电子束辐照海水鱼糜凝胶特性的变化及其机理研究

Known as one of the cold sterilization methods, electron beam (EB) irradiation has been widely used in food preservation, quality and safety control, as well as quality improvement, and other fileds. Surimi, mainly composed of fish myofibrillar protein, is an important material in seafood industry. The gel property is one of the most important index to evaluate the quality of surimi and its products. EB irradiation can change the conformation of surimi protein, leading to protein denaturation, aggregation or gelation. This phenomenon is expected to improve the gel properties of surimi and surimi products. The aim of this project is to investigate the effect of EB irradiation on the gel property of marine surimi made from Trichiurus haumela and Collichthys niveatus.During the formation of surimi gel, the conformation and chemical interactions of protein will be assayed by raman spectrum and circular dichroism spectrum. On the other hand, combined with the physiochemical parameters, such as composition of myofibrillar protein, activity of endogenous cathepsin and transglutaminase, texure and microstructure of surimi gel, the role of chemical interactions and protein conformation in maintaining stable surimi gel network and the effect of EB irradiation on the conformation and gel properties of surimi protein will be clarified at the molecular level. The results of this study will elucidate the change mechanisms of gel property of irradiated surimi and provide a theoretical foundation for using EB irradiation to improve the quality of surimi and surimi products.

有"冷杀菌"之称的电子束辐照技术已被广泛应用于食品保鲜、食品质量和安全控制、食品品质改进等领域；鱼糜是海洋食品加工中的一种重要原料，主要由鱼肉肌原纤维蛋白组成，其凝胶特性是评价鱼糜及其制品质量的重要指标。电子束辐照能引起鱼糜蛋白构象的改变，导致蛋白质变性、聚集或凝胶化，有望改善鱼糜及其制品的凝胶特性。 本项目以海水带鱼、梅鱼鱼糜为原料，采用电子束辐照处理，利用拉曼光谱、圆二色光谱等表征鱼糜及其凝胶形成过程中蛋白质的化学作用力及其分子构象，结合肌原纤维蛋白分子组成、内源性蛋白酶和转谷氨酰胺酶活性及鱼糜凝胶质构、微观结构等，解析化学作用力及蛋白构象对鱼糜凝胶网络结构形成的作用，从分子水平研究辐照对鱼糜蛋白结构及其凝胶特性的影响，阐明电子束辐照诱导鱼糜凝胶特性的变化机理，为鱼糜及其制品加工提供理论依据。

以带鱼鱼糜、梅鱼鱼糜等为原料进行电子束辐照处理，利用拉曼光谱、圆二色光谱等表征鱼糜及其凝胶形成过程中蛋白质的化学作用力及其分子构象，结合肌原纤维蛋白分子组成、内源性蛋白酶和转谷氨酰胺酶活性、鱼糜凝胶流变学性质、质构及其微观结构等，解析了化学作用力及蛋白构象对鱼糜凝胶网络结构形成的作用，显示二硫键对凝胶网络形成起重要作用，辐照可促进鱼糜蛋白热诱导过程中二硫键的形成，抑制鱼糜内源组织蛋白酶活性，影响鱼糜蛋白螺旋结构的形成，从分子水平研究了辐照对鱼糜蛋白结构及其凝胶特性的影响，阐述了辐照诱导鱼糜凝胶特性的变化机理，填补了电子束辐照对鱼糜凝胶特性影响机理的研究空白；利用顶空固相微萃取-气质联用和电子鼻分析，结合相对气味活度值研究辐照前处理对鱼糜凝胶挥发性风味的影响，显示低剂量处理能较好地保持鱼糜凝胶良好风味，而高剂量辐照会导致梅鱼鱼糜凝胶鱼香味减弱。基于电子束辐照对鱼糜凝胶质构、白度、持水力和风味等影响，确定了处理带鱼鱼糜和梅鱼鱼糜的合适剂量，可在改善鱼糜凝胶性能的同时保持其良好风味，为高品质鱼糜及其制品加工提供理论依据。