超高压处理对凡纳滨对虾虾仁蛋白质和微观结构的影响

为丰富超高压技术在虾类保鲜与加工中的应用基础理论并实现工业化生产,实验以未处理的凡纳滨对虾虾仁为对照,用超高压(100、300、500 MPa)分别处理虾仁5、10、20、30 min,分析蛋白质含量、组成和热稳定性的变化,观察虾仁肌肉组织的微观结构。结果显示,100 MPa处理使虾仁的肌浆蛋白含量增加,300和500 MPa处理使肌浆蛋白含量显著下降。超高压处理使肌原纤维蛋白含量显著下降,使虾仁蛋白质发生了变性、肌球蛋白和肌动蛋白的热稳定性降低;随着压强的升高和处理时间的延长,虾仁肌原纤维排列变得紧实致密,肌节严重收缩,肌纤维之间空隙变模糊而呈现出絮状结构。研究表明,超高压处理能使对虾蛋白质变性而产生凝胶化,从而有利于人体的消化和吸收,说明超高压可以用于加工即食虾类产品。

Effects of high hydrostatic pressure on protein and microstructure of Litopenaeus vannamei

In order to enrich the basis theory of high hydrostatic pressure (HHP) technology in shrimp preservation and processing and to realize industrial production, regarding untreated peeled shrimps as a control, the peeled shrimp were treated by HHP at 100, 300, 500 MPa for 5,10 , 20 and 30 min, respectively. The content, composition and thermostability of protein were analyzed. The microstructure of shrimp muscle tissues was observed by optical microscope and transmission electron microscope. The results showed that the content of sarcoplasmic protein slightly increased at 100 MPa, and decreased significantly at 300 and 500 MPa, and the content of myofibrillar protein significantly decreased. HHP treatment resulted in denaturation of peeled shrimp protein and decreased the thermostability of myosin and actin. With the increase of pressure and treatment time, HHP makes the arrangement of peeled shrimp myofibril tight and compact, and even the structure of myofibril collapse, sarcomere severe contraction, the gap among muscle fibers fuzzy and showing a flocculent structure. Therefore, high hydrostatic pressure can make the shrimp protein denaturation and gelation, which is conducive to digestion and absorption of the human body. The results show that high hydrostatic pressure can be used for processing instant shrimp products.