Abstract：
Frozen surimi quality generally correlates with oxidation, but impacts of protein oxidation on salt-dissolved myofibrillar protein (MP) sol in surimi remain unclear. Hence, physicochemical and gelling properties of MP sol with different oxidation degrees were investigated subjected to freeze-thaw cycles. Results showed that mild oxidation (≤1 mmol/L) improved unfrozen MP gel quality with lowest cooking loss (3.29 %) and highest hardness (829.76 N). Whereas, oxidized sol suffering freeze-thawing degenerated severely, showing reduction of 23.85 % of salt soluble protein contents with H2O2 concentrations of 10 mmol/L. Shearing before heating influenced gelling properties of freeze-thawed sol, depending on oxidation levels. Oxidized gel with shearing displayed disorganized network structures, whereas gel without shearing displayed relatively complete appearances without holes under high oxidation condition (10 mmol/L). Overall, freeze-thaw process aggravated denaturation extents of MP sol subjected to oxidation, further causing high water loss and yellow color of heat-induced gel, especially to gel with shearing.
摘要：
冷冻鱼糜的质量通常与氧化有关，但是蛋白质氧化对鱼糜盐溶肌原纤维蛋白（MP）溶胶的影响尚不清楚。因此，研究了不同氧化程度的MP溶胶在冻融循环中的理化和胶凝性能。结果表明，温和氧化（≤1mmol/L）改善了未冷冻MP凝胶的质量，蒸煮损失最低（3.29％），硬度最高（829.76N）。然而,氧化溶胶冻融退化严重，H2O2浓度为10mmol/L时，盐溶性蛋白质含量降低了23.85％。加热前剪切会影响冻融溶胶的胶凝性能，取决于氧化水平。剪切氧化凝胶显示出无序的网络结构，而没有剪切的凝胶在高氧化条件下（10mmol/L）表现出相对完整的外观，没有孔。总的来说,冻融过程加剧了MP溶胶的氧化变性程度，进一步导致高失水和黄色的热诱导凝胶，特别是剪切凝胶。
