CA1044509A - Process for pasteurizing raw poultry - Google Patents

Abstract

PROCESS FOR PASTEURIZING RAW POULTRY

ABSTRACT OF THE DISCLOSURE
A process for treating raw poultry to pasteur-ize the surface thereof by dipping the poultry in oil having a temperature from 180-315°F. for a period of from 0 to 60 seconds to reduce the surface bacteria without materially affecting the natural bloom of the poultry.

Description

1C~4~509 This invention relates to a process for treating raw poultry to pasteuri~e it, and more particularly to ~ such a process which avoids heating the poultry internally --~ and which leaves the poultry with the natural appearance of , ;~
raw poultry.
BACKGROUND
'~ For many years there has been interest on the part ;, of governmental agencies and also consumers in the bacterial contamination of poultry and there has been a need for some ~-10 way of controlling the microbial flora on the surface of the poultry without impairing the appearance, flavor and other ~-~ quality attributes of the poultry.
-~ The poultry may be heated in water to the degree :
that heat penetrates at least through the skin and this does -~
~ reduce the bacterial flora on the skin, but it also results ,.`tj~ in a changed appearance The skin looses its natural bloom, becomes a grey color and has a "cooked" appearance.
" Attempts have also been made to treat the surface ;~ ~ of the poultry with chemicalsolutions at below cooking tem- -20 peratures, and in some instances limited success has been achieved, but such methods are open to the criticism that the chemical may be absorbed into the poultry and in itself be a source of contamlnation.
~- SUMMARY
~ - I have discovered that by dipping the poultry i ~ carcass in an edible oil which has been heated to a tempera-ture of from 180 to 315F. for a very short period of time, from 10 to ~0 seconds, the bactexia on the surface of the poultry can be materially reduced. This treatment increases 30 shelf life while at the same time leaving the poultry with a ~tural raw appearance with good bloom. I am surp~ised that ~: ' ` ' I
~ such a result is obtained by the oil treatment especially ;~'.`il ' :~ cb/
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~.. , ,' , , S~J9 since such a treatment with water gives either unqatisfactory pasteurizatiOn or a cooked appearance, depending on the tempera-tures used.

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DESCRIPTION
The treatment of this invention applies to poultry generally, but rnore especially to turkeys and chickens which arè produced in large numbers. The poultry is slaughtered and the feathers and entrails removed~ This carcass, with its skin still on, may then be treated in accordance with my ~;
invention by hand dipping the carcass in the heated oil, but preferably the process is carried out by attaching the~carcass by its feet to a conveyor chain and arranging a vat of hot ~-~ ^ , oil through which the carcass is passed as the conveyor chain moves forwardly, the speed of the conveyor~being such that the carcass remains immersed for the period of time prescribed.
The process may also be carried out by placing poultry carcasses in a wire basket and immersing the basket into hot fat in a suitable container. After the prescribed period of time the basket is removed from the fat the poultry drained, :
chilled and sent on its way 1n the usual packing operation~
The.fat~in~which the poultry is immersed may be any animal or vegetable oil or~any edible triglyceride which is liquid~at~a tempernture of about 150F~ For example, I
may use corn oil, cottonseed~oil, soya oil, lard, or mixtures of natural or synthetic triglycerides.
The oil may be placed in a suitable container and heated to a temperature of from 180F~. to 315F., and this ~ temperature maintained during the treatment of the poultry~
;~ The poultry is then immersed in a heated oil as above explain-ed and left immersed for a period of from lO to 60 seconds at which time it is remoYed f~om the oil. After the excess oil drains from the carcass it may be packed in accordance with usual practices and passed into marketing channels.

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The tcm~ratures and times just mentioned are ~;
critica] to thc success of the treatment. If the temperature of the fat is too low and/or the time of immersion too low, the pasteurization of the-surface of the poultry will be in~
adequate, and if the temperature of the fat is too high and/or the time of immersion is too great the treated poultry will appear to be "cooked" and the natural bloo~ of the raw poultry will be lost. It may also be understood that somewhat greater immersion times may be coupled with low~r temperatures and 10 lower immersion times with higher temperatures, within the ~-ranges specified.
I find that better results are obtained when the poultry to be treated is chilled to a temperature within ~ -the range of about 32 to 42F. before it is subjected to immersion in the fat. Chilling the poultry permits surface ~ -: .
heating without substantially raising the temperature of the caracas or the part which is being treated. The treated poultry may then be packaged for shipment without further chilling and while avoiding recontamination.
~;20 In the usual practice of my inyention the carcasses, ~ ~ .
after the dipping treatment, are drained of excess fat and packaged, chilled and marketed. If desired, the carcasses may be frozen, either~before~or after the treatment in hot oil.
The benefits from the improved process appear to flow principally from the lower bacteria count on the skin surface o the poultry. I find that this count is very dramatically reduced by the fat treatment, and this may be a reduction from a count of about 10,000 without the treat- ~ -ment to a count of about 40 with the fat treatment, a reduction of about 99~. At the same time the txeated poult~y retains ~ts natural bloom and appearance and has increased shelf life cb/ - 3 -:, .

