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Inactivation Kinetics of Vibrio Vulnificus in Phosphate‐Buffered Saline at Different Freezing and Storage Temperatures and Times
Author(s) -
Seminario Diana M.,
Balaban Murat O.,
Rodrick Gary
Publication year - 2011
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1750-3841.2010.02036.x
Subject(s) - vibrio vulnificus , congelation , kinetics , cold storage , chemistry , liquid nitrogen , food science , zoology , biology , bacteria , horticulture , physics , genetics , organic chemistry , quantum mechanics , thermodynamics
Vibrio vulnificus ( Vv ) is a pathogen that can be found in raw oysters. Freezing can reduce Vv and increase the shelf life of oysters. The objective of this study was to develop predictive inactivation kinetic models for pure cultures of Vv at different frozen storage temperatures and times. Vv was diluted in phosphate‐buffered saline (PBS) to obtain about 10 7 CFU/mL. Samples were frozen at −10, −35, and −80 °C (different freezing rates), and stored at different temperatures. Survival of Vv was followed after freezing and storage at −10 °C (0, 3, 6, and 9 d) and at −35 and −80 °C (every week for 6 wk). For every treatment, time–temperature data was obtained using thermocouples in blank vials. Predictive models were developed using first‐order, Weibull and Peleg inactivation kinetics. Different freezing temperatures did not significantly (α= 0.05) affect survival of Vv immediately after freezing. The combined effect of freezing and 1 wk frozen storage resulted in 1.5, 2.6, and 4.9 log10 reductions for samples stored at −80, −35, and −10 °C, respectively. Storage temperature was the critical parameter in survival of Vv . A modified Weibull model successfully predicted Vv survival during frozen storage: . N o and N t are initial and time t (d) survival counts, T is frozen storage temperature, Celsius degree. Practical Application: Vibrio vulnificus can be inactivated by freezing. Models to predict survival of V. vulnificus at different freezing temperatures and times were developed. This is the first step towards the prediction of V. vulnificus related safety of frozen oysters.