Combination of organic acids and low-dose gamma irradiation as antimicrobial treatment to inactivate Shiga toxin-producing Escherichia coli inoculated in beef trimmings: Lack of benefits in relation to single treatments

CAP, MARIANA; CINGOLANI, CELESTE; LIRES, CARLA; MOZGOVOJ, MARINA; SOTERAS, TRINIDAD; SUCARI, ADRIANA; GENTILUOMO, JIMENA; DESCALZO, ADRIANA; GRIGIONI, GABRIELA; SIGNORINI, MARCELO; HORAK, CELINA; VAUDAGNA, SERGIO; LEOTTA, GERARDO

PLOS ONE

PUBLIC LIBRARY SCIENCE

Año: 2020 vol. 15

1932-6203

The aim of this study was to assess the efficacy of lactic acid (LA), caprylic acid (CA), high- (HDI) and low- (LDI) dose gamma irradiation and LDI combined with LA or CA on the inactivation of a pool of Shiga toxin-producing Escherichia coli (STEC) strains inoculated on beef trimmings. The three most efficacious treatments were selected to study their effect on meat quality parameters and sensory attributes. The inoculum included five native STEC serogroups (O26, O103, O111, O145 and O157). The treatments applied were 0.5% LA, 0.04% CA, 0.5 kGy LDI, 2 kGy HDI, LDI+LA and LDI+CA. Beef trimmings were divided into two groups; one was inoculated with high (7 log CFU/g) and the other with low (1 log CFU/g) level of inoculum. Efficacy was assessed by estimating log reduction and reduction of stx- and eae-positive samples after enrichment, respectively. Results showed that treatments with organic acids were not effective in reducing STEC populations. The most effective treatment was HDI followed by LDI+LA, and LDI alone or combined with CA. Whereas LDI+LA modified significantly chromatic parameters and shear force compared with the control, HDI was more effective in preserving meat quality parameters than LDI+LA. As to sensory attributes, no off-flavors were detected in treated samples.