food Agric. 2022 May;102(7):3000-3009. doi: 10.1002/jsfa.11640. Epub 2021 Nov 25.
Freshness is an important quality of squid with respect to determining the market price. The methods of evaluation of freshness fail to be widely used as a result of the lack of rapidity and quantitation. In the present study, a rapid and non-destructive quantification of squid freshness by Fourier transform infrared spectroscopy (FTIR) spectra combined with chemometric techniques was performed.
The relatively linear content change of trimethylamine (TMA-N) and dimethylamine (DMA-N) of squid during storage at 4 °C indicated their feasibility as a freshness indicator, as also confirmed by sensory evaluation. The spectral changes were mainly caused by the degradation of proteins and the production of amines by two-dimensional infrared correlation spectroscopy, among which TMA-N, DMA-N and putrescine were the main amines. The successive projections algorithm (SPA) was employed to select the sensitive wavenumbers to freshness for modeling prediction including partial least-squares regression, support vector regression (SVR) and back-propagation artificial neural network. Generally, the SPA-SVR model of the selected characteristic wavenumber showed a higher prediction accuracy for DMA-N (R = 0.951; RMSE = 0.218), whereas both SPA-SVR (R = 0.929; RMSE = 2.602) and Full-SVR (R = 0.941; RMSE = 2.492) models had a higher predictive ability of TMA-N.
The results of the present study demonstrate that FTIR spectroscopy coupled with multivariate calibration shows significant potential for the prediction of freshness in squid. © 2021 Society of Chemical Industry.
新鲜度是鱿鱼的一项重要品质指标，关乎其市场价格的确定。由于缺乏快速性和定量性，现有的新鲜度评估方法未能得到广泛应用。在本研究中，采用傅里叶变换红外光谱（FTIR）结合化学计量学技术，对鱿鱼新鲜度进行了快速、无损定量分析。
鱿鱼在4°C储存期间三甲胺（TMA-N）和二甲胺（DMA-N）含量呈相对线性变化，表明它们可作为新鲜度指标，感官评价也证实了这一点。二维红外相关光谱分析表明，光谱变化主要是由蛋白质降解和胺类物质生成引起的，其中TMA-N、DMA-N和腐胺是主要的胺类物质。采用连续投影算法（SPA）选择与新鲜度相关的敏感波数进行建模预测，包括偏最小二乘回归、支持向量回归（SVR）和反向传播人工神经网络。总体而言，所选特征波数的SPA-SVR模型对DMA-N的预测准确率较高（R = 0.951；RMSE = 0.218），而对于TMA-N，SPA-SVR（R = 0.929；RMSE = 2.602）和全谱SVR（R = 0.941；RMSE = 2.492）模型均具有较高的预测能力。
本研究结果表明，FTIR光谱结合多变量校准在预测鱿鱼新鲜度方面具有显著潜力。© 2021化学工业协会。
