南美白对虾微冻贮藏期间蛋白质品质变化及预测模型的建立

The Changes and Prediction Model of Protein Quality of Litopenaeus vannameiduring Partial Freezing Storage

以南美白对虾为原料,研究微冻条件(-3℃)下不同贮藏时间其肌肉蛋白质品质特性的变化,利用相关蛋白质指标建立径向基函数神经预测模型。结果表明:与新鲜虾样品相比,在微冻贮藏30 d后,表面疏水性、羰基含量、TCA溶解肽、肌原纤维小片化指数、疏水相互作用力、二硫键含量分别显著上升到(68.12±0.19)μg,(2.02±0.08)nmol/mg pro,(6.29±0.14)μmol酪氨酸/g肌肉,55.11±2.79,(7.82±0.17)mg/mL,(5.77±0.06)mg/mL;Ca2+-ATPase、总巯基含量、离子键、氢键含量、内源荧光强度分别显著下降到(0.13±0.13)U/mg pro,(68.45±0.47)μmol/g pro,(3.12±0.48)mg/mL,(1.67±0.14)mg/m L,579.71±20.67,使虾肌肉蛋白质发生不同程度的变性、氧化和降解,蛋白质的三级结构发生变化。电泳结果表明,贮藏时间延长,大分子质量蛋白质发生降解。建立的径向基函数神经预测模型的预测值和试验值之间的误差均在±10%内,表明该模型可以较好地预测微冻贮藏过程中南美白对虾肌肉蛋白质品质的变化。

In this work,Litopenaeus vannamei was used as a raw material to study the changes of muscle protein quality characteristics at different storage times under partial freezing condition(-3℃),and the radial basis function neural prediction model was established based on related protein indexes.The results showed that compared with fresh shrimp samples,after 30 d of partial freezing storage,the surface hydrophobicity,carbonyl content,TCA soluble peptide,myofibril fiber fragmentation index,hydrophobic interaction force,and disulfide bond content significantly increased to(68.12±0.19)μg,(2.02±0.08)nmol/mg pro,(6.29±0.14)μmol tyrosine/g muscle,55.11±2.79,(7.82±0.17)mg/mL,(5.77±0.06)mg/mL,respectively.Ca2+-ATPase,total sulfhydryl content,ionic bonding,hydrogen bonding content,and endogenous fluorescence intensity significantly decreased to(0.13±0.13)U/mg pro,(68.45±0.47)μmol/g pro,(3.12±0.48)mg/mL,(1.67±0.14)mg/mL,579.71±20.67,respectively.Shrimp muscle proteins were denatured,oxidized and degraded in varying degrees,and the tertiary structure of proteins changed.The results of sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed that the storage time was prolonged,and the large molecular weight proteins were degraded.Meanwhile,electrophoresis results showed that the storage time was prolonged and the large molecular weight protein was degraded.The error between the predicted value of the radial basis function neural prediction model and the experimental value was within±10%.The results showed that the model could predict the protein quality of L.vannamei during partial freezing storage.