Growth prediction and time–temperature criteria model of Vibrio parahaemolyticus on traditional Korean raw crab marinated in soy sauce (ganjang-gejang) at different storage temperatures

Abstract

Vibrio parahaemolyticus is one of the most common causes of seafood-borne illnesses in South Korea and is typically found on traditional Korean raw crab marinated in soy sauce (ganjang-gejang). In this study, we investigated the growth of a cocktail of three V. parahaemolyticus strains (NCCP13712, NCCP13714, and NCCP14551) from ganjang-gejang stored at different temperatures (5 °C, 10 °C, 15 °C, 20 °C, 25 °C, and 30 °C) for up to 144 h. The growth data were fitted to a curve to estimate primary kinetic parameters including lag time (LT), specific growth rate (SGR), and maximum population density (MPD) using DMFit. The model performance was evaluated by calculating bias (Bf) (1.0002–1.0032) and accuracy (Af) (1.0226–1.0431). A secondary model of LT, SGR, and MPD was developed as the four-parameter polynomial model (all R2 = 1). Based on the developed predictive model, we established the time-temperature criteria (TTC) model for determining the time and temperature for ensuring microbiological food safety. According to the model, V. parahaemolyticus on ganjang-gejang increases about 1 log growth ratio (LGR) from the initial cell number after storage for 10.8, 5.2, and 4.7 h at 16 °C, 22 °C, and 28 °C, respectively. If 1 LGR is set as the food safety standard, these time and temperature values are recommended as the appropriate TTC values for V. parahaemolyticus on ganjang-gejang. Thus, the predictive TTC model can provide a guideline for safe storage parameters that ensure microbiological food safety in the context of certain foodborne pathogens.