Han Wan-qing, Luo Hai-ying, Xian Yan-ping, Luo Dong-hui, Mu Torng-na, Guo Xin-dong
Guang Pu Xue Yu Guang Pu Fen Xi. 2015 Feb;35(2):379-83.
Sixty-four pieces of shark fin dried products (including real, fake and artificial shark fin products) and real products coated with gelatin were rapidly and nondestructively analyzed by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). The characteristic of IR spectrograms among the above four kinds of samples were systematically studied and comparied, the results showed that the spectrograms of the same kind of samples were repeatable, and different kinds of shark fin products presented significant differences in the spectrograms, which mainly manifested as the specific absorption peaks of amido bonds in protein (1650, 1544 cm(-1)) and skeletal vibration in polysaccharide (1050 cm(-1)). The spectrograms of real shark fins were characterized by the strong absorption peaks of protein characteristic amide I and II absorbent (1650, 1544 cm(-1)) and relatively weak C--O--C vibration absorbent (1050 cm(-1)) owing to the high content of protein and relatively low level of polysaccharide. For fake shark fin products that were molded form by mixing together with the offcut of shark, collagen and other substances, the introduction of non-protein materials leaded to the weaker amido bonds absorbent than real products along with a 30 cm(-1) blue shift of amide I absorbent. Opposite to the real sample, the relatively strong absorption peak of polysaccharide (approximately 1047 cm(-1)) and barely existed amide absorbent were the key features of the spectrogram of artificial samples, which was synthersized by polysaccharide like sodium alginate. Real samples coated with gelatin, the peak strength of protein and polysaccharide were decreased simultaneously when the data collection was taken at the surface of sample, while the spectrogram presented no significant difference to real samples when the data was collected in the section. The results above indicated that by analyzing the characteristic of IR spectrograms and the value range of Apro/Apol collected by ATR-FTIR method could perform the undamaged and rapid identification for shark fins.
采用衰减全反射傅里叶变换红外光谱法（ATR-FTIR）对64份鱼翅干制品（包括真、假及人造鱼翅制品）以及涂有明胶的真品进行了快速无损分析。系统研究并比较了上述四类样品的红外光谱特征，结果表明，同类样品的光谱图具有重复性，不同种类的鱼翅制品在光谱图上呈现出显著差异，主要表现为蛋白质中酰胺键的特定吸收峰（1650、1544 cm⁻¹）和多糖中的骨架振动（1050 cm⁻¹）。真鱼翅的光谱图特征为蛋白质特征酰胺Ⅰ和Ⅱ吸收峰（1650、1544 cm⁻¹）较强，而由于蛋白质含量高、多糖含量相对较低，C-O-C振动吸收峰（1050 cm⁻¹）相对较弱。对于由鲨鱼边角料、胶原蛋白等物质混合成型的假鱼翅制品，非蛋白质物质的引入导致酰胺键吸收峰比真品弱，同时酰胺Ⅰ吸收峰发生30 cm⁻¹的蓝移。与真品相反，人造样品光谱图的关键特征是多糖的相对强吸收峰（约1047 cm⁻¹）和几乎不存在的酰胺吸收峰，人造样品是由海藻酸钠等多糖合成的。涂有明胶的真品，在样品表面采集数据时，蛋白质和多糖的峰强度同时降低，而在截面采集数据时，光谱图与真品无显著差异。上述结果表明，通过分析红外光谱图特征以及ATR-FTIR法采集的Apro/Apol值范围，可以对鱼翅进行无损快速鉴定。
