Патент USA US2560013

Patented July 10, ‘1951
2,560,011
UNITED STATES PATENT OFFICE
2,560,011
1
RAW FISH TREATING PROCESS
Marcel Trudel, Montreal, Quebec, Canada
No Drawing. Application July 18, 1950,
Serial No. 174,571
11 Claims. (Cl. 99-2)
The present invention relates to a food pro
ducing process and more particularly to a ?sh
treating process for the production of ?sh meal.
Fish meal is commonly used as an animal and
poultry feed and also as manure.
According to one conventional method, ?sh
meal is prepared by simply dehydrating, pressing
and pulverizing the whole ?sh and/or ?sh waste
2
present invention, is the provision of a ?sh treat
ing process which will be applicable to fat ?sh
material such as mackerel, herring, sardines and
the like as well as to ?sh material having a low
concentration of fat such as cod, fresh water ?sh
and the like.
'
Still another important object, according to
the present invention, is the provision of a ?sh
and the like and preferably with the use of
treating process for the production of ?sh meal,
vacuum or centrifugal means.
10 resulting in a product which will be remarkably
According to another better method, the ?sh
non-hygroscopic, the humidity percentage of
material is steamed, pressed, dried and then
which remaining remarkably constant despite
pulverized to obtain the desired product.
humidity variations in the surrounding air.
The above mentioned processes are long and
Another important object of the present in
tedious and require expensive equipment. Fur 15 vention is the provision of a ?sh treating process
thermore, because no separation of the various
for the production of ?sh meal .which will per
constituents of the ?sh material is contemplated,
mit the easy separation of a number of valuable
valuable ?sh by-products are lost.
by-products such as ?sh glue, relatively pure
It has been found also, that ?sh meal, pro
protein, vitamins and others.
duced according to any of the above mentioned
Another important object of the present in
processes, is very hygroscopic because of the
vention is the provision of a ?sh treating process
presence of ?sh glue therein, which absorbs water.
for the production of a ?sh meal product having
Therefore, special precautions are necessary for
remarkable keeping qualities.
the handling of such a material.
Another important object of the present in
It has also been proposed to boil the ?sh in 25 vention is the pro-vision of a ?sh treating process
water prior to the pressing and drying opera
for the production of ?sh meal, which requires
tion in order to activate the disintegration of
a minimum of equipment and is not expensive
the ?sh. But when the ?sh is placed in warm
to carry out in practice.
‘
water and digested, a pasty product is obtained
Still another important object, according to
which is very hard to separate from the water, 30 the present invention, is the provision of a meth
thereby causing great waste of ?sh material.
od or process for the production of ?sh meal,
According to the process of the present inven
embodying the cooking of the ?sh prior to the
tion, the gelatin contained in the raw ?sh is
drying operation and characterised by adjust-7
separated along with other valuable materials
ment of the pH of the cooking solution.
from the ?sh ?bers which latter are then dried 35
The foregoing and other important objects of
and powdered for obtaining ?sh meal.
' the present invention will become more apparent
The above mentioned separation is e?ected by
during the following disclosure.
dissolving the gelatin or ?sh glue in acidi?ed
According to the invention, whole raw ?sh
water.
and/or raw ?sh waste and the like is placed in
According to the present invention, it has been 40 a substantially equal weight of water at a warnr
found that if the pH of the ?sh and water mix
temperature but below the boiling point of the
ture is suitably adjusted, upon digesting this
same, the pH of the water having been ‘previously
mixture at a relatively low temperature, the ?sh
adjusted within the pH range of 3 and 3.5 by the
is quickly disintegrated, the gelatin or ?sh glue
addition thereto of a water soluble acid in suit
going into solution, but at the same time the 45 able concentration.
?bers are not dissolved and remain in a substan
The mixture is then digested from half an hour
tially solid state in needle-like form without
or less to one hour or more between the tem
forming a milky or pasty product. It is thus a
peratures of 50° C. and 80° C.
simple matter to separate the solid residue from
This digestion causes the solution of the/gela
the solution and to dry said residue in order to 50 tin which is hydrolized into ?sh glue. The gela
obtain the ?sh meal according to the invention.
tin binds the ?bers of the ?sh together, there
Therefore the main object of the present in
fore said ?bers are set loose, but are not disinte
vention is the provision of a ?sh treating process
grated because low water temperatures are em-'
for the production of ?sh meal in a quick and
ployed and because the acid has a somewhat co
easy manner.
Still another important object, according to the
agulating action on the same.
