The Richmond Virginian. (Richmond, Va.) 1910-1920, 1913-06-22
METALS |NJURE
BUTTER FLAVOR
CHEMICAL CHANGES WHICH CAUSE
DETERIORATION OFTEN ESCAPE
LABORATORY ARTIST.
HAVE MARKED EFFECT
EXPERIMENTS SHOW THAT BOTH
IRON AND COPPER WILL FLA
voR, WHICH GREATLY Les
SEN VALUE OF PRODUCT.

Economic conditions make II neces-
sary at present to hold butter in stor-
age from the summer season. when
III is plentiful, to the winter season,
when it is scarce. IL the butter Is
t property made this can be done with
out materially !njuring its quality. II
often occurs. however, that butter
which has been held in storage for
/ some months develops disagreeable
fiavors that greatly lessen its value.
These bad fiavors that will often pass
funnoticed when the butter is fresh
may become so serious a defect after
three or four months in storage as to
render the butter almost unstable.
The chemical changes which cause
these bad fiavors are often TOO small
to be detected by the ordinary ana
/ lytical methods of the laboratory, but
the senses OF smell and taste are far
more delicate, and as soon as bad
flavors are detected by them the value
of the product is lessened.
Some metals either cause or greatly
accelerate certain bad ffavors in but
ter. although most of the experiments
along this line have not included stor-
age buffers.
Recent Experiments.
Recently the scientific staff OF the
dairy division OF the bureau Of amin al
ment of agriculture has reported that
the presence of very small amounts of
iron in cream causes certain undesir-
able fiavors TO increase in intensity
during storage. These favors are
often designated by butter experts as
metallic" "oily" or "fishy." The in
furious effect OF iron was found by
adding iron in known quantities, vary
ing from l to 500 parts, to million
~ At,fr da fysnV
such cream was compared with that
made from cream where all precau-
tons were taken to avoid any undue
contact with iron during the whole
process Of butter making. The butter
was stored at s to 10 degrees Fahren-
heit, and the quality Of the butter was
scored by experts at different times.
In every instance when the butter
was scored few days after making
the samples to which iron had been
added scored lower than the butter
made from cream which contained no
iron. This held true In most cases on
the second and third scoring. which
occurred at intervals varying from
20 to 1877 days. The most noticeable
feature was the rapid development OF
bad flavor in the butter containing the
iron. When both the control and the
experimental butter became fishy II
was noticed that the control butter
was the last to become So. There was
a marked oily flavor present in most
samples that subsequently became
fishy. Only a small proportion OF
the iron added to the cream was
/ found in the butter. the remainder
having been taken up by the butter
milk and wash water.
The metallic" Taste.
Butter was also made from cream
which had stood in rusty cans. and
in every case this butter had a Pc
out from all other samples. The but
termilk also had a decided metallic
taste. -.
! The influence Of copper on the fla
vor OF butter was studied in a SINH
lar manner, and it was found that
copper even in small quantities.
seemed to cause more marked
changed Of flavor in butter than did
the iron, with a decided tendency to-
ward a fishy favor in storage. Two
experiments showed very plainly the
harmful effect Of using poorly timed
pasteurizers, even though the cream
came In contact with the copper sur
face for only few seconds, for aside
from this all other conditions were ex-
actiy alike during the complete pro-
cess of butter manufacture.
This work shows that II cream Is
kept in rusty cans or comes in contact
with iron or copper at any time dur
ing the process Of butter making II
may take up iron or copper from
rusty cans. exposed bolt heads OF
other metal parts of pasteurizers OF
churns In sufficient quantities to affect
the flavor OF storage butter. Though
there Is nothing to show that the ma
ture of the flavor is appreciably
changed. it does demonstrate very
clearly that the rate Of development
! of the undesirable flavor Ia greatly &C
| federated during storage by very small
quantities OF either iron or copper.