Evening star., 1934-08-19
Pineapple Juice Aids Packers

ONE Of the problems Of fruit marketing
- how to prevent dscoloration Of fruits
when cut and prepared for market with the
skin broken-has been solved by Department
Of Agriculture research workers with a method
beneficial to the producer of the crop and the
producer of pineapples as WELL 1t has been
found that fruit sprayed with pineapple juice
will not discolor when cut and exposed to air.
DR.. A. K. Balls and Walter S. Hale of the
food research division, Bureau of Chemistry
and Soils, have found that apples will retain
their original color If Immediately after being
cut they are simply sprayed with pineapple
juice, by-product in the canning of pine
apples In other words, merely by putting two
agricultural products together the value Of
both commodities is increased. In agricultural
technology such combination Of circumstances
is rare. Usually an improvement in one direc-
ton Is a loss in another.
The department has applied for a public
service patent on the new process to make it
available free to all residents of the United
States.
For years commercial fruit driers have met
the "darkening" tendency Of fruits by treating
them with sulphur dioxide. The dried fruit
after "sulphuring" has q good color, but still
contains considerable sulphur dioxide This is
Objectionable to many consumers. Conse-
quently the dried fruit industry itself has
diligently searched for a satisfactory substitute
for sulphur dioxide.
Very little untreated dried apples pears and
apricotS are marketed. Slices of apple, for
example, If untreated, retain their original
color for only q few minutes and by the time
they have been left In the air long enough to
dry they are usually deep brown. This Is
serious loss, because such dark-colored products
are not received well on the market. It is
impossible to prepare from them an article
of food which even remotely resembles the
original fruit in respect to color.
What Mr. Hale and really set out to do"
DIR. Balls states was to find a method of pre-
venting discoloration Of cut fruit which could
displace the 'sulphuring process. We began
with a long and highly theoretical study of
the engine reactions which caused the dark
ening of the fruits. We succeeded in producing
these reactions in the test tube
"As a result, it seemed to us that several
classes of substances ought to possess the
property of inhibiting the discoloration. Most
of these were poisonous. However, one class
was without doubt harmless because it occurs
in many foods. This was the class Of sui
phydryl containing amino acids and peptides.
typified by glutathione and cysteine.
I'VE tried these substances ON q variety Of
apple which darkens especially fast when cut.
The substances did possess the predicted prop
erty. and to such an extent that only very small
amounts were necessary to inhibit completely
the darkening Of apples"
The application made by Balls and Hale was
very simple The sliced apples were sprayed
with q very dilute solution of the chemical
and then placed in q drier where they were
dried as in an apple drying plant.
'Glutath1one and cysteine are rather rare
although II there were any great demand for