南美白对虾蒸制过程中水分状态及质构的变化

Change of Moisture Status and Texture for Shrimp(Penaeus vannamei) during Steaming

研究南美白对虾在蒸制过程中的水分状态和质构变化,以及虾肉组织结构对其的影响。采用直接干燥法分析虾肉水分含量的变化,水分活度仪、低场核磁共振仪(LF-NMR)研究虾肉水分活度和水分状态,质构仪分析虾肉硬度、咀嚼度、回复性和黏聚性变化,V.G.染色法观察虾肉组织结构的变化。结果表明:随着蒸制时间的延长,虾肉水分含量、Aw下降;结合水和中间水含量变化不显著,而自由水含量显著降低;硬度、咀嚼度、回复性和黏聚性升高;肌肉纤维收缩和聚集,肌纤维束间的空隙逐渐加大,造成流动性最强的自由水损失,虾肉质构发生变化。

The objective of this paper was to investigate the change of moisture status and texture for shrimp（Penaeus vannamei） during steaming, and elaborate deeply the effect of organizational structure of shrimp meats on the moisture state and texture. Moisture content of shrimp meats was analyzed by the direct drying method. Moisture activity and moisture status was evaluated respectively using water activity meter and low field nuclear magnetic resonance（LFNMR）. Change of hardness, chewiness, resilience and adhesiveness of shrimp meats was measured by texture analyzer and histological structure of shrimp meats was observed by V.G. staining. Results showed that with the increase of steaming time, moisture content and Aw decreased respectively; Content of bound water and intermediate water changed very little, whereas free water content significantly decreased. Hardness, chewiness, resilience and adhesiveness improved gradually. Muscle fibers Shrinked and gathered, resulting in the increase of gap among muscle fiber bundles, loss of Free water possessing the strongest fluidity and the change of shrimp meats texture.