为探究超低温条件下的小黄鱼品质变化，该实验通过冻结曲线、总挥发性盐基氮（TVB-N）含量、持水力、Ca2+-ATPase（Ca2+-腺苷三磷酸酶）活性含量、羰基含量、总巯基含量以及冰晶形态等指标，综合表征-18、-25和-45 ℃等3种冻藏温度对小黄鱼品质变化的影响。结果表明-18、-25和-45 ℃组通过最大冰晶生成区域时间分别为230、95和60 min，超低温（-45 ℃）组用时最短；且-45 ℃冻藏下小黄鱼组织中的冰晶面积和直径比其他两组小、分布更均匀，150 d时，肌肉组织间隙均增大，而-18和-25 ℃两组间隙远大于-45 ℃组；冻藏200 d，-45 ℃组的小黄鱼TVB-N含量与羰基含量最小，分别为7.96 mg/100 g与30.60 nmol/mg prot；持水力、总巯基含量与Ca2+-ATPase活性含量最高，分别为74.62%、0.36 mmol/g prot与4.78 μmol/mg，显著优于-18和-25 ℃组（P<0.05）。随着贮藏时间的延长，各温度下的小黄鱼品质均变化，但超低温（-45 ℃）下的小黄鱼品质变化最缓。因此，超低温冻藏对长期贮藏小黄鱼的品质劣变有延缓作用，能更有效保持其食用价值。

Toassessthe quality changes of Larimichthys polyactis under ultra-low temperatures, the effects of -18, -25, and -45 ℃ on the quality changes of Larimichthys polyactis were investigated. In particular, the freezing curve, total volatile basic nitrogen (TVB-N) content, water holding capacity (WHC), Ca2+-ATPase activity content, carbonyl group, total sulfhydryl group, and ice crystal morphology were examined. The time taken for samples frozen at -18, -25, and -45 ℃ to cross the maximum ice crystal formation zonewas 230, 95, and 60 min, respectively, with the ultra-low temperature (-45 ℃) group taking the shortest time. The area and diameter of the ice crystals in Larimichthys polyactis frozen at -45 ℃ were smaller than those in Larimichthys polyactis frozen at the other temperatures, and displayed a more uniform distribution. At 150 days, the gaps in the muscle tissue increased; however, the gap in the -18 and -25 ℃ groups was markedly larger than that in the -45 ℃ group. The samples frozen at -45 ℃ had the lowest content of total volatile basic nitrogen (TVB-N) (7.96 mg/100 g) and carbonyl groups (30.60 nmol/mg prot), the highest values for water holding capcity (74.62%), total sulfhydryl content (0.36 mmol/g prot), and Ca2+-ATPase activity content (4.78 μmol/mg); these values were significantly better than those of samples frozen at -18 and -25 ℃ (P<0.05). Furthermore, as the duration of storage extended, the quality of Larimichthys polyactis at all temperatures changed; however, the samples frozenat the ultra-low temperature (-45 ℃) changed the least compared with those frozen at the other two temperatures. This result indicates that ultra-low temperatures can delay the deterioration of the quality of Larimichthys polyactis and more effectively maintain its edible value.

国家重点研发计划项目（2020YFD0900900）