MODELAGEM MATEMÁTICA DO CRESCIMENTO DE Brochothrix thermosphacta EM TAINHA VERMELHA EM DIFERENTES TEMPERATURAS

Abstract

The present study aimed to mathematically model the growth of Brochothrix thermosphacta in red mullet (Mullus barbatus) under different temperature conditions, in order to evaluate its effects on fish quality and preservation. This psychrotrophic bacterium, frequently associated with the spoilage of meat and fish products, has the ability to multiply even under refrigeration, leading to sensory and economic losses. The data were obtained from the ComBase database, considering temperatures of 0, 4, 10, 15, and 20 °C, with a fixed pH of 6.25. Growth parameters were fitted using the Baranyi and Roberts model, demonstrating a strong influence of temperature on microbial kinetics. The lag phase ranged from 32.37 h at 0 °C to 3.1 h at 20 °C, while the maximum growth rate (µmax) increased from 0.022 h⁻¹ at 0 °C to 0.199 h⁻¹ at 20 °C, with excellent model fitting (R² > 0.94). The maximum population (Ymax) remained relatively stable (6.18–5.89 log10 CFU/g), suggesting regulation by intrinsic factors of the food matrix. It can be concluded that refrigeration at 0–4 °C, although it does not prevent the growth of B. thermosphacta, significantly slows its multiplication, thereby extending the shelf life of fish. In contrast, temperatures above 10 °C accelerate spoilage. These results highlight the importance of strict cold chain control and demonstrate the applicability of predictive microbiology in risk assessment and in the development of preservation strategies for perishable foods.