电子束辐照对梅鱼鱼糜肌原纤维蛋白结构及凝胶特性的影响

Effects of Electron Beam Irradiation on the Myofibrillar Protein Structure and Gel Properties of Collichthys lucidus Surimi

以梅鱼鱼糜为原料,研究不同电子束辐照剂量(0～9 k Gy)对鱼糜肌原纤维蛋白结构及其凝胶特性的影响,确定提高鱼糜凝胶品质的最适剂量。结果表明:低剂量(≤5 k Gy)组总巯基和活性巯基含量下降不明显,但7 k Gy和9 k Gy组下降明显;随辐照剂量的增加,Ca2+-ATPase活性明显下降,而表面疏水性先增大后减小,5 k Gy组表面疏水性值达到最大。SDS-PAGE和DSC分析显示,随辐照剂量的增加,尤其在7 k Gy和9 k Gy组,肌球蛋白重链、肌球蛋白和肌动蛋白的热稳定性下降明显;鱼糜凝胶特性结果表明,经5 k Gy电子束处理,梅鱼鱼糜的凝胶强度、白度值和持水性均高于对照及其它剂量组。综上所述,5 k Gy辐照剂量可有效改善梅鱼鱼糜的凝胶特性,且相比于高剂量(≥7 k Gy)组,低剂量辐照对梅鱼鱼糜肌原纤维蛋白结构的影响不显著。电子束辐照处理可以成为改善梅鱼鱼糜凝胶品质的一种有效手段,合适剂量为5 k Gy。

To determine the optimal radiation dose, the effects of electron beam irradiation（0～9 k Gy） on the myofibrillar protein structure and gel properties of Collichthys lucidus surimi were evaluated. The results showed that at radiation doses of 7 k Gy and 9 k Gy, the total sulfhydryl group and active sulfhydryl group content decreased significantly, compared to those treated with lower doses（≤5 k Gy）. With increasing doses of radiation, the activity of calcium ATPase decreased significantly, while the surface hydrophobicity of surimi myofibrillar proteins increased initially and then decreased. The highest surface hydrophobicity was reached at 5 k Gy. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis（SDS-PAGE） and differential scanning calorimetry（DSC） revealed that the thermal stability of myosin heavy chains（MHC）, myosin, and actin decreased significantly with the increase in radiation doses, especially in the 7 k Gy and 9 k Gy groups. The gel strength, whiteness, and expressible water content of surimi gel were the highest when 5 k Gy of electron beam irradiation was performed. Compared to the high-dose groups（≥7 k Gy）, the low-dose groups did not significantly affect the structure of surimi myofibrillar proteins. Thus, irradiation with 5 k Gy could effectively improve the gel properties of Collichthys lucidus surimi.