Recent Research Findings: Novel Antimicrobial Intervention for Beef Trimmings and Cheek Meat

Research funded by the Foundation through its fiscal year 2019 contract with the Beef Checkoff has recently been completed.  The study is pending publication.  However, the abstract follows:

Novel Antimicrobial Intervention for Beef Trimmings and Cheek Meat Using Radiant Catalytic Ionization (RCI) in Combination with Zinc Oxide Nanoparticles

N. Kalchayanand, T. L. Wheeler, and J. M. Bosilevac

USDA, ARS – U.S. Meat Animal Research Center

Several antimicrobial spray interventions for beef trimmings and offal products which are high priorities for improving safety and shelf-life are restricted by FSIS regulation of 0.5% limitation of retained water in raw beef after application of antimicrobials. Radiant catalytic ionization (RCI) treatment and zinc oxide nanoparticles (ZnO_NP) are novel technologies that can be applied as post-harvest interventions on surfaces of fresh meat to meet the needs for energy saving, non-thermal, and water conservation antimicrobial treatments. The objectives were to determine effectiveness of RCI, ZnO_NP, and a combined RZnO treatments on the reduction of Shiga toxin-producing Escherichia coli (STEC; O157 and non-O157) and Salmonella (AMR and non-AMR) inoculated fresh beef trimmings and cheek meat and to evaluate these technologies on improving shelf-life and their effect on meat quality. Beef flanks and cheeks were inoculated with cocktail mixtures of STEC strains (O26, O45, O103, O111, O121, O145, and O157:H7) and Salmonella. Inoculated fresh beef tissues were subjected to RCI for 0, 15, 30, 60, and 120 s and to ZnO_NP at 0, 1, 2, and 4 mg/ml and stored for 3 d at 4 ^oC. RCI reduced (P < 0.05) pathogens on surfaces of beef flanks and cheeks ranging from 0.50 to 1.69 log and 0.6 to 1.18 log, respectively. ZnO_NP at 1, 2, and 4 mg/ml produced the same (P > 0.05) reduction of pathogens both on beef flanks and cheeks. Estimated decimal reduction time (D values) for tested pathogens indicated that inactivation time of pathogens on cheeks was longer (P < 0.05) than on beef flanks. Beef flanks and cheeks were treated with a combination of RCI (150 s) and ZnO_NP (1 mg/ml) and stored at 4 ^oC for 21 d. The combination treatment increased shelf-life of beef flanks and cheeks 2 d and 1.5 d, respectively. The combination treatment had minimal effect on a* (20.83 versus 17.49) of beef flanks, but had no effect on a* (15.40 versus 14.20) of cheek meat. Rancidity of beef flanks and cheeks treated with a combination of RCI and ZnO_NP was undetected (TBARS < 1.0 mg MDA/kg of meat) during storage at 4 ^oC for 7d.