Influence of temperature, pH and NaCl concentration on the maximal growth rate of Brochothrix thermosphacta and a bioprotective bacteria Lactococcus piscium CNCM I-4031

Autor: Françoise Leroi, Papa Abdoulaye Fall, Marie France Pilet, Frédérique Chevalier, Régis Baron
Přispěvatelé: Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), UMR 1014 SECurité des ALIments et Microbiologie, Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS), LUNAM Université [Nantes Angers Le Mans]
Rok vydání: 2012
Předmět:
Zdroj: Food Microbiology (0740-0020) (Academic Press Ltd-Elsevier Science Ltd), 2012-09, Vol. 31, N. 2, P. 222-228
Food Microbiology
Food Microbiology, Elsevier, 2012, 31 (2), pp.222-228. ⟨10.1016/j.fm.2012.02.014⟩
ISSN: 0740-0020
1095-9998
DOI: 10.1016/j.fm.2012.02.014
Popis: International audience; The maximum specific growth rate (mu(max)) of Brochothrix thermosphacta, a spoilage bacteria of cooked peeled shrimp, and Lactococcus piscium CNCM I-4031, a bioprotective strain, was investigated under different conditions of temperature, NaCl concentrations and pH. The basic modelling approach used was the Gamma concept (gamma-concept) and the model developed was then adapted to shrimp. Cardinal growth parameters were quite similar for the two strains, except for NaCl. No NaCl was required for growth and the NaClmax was three-times higher for B. thermosphacta than for L. piscium (62 and 23 g l(-1) respectively). However, tolerance to NaCl was higher in seafood than in liquid broth, possibly due to presence of osmoltically active molecules. L. piscium and B. thermosphacta were psychrotolerant, with T-min = -4.8 and -3.4 degrees C, T-opt = 23.4 and 27.0 degrees C and T-max = 27.2 and 30.8 degrees C respectively. The optimal pH was neutral and growth possible till pH = 4.8 for the two strains, assuming possible applications of the bioprotective strain in lightly marinated seafood. The mu(max) of B. thermosphacta in shrimp was a little higher than in L piscium whatever the environmental conditions. Validation of the model showed that the gamma-concept was suitable for predicting mu(max) of B. therm osphacta in shrimp. Data generated in this study can be used to adapt the model to other foods with few additional experiments and the effect of different parameters may be added in the future. The model was less accurate for the bioprotective strain and the effect of NaCl must be studied in more detail directly in the matrix. (C) 2012 Elsevier Ltd. All rights reserved.
Databáze: OpenAIRE
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