London's Pulse: Medical Officer of Health reports 1848-1972

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Greenwich 1961

[Report of the Medical Officer of Health for Greenwich Borough]

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120
these Regulations, operative from 27th April, 1959 require, inter
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 1J 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 38 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 takenTime taken to Reduce Methylene BlueProvisional GradeObservations
10hours or more1Satisfactory
122½ to 4 hours2Sub-standard
6½ to 2 hours3Unsatisfactory
20 hours4Most Unsatisfactory
8Ice-lolliesPlate count and bacteria reports showed these samples to be satisfactory.

On receipt of a Grade 3 or 4 report it is the practice in this
Borough to obtain further samples from a vendor before administrative
action is taken. It was not necessary during the year to have
recourse to " administrative action."