Death kinetics of E. coli 0157: H7, E. coli and natural contaminant coliforms in minced beef during irradiation treatment and storage

Kıymada 0.0 - 1.5 kGy arasında uygulanan ışınlama sonrasında ve -18 °C'da 30 güne kadar yapılan depolama sırasında Escherichia coli 0157:H7 ve E. coli tip 1'in ölüm kinetiği incelenmiştir. E. coli 0157:H7, E. coli tip l ve doğal kontaminant koliformların D10 değerleri sırasıyla, 0.245 kGy, 0.552 kGy ve 0.293 kGy olarak belirlenmiştir. Bulgular, 1.5 kGy ışınlamanın 105EMS/g 0157:H7 serotipi ve 103EMS/g E.coli tip 1'i inaktive ettiğini ve kıymanın güvenilir bir biçimde tüketilebilmesi için bu inaktivasyon değerinin yeterli olduğunu, E. coli tip 1'in, E.coli 0157:H7 için iyi bir ışınlama indikatörü olduğunu göstermiştir. Donmuş depolama boyunca bakteri sayılarında istatistik açıdan önemli bir değişme olmamıştır.

E. coli 0157:H7, E. coli ve doğal kontaminant koliformların kıymada ışınlama ve depolama sırasında ölüm kinetiği

The death kinetics of Escherichia coli0157:H7, E. coli type 1 and total conforms after irradiation treatment in minced beef were evaluated to analyze the effect of increasing irradiation doses. Irradiation doses ranging from 0.0 kGy to 1.5 kGy were evaluated for reducing numbers of E.coli during frozen storage conditions at -18 °C for 30 days. D10 values of E.coli0157:H7, E. coli type 1, and total coliforms were 0.245 kGy, 0.552 kGy and 0.293 kGy, respectively. An irradiation dose of 1.5 kGy was shown to inactivate 10sMPN/g of serotype 0157:H7and 103MPN/gof E.coli type 1. This inactivation level might be considered safe for the consumption of minced beef. Finally, E.coli type 1 was found to be a suitable indicator for assessing the impact of irradiation on E.coli 0157:H7 serotype. There was no significant change in numbers of bacteria during frozen storage.

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