Changes in the myosin secondary structure and shrimp surimi gel strength induced by dense phase carbon dioxide

卷:227

Guo, Minghui ; Liu, Shucheng ; Ismail, Marliya ; Farid, Mohammed M. ; Ji, Hongwu ; Mao, Weijie ; Gao, Jing ; Li, Chengyong

Guangdong Ocean Univ

关键词: Dense phase carbon dioxide;    Secondary structure;    Gel strength;    Myosin;    Shrimp surimi;   

DOI  :  10.1016/j.foodchem.2017.01.050

学科分类：食品科学和技术

【 摘 要 】

Dense phase carbon dioxide (DPCD) could induce protein conformation changes. Myosin and shrimp surimi from Litopenaeus vannamei were treated with DPCD at 5-25 MPa and 40-60 degrees C for 20 min. Myosin secondary structure was investigated by circular dichroism and shrimp surimi gel strength was determined using textural analysis to develop correlations between them. DPCD had a greater effect on secondary structure and gel strength than heating. With increasing pressure and temperature, the alpha-helix content of DPCD-treated myosin decreased, while the beta-sheet, beta-turn and random coil contents increased, and the shrimp surimi gel strength increased. The a-helix content was negatively correlated with gel strength, while the beta-sheet, beta-turn and random coil contents were positively correlated with gel strength. Therefore, when DPCD induced myosin to form a gel, the a-helix of myosin was unfolded and gradually converted to a beta-sheet. Such transformations led to protein-protein interactions and cross-linking, which formed a three-dimensional network to enhance the gel strength. (C) 2017 Elsevier Ltd. All rights reserved.