2011 Annual Report
1a.Objectives (from AD-416)
The overall objective of the proposed project is to evaluate the efficacy of and feasibility of integration of several processing technologies (infrared radiation, electrolyzed (EO) water, a levulinic acid plus sodium dodecyl sulfate (SDS) sanitizer, germicidal UV light, and UV activated TiO2 photocatalysis treatment) into cattle slaughter establishments and meat processing facilities as multiple hurdles to inactivate Shiga toxin producing Escherichia coli and human Noroviruses on beef and non-intact beef products. The full proposal has a total of 11 objectives. The specific objectives that USMARC scientists will be involved in the completion of are:
Obj 1. Identify optimal treatment conditions EO water and levulinic acid with sodium dodecyl (LA-SDS) wash, IR heating, and radio frequency (RF) treatment for achieving greatest STEC and indicator microorganism reductions on beef carcasses.
Obj 2. Identify optimal treatment conditions for EO water and LA-SDS wash, IR heating, RF treatment, and UV irradiation for achieving greatest STEC and indicator microorganism reduction on non-intact beef products.
Obj 3. Evaluate the quality attributes of non-intact beef products subjected to the optimal treatments identified in Objective 2.
Obj 7. Working with our equipment partners to design prototype equipment for pilot plant testing based on research findings.
Obj 9. Working with our meat industry partners to conduct pilot plant testing on each technology individually and as a multi-hurdle and document the degree of inactivation of STEC, and indicator microorganisms as well as disruption on meat quality.
Obj 11. Refine technologies and equipment design based on the findings from Objective 8 for development of equipment for large, medium and small processors.
1b.Approach (from AD-416)
This proposal plans to evaluate six technologies individually and/or in combination for use in beef processing, fabrication, and RTE beef products (i.e., deli, food service). Inputs from an advisory committee of beef processors, equipment manufacturers, regulatory agencies, and beef organizations will be obtained throughout the 5-yr project period. Their comments will be integrated into application of the technologies ensuring adoptability by the beef industry. Results will be shared through extension and workshops, while economic feasibility and cost-benefit analysis will provide guidance on adopting the technologies for application. USMARC scientists will be part of this integrated collaboration and be involved in objectives listed above. Their approach to the experiments is as follows: Expts. will be conducted to reduce STEC and indicator microorganisms on hide and on beef carcasses using IR, RF, EO water, and LA-SDS treatment. These treatments will simulate interventions used during slaughter processing to reduce microorganisms on beef carcasses prior to further processing. Ten strains of STEC, five strains of Salmonella, and two non-pathogenic E. coli will be used in the study. Hide and fresh beef carcass will be inoculated with the organisms. The hide and beef carcass tissues will be subjected to IR heating, RF treatment, or spray-wash with acidified chlorine, lactic acid, EO water, or LA-SDS individually and/or in combination. The hides and each carcass tissue (lean or fat-excised aseptically) will be sampled before and after. All samples will be subjected to microbiological analysis consisting of enumeration and prevalence. Similar studies will be repeated using two different non-intact beef products. Beef loin will be used to simulate beef cuts used for needle tenderization, and beef trimmings will be used to simulate beef destined for ground beef. Beef loins and trimmings will be inoculated, and half of the inoculated trim will be immediately treated while the other half will be frozen then partially thawed before treatment. In addition to the above mentioned treatments, a UV irradiation device will also be tested. The treated cuts or trim will be sampled and subjected to microbiological analysis as described above. During these experiments, EO water and LA-SDS will also be evaluated for their efficacy after reuse for repeated applications. For frozen inoculated sample, effect of degree of thawing on treatment efficacy will also be studied. Non-inoculated subprimals beef loins and trimmings will be subjected to the optimal treatments identified from the outcomes of the first two objectives and treatment effects on sample quality evaluated. Three experiments will be performed to evaluate the four most optimal treatments identified in Objective 2 against a negative control for non-intact steak products and beef patties. In expt. 1, interventions will be applied immediately following fabrication and prior to aging. In expt. 2, interventions will be applied after aging, but before blade tenderization and steak cutting. Expt. 3 will simulate the application of interventions to beef trimmings before grinding.
FY2011 is the first year in this project's five year research plan. Electrolyzed water of varying pH, that is, acidic EO water, alkaline EO water, and slightly acidic EO water will be used as beef targeted washing interventions to reduce E. coli O157:H7 and representative non-O157 STEC. The test strains have been prepared and the source materials identified (hides from processing plant and pre-evisceration beef carcass flank tissues). Effects of various EO treatments at reducing pathogens will identify a hierarchy of the most to least effective treatments. The treatments will then be applied to beef cuts for color stability and initial sensory analysis and will be further evaluated as antimicrobials in Year 2 to identify the greatest antimicrobial effect that has the minimum impact on sensory analysis. UV treatments of pathogen-inoculated beef flank tissues have also been performed and it was determined that UV (at 254 nm) at different intensities has an effect in reducing E. coli O157:H7, Salmonella, and L. monocytogenes on surfaces of fresh meat. At certain wavelengths, UV light produces ozone, which enhances the antibacterial effect. Evaluation of effectiveness of UV and UV-ozone will be investigated as a non-thermal intervention of red meat.