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50
Registered Artificial Cream Premises.
(At present dealing in Synthetic Cream).
Number of visits—1.
ICE CREAM.
Ice Cream (Heat Treatment) Regulations, 1947.
Ice Cream (Heat Treatment) Amendment Regulations, 1948.
Supervision of the Manufacture of Ice Cream.
Ice cream is a food which is now commonly manufactured and sold throughout
the year, although naturally the summer sale is greater than the winter sale. Certain
examinations are customarily carried out which give some indication of the probable
bacteriological risks of the ice cream, but unfortunately it has not so far been found
practicable to propose statutory standards of bacteriological purity, and the
examinations done carry no statutory authority. It will be noted from the report
to follow that 92 premises in Islington are registered under the Food & Drugs Act,
1938, for the manufacture/sale/storage of ice cream. Some of these manufacturers
make considerable quantities and sell only through distributors or to retail concerns.
Ice cream, therefore, contaminated at the manufacturing end might in the case of
a large firm have a widespread distribution and sampling might be done and an
unsatisfactory result first obtained in the area of the local authority where the
retail sale took place and not in the area of manufacture.
In the manufacture of ice cream on a large scale, highly specialised and
expensive machinery and equipment is essential. The Ice Cream (Heat Treatment)
Regulations, 1947, require that subject to certain qualifications the ingredients of
ice cream shall be heat treated after being mixed, and that the mixture shall then be
cooled until the freezing process is begun. The heat treatment requirements are
very specific, and the effect is similar to that produced by the pasteurisation of milk.
However, bacteria might be introduced after heat treatment, and if this is the case
then the final product would be bacteriologically contaminated.
It is not always obvious where contamination occurs, particularly where the
equipment is up-to-date, the premises appear very suitable and the handling of the
material appears to be reasonably careful. In one instance where it was necessary
to investigate the ice cream production of a firm manufacturing large quantities,
these requirements were fulfilled and yet unsatisfactory samples were obtained.
Investigations were carried out with the full co-operation of the management and
staff of the firm concerned, and bacteriological examinations were carried out by the
Central Public Health Laboratory.
It was found necessary to sample the mixture at 15 different stages of manufacture,
from the initial mixing to the final product in the carton. Members of the
staff also agreed to have their hands swabbed for detection of any organisms which
might have been found in the ice cream. As a result of these examinations, it was
found that there was a limited degree of contamination in a holder known as the
" ageing vat " in which the ice cream is held for a time while cooling and prior to
its being pumped through to be made into ice cream blocks or filled into cartons.
It is a difficult task to cleanse thoroughly all machinery in a large plant such as this.
After manufacture all holders, pipes, connections, etc. must be dismantled and
washed or rinsed through with disinfectant solutions, after being cleansed. In this