Effects of ionizing irradiation and hydrostatic pressure on Escherichia coli O157:H7 inactivation, chemical composition, and sensory acceptability of ground beef patties.

A randomized complete block design with three replications was utilized to determine the effects of ionizing irradiation and hydrostatic pressure on the inactivation of Escherichia coli O157:H7, volatile composition, and consumer acceptability (n=155) of frozen ground beef patties. E-beam and X-ray irradiation (2kGy) inactivated E. coli O157:H7 below the limit of detection, while hydrostatic pressure treatment (300mPa for 5min at 4°C) did not inactivate this pathogen. Solid-phase microextraction (SPME) was used to extract volatile compounds from treated ground beef patties. Irradiation and hydrostatic pressure altered the volatile composition (P<0.05) of the ground beef patties in respect to radiolytic products. However, results were inconclusive on whether these differences were great enough to use this method to differentiate between irradiated and non-irradiated samples in a commercial setting. Irradiation did not affect (P>0.05) consumer acceptability of ground beef patties when compared to untreated samples, but hydrostatic pressure caused decreased acceptability (P<0.05) when compared to other treatments.