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, ", " : 1 , , . ,; , . , ' "',,, sas at re~rigerated tcmp~rature~. Cooking of the treated poultry demonstratcs that it is unchanged in ~lavor, tendernes~, and juiciness. ~y this proccss the consumer lS provlded wi-th a wholesome poultry product free of pathogenic organisms such as salmonella and staphylococcus, and having a very low count of totalsurface bacteria. Further, the thin surface coating of the fat which is retained on the poultry serves to reduce the moisture lost through dripping during distri-~ bution and marketing, and when the poultry is cooked the thin10 fat layer provides initial basting material.
Instead of dipping the whole carcass into the fat as above described, the carcass may be cut up into thighs, breasts, or other parts, and these parts subjected to dipping in the hot fat. In such case the bacteria on the skin of the ~ -various parts are substantially reduced and the skin retains ~ `
the original appearance of raw poultry. -.
The following examples demonstrate more specifi-cally the practice of my process and the benefits to be ~;; obtained from it.

Whole fresh chickens in cut up form, were obtained from a market and swabs were taken on the breasts and thighs and the bacteria count determined to be of the order of 10,000 per square inch.
The parts were dipped in a hydrogenated vegetable fat heated to 250~F,, for 10 seconds. After dipping, swabs of the treated parts were again tested and the bacteria count was found to be reduced by the order of 90%.
~` The above t~eatment was repeated using oil having a temperature of 300F.
No noticeable changes were noted on the parts except for the llver and gizzard. At the 300F. temperature ' , cb/ ~ 4 ~

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, ' ,, S~9 some whi~ening of the exposcd flesll ~id occur, but this was not objectionable, and this effec~ tendcd to diminish ater ~ -~
a time. Upon draining, the oil left a very thin co~ting on the chicken p~rts. -~
EXArqPLE 2 A series of tests were planned to demonstrate the effect of using oil instead of water and the effect of differ-ent oil temperatures and dipping times both as to the reduction in bacterial count and appearance of the treated poult~y. In each case a count of bacteria was taken before and after treat-ment. The bacteria counts before and after each of the differ-ent tests is given as follows:

Total Plate Count Before using water at 212F. for 20 seconds 44,000 Before using water at 212F. for 40 seconds 37,000 After using water at 212F. for 20 seconds 23 After using water at 212F. for 40 seconds ~ ~ 44 Before using oil at 3000F. for 5 seconds 18,000 . .
Before using oil at 300F. for 10 seconds 9,200 ~;20 Before using oil at 300F. for 15 seconds S,000 After using oil at 300F. for 5 seconds 450 After using oil at 300F. for 10 seconds 500 After using oil at 300F. for 15 seconds 980 Before using oil at 325F. for 5 seconds 4,600 ~;; Before using oil at 325F. for 10 seconds 1,600 Before using oil at 325F. for 15 seconds 8,Q00 After using oil at 325F. for 5 seconds 1,400 After using oil at 325F. for 10 seconds 180 After using oil at 325F, for 15 seconds 2 Both tests using boiling water produced a cooked appearance on the chicken which would be unacceptable in the market.
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--~` ` 104~509 The test~ usiny 300F. fat produced a poultry product which looked good with subs~arltially no change from the prior natural raw appearance.
The tests using 325F. fat produced a boiling efect about the chicken parts when they were immersed and the treated -poultry showed some change toward a cooked appcarance.
The poultry subjected to the above tests had been chilled to a temperature of about 40F. to test the effect of temperature of the poultry which is subjected to treatment.
Two parts of chilled poultry were left to stand at room temperature for an hour and then were dipped in 300F. fat for 15 seconds. This treated poultry appeared not to be quite as desirable as the poultry which, in chilled condition, was subjected to immersion in 300F. fat for lS seconds.
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~ EXAMPLE 3 ~ : .
To test the reduction in bacterial count comparing oil with water and variation of temperature between 180F.

