EFFECTS OF ENHANCEMENT SOLUTION RECYCLING ON MICROBIOLOGICAL QUALITY OF BEEF STRIP LOINS

ABSTRACT

The objective of this study was to determine whether recycling of the enhancement solution would increase the microbial load in the solution and in enhanced steaks, and whether sodium lactate (SL) or a sodium lactate/diacetate mixture would counteract this microbial buildup. Strip loins were cut into 7.5-cm-thick strip steaks, then inoculated with 10⁴ cfu/mL Escherichia coli K12. Five steaks were injected to 110% over initial weight with each of three enhancement solutions: 0.4% salt + 0.4% phosphate (C; control), salt + phosphate + 3% SL or salt + phosphate + SL + 0.25% sodium diacetate. After injection, the enhancement solution runoff from the steaks was returned to the feed tank, and the injection process was repeated three more times recycling the solution each time. Total plate counts (TPCs) and coliform counts were determined on the enhancement solution runoff from the steaks, the enhancement solution in the feed tank and the enhanced steaks. Shelf life-enhancing ingredients had no inhibitory effects on the initial TPCs when compared with the control. The enhancement solution feed tank had significantly more total bacteria after each recycling round than during the previous recycling round.

PRACTICAL APPLICATIONS

Total plate counts (TPCs) in steaks were affected by both enhancement solution ingredients and by the number of times the enhancement solution was recycled. Steaks had higher TPCs after the solution had been recycled two or three times than prior to recycling or after the solution was recycled once. Steaks enhanced with the salt + phosphate (no shelf life enhancers) solution had higher TPCs than those enhanced with the solutions containing sodium lactate and sodium lactate/sodium diacetate. Using shelf life enhancers in enhancement solutions had positive effects on plate counts. Recycling, possibly because of microbial dilution, did not appear to result in buildup of microbes.