Escherichia
coli O157:H7
Note: This is a pathogenic microbe that MAY jeopardize
cider safety.
One of several types of pathogenic E. coli found in animal
intestines. Unpasteurized apple cider has been associated with outbreaks
of food illness caused by pathogenic E. coli 0157:H7. The apples
used to make the cider were believed to have become contaminated with
cow manure either from grazing cows in the apple orchard or from the
use of cow manure as a fertilizer. Contamination of the apple cider
with E. coli resulted from improperly cleaning of the apples
prior to pressing the juice and/or cross contamination from the raw
apples to the finished apple cider. Studies on the survival of E.
coli 0157:H7 in unpasteurized apple cider with a pH between 3.6 and
4.0 have shown the organism to be acid tolerant. The use of sodium
benzoate 0.1% was shown to reduce the survival rate and have a preservative
effect.
CHARACTERISTICS
Extremely
acid tolerant (may survive 10 - 21 days in refrigerated apple
cider)
Very
low infective dose (<1000 cells)
Sodium
benzoate appears to be an effective additive for killing E. coli
O157:H7, but does NOT meet the FDA pathogen reduction requirements.
Not
exceptionally heat-resistant
ASSOCIATED ILLNESS(ES)
Causes 3 types of illnesses including:
- Hemorrhagic
colitis, primary symptom is grossly bloody diarrhea. Usually appears
2 - 3 days after organism is ingested.
- In some cases,
enough toxin is produced to impair kidney function and results in
Hemolytic Uremic Syndrome (HUS). Consequences of HUS are severe
and can include a lifelong need for kidney dialysis or death.
- In rare cases,
thrombotic thrombocytopenic purpura may occur. In this syndrome,
blood clots affect the brain. Death usually occurs.
KEY
STRATEGIES FOR CONTROLLING
Heat, pasteurization or UV treatment are effective at destroying this pathogen.
Do not use drop apples.
Do not use decayed or damaged apples (the pH of these apples can be high to enhance survival or growth of E. coli O157:H7.
See also GMPs
PASTEURIZATION
Currently, there are 3 Options Available:
- FDA
Standards for Milk: At least 161 degrees for at least
15 seconds
- Cornell
University Recommendation:
For cider containing less than half Red Delicious apples = at least
160 degrees F for at least 6 seconds. If cider is made from 50%
or more Red Delicious apples than the options are at least 160 degrees
F for at least 11 seconds or at least 170 degrees F for at least
2 seconds
- University
of Wisconsin Recommendation:
For typical Wisconsin cider blends, you can safely use at least
155 degrees F for at least 14 seconds
