New-York tribune., 1905-06-25
DR.. w. d. Bigelows of the u.
S. Bureau of Chemistry,
Tells How to Detect It.

The present generation has seen a great in
crease in the number and diversity of prepared
foods that may be obtained the market
Many foods that were formerly prepared chiefly
entirely in the home may now be secured of
the grocer ready for the table A great burden
has thus been lifted from the shoulders of the
housewife, but her responsibilities have not been
lessaned. a study must be made Of the subject
of prepared foods if her table is to be supplied
with foods of the same quality as those that
mother used to make" Homemade Jellies
made from fruit juice and granuated sugar. ana
jams from the pulped fruit and sugar. Some
manufacturers aim to produce article that is
equal to the homemade in every respect. while
others supply the demand for cheaper goods by
using lower priced substitutes for the fruit
sugar. or both Thus apple juice, or solution
prepared from dried apple cores and peelings, is
Cften used where higher priced fruits are under
stood to be employed, and glucose is frequently
used in place of sugar
Jellies and jams are both commonly adul-
terated with preservatives usually salicylic
acid and benzoic acid), cooring matter and
glucose. Artificial coloring matter is frequently
employed sometimes to give fictitious appear
Gnce 10 relatively cheap goods. sometimes with
q high grade article. in order that the color may
be permanent when exposed to light for long
periods of time on grocers' shelves.
Natural fruit jellies become liquid on being
warmed. \ spoonful dissolves readily in warm
water although considerable time is required
with those that especially firm The small
fruits contain practically no starch. apples
do, and the presence of starch in jelly ndi
Gates that apple juice has been used in
it's preparation.
Starch may be detected as follows: Dissolve
a teaspoonful of jelly in half teacupful of hot
water. heat to boiling and add. drop by drop,
while stirring with teaspoon a solution OF
potassium permanganate until the solution Is
almost colorless Then allow the solution to
cool and add single drop of tincture of iodine
If starch is present clear blue color is pro-
Guced. Artifcally colored jelles are sometimes
not decolorized by potassium perInanganate.
Even without decolorizinS, however the blue
color can usually be seen. Both potassium per-
r1anganate and tincture of iodine cam OF course.
be secured at any drug store.
For the detection OF glucose. a teaspoonful of
the jelly may be dissolved in glass tumbler or
bottle in two or three tablespoonfus of water
The vessel in which the jelly is dissolved may
be placed in vessel of hot water if necessary to
hasten the solution. In jam MARINA
lade is being examined the mixture is filtered to
separate the tnsoluble matter The solution is
allowed to cool, and equal volume or a little
more, Of strong alcohol is added. II the sample
is pure fruit product the addition OF alcohol
causes no precipitation, except that very slight
amount OF proteid bodies is thrown down IF
glucose has been employed in its manufacture
however, dense white precipitate separates
and after a time settles to the bottom of the
LIQUID
In addition to the form of aduteration TO
which jellics are subject, jams are sometimes
manufactured from the exhausted fruit pulp left
after removing the juice for making Jelly When
this is done residues from different fruits are
sometimes mixed. Exhausted raspberry or
blackberry pulp Is sometimes used in making
strawberry JAM and vice versa, Some in
stances are reported of various small seeds being
used with jams made from seedless pulp.
With the aid OF n small magnfying glass
such forms Of adulteraton may he detected. the
observer familiarizins himself with the seeds OF
the ordinary fruits Many OF the artificial colors