Aug- 21, 1951
c. H. KOQNZ Em
‘
2,565,311
EGG PASTEURIZATION
Filed June 2_, 1948
SHELLED WHOLE Eaas
HAsHlNa
./-10
V
‘FLASHOHEATQHHG
"114
1325 w 150 F
VAT PASTEURIZATION
125° To 145%
“~13
CH l LLING
40°10 55’F
/_l4
L.
PAcKAc-HNG AND
n15
FREEZING
L
r
FROZ as PASTEUR azs 0 Bass
1N VEN TOR8
.
?
'
Car/J6‘. Kooné,
_
‘Fé’iocyd ‘Lt, Kauffman
8y
-
A TI'ORNE 2/
Patented Aug. 21, 1951‘ , 1
2,565,311
UNITED STATES‘ PATENT OFFICE.‘
2,505,311
'
_
‘
.
EGG PASTEURIZATION
Carl B. Koonz and Floyd L. Kau?'man, Chicago,
IlL, assignors to Swift & Company, Chicago,
111., a corporation of Illinois
" V
-
Application June 2, 1948, Serial No. 30,605
5 Claims. (Cl. 119-161)
This invention relates to egg pasteurization
and, more particularly, to a process by, which
' fresh whole eggs are treated in a manner to
destroy bacteria therein.
.
'
The functions of pasteurizing eggs are gen-v
tive pasteurization temperature, is then trans
ferred to a vat for conducting the second step
of our process. The vat preferably has such a
capacity and suitable temperature controls so
that the product can be held for su?icient length
erally twofold. One is to improve the keeping
of time at the effective pasteurization tempera
ture to produce the desired pasteurization. For
destroyed during pasteurization; consequently,
example, we have found a, holding period of about
when the frozen pasteurized product is defrosted,
2 to 30 minutes at 125° F. to 145° F., and pref
it will show an improved keeping time in the 10 erably about 10 minutes at 140° F., to be satis
bake shop. The other function of pasteurization
is to kill or destroy bacteria organisms that are
Prior suggestions relative to vat pasteurization
potentially pathogenic.
of eggs have involved the slow heating of the
Heretofore, essentially two methods of pas
eggs after they have been introduced into a large
teurizing eggs have been used. One has been 15 container or vat, holding them at the elevated
called “vat pasteurization" which, if conducted
temperature for a substantial period of time, and
properly, will often kill sufficient of the bacteria
then cooling the eggs in the vat. Constant agi
to improve the keeping time in the bake shop
tation of the eggs in the vat has been required in
and will substantially destroy the pathogenic
‘an effort to uniformly heat the contents of the
organisms. Vat pasteurization, however, is not
vat. Despite the constant agitation, it has been
particularly suitable for handling a large volume
found impossible to prevent coagulation of a
of product in commercial practice. I The prod
substantial portion of the egg material due to
uct is often overheated, and the eggs frequently
local overheating. A layer of coagulated material
show evidence of undue coagulation. Also, the ' builds up on the walls of the vat or upon heat
time element involved in the type of operation 25 ing elements immersed in the vat since the tem
is unfavorable for large operations, as a consider
perature of the heated walls or heating elements
able length of time is required for ?lling the vat
must be substantially higher than the average
and heating the contents to pasteurization tem
temperature of the eggs in order to impart heat
peratures.
‘
to the contents of the vat. Such coagulated
The second method for pasteurizing eggs that 30 layers constitute heat insulation, further increas
I has been used is referred to as “?ashpasteuriza
ing the dif?culties of heating the egg material.
tion.” In accordance with this method a sum»
It is, therefore, an object of the present inven
cient number of bacteria are destroyed so that
tion to proivde an improved process of pasteuriz
the keeping time of the product in the bake shop ‘ ing eggs in which bacteria in the-eggs are sub
is de?nitely improved, but it is di?icult to hold 35 stantially destroyed without coagulation of the
eggs.
the product for a su?icient length of time at .the
pasteurizing temperatures employed (140° to
Another object of the invention is to provide
150° F.) to destroy the pathogenic bacteria. The
an improved process of pasteurizing eggs which
?ash pasteurization usually involves the use of
is especially effective in ‘killing su?‘icient num
a tubular type of heater, and attempts have been 40 bers of predominant ?ora in eggs to improve the
made to use a sufficient length of pipe to cause
keeping time in the bake shop and at the same
destruction of the pathogenic organisms. How
time to destroy substantially all of the pathogens
which may be present. .
ever, such equipment presents dimculties in han
dling large volumes of product.
The steps of the present process are indicated
In accordance with the present invention, the 45 in the attached drawing which is a schematic
egg material, which may be of a homogenous
flow sheet of the steps of the process.
mixture of a whole egg product, is subjected to
Referring to the drawing, whole eggs are
a two-step pasteurization process. In the ?rst
hashed or mixed, as indicated at l0, and are de
step, the product is rapidly heated or ?ash heated
livered to a ?ash-heating step, indicated by i l.
to around the pasteurization temperature: for 60 The apparatus employed in the ?ash-heating step
example, about 138° F. to 150° F. and preferably
may be any known or suitable device convention
approximately 140° F. This initial heating op
' ally employed for ?ash-heating operations. The
time in the bake shops. Most of the bacteria are
factory.
