title: Probabilistic Models to Predict the Growth Initiation Time for Pseudomonas spp. in Processed Meats Formulated with NaCl and NaNO2.
abstract: This study developed probabilistic models to determine the initiation time of growth of Pseudomonas spp. in combinations with NaNO2 and NaCl concentrations during storage at different temperatures. The combination of 8 NaCl concentrations (0, 0.25, 0.5, 0.75, 1, 1.25, 1.5, and 1.75%) and 9 NaNO2 concentrations (0, 15, 30, 45, 60, 75, 90, 105, and 120 ppm) were prepared in a nutrient broth. The medium was placed in the wells of 96-well microtiter plates, followed by inoculation of a five-strain mixture of Pseudomonas in each well. All microtiter plates were incubated at 4, 7, 10, 12, and 15℃ for 528, 504, 504, 360 and 144 h, respectively. Growth (growth initiation; GI) or no growth was then determined by turbidity every 24 h. These growth response data were analyzed by a logistic regression to produce growth/no growth interface of Pseudomonas spp. and to calculate GI time. NaCl and NaNO2 were significantly effective (p<0.05) on inhibiting Pseudomonas spp. growth when stored at 4-12℃. The developed model showed that at lower NaCl concentration, higher NaNO2 level was required to inhibit Pseudomonas growth at 4-12℃. However, at 15℃, there was no significant effect of NaCl and NaNO2. The model overestimated GI times by 58.2±17.5 to 79.4±11%. These results indicate that the probabilistic models developed in this study should be useful in calculating the GI times of Pseudomonas spp. in combination with NaCl and NaNO2 concentrations, considering the over-prediction percentage.
authors.affiliation: Department of Food and Nutrition, Sookmyung Women's University, Seoul 140-742, Korea.
authors.forename: Hyunji
authors.initials: H
authors.lastname: Jo
authors.affiliation: National Institute of Animal Science, RDA, Suwon 441-706, Korea.
authors.forename: Beomyoung
authors.initials: B
authors.lastname: Park
authors.affiliation: National Institute of Animal Science, RDA, Suwon 441-706, Korea.
authors.forename: Mihwa
authors.initials: M
authors.lastname: Oh
authors.affiliation: Department of Food and Nutrition, Sookmyung Women's University, Seoul 140-742, Korea.
authors.forename: Eunji
authors.initials: E
authors.lastname: Gwak
authors.affiliation: Department of Food and Nutrition, Sookmyung Women's University, Seoul 140-742, Korea.
authors.forename: Heeyoung
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Food and Nutrition, Sookmyung Women's University, Seoul 140-742, Korea.
authors.forename: Soomin
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Food and Nutrition, Sookmyung Women's University, Seoul 140-742, Korea.
authors.forename: Yohan
authors.initials: Y
authors.lastname: Yoon
keywords: NaCl; NaNO2; Pseudomonas aeruginosa; Pseudomonas fluorescens; processed meats