 |
|
Title of Research:
Antimicrobial Intervention and Process Validation in Beef Jerky
Processing |
|
|
|
Place:
University of Georgia
Authors:
Drs. Mark A. Harrison, Rakesh K. Singh, Judy A. Harrison,
and Nepal Singh
Purpose:
To evaluate the use of a marination step, chemical
pretreatment, and drying procedures using either a dehydrator or
smokehouse as antimicrobial interventions and process validation in
beef jerky processing.
Summary:
Beef jerky strips were made using either a horizontal-flow
dehydrator or a commercial-type smokehouse (set at 33% relative
humidity) in combination with either acidified calcium sulfate (1:2
and 1:3 water:calcium sulfate ratios) or chlorine dioxide (500 and
1200 ppm) pretreatments to determine the effectiveness of the
treatments in the inactivation of Salmonella, E. coli
O157:H7, and Listeria monocytogenes on whole strip beef
jerky. Inoculated strips were marinated overnight in a marinade
containing water, salt, sugar, nitrite, garlic powder, sodium
erythrobate, MSG, Vinegar, Worchestershire sauce, and thyme before
drying.
Statistical analysis showed E. coli O157:H7 was reduced by
at least 5 logs cfu/strip for all the treatments except for jerky
pretreated with the lower concentration of chlorine dioxide and
dried in the dehydrator. For L. monocytogenes, 5 log
reductions were noted for all the treatments regardless of the
drying method. Salmonella was reduced by more than 6.5 logs
on jerky strips that were pretreated with the higher concentration
of acidified calcium sulfate and dried in the dehydrator and jerky
pretreated with the 1200 ppm concentration of chlorine dioxide ands
dried in the smokehouse. Populations were reduced almost as well on
jerky pretreated with calcium sulfate, both concentrations, and
dried in the smokehouse.
There was no statistical difference in the effectiveness of the
pretreatments in contributing to the reduction of E. coli
and L. monocytogenes, although it is possible to rank them
with the higher concentration of acidified calcium sulfate being
more effective and the lower concentration of chlorine dioxide being
least effective. For Salmonella, both concentrations of the
acidified calcium sulfate were the most effective in reducing the
populations while the lower concentrations of chlorine dioxide were
least effective.
Benefits:
This study is important in that it compared the effectiveness
between a smokehouse and dehydrator. Previous studies have used
either a smokehouse or dehydrator and did not compare the two.
Humidity has been identified as an important processing factor in
the manufacture of jerky products. While the humidity can be
measured and controlled in a smokehouse, the humidity in a
dehydrator in not easily controlled and is greatly affected by the
relative humidity in the surrounding atmosphere. While effective
treatments may be attained using a dehydrator coupled with an
antimicrobial pretreatment, processing jerky in the smokehouse with
similar temperature conditions was more effective. In general, the
acidified calcium sulfate was a more effective pretreatment than
chlorine dioxide. Small processors using dehydrators with little
control over maintaining consistent relative humidity conditions
within the drying chamber may find the use of antimicrobial
treatments beneficial in achieving the desired level of pathogen
reduction. This research should help minimize their operating cost
while helping them to ensure food safety and public health
protection. Plants will, however, need to validate that their
methodology achieves these parameters.
The full report on this research can be found on the Fiscal Year 2004 table under the column Food Safety Technologies - Additional Information.
|
|
|
|
|
|
