This study aimed to assess the growth of spp. and psychrotrophic bacteria in chilled Pacu (), a native South American fish, stored under chilling conditions (0 to 10 °C) through the use of predictive models under isothermal and non-isothermal conditions. Growth kinetic parameters, maximum growth rate (μ 1/h), lag time (t h), and (N Log CFU/g) were estimated using the Baranyi and Roberts microbial growth model. Both kinetic parameters, growth rate and lag time, were significantly influenced by temperature (P < 0.05). The square root secondary model was used to describe the bacteria growth as a function of temperature. Secondary models, √μ = 0.016 (T + 10.13) and √μ =0.017 (T + 9.91) presented a linear correlation with R values >0.97 and were further validated under non-isothermal conditions. The model's performance was considered acceptable to predict the growth of spp. and psychrotrophic bacteria in refrigerated Pacu fillets with bias and accuracy factors between 1.24 and 1.49 (fail-safe) and 1.45–1.49, respectively. Fish biomarkers and spoilage indicators were assessed during storage at 0, 4, and 10 °C. Volatile organic compounds, VOCs (1-hexanol, nonanal, octenol, and indicators 2-ethyl-1-hexanol) showed different behavior with storage time (P > 0.05). H NMR analysis confirmed increased enzymatic and microbial activity in Pacu fillets stored at 10 °C compared to 0 °C. The developed and validated models obtained in this study can be used as a tool for decision-making on the shelf-life and quality of refrigerated Pacu fillets stored under dynamic conditions from 0 to 10 °C.

中文翻译：

---

冷冻 Pacu (Piaractus mesopotamicus) 鱼片：模拟假单胞菌属 (Pseudomonas spp.) 和耐冷细菌的生长，并在储存期间通过 1H NMR 和 GC-MS 监测腐败指标

本研究旨在评估 spp 的生长。通过使用等温和非等温条件下的预测模型，研究了冷藏 Pacu（一种南美本土鱼类）中的耐冷细菌，该鱼类在冷藏条件（0 至 10 °C）下储存。使用 Baranyi 和 Roberts 微生物生长模型估算生长动力学参数、最大生长速率 (μ 1/h)、滞后时间 (th) 和 (N Log CFU/g)。生长速率和滞后时间这两个动力学参数均受温度影响显着（P < 0.05）。平方根二次模型用于描述细菌生长随温度的变化。二级模型 √μ = 0.016 (T + 10.13) 和 √μ =0.017 (T + 9.91) 与 R 值 >0.97 呈线性相关，并在非等温条件下得到进一步验证。该模型的性能被认为可以用来预测 spp 的生长。冷藏 Pacu 鱼片中的耐冷细菌和耐冷细菌，偏差和准确度系数分别在 1.24 和 1.49（自动防故障）和 1.45–1.49 之间。在 0°C、4°C 和 10°C 储存期间评估鱼类生物标志物和腐败指标。挥发性有机化合物、VOC（1-己醇、壬醛、辛烯醇和指示剂2-乙基-1-己醇）随着储存时间的变化表现出不同的行为（P > 0.05）。H NMR 分析证实，与 0 °C 相比，10 °C 下储存的 Pacu 鱼片的酶活性和微生物活性有所增加。本研究中获得的开发和验证模型可用作在 0 至 10 °C 动态条件下储存的冷藏 Pacu 鱼片的保质期和质量决策工具。