Shen Zhifeng, Wang Honghai, Liang Jingjing, Zhao Qiaoling, Lu Weibo, Cui Yiwei, Wang Pingya, Shen Qing, Chen Jian
Collaborative Innovation Center of Seafood Deep Processing, Zhejiang Province Joint Key Laboratory of Aquatic Products Processing, Institute of Seafood, Zhejiang Gongshang University, Hangzhou, China.
Zhejiang Provincial Institute for Food and Drug Control, Hangzhou 310052, China.
Food Chem X. 2024 Aug 5;23:101705. doi: 10.1016/j.fochx.2024.101705. eCollection 2024 Oct 30.
Freezing is one of the most commonly used preservation methods for Bluefin tuna (). However, repeated freezing and thawing would inevitably occur due to the temperature fluctuation, leading to the microstructure damage, lipid oxidation and protein integrity decline of tuna muscle without notable visual appearance change. In this study, we used a rapid evaporative ionization mass spectrometry (REIMS) technique for the real-time determination of the extent of repeated freezing and thawing cycles in tuna fillets. We found significant variance in the relative abundance of fatty acids between bluefin tuna and its fresh counterpart following freeze-thaw cycles. Meanwhile, the difference is statistically significant ( < 0.05). The quality of tuna remains largely unaffected by a single freeze-thaw cycle but significantly deteriorates after freeze-thaw cycles (freeze-thaw count ≥2), and the relative fatty acid content of the ionized aerosol analysis in the REIMS system positively correlated with the number of freeze-thaw cycles. Notably, palmitic acid (C 16:0, / 255.23), oleic acid (C 18:1, m/z 281.24), and docosahexaenoic acid (C 22:6, m/z 327.23) displayed the most pronounced changes within the spectrum of fatty acid groups.
冷冻是蓝鳍金枪鱼最常用的保存方法之一。然而，由于温度波动，不可避免地会出现反复冷冻和解冻的情况，这会导致金枪鱼肌肉的微观结构受损、脂质氧化和蛋白质完整性下降，而外观却没有明显变化。在本研究中，我们使用了快速蒸发电离质谱（REIMS）技术实时测定金枪鱼鱼片反复冷冻和解冻循环的程度。我们发现，经过冻融循环后，蓝鳍金枪鱼与其新鲜样本之间脂肪酸的相对丰度存在显著差异。同时，这种差异具有统计学意义（P<0.05）。金枪鱼的品质在单次冻融循环后基本不受影响，但在多次冻融循环（冻融次数≥2）后会显著下降，并且REIMS系统中电离气溶胶分析的相对脂肪酸含量与冻融循环次数呈正相关。值得注意的是，棕榈酸（C16:0，m/z 255.23）、油酸（C18:1，m/z 281.24）和二十二碳六烯酸（C22:6，m/z 327.23）在脂肪酸组谱中显示出最明显的变化。
