View report page

Report of the Medical Officer of Health. 295
or amount of preservative permitted to be employed, but the
recommendation of the Departmental Committee on Food Preservatives,
1899, namely, "that the only Preservative permitted to be
used in butter and margarine be boric acid, or mixture of boric
acid and borax, to be used in proportions not exceeding 0.5 per
cent., expressed as boric acid," has met with general acceptance,
and is the standard adopted by the Public Analyst in forming a
judgment as to the "genuineness" of samples in this respect.
In regard to the choice of the fats and oils employed in the
making of margarine, the manufacturer has only one official
limitation (referred to above) imposed upon him, namely, that the
fat of the finished article must not contain more than 10 per cent,
butter fat.
The fats and oils usually employed are of both animal and
vegetable origin, their nature and proportion employed at any one
time depending to a large extent on market conditions. Among
the animal fats used at the present moment may be mentioned
neutral lard and "oleo" oil; and of the vegetable fats, coconut
and palm kernel oils, cotton-seed oil, sesame oil, earth-nut oil, and
soya-bean oil.
The following brief description affords a rough sketch of the
processes involved in the manufacture of margarine. At the
commencement of operations a suitable quantity of separated milk
is pasteurised, and then inoculated with a souring culture in receptacles
termed "souring tanks" This souring culture is usually
prepared in the bacteriological laboratory with great care, since the
"buttery" flavour of the finished article is dependent on this.
After ripening, the milk thus prepared is mixed with the desired
proportions of animal and vegetable fats and the whole churned,
and small proportions of casein and milk sugar—to provide the
"curd "—are also added.
Further processes convert the mixture into a solidified mass,
when it is removed in wooden wagons to the fermenting rooms
where the excess of water is allowed to drain off and the souring
culture in the milk allowed to develop and flavour the whole
preparation. When sufficiently "ripened" the mass is passed to
the kneading machines, where it loses all exces; of moisture and