Wang Jinfeng, Zhang Hanwen, Xie Jing, Yu Wenhui, Sun Yuyao
College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China.
Shanghai Professional Technology Service Platform on Cold Chain Equipment Performance and Energy Saving Evaluation, Shanghai 201306, China.
Foods. 2022 Aug 3;11(15):2315. doi: 10.3390/foods11152315.
The effects of different freezing temperatures on the water-holding capacity and physicochemical properties of bluefin tuna were studied. The naked body, big belly and middle belly parts of bluefin tuna were stored at -18 °C and -55 °C for 180 days. The tuna was evaluated by determining the water-holding capacity, color difference, malondialdehyde (MDA), salt-soluble protein content, free amino acid (FAA), endogenous fluorescent proteins and water distribution and migration. The salt-soluble protein content was measured by the Bradford method. The color difference was measured by a CR-400 color difference meter. The water distribution and migration were analyzed by the low-field nuclear magnetic resonance (LF-NMR). The results showed little quality change during short-term frozen storage, but the frozen storage temperature of -55 °C significantly improved the quality of tuna compared with the frozen storage temperature of -18 °C. There were great differences in the salt-soluble protein content, water-holding capacity and water content the different parts of the tuna. The water-holding capacity and the protein content were the highest, and the water distribution of the naked body part was the most uniform of the three different parts. Because of the high fat content in the big belly and the middle belly, the MDA content and the odor of amino acid increased rapidly and the quality seriously decreased during the frozen storage.
研究了不同冷冻温度对蓝鳍金枪鱼持水能力和理化性质的影响。将蓝鳍金枪鱼的裸身、大腹和中腹部位分别在-18℃和-55℃下储存180天。通过测定持水能力、色差、丙二醛（MDA）、盐溶性蛋白含量、游离氨基酸（FAA）、内源性荧光蛋白以及水分分布和迁移情况对金枪鱼进行评估。盐溶性蛋白含量采用考马斯亮蓝法测定。色差用CR-400色差仪测定。水分分布和迁移通过低场核磁共振（LF-NMR）分析。结果表明，短期冷冻储存期间品质变化较小，但与-18℃的冷冻储存温度相比，-55℃的冷冻储存温度显著提高了金枪鱼的品质。金枪鱼不同部位的盐溶性蛋白含量、持水能力和水分含量存在很大差异。持水能力和蛋白质含量最高，裸身部位的水分分布在三个不同部位中最为均匀。由于大腹和中腹脂肪含量高，冷冻储存期间MDA含量和氨基酸气味迅速增加，品质严重下降。
