512 Modern Food Microbiology
Whenever two of four successive samples do not meet the standard, a fifth sample is tested;
and if this exceeds any standard, the permit from the health authority may be suspended.
It may be reinstated after compliance by four successive samples has been demonstrated.
B. Certified milk (American Association of Medical Milk Commissions, Inc.)
a. Certified milk (raw): Bacterial plate count not exceeding 10,000 colonies per milliliter;
coliform colony count not exceeding 10 per milliliter.
b. Certified milk (pasteurized): Bacterial plate count not exceeding 10,000 colonies per
milliliter before pasteurization and 500 per milliliter in route samples. Milk not exceeding
10 coliforms per milliliter before pasteurization and 1 coliform per milliliter in route
samples.
C. Milk for manufacturing and processing (USDA, 1955)
a. Class 1: Direct microscopic clump count (DMC) not over 200,000 per milliliter.
b. Class 2: DMC not over 3 million per milliliter.
c. Milk for Grade A dry milk products: must comply with requirements for Grade A raw
milk for pasteurization (see above).
D. Dry milk
a. Grade A dry milk products: at no time a standard plate count over 30,000 per gram, or
coliform count over 90 per gram (U.S. Public Health Service).
b. Standards of Agricultural Marketing Service (USDA):
(1) Instant nonfat: U.S. Extra Grade, a standard plate count not over 35,000 per gram, and
coliform count not over 90 per gram.
(2) Nonfat (roller or spray): U.S. Extra Grade, a standard plate count not over 50,000 per
gram; U.S. Standard Grade, not over 100,000 per gram
(3) Nonfat (roller or spray): Direct microscopic clump count not over 200 million per gram;
and must meet the requirements of U.S. Standard Guide. U.S. Extra Grade, such as used
for school lunches, has an upper limit of 75 million per gram.
c. Dried milk (International Dairy Federation proposed microbiological specifications,
1982).
Mesophilic count: n = 5, c = 2, m = 5 × 10
4 , M = 2 × 10
5
Coliforms: n = 5, c = 1, m = 10, M = 100
Salmonella: n = 15, c = 0, m = 0.
E. Frozen desserts
States and cities that have bacterial standards usually specify a maximal count of 50,000 to
100,000 per milliliter or gram. The U.S. Public Health Ordinance and Code sets the limit at
50,000 and recommends bacteriological standards for cream and milk used as ingredients.
Few localities have coliform standards.
5. Standard for Tomato Juice and Tomato Products—Mold-count Tolerances (Food and Drug
Administration)
The percentage of positive fields tolerated is 2% for tomato juice and 40% for other comminuted
tomato products, such as catsup, pur´ ee, paste, and so forth. A microscopic field is considered
positive when an aggregate length of not more than three mold filaments present exceeds onesixth of the diameter of the field (Howard mold count method). This method has also been applied
to raw and frozen fruits of various kinds, especially berries.
Other Criteria/Guidelines
1. Sampling plans and microbiological limits for nine products as recommended by ICMSF
8 are
presented in Table 21–3 (for an explanation of plan stringency or case, see Table 21–4). The
Whenever two of four successive samples do not meet the standard, a fifth sample is tested;
and if this exceeds any standard, the permit from the health authority may be suspended.
It may be reinstated after compliance by four successive samples has been demonstrated.
B. Certified milk (American Association of Medical Milk Commissions, Inc.)
a. Certified milk (raw): Bacterial plate count not exceeding 10,000 colonies per milliliter;
coliform colony count not exceeding 10 per milliliter.
b. Certified milk (pasteurized): Bacterial plate count not exceeding 10,000 colonies per
milliliter before pasteurization and 500 per milliliter in route samples. Milk not exceeding
10 coliforms per milliliter before pasteurization and 1 coliform per milliliter in route
samples.
C. Milk for manufacturing and processing (USDA, 1955)
a. Class 1: Direct microscopic clump count (DMC) not over 200,000 per milliliter.
b. Class 2: DMC not over 3 million per milliliter.
c. Milk for Grade A dry milk products: must comply with requirements for Grade A raw
milk for pasteurization (see above).
D. Dry milk
a. Grade A dry milk products: at no time a standard plate count over 30,000 per gram, or
coliform count over 90 per gram (U.S. Public Health Service).
b. Standards of Agricultural Marketing Service (USDA):
(1) Instant nonfat: U.S. Extra Grade, a standard plate count not over 35,000 per gram, and
coliform count not over 90 per gram.
(2) Nonfat (roller or spray): U.S. Extra Grade, a standard plate count not over 50,000 per
gram; U.S. Standard Grade, not over 100,000 per gram
(3) Nonfat (roller or spray): Direct microscopic clump count not over 200 million per gram;
and must meet the requirements of U.S. Standard Guide. U.S. Extra Grade, such as used
for school lunches, has an upper limit of 75 million per gram.
c. Dried milk (International Dairy Federation proposed microbiological specifications,
1982).
Mesophilic count: n = 5, c = 2, m = 5 × 10
4 , M = 2 × 10
5
Coliforms: n = 5, c = 1, m = 10, M = 100
Salmonella: n = 15, c = 0, m = 0.
E. Frozen desserts
States and cities that have bacterial standards usually specify a maximal count of 50,000 to
100,000 per milliliter or gram. The U.S. Public Health Ordinance and Code sets the limit at
50,000 and recommends bacteriological standards for cream and milk used as ingredients.
Few localities have coliform standards.
5. Standard for Tomato Juice and Tomato Products—Mold-count Tolerances (Food and Drug
Administration)
The percentage of positive fields tolerated is 2% for tomato juice and 40% for other comminuted
tomato products, such as catsup, pur´ ee, paste, and so forth. A microscopic field is considered
positive when an aggregate length of not more than three mold filaments present exceeds onesixth of the diameter of the field (Howard mold count method). This method has also been applied
to raw and frozen fruits of various kinds, especially berries.
Other Criteria/Guidelines
1. Sampling plans and microbiological limits for nine products as recommended by ICMSF
8 are
presented in Table 21–3 (for an explanation of plan stringency or case, see Table 21–4). The