; and 315F. and variation of times between 10 and 60 seconds, I made the tests described as follows:

; Total Plate Approximate Count Reduction Before treatment of poultry in 180F. oil for 60 secs 74,000 :
After treatment in 180F. oil for 60 sec 160 99.7%

Before treatment in hot water at 180F. for 10 sec210,000 After treatment in hot water at 180F. for 10 sec12,000 94%

Before treatment in hot oil at 210F. for 60 sec 350,000 After treatment in hot oil at 210F. for 60 sec50,000 88%

Before treatment in hot water at 212F. for 5 sec- 360,000 After treatment in hot water at 212F. for 5 sec12,000 96%

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so9 Total ~late ~pproximate Coul~t Rcduction Before treatment in oil at 250OI~
for 25 sec 300,000 ~fter treatm~nt in oil at 250F.
or 25 ~ec ll,000 9 Before treatment in oil at 250F.
for 15 sec l,100,000 After treatment in oil at 250F, for 15 sec 140,000 87%
Before treatment in oil at 275F.
for 10 sec 1,100,000 After treatment in oil at 275F.
for lO sec 26,000 97 Before treatment in oil at 275Y.
for lS sec 650,000 After treatment in oil at 275F.
for 15 sec 9,800 98.5%
Before treatment in oil at 300F.
for 5 sec 120,000 After treatment in oil at 300F.
for 5 sec 9,800 91.8%
Before treatment in oil at 300F. ;~
~ for 10 sec 130,000 , After treatment in oil at 300F.
for 10 sec S,000 96% ;~
Before treatment in oil at 315F.
for 5 sec 4,000 After treatment in oil at 315F.
for 5 sec 33 99.1%
Before treatment in oil at 315F.
for lO sec 3,500 After treatment in oil at 315F.
for lO sec 5 99 9%
~:~ , . - -Although a reduction in bacteria count was obtained also when using water as the liquid in which the chicken was ~ dipped, the appearance of the chicken subjected to water treat- .
`~ ment was so altered as to be unacceptable in the market place.

In order to demonstrate the effectof the improYed process on ~rozen poultr~ carcass parts, chicken thighs and ~ 7 cb/

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chick~n dr~ns~icks Wcre purchased ~t a local supermarket, placed in a freczer and left over ni.ght. The following day the fro~en chicken parts were dipped into a hydrogenated vegetable shortening for various times and temperatures.
The poultry was tested for development of bacteria both before and after treatment by swabing one square inch of surface on the parts or by removing skin samples before and after treatment. In the case of the skin samples the skin was blended in sterile water and plated out usiny Difco Plate Count Ayar.
The results are tabulated as follows:

Temperature Time of Emer- Total Bacteria Count of the oil sion (seconds) Before After Percent Treatment Treatment Kill ~ ~ -a drumsticks 310 30 6.6 X 106 1.1 X 104 99.8 310 20 5.8 X 107 4,2 X 105 99.3 310 lS 3.5 X 106 1.1 X 105 96.9 20 b. thighs 325 30 3.0 X 104 1.0 X 103 96.5 310 20 2.6 X 104 1.3 X 103 95.0 310 10 5.7 X 104 5.5 X 10 90.5 EXAMPL~ 5 . .
Two whole turkey carcasses which had been held in frozen storage werethawed and dipped into a heated vegeta~le shortening for 15 seconds and also for 20 seconds. Bacterial counts were m,ade before and after dipping as to the breast and as to the cavity of each carcass. The results were as follows:

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Temp~ature Time o~ Emer- 'rotal Bact~ria Count of the oil sion (~eco~d~) B~forc Afte~ Percent ~rreatment Treatm~nt ~ill ~ , a. breast - Sample No. 1 300 15 4.1 X 104 1.8 X 103 95.6 300O 20 2.7 X 104 4.0 X 102 98.5 b breast - Sample No. 2 300 15 2.2 X 104 2.0 X 102 99.1 10300 20 1.8 X 104 1.0 X 102 99, c. cavity - Sample No. 1 300 15 6.0 X 102 2.0 X 102 6~
3000 20 1.7 X 103 1.0 X lo2 94.1 ~:
;.' d cavity - Sample ~lo. 2 300 15 1.7 X 103 5.0 X 102 70.6 300 20 1.0 X 103 1:.0 X 10 90.0 ~1 While only certain embodiments of my invention : ~ ~:
have been described in detall it is to be understood that many embodiments may be practiced and many changes and variations :: : : ..
:: 20 made all within the spirit of:the invention and with the scope .. :~
of the appended claims.

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Claims (8)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process for pasteurizing raw poultry comprising immersing the poultry in an edible oil having a temperature of from 180°F. to 315°F. and after a period of from 10 to 60 seconds removing the poultry from said oil.

2. A process as set forth in claim 1 wherein said poultry is chicken.

3. A process as set forth in claim 1 wherein said poultry is turkey.

4. A process as set forth in claim 1 wherein said poultry is a whole poultry carcass.

5. A process as set forth in claim 1 wherein said poultry is only a part of the whole carcass.

6. A process as set forth in claim 1 which includes the step of chilling the poultry to a temperature of about 32 to 45°F. and while the poultry is at said temperature immersing it in said oil.

7. A process as set forth in claim 1 which includes the step of draining said poultry after dipping to remove excess oil from the surface thereof.

8. A process as set forth in claim 1 wherein said poultry is frozen when immersed.