After the digestion of the mixture, the same is
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4
3
?ltered over a relatively coarse mesh screen and
the collected solid residue is then very easily and
quickly pressed and dried and may thereafter be
pulverized by any known means. The resulting
dried product constitutes the ?sh meal according
to the invention.
It should be noted that the digested ?bers have
a needle like form which provides a very good
The ?sh meal obtained was white and ?brous
and very easily comminuted.
Example 2.—One pound of raw whole cod ?sh
was put in one pound of water at 90° C’. and previ
6 ously acidi?ed at a pH of 3.4 with 2.3 cc. or 0.5%
concentration of acetic acid relatively to the
weight of water, said solution being at 90° C.
.The resultant mixture was then digested for
three-quarters of an hour at 80° C. and then
?ltering mat easily separated from the water
without the use of centrifugal apparatus or the 10 poured over a screen resulting in the ?ltration of
'the ?bers of the ?sh. These ?bers were then
like.
:
. '
pressed and dried and thereafter comminuted
giving a white ?sh meal powder.
eration, contains a suspension of protein which
- ,- The protein in suspension in the ?ltrate
quickly settles out and therefore is easily sepa
rated from the liquid medium. This protein is 15 quickly settled down and was separated to give a
The liquid obtained during the?ltrating op
584% pure protein. Fish glue was also obtained.
very pure (98% and over) and constitutes a val
' Other experiments were similarly carried out
uable by-product of the process according to the
present invention.
using hydrochloric acid in a concentration of
_
0.02% relative to the weight of water and in
which case the ?sh quickly disintegrated but did
give a pasty product which was dii?cult to ?l
trate. Phosphoric acid was also used in another
experiment to the amount of 0.1 cc. per pound of
water giving the same results as the experiment
The screened or ?ltered waters also contain
?sh glue which may be easily separated. by vacu
um evaporation or other known means.
‘
'
When the ?sh material is relatively fatty, oil
is collected by decantation over the water and
?sh mixture after digestion of the same. Some
oil is also entrained with the screened water and
is separated from the same by decantation or
with hydrochloric acid.
'
Experimentation was also carried out on ?sh
waste giving ?sh meal containing 67% of pro
tein and 4% humidity.
The adjustment of the pH. of the water to be
Obviously, when using whole ?sh and/or ?sh
added to the ?sh material is preferably made
by the addition of an acid chosen from the group 30 waste, the solid residue collected on the screen
during the filtration or screening operations may
of the lower aliphatic acids and their isomers
be further passed in a selective screen such as a
which are soluble in water even if only in small
rotary screen of increasing wire mesh for sepa
concentration.
.
rating the ?sh bones from the ?sh ?bers there
Experimentation has also been carried out with
by giving a ?sh meal product of improved quality
mineral acids such as hydrochloric or phosphoric
that is containing a higher percentage of protein.
or like acids; they have been found to disinte
Experimentation was also carried out on
grate the ?sh very rapidly but to give a pasty
mackerel and herring and it was found out that
product which is difficult to ?lter, press and dry.
the fish oils were easily separated along with the
Moreover, the pure protein in the suspension
in the ?ltrate is more ?nely divided and is more 40 ?ltrate from the ?sh residue and was easily col
lected by'decantation.
difficult to separate. It has also been found that
In all cases it appears that the pH of the water
with these acids a lower percentage of water is
serving to the digestion of the ?sh must be ad
squeezed out of the wet ?sh cake prior to drying
justed between 3 and 3.5 for best results. Be
the same.
cause extremely good results have been obtained
Very good results have been obtained by acidi
with. acetic and formic acid, it appears that the
fying the water with formic acid or acetic acid;
lower aliphatic acids including pentanoic acid,
a white ?brous product results which is very easy
their isomers and their anhydride could be used
to manipulate during the ?ltering, pressing and
other means.
drying operations. Moreover, the pure protein
with comparably good results.
.
,
Apartfrom a considerably simpli?ed and fast
in suspension in the ?ltrate is very easily‘ sepa 50
procedure over existing methods, the present
rated.
process has the further advantage of providing
For best results, the pH of the water must be
valuable Icy-products which may be easily sepa
adjusted in the range 3-3.5, the following concen
rated from the ?ltrate and from one another.
trations of acid being preferably used: acetic
While examples of the ?sh treating process
55
acid: 03-05%; formic acid: 01-03%.
according to the present invention have been de
The following are illustrative examples of the
scribed, it is understood that various modi?ca
process according to the present invention.
tions may be resorted to without departing from
Example 1.-One pound of fresh cod ?sh was
mixed with one pound of water acidi?ed to a pH . the spirit and scope of the appended claims.
