基于二维相关红外光谱的鱼糜品质检测可行性分析

对二维相关光谱在鱼糜品质检测中的可行性进行了分析。利用二维相关技术结合中红外光谱技术对冻融处理后白鲢鱼糜蛋白二级结构变化进行了分析。在冻融次数和温度双重外扰的作用下对样品进行了分析。以冻融次数为外扰的二维相关光谱分析结果揭示了鱼糜蛋白二级结构的变化顺序： α-螺旋结构、分子内聚集的β-折叠结构→反平行的β-折叠结构→羰基结构；基于温度外扰的二维相关光谱分析结果表明： 冻融处理1次和2次后鱼糜蛋白二级结构变化轻微。而冻融处理3次之后鱼糜蛋白二级结构已遭到严重破坏。结果分析还发现： 外扰温度为45℃时，温度对羰基的影响比大大小于冻融循环对鱼糜蛋白二级结构的影响。以上结果说明二维相关光谱技术可以探测并直观的反应出鱼糜蛋白二级结构变化程度。如果能将这种变化程度量化，则可以利用该技术对鱼糜新鲜度等品质进行快速检测。

Feasibility of 2DCOS Based on ATR-MIR in Surimi Quality Inspection

The feasibility of 2DCOS (two-dimensional correlation spectroscopy) in the quality inspection of surimi was tested in this study.The changes of silver carp surimi protein secondary structure induced by freeze-thaw treatment were studied in suit using 2DCOS combined with ATR-MIR (attenuated total reflectance mid-infrared). The results showed that freeze-thaw cycles accelerated the oxidation process of surimi protein. The content of α-helix and intramolecular aggregated β-sheet all decreased, however the content of the anti-parallel β-sheet increased. 2DCOS analysis under the external perturbation of freeze-thaw cycles showed the change order was: α-helix, intramolecular aggregated β-sheet→antiparallel β-sheet→carbonyl. 2DCOS analysis under the perturbation of temperature showed that the protein secondary structure has been seriously damaged after three freeze-thaw cycles. And the effect of temperature on the carbonyl group of proteins was much smaller than that of the freeze-thaw cycles. These results indicated that the 2DCOS could explore and reflect the change degree of surimi protein. If these changes can be quantified, the 2DCOS could be used to detect the freshness of surimi.