But an FSIS official cautions against beingoverly optimistic until more data is compiled
Initial test results of the proposed steam vacuuming process to remove contamination from beef carcasses is showing a reduced number of microbes, as well as a visual improvement in the product.
However, an official from FSIS' Slaughter Inspection Standards and Procedures Division cautions against being overly optimistic.
"In the early data we have seen an improvement in removing visible contamination from carcasses," says Howard Early, who is overseeing the tests for FSIS. "[The data] looks positive. There has been an impressive drop in bacterial levels."
But Early notes that testing has only been done in a limited number of beef plants, most of which are owned by Dakota City, Neb.-based IBP inc.
Several smaller packers are also testing the steam vacuum process. In addition, Minneapolis-based Excel Corp. and Greeley, Colo.-based Monfort Inc. have begun testing.
"The only data we have thus far is from 11 plants owned by one company," he points out. "We cannot make judgments on the effectiveness of the process until we have data involving several plants and several companies."
After a plant tests the process for two weeks, FSIS performs a rapid evaluation of the data to determine if visible feces, ingesta, other contaminants and associated bacteria are being removed. The steam vacuum tests are immediately suspended in plants where data does not support continued testing.
The patented process, developed by Monrovia, Calif.-based Kentmaster Inc., was approved for commercial test trials by USDA in March. It involves a hot water spray in a vacuum nozzle, with steam sprayed above and below the vacuum head.
The industry hopes that the steam vacuum will eventually replace knife-trimming of visible contaminants as required by USDA's zero-tolerance policy for fecal matter.
"The data supports the hypothesis that under certain conditions, visible contaminants and associated bacteria can be removed at least as effectively by steam vacuuming as knife trimming," notes Michael R. Taylor, USDA undersecretary for Food Safety.
Attacking contamination
Steam vacuuming must occur in the pre-evisceration phase of slaughtering. It can be used only if a plant is operating under a quality control program designed to minimize contamination.
These are the parameters for steam vacuuming:
-- Water temperature must not be less than 185 degrees F.
-- Water pressure must be 10 psi to 20 psi, depending on water pattern extending beyond the nozzle.
-- Steam pressure must be 50 psi to 70 psi.
-- Knife trimming must be used if visible contamination remains.
The steam vacuum is used on either the hind leg or medial mid-line of the carcass where knife cuts are made through the hide.
The carcass surface is sampled using a Whirl-Pak Specie Sponge. The total aerobic plate count at 95 degrees F will be determined for each surface.
The surface area evaluated is the superficial tissue above the gracilis and semi-membrane anterior to the gambrel cord. The sponged area begins two inches from the anterior attachment of the gambrel cord and extends six inches (see illustration).
Each half-shift is divided into 15-minute increments, and a random timetable is used to select sampling times. Three numbers are selected for each half-shift to represent sample times. In double-shift plants, one carcass is sampled at each sample time. In single-shift plants, two carcasses are sampled at each sample time.
This results in three trimmed and three steam vacuum samples a shift, or six a day in double-shift plants, and six trimmed and steam vacuumed a day in single-shift plants.
The surface areas steam vacuumed and trimmed are evaluated for hide contaminants by measuring the presence of any fecal or ingesta in a length-width measurement, and counting unidentifiable specs and hairs.
The area evaluated is a six-by-four-inch wide area corresponding to the area sponge sampled. An FSIS quality control inspector is the evaluator.
FSIS' Early says that if results continue to be positive, the agency could begin the process of mandating the steam vacuum procedure in beef slaughtering plants by the end of the year.