View report page

97
colour of preserved sultanas is due to the bleaching action of sulphur dioxide;
herring and tripe are bleached with hydrogen peroxide; sulphur dioxide has
been used to bleach ground ginger, pepper, pearl barley and starch. It might
seem that in order to get a white product it would be better to bleach pepper,flour,
etc., rather than grind a great deal of the goodness out of it, but there is
always the possible action of the bleaching agent on the vitamins and other
constituents to be considered. The present tendency appears to be to use the
bleaching agent and then to get rid of the excess before the product is marketed.
(See Pepper and Herrings in this Report.) Flour is either bleached or
"improved" by the use of such chemicals as nitrogen peroxide, chlorine,
nitrogen trichloride, benzoyl peroxide and potassium persulphate. Apart from
extraneous dirt, etc., the colour of flour is due to the presence of the vital food
factor carotene, which is yellow in colour, and the object of the bleaching is
to convert the yellow carotene into a colourless compound.
The "polishing" of rice removed the outer layer containing the vitamins
from the grain and caused disease in those countries where rice is the main
food. Polished rice is rarely met with, but pearl barley is still "faced" with
talc in order to improve its appearance.
Foods are often treated with fumigants of a noxious character. Recently,
unripe fruit has been exposed to certain gases in order to change the colour
of the skin from green to yellow and give the impression that the fruit is ripe.
The yellow colour of butter is an index of its vitamin content but this colour
can be imitated by the use of dyes.
143 samples of butter were examined. All the samples were genuine
and free from preservatives and prohibited dyes; 24 samples contained a
slight amount of artificial colouring matter.
Butter.
Two samples of condensed milk and one sample of dried milk were genuine
and free from preservative.
These samples complied with the requirements of the Condensed Milk and
Dried Milk Regulations respectively as regards percentage composition of
milk fat and milk solids, and each tin contained sufficient condensed or dried
milk to produce the number of pints of standard milk as stated on the label.
One sample of machine-skimmed condensed milk was slightly deficient in
total milk solids and the tin contained slightly less condensed milk than that
required to be equivalent to the number of ounces of standard skimmed milk
declared on the label.
Condensed
and Dried
Milk.