Evaluating the effect of lactic acid submersion on microbiological and organoleptic qualities of lamb carcasses

Lamb carcasses were used to evaluate the effectiveness of carcass submersion treatments in the reduction of microbial load, enhancement of carcass chilling rate, and minimization of carcass shrinkage, while maintaining acceptable organoleptic qualities of meat. The following 3 treatments of 4.7% (±0.3%) lactic acid (LA) solution were applied on lamb carcasses following standard dressing procedures: LA spray as the control (spray), LA spray and full carcass submersion (spray-submersion), and LA spray and full carcass submersion with agitation (spray-agitation), respectively. Each carcass was evaluated at 0 h pre-treatment (pre-trt), 1 h-, 24 h-, and, and 72 h- post-treatment stored at 2 oC (± 1 °C). Surface tissue pH and instrumental color were measured at each of the mentioned time-points. Microbiological samples for each carcass were evaluated at pre-trt, 1 h, and 72 h. Carcass weights (CW) were measured at pre-trt, 1 h, and 24 h. The following locations on the carcass were used as sampling sources on each carcass: foresaddle, hindsaddle, and internal body cavity (internal). At each sampling location, total aerobic bacteria (APC), coliforms (COL), and generic E. coli (EC) were enumerated. Internal carcass temperature was monitored immediately post-treatment and up to 24 h post-treatment to evaluate carcass chilling rate. EC and COL numerations exhibited complete elimination after 72 h when exposed to spray-submersion and spray-agitation interventions, while the carcass spray technique did not perform total elimination of the bacteria. APC populations experienced an average log reductions after 72 h for spray, spray-submersion, and spray-agitation treatments of 1.28, 1.75, and 2.50 log CFU/cm2, respectively. Treatment effect on surface tissue pH after 72 h of storage remained congruent among the treatments. Differences in internal carcass temperature within 24 h of storage were not detected across treatments. After 24 h of storage, spray-submersion and spray-agitation treated carcasses resulted in less carcass shrinkage as compared to spray treated carcasses. Lab* color values displayed comparable trend lines in which color values were affected 24 h after treatment exposure and restoration of color typically occurred after 72 h of storage; notwithstanding, differences of Lab* values among treatments and locations were detected at 72 h of storage. Hue angle on lean surfaces increased over time and were within the range of typical redness values in the ab quadrant for fresh meat among all treatments and locations. In addition, chroma lean values generally increased across time-point evaluations among treatments and locations. Although lamb carcass LA submersion was proven to be elemental in APC reduction and carcass shrinkage management, further studies should be conducted using inoculated beef carcasses to validate the treatment effectiveness in microbial log reduction and to ensure the preservation of meat quality characteristics.