#07-195

Complete

Date Full Report Received

05/29/2009

Date Abstract Report Received

05/29/2009

Investigation

Institution:
Primary Investigator:

To eliminate occurrences of pathogens in fresh or further processed pork products, coupled with the increased consumer demand for fresh, minimally processed foods, non-thermal technologies for pathogen reduction, such as ultrasonics, have been emerging. It was hypothesized that ultrasound could be used to decontaminate surfaces of raw and ready-to-eat pork products in order to reduce contamination and improve the microbiological safety of the food supply. The objectives of the study were to apply ultrasound technology to reduce microbial loads, enhance product quality, and extend shelf life of fresh and ready-to-eat pork products and to determine consumer acceptability of ultrasound-treated pork products and feasibility of using the technology in commercial pork processing operations. After a series of experiments with ultrasound demonstrated significant reductions in pathogens when suspended in buffers, experiments were performed with experimentally inoculated and vacuum packaged chops and ham slices. Vacuum packaged meats were used in subsequent experiments to simulate commercially processed products and to prevent the spread/aerosolization of pathogens during experiments. For the latter experiments, several different contact and non-contact ultrasound systems were identified, constructed, and/or evaluated. Despite observations of ultrasound activity and surface changes to the fresh pork surfaces, it does not appear that either contact or non-contact ultrasound under the conditions examined in this project can penetrate the 2 mil vacuum packaging materials and reduce pathogens (L. monocytogenes and S. Typhimurium) associated with the surface of the ham steaks or pork chops. Based on these findings, other non-thermal technologies (e.g. irradiation) may be better suited for controlling pathogens associated with packaged ready-to-eat and fresh pork products than ultrasound under the conditions described. Since we were not able to afford any reduction in the pathogens using ultrasound, and therefore could not demonstrate efficacy, no consumer sensory studies were conducted in this study.