J 2017

Growth potential of Yersinia enterocolitica in pasteurised cow's and goat's milk stored at 8 °C and 24 °C

BURSOVÁ, Šárka, Lenka NECIDOVÁ, Danka HARUŠTIAKOVÁ and Bohumíra JANŠTOVÁ

Basic information

Original name

Growth potential of Yersinia enterocolitica in pasteurised cow's and goat's milk stored at 8 °C and 24 °C

Authors

BURSOVÁ, Šárka (203 Czech Republic), Lenka NECIDOVÁ (203 Czech Republic), Danka HARUŠTIAKOVÁ (703 Slovakia, guarantor, belonging to the institution) and Bohumíra JANŠTOVÁ (203 Czech Republic)

Edition

Food Control, Oxford, Elsevier Science, 2017, 0956-7135

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

30308 Nutrition, Dietetics

Country of publisher

United Kingdom of Great Britain and Northern Ireland

Confidentiality degree

není předmětem státního či obchodního tajemství

Impact factor

Impact factor: 3.667

RIV identification code

RIV/00216224:14110/17:00096204

Organization unit

Faculty of Medicine

UT WoS

000405537400078

Keywords in English

Baranyi-Roberts model; Risk assessment; Foodborne pathogen

Tags

Tags

International impact, Reviewed
Změněno: 13/3/2018 19:33, Soňa Böhmová

Abstract

V originále

Milk and dairy products are among the most commonly consumed foods. The shelf life of pasteurised milk and many other dairy products is guaranteed, among others, when stored at 4–8 °C. These temperatures, however, will not prevent the growth of psychrotrophic bacteria, including some foodborne pathogens such as Yersinia enterocolitica. The study examines the growth potential of Y. enterocolitica in pasteurised cow's and goat's milk at different storage conditions (at a refrigerated temperature of 8 °C and an improper storage temperature of 24 °C). Y. enterocolitica growth dynamics was studied using a mathematical model for microbial growth. The behaviour of Y. enterocolitica depends on storage temperature and inoculum size and does not differ between cow's and goat's milk. The growth curve of Y. enterocolitica cultivated at 8 °C included the lag, exponential, and stationary phases. Both, the duration of the lag phase and growth rate did not differ between milk samples inoculated with the low (approximately 1 log cfu ml-1) or high (3 log cfu ml-1) inoculum size. The stationary phase was reached (with the peak number of the bacteria produced) within eight and six days with the low and high inoculum size, respectively. The growth of the bacteria at 24 °C was exponential from the first hour, peaking within two to three days or slightly later with the low inoculum size. The maximum cell concentration did not depend on inoculum size and cultivation temperature, reaching 9 log cfu ml-1 in all cases. Due to its composition and absence of competitive microflora, pasteurised milk provides a favourable environment for the growth of Y. enterocolitica. In case of contamination of pasteurised milk, even with a low amount of Y. enterocolitica, the bacterium multiplies to an infective dose within hours or days, depending on the storage temperature.