' eration is almost instantaneous, usually requiring
merely a matter ,of seconds. The homogenous
egg mixture, brought to at least _about an effec
'
.
‘
most satisfactory ?ash-heating apparatus for
eggs involves the spreading of the hashed eggs
as a thin layer upon a heated surface,’ followed
2,665,811
3 ,
6
While we have disclosed the preferred embodi
by rapid removal or the heated material from
the heated surface. Suitable devices for this
purpose are known in the art. Examples of such
devices are various types of plate heaters. Also,
ment or our invention. it is understood that the
details thereof may be varied within the scope
of the following claims.
We claim:
“Votators,”-such as shown in U. S. Patents Re.
1. The process of continuously pasteurizing
whole fresh eggs which comprises: ?ash heating
21,406; 1,783,865; 1,783,366; 1,847,149; 1,940,473;
1,965,618; 2,013,025; and 2,063,066, may be used.
a stream oi.’ hashed whole eggs to a temperature
Flash heating may also be accomplished by pump
between approximately 138° F. and 150° F. by
ing the material through pipe coils surrounded
by a heatingmedium, although heaters of the 10 passing the hashed eggs in a thin layer through
a heating zone, promptly subjecting the heated
eggs to a temperature between about 125° F. and
145° F., holding the eggs at the last-mentioned
temperature for about 2 to 30 minutes to substan
tially completely destroy bacteria contained in
said eggs, and thereafter promptly chilling said
“heated plate" or "Votator” type are preferred.
In such heating devices, the temperature of the
hashed eggs may be raised from room tempera
ture to about 138° F. to 150° F, in a short period
of time ranging from approximately 20 seconds
to 5 minutes, depending upon the particular de
vice employed, without increasing the tempera
eggs.
'
.
ture of any portion of the eggs substantially
2. A process of pasteurizing eggs which com
prises: passing a stream of the egg material in
above the temperature given above.
The heated material discharged from the heat 20 a thin layer through a heating zone wherein said
ing step is subjected to a. vat pasteurization step
egg material is ?ash heated to a pasteurizing
temperature of about l38°-l50° F. and thereafter
maintaining the heated eggs‘ at a pasteurizing
and held without agitation for the desired period
temperature of about 125°~l45° F. for about 2 to
of time. The walls of the vat or container may 25 30 minutes to destroy the predominant ?ora of
be heat insulated to prevent a drop in tempera
bacteria in the eggs.
3. A process of pasteurizing fresh eggs which
ture of the outer portions of the material there
comprises: subjecting egg material in a thin
in.‘ The period of time during which the eggs
layer to flash heating whereby the egg material
are held at a temperature between 125° F. and
as indicated at l3. In the vat pasteurization step,
the material is introduced into a vat or container
145° F. will depend upon the exact temperature 30 is raised to a ‘pasteurizing temperature about
selected but will usually range from approxi
138°~l50° F. in several seconds, maintaining the
‘
heated egg material at a pasteurizing tempera
The eggs which have been heat treated in the
ture of about 125°-l50° for several minutes to de‘—
vat pasteurization step 13 are withdrawn from
stroy the bulk of the bacteria in the eggs, and
the vat and chilled in any desired manner in a 35 promptly chilling the eggs.
mately 2 minutes to 30 minutes.
chilling step, indicated at I 4, to a temperature
4. A process substantiallyas described in claim
between approximately 40° F. and 55° F. in any
suitable type of apparatus, such as that discussed
3 in which the eggs are ?ash heated to about
140° F.
5. A process substantially as described in claim
3 in which the eggs, after ?ash heating, are main
tained at a pasteurizing temperature of about
140° F. for a period of about 10 minutes.
CARL H. KOONZ.
FLOYD L. KAUFFMAN.
above with respect to the heating step ii. The
material may then be introduced into a suitable
type of package, such as metal cans or waxed
paper cartons, after which the chilled material
may be frozen, the packaging and freezing steps
being indicated at 15. The frozen, pasteurized
eggs may then be marketed in frozen form.
45
REFERENCES CITED
The present invention has the advantage of
providing a simple and ef?cient method for pas
The following references are of record in the
teurization of large volumes of eggs. Also, the
?le of this patent:
method of the invention is substantially fool
UNITED STATES PATENTS
proof in that all portions of the egg are subjected 50
Number
Name '
Date
to uniform temperature treatment. The prod
Re. 19,898
Fousek __________ __ Mar. 24, 1936
uct of the present invention is substantially ster
i111; and yet is practically free of coagulated mate
r
l.
"
2,093,786
2,423,233
Swarthout ______ .... Sept. 21, 1937
Funk _____________ __ July 1, 1947