Each year, foodborne pathogens cause numerous
illnesses and deaths.
One particular group of bacterial pathogens
which causes concern are the shiga toxin-producing
E. coli or STEC.
These organisms can cause flu-like symptoms
that can range from mild to life-threatening.
Serious complications can arise such as hemolytic
uremic syndrome which can result in kidney
failure and death.
While STEC can be found in a number of food
borne sources, the USDA has declared 7 serotypes
adulterants when found in raw, non-intact
beef.
Beef processors have implemented food safety
and processing controls in order to reduce
the risk of STEC in their products.
In particular, control measures have been
taken for ground beef and non-intact beef
production.
These products require grinding, cubing, or
other tenderization methods which break the
surface of the meat and can redistribute STEC
within the product.
One control measure that can be used is the
application of organic acids, via dip method,
to beef subprimals to reduce the food safety
risk of STEC in finished product.
There has been considerable research on the
use and effectiveness of organic acids to
reduce the food safety risk of STEC in ground
and non-intact beef products.
This video is targeted at small business beef
processors who often are challenged to find
supporting documents to match the resources
of their operations.
For this reason, research by the University
of Nebraska-Lincoln has focused on identifying
application methods and organic acid options
that can be used in small operations.
This video will specifically address the application
of a lactic acid solution by a dipping method,
to beef subprimals.
Other organic acids and the appropriate supporting
documentation, for application, can be used
for the reduction of STEC.
It is very important that the critical parameters
used by the operation match those in the supporting
documentation.
Some common examples of critical parameters
include time of application, temperature of
the solution, application method, concentration
of the solution, and the type of acid used.
Product surface temperature may also be identified
as a critical parameter.
One note on the dipping method is, when compared
to a hand spraying method, a greater volume
of lactic acid will be used because larger
quantities of lactic acid solution may be
needed to ensure product coverage.
There are some general safety precautions
that must be taken when working with any organic
acids.
First, be sure to review the Safety Data Sheet,
or SDS, for the specific product you are using.
This can be obtained from the organic acid
supplier or manufacturer and may be available
on their website.
The SDS will include the specific Personal
Protective Equipment, or PPE, that should
be worn when working with the acid, any hazards
associated with the product including reactive
substances, and any special storage needs.
It is important to read the label on the product
and make sure it is appropriate for the intended
use.
Some general PPE that may be needed is a frock
or apron, chemical resistant gloves, and goggles
or a face shield.
Additionally, plant required safety equipment,
such as a hardhat and steel toed boots, should
be worn.
Be sure all items are clean and in good repair.
Follow all plant good manufacturing practices,
including hair net use and hand washing procedures,
before beginning.
Because we are working with acid, it is important
that equipment and supplies be made of corrosion
resistant materials, such as some food grade
plastics and stainless steel.
For the dip application of lactic acid, you
will need the following:
For the purposes of this video, we are using
88% lactic acid concentrate
A graduated cylinder will be needed for accurate
measurement of the lactic acid concentrate
A food grade container that can be used to
measure out and transfer the needed water
A food grade container that is large enough
to accommodate the amount of solution that
will be mixed AND the volume of product to
be dipped
You will need access to water of 70-75°F
To ensure the correct amount of water is used,
we will be weighing it and need a scale capable
for the necessary amount.
One gallon of water weighs 8.34 pounds at
70°F. The weight of a gallon of water will
vary slightly with temperature outside of
the range previously indicated.
A calibrated thermometer will be used to measure
the temperature of the water
The dilution chart for this product shows
the amount of 88% lactic acid needed to reach
the desired concentration in both ounces and
milliliters.
For the purpose of this video, we will be
using a graduated cylinder to measure milliliters.
A spoon, paddle, or other stirring device
will be needed for mixing the lactic acid
solution.
It should be long enough to reach the bottom
of the container.
Your acid supplier or manufacturer should
be able to supply a titration kit.
This will allow you to verify the concentration
of your solution before application.
This kit will include instructions for completing
the test, as well as a titration chart for
interpreting the results.
Finally, a clean work station will be needed
that allows excess lactic acid to drain from
the subprimals.
This can either be a table that allows drainage
or can be accomplished with elevated, food
grade racks over the table top, as you will
see later in this video.
