Liu Yuan, Hu Wei, Guo Xiao-Xi, Wang Xi-Chang, Sun Su-Qin, Xu Chang-Hua
College of Food Science & Technology, Shanghai Ocean University, Shanghai 201306, PR China.
Analysis Center, Tsinghua University, Beijing 100084, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2015;149:516-22. doi: 10.1016/j.saa.2015.04.116. Epub 2015 May 7.
A Tri-step infrared spectroscopy (Fourier transform infrared spectroscopy (FT-IR) integrated with second derivative infrared (SD-IR) spectroscopy and two-dimensional correlation infrared spectroscopy (2DCOS-IR)) combined with Principal Component Regression (PCR) were employed to characterize and discriminate three marine fish surimi (white croaker surimi (WCS), hairtail surimi (HS) and red coat surimi (RCS)). The three surimi had similar IR macro-fingerprints (similarity>0.7) especially for the absorption bands of amide groups. Compared to the other two surimi, however, RCS had a middle strong characteristic peak of lipids at 1745 cm(-1), indicating that RCS had the highest content of lipids. SD-IR spectra of the three surimi enhanced the spectral resolution and amplified the small differences, especially at about 1682 cm(-1), 1679 cm(-1), 1656 cm(-1) and 1631 cm(-1), suggesting that the three had different profiles of proteins. Moreover, evident differences were observed in 2DCOS-IR spectra of 1500-1800 cm(-1). WCS had one strong (1620 cm(-1)) and three weak auto-peaks (1520 cm(-1), 1552 cm(-1), 1706 cm(-1)). HS had three strong (1621 cm(-1), 1648 cm(-1), 1708 cm(-1)) and two weak auto-peaks (1523 cm(-1), 1553 cm(-1)), whereas RCS had one strong (1623 cm(-1)) and three weak auto-peaks (1525 cm(-1), 1709 cm(-1), 1738 cm(-1)). Furthermore, sixty batches of surimi (twenty for each surimi) were objectively classified by PCR. It was demonstrated that the Tri-step infrared spectroscopy combined with PCR could be applicable for discrimination of precious marine fish surimi in a direct, rapid and holistic manner.
采用三步红外光谱法（傅里叶变换红外光谱（FT-IR）与二阶导数红外光谱（SD-IR）以及二维相关红外光谱（2DCOS-IR）相结合）并结合主成分回归（PCR）对三种海鱼鱼糜（白姑鱼鱼糜（WCS）、带鱼鱼糜（HS）和红衫鱼鱼糜（RCS））进行表征和鉴别。这三种鱼糜具有相似的红外宏观指纹图谱（相似度>0.7），尤其是酰胺基团的吸收带。然而，与其他两种鱼糜相比，RCS在1745 cm⁻¹处有一个中等强度的脂质特征峰，表明RCS的脂质含量最高。三种鱼糜的SD-IR光谱提高了光谱分辨率并放大了微小差异，特别是在约1682 cm⁻¹、1679 cm⁻¹、1656 cm⁻¹和1631 cm⁻¹处，表明这三种鱼糜的蛋白质谱不同。此外，在1500 - 1800 cm⁻¹的二维相关红外光谱中观察到明显差异。WCS有一个强自相关峰（1620 cm⁻¹）和三个弱自相关峰（1520 cm⁻¹、1552 cm⁻¹、1706 cm⁻¹）。HS有三个强自相关峰（1621 cm⁻¹、1648 cm⁻¹、1708 cm⁻¹）和两个弱自相关峰（1523 cm⁻¹、1553 cm⁻¹），而RCS有一个强自相关峰（1623 cm⁻¹）和三个弱自相关峰（1525 cm⁻¹、1709 cm⁻¹、1738 cm⁻¹）。此外，通过PCR对六十批鱼糜（每种鱼糜二十批）进行了客观分类。结果表明，三步红外光谱法结合PCR能够以直接、快速和全面的方式用于鉴别珍贵的海鱼鱼糜。
