Submitted to: Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 1/31/2014
Publication Date: 3/5/2014
Citation: Hasty, J., Henson, J., Acuff, G., Burson, D., Luchansky, J.B., Phebus, R., Porto Fett, A.C., Thippareddi, H. 2014. Improving the microbiological safety of veal: validation of hot water rinse plus lactic acid spray in combination with scalding for hide-on carcasses to control Shiga-toxin producing Escherichia coli (STEC). Meeting Abstract. Abstracts of the Annual Meating of the Beef Industry Food Safety Council. Interpretive Summary:
Technical Abstract: Bob veal calves (n=6) were assigned to six hide-on carcass treatments for each of 5 replications. Primary treatments were no-scald, scald, or scalding with chemical; secondary treatments were no-treatment control or lactic acid. Hides were inoculated with non-pathogenic rifampicin-resistant Escherichia coli (STEC surrogates). No-scald control carcasses were washed with 180F water prior to chilling. Hide-on carcasses receiving the scalding treatment were immersed in scald water or scald water containing scalding agents (water pH >11.0) at ca. 140F for 5 min in a hog scalder (no paddles applied). After scalding, carcasses were rinsed with =180F water, eviscerated, trimmed, rinsed with 180F water (final wash), and chilled. For the treatments receiving lactic acid, hides were sprayed with 4.5% lactic acid and chilled. Samples were collected after inoculation, scalding, first rinse, final rinse, lactic acid application, and 24-h chilling (total 200 cm2 hide area). Sponge samples were diluted with 0.1% peptone water containing rifampicin (100 ppm) and plated on Petrifilm APC. An E. coliRif inoculation level of ca. 6.9 log CFU/100 cm2 of hide was achieved (all microbial reductions reported on a log CFU/100 cm2 basis). For hide-on carcasses receiving no scalding treatments, spraying with 180F water as a final wash resulted in a 4.5-log reduction, and an additional 1.2-log reduction was achieved by subsequently spraying eviscerated carcasses with 4.5% lactic acid. A slight increase in E. coliRif population (0.4-0.6 log for no-scald carcasses with and without lactic acid, respectively) was observed after 24 h of chilling. Scalding hide-on carcasses (no chemicals) resulted in an immediate 2.1 log reduction, and a subsequent preevisceration 180F water rinse provided an additional 2.9 log reduction. Lactic acid sprayed onto scalded hide-on carcasses (after 180F rinse) resulted in a 0.4 log cycle further reduction. Adding scalding agents to the water resulted in a 4.1-log (1.9 logs greater than scalding without chemicals) reduction, and the first 180F wash provided an additional 2.5-log reduction. No additional reduction was observed after a final 180F water rinse and the population remained unchanged after chilling. Lactic acid spraying after scalding with agents and subsequent application of the two hot water washes resulted in undetectable counts (detection limit = 1.0 log CFU/100 cm2). With recent regulatory STEC considerations, the practice of bob veal hide-on chilling has decreased. A >5.0 log reduction of STEC surrogate levels can be achieved on hide-on bob veal carcasses using a 180F final water rinse in combination with a 4.5% lactic acid spray prior to chilling. Although scalding is customarily utilized by the pork industry to remove carcass hair, applying it to hide-on veal carcasses in combination with a final 180F water wash (prior to chilling) resulted in >6.0 log reduction of a STEC surrogate population. The availability of validated antimicrobial interventions will allow bob veal processors to weigh the quality and yield advantages of chilling carcasses with hide-on in relation to their overall food safety objectives.