What I claim is:
I
I
.
of 3.1 with 0.5 cc. of formic acid (formic acid 60
1. A process for the production of ?sh meal
concentration 0.1% relatively to the weight of
from raw ?sh material containing gelatin, com
water). The mixture was heated at 70° C. for
prising the steps of adding water to the ?sh ma
half an hour and then screened and pressed
terial, adjusting the pH between 3.0 and 3.5
thereby obtaining 21 ozs. of ?ltrate and 8 ozs. of
65 digesting the resultant mixture at a temperature
wet ?sh cake.
between 50° and 80° C. ?ltering the solid residue.
The wet ?sh cake was then dried giving 3 ozs.
2. A process for the production of ?sh meal
of dried ?sh meal at 4% humidity or a yield of
from raw ?sh material containing gelatin, com
17% relatively to the weight of fresh ?sh.
prising the steps of adding to the ?sh material,
The ?ltrate carried a suspension of protein
which quickly settled down and was separated to 70 water containing a water soluble organic acid
selected from the group consisting of the lower
give a 0.4 yield of 98% pure protein; 6.5% of ?sh
aliphatic acids and their isomers, said acid being
soluble containing 53% of solid matter was also
present‘in such an amount as to have the pH
separated from the ?ltrate by vacuum evapora
tion.
This ?sh soluble gave a ?sh glue of very -
good quality.
lying between 3.0 and 3.5, digesting the resultant
15 mixture at a temperature between 50° and ‘80°C.
5
2,560,011
to dissolve said gelatin, and ?ltering the solid
residue.
3. A process for the production of ?sh meal
from raw ?sh material containing gelatin, com—
prising the steps of adding water to the fish ma
terial, adjusting the pH of the Water and ?sh
mixture by the addition thereto of a water solu
ble acid in the concentration between 0.01 and 1%
relatively to the weight of water, digesting the
resultant mixture at a temperature between 50° C. 4
and 80° C. until the gelatin is dissolved, ?ltering
and drying the solid residue.
4. A process for the production of dried ?sh
meal from raw ?sh material containing gelatin,
comprising the steps of adding water to the ?sh
material, the pH of the water being adjusted be
6
9. A process as claimed in claim 6, wherein the
acid is acetic acid.
10. A process for the production of dried
?sh meal from raw ?sh material containing gela
tin, comprising the steps of adding Water to the
?sh material in substantially equal weight, the pH
of said water having been previously adjusted by
the addition thereto of formic acid in a concen
tration comprised between 0.1 and 0.3 % ,- digest-v
ing the resultant ?sh and water mixture between
half an hour and one hour at a temperature corri-v
prised between 50° C. and 80° C., ?ltering, press
ing, drying and comminuting the solid residue.
11. A process for the production of dried ?sh
.. meal from raw ?sh material containing gelatin,
ble acid, digesting the resultant mixture between
comprising the steps of adding water to the ?sh
material in substantially equal weight, the pH of
said water having been previously adjusted by
half an hour and one hour at a temperature com
the addition thereto of acetic acid in a concen
tween 3.0 and 3.5 by the addition of a water solu
prised between 50° C. and 80° C., ?ltering and 20 tration comprised between 0.3 and 0.5%, digest
drying the solid residue.
ing the resultant mixture between half an hour
5. A process as claimed in claim 4 wherein the
and one hour at a temperature comprised between
acid is selected from the group of the water solu
50 and 80° C., ?ltering, pressing, drying and
ble lower aliphatic acids and their isomers.
comminuting the solid residue.
6. A process for the production of ?sh meal,
from raw ?sh material containing gelatin, com
MARCEL TRUDEL.
prising the steps of adding water to the ?sh ma
terial, the pH of the water being adjusted be
REFERENCES CITED
tween 3 and 3.5 by the addition thereto of a Wa
ter soluble organic acid, digesting the resultant “
?sh and water mixture at a temperature com
prised between 50° C. and 80° C. until the gelatin
is dissolved, and ?ltering and drying the solid
residue.
'7. A process as claimed in claim 6, wherein the .
acid is selected from the group comprising the
lower aliphatic acids and their isomers.
8. A process as claimed in claim 7, wherein the
acid is formic acid.
The following references are of record in the
?le of this patent:
UNITED STATES PATENTS
Number
Name
Date
1,550,268
2,193,871
2,403,174
2,406,249
Kramer _________ __ Aug. 18,
Hanno __________ __ Mar. 19,
Ernst _____________ __ July 2,
Pari‘entjev ______ __ Aug. 20,
1925
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1946
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