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121
alia, that ingredients used in the manufacture of ice-cream be
pasteurised by one or other of three specified methods, viz.:—
Method I. The mixture shall be raised to and kept at a temperature
of not less than 150°F. for at least 30
minutes.
Method II. The mixture shall be raised to and kept at a temperature
of not less than 160°F. for at least 10
minutes.
Method III. The mixture shall be raised to and kept at a temperature
of not less than 175 °F. for at least 15
seconds.
An alternative to pasteurisation is given, namely, sterilisation
and in this instance the mixture shall be raised to and kept at a
temperature of not less than 300 °F. for at least 2 seconds.
Subsequent to pasteurisation or sterilisation the mixture shall
be reduced to a temperature of not more than 45°F. within 1½ hours
and shall be kept at such a temperature until frozen, after which it
must be kept at a temperature not exceeding 28°F. up to the time
of sale.
Ice Cream Sampling. (Bacteriological Examination).—As in the
previous year the Council continued to make use of the Public
Health Laboratory Service as provided for under the National
Health Act and 60 samples were submitted for examination and
the ice-cream graded according to the Ministry's provisional
Grading Scheme. The grading is based on the results of the Methylene
Blue Reductase Test and a summary of this year's reports is
given below :—
Samples
taken
Time taken to Reduce
Methylene Blue
Provisional
Grade
Observations
29 4½ hours or more 1 Satisfactory
11 2½ to 4 hours 2 Sub-standard
14 ½ to 2 hours 3 Unsatisfactory
5 0 hours 4 Most Unsatisfactory
1 Ice-lolly Plate count and bacteria reports
showed this sample to be satisfactory.