The lactic acid solution should be mixed as
close to the time of use as possible.
Before adding water to the mixing vessel,
it is important to make sure it has reached
the proper temperature.
Allow the water to run for several seconds
before adding water to the container.
The water will be weighed to ensure the accuracy
of dilution.
Place the container used for water transport
on the scale and tare it.
Begin adding water until the desired weight
is reached.
We will be making 4 gallons of solution today
and need 33.36 pounds of water.
It is important to note that while adding
water, you will need to pause and allow the
scale to settle on a weight to be sure you
have enough water.
Once the appropriate amount of water is in
the container, use a calibrated thermometer
to make sure the water temperature is between
70 and 75°F.
We will use a clean container to reserve a
small amount of water for rinsing the graduated
cylinder after measuring lactic acid.
Pour the remaining weighed water into the
container that will be used for mixing and
dip application of lactic acid.
We are targeting 4.5% lactic acid solution.
As we can see on the dilution chart, that
requires 194 milliliters of 88% lactic acid
concentrate per gallon of water.
Very carefully, measure out the necessary
amount of 88% lactic acid concentrate into
the graduated cylinder.
Accuracy is important to ensure the correct
concentration of the lactic acid solution.
Because we are making 4 gallons of solution,
we will use a total of 776 milliliters of
88% lactic acid concentrate.
This is specific to the lactic acid we are
using so be sure to consult the dilution chart
for your acid.
The lactic acid can now be added to the water.
Adding water to the acid could cause the concentrated
lactic acid to splash and cause injury or
damage.
Use the reserved water from earlier to rinse
the graduated cylinder.
The concentrated lactic acid is thick and
may not pour completely so rinsing is important
to ensure all measured lactic acid is added
to the solution.
Add any remaining reserved water to the mixing
vessel.
Carefully, stir the solution.
Be sure to follow the specific instructions
that come with your titration kit as they
may vary by organic acid and supplier.
It is important to hold the reagent bottles
straight up and down to allow uniform drops
and prevent air bubbles.
Do not touch the tip of the dropper to the
test tube and add drops slowly to ensure an
accurate result.
The regulatory maximum concentration for lactic
acid is 5.0%.
We are targeting 4.5% to ensure we meet the
concentration identified in our research and
do not exceed the maximum regulatory concentration.
Adjust the solution with additional water
or 88% lactic acid concentrate as needed to
reach the desired concentration.
The final concentration of the dip solution
should be recorded and kept for production
records.
A document like this example can be used as
a running log for several production dates.
Using gloved hands, pick up an individual
subprimal.
Slowly, dip the subprimal into the lactic
acid solution until it is completely submerged.
It should remain in the solution for at least
15 seconds, based on our research.
After the specified amount of time, slowly
pull the product out of the lactic acid solution.
Make sure all areas of the subprimal are treated.
After dipping the subprimal, it should be
moved to a draining surface.
It is important that subprimals not sit in
a pool of lactic acid and be allowed to drain
until all excess or pooling is eliminated
from the meat surface.
This helps prevent over application of lactic
acid and possible quality defects from overexposure.
In our study, draining took approximately
60 seconds.
Repeat these steps until all subprimals have
been treated and drained.
During the dipping process, it is important
to monitor the lactic acid solution for excessive
blood, fat, or other material build up.
It may be necessary to mix a new batch of
solution in order to ensure the efficacy of
the lactic acid intervention.
Proper disposal will be determined by the
organic acid used, amount used, and local
regulations.
All equipment and utensils should be washed
thoroughly according to plant sanitation standard
operating procedures.
Rinsing before cleaning is very important
to remove any residual lactic acid and prevent
corrosion.
Organic acid interventions can be an effective
tool against the threat of E. coli O 1-5-7
and non-O 1-5-7 STEC.
Their use should be combined with good manufacturing
practices and sanitation procedures for the
most effective results.
This video has outlined a standard procedure
that can be used for the dip application of
lactic acid to beef subprimals.
Specifically, the procedure described here
can be used by small business beef processors
producing ground beef or non-intact beef.
A similar process may be used for applying
other approved organic acids, provided the
critical parameters are adjusted to match
the supporting documentation.
