Effect of gamma irradiation on inactivation of Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes on pistachios

This study evaluated the efficacy of gamma irradiation to inactivate foodborne pathogens on pistachios (Pistacia vera L.). Pistachios inoculated withEscherichia coli O157:H7,Salmonella Typhimurium andListeria monocytogenes were subjected to gamma irradiation in the range of 0, 0.5, 1, 3 and 5 kGy, and color change was evaluated after treatment and during storage at room temperature. Pathogen populations decreased with increasing treatment doses. A gamma irradiation dose of 5 kGy decreased the three pathogens on pistachios to under the detection limit (1.0 log CFU g−1) without effecting color change. During storage following treatment, pathogens were reduced due to the post irradiation effect. D ‐values of pathogens on pistachios showed thatL. monocytogenes was more resistant to gamma irradiation than wasE. coli O157:H7 orS. Typhimurium. During gamma irradiation treatment,L, a andb values of pistachios did not significantly change but these values changed during storage. These results show that gamma irradiation has potential as a non ‐thermal process for inactivating foodborne pathogens in pistachios without inducing color changes.This article is protected by copyright. All rights reserved.
Source: Letters in Applied Microbiology - Category: Microbiology Authors: Tags: Original Article Source Type: research