CA1093894A - Method and apparatus for processing food products - Google Patents
Method and apparatus for processing food productsInfo
- Publication number
- CA1093894A CA1093894A CA278,968A CA278968A CA1093894A CA 1093894 A CA1093894 A CA 1093894A CA 278968 A CA278968 A CA 278968A CA 1093894 A CA1093894 A CA 1093894A
- Authority
- CA
- Canada
- Prior art keywords
- product
- mist
- bath
- parts
- steam
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47J—KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
- A47J37/00—Baking; Roasting; Grilling; Frying
- A47J37/12—Deep fat fryers, e.g. for frying fish or chips
- A47J37/1214—Deep fat fryers, e.g. for frying fish or chips the food being transported through an oil-bath
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
- A23L5/00—Preparation or treatment of foods or foodstuffs, in general; Food or foodstuffs obtained thereby; Materials therefor
- A23L5/10—General methods of cooking foods, e.g. by roasting or frying
- A23L5/11—General methods of cooking foods, e.g. by roasting or frying using oil
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
- A23L5/00—Preparation or treatment of foods or foodstuffs, in general; Food or foodstuffs obtained thereby; Materials therefor
- A23L5/10—General methods of cooking foods, e.g. by roasting or frying
- A23L5/13—General methods of cooking foods, e.g. by roasting or frying using water or steam
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Food Science & Technology (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Health & Medical Sciences (AREA)
- Nutrition Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Polymers & Plastics (AREA)
- Preparation Of Fruits And Vegetables (AREA)
- General Preparation And Processing Of Foods (AREA)
- Frying-Pans Or Fryers (AREA)
Abstract
Method and apparatus is disclosed for processing food products such as potato chips and the like. A
frying medium mist is contained in a vat in which the water vapor or steam being released from the product and the frying medium being generated rises upwardly through a pre-treatment chamber in which a pair of superposed perforate conveyors are mounted. The product is sliced or cut into parts which are conveyed to the feed end of the upper conveyor. The upper conveyor moves the product in a path along the length of the vat for dis-charge onto the lower conveyor, which moves the product along a reverse path for discharge into the vat. The product passes through the chamber in an atmosphere of the frying medium mist and steam. The speed of the conveyors is selectively controlled at a rate which causes the product to remain in contact with the atmosphere for an optimum dwell time for partial cooking as the frying medium mist and steam deposit on the product. A plurality of paddle wheels are rotated in the vat for controlling the rate of movement of the product through the heated frying medium for an optimum final cooking time.
frying medium mist is contained in a vat in which the water vapor or steam being released from the product and the frying medium being generated rises upwardly through a pre-treatment chamber in which a pair of superposed perforate conveyors are mounted. The product is sliced or cut into parts which are conveyed to the feed end of the upper conveyor. The upper conveyor moves the product in a path along the length of the vat for dis-charge onto the lower conveyor, which moves the product along a reverse path for discharge into the vat. The product passes through the chamber in an atmosphere of the frying medium mist and steam. The speed of the conveyors is selectively controlled at a rate which causes the product to remain in contact with the atmosphere for an optimum dwell time for partial cooking as the frying medium mist and steam deposit on the product. A plurality of paddle wheels are rotated in the vat for controlling the rate of movement of the product through the heated frying medium for an optimum final cooking time.
Description
3'~
Backgro~md of the Invention This invention relates in general to food processing, and in particular relates to the cooking of food products.
Many food products such as potato chips and french fries are conventionally cooked by ;mmersion in a vat of heated frying medium. In one method for processing potato chips paddle wheels are rotated in the vat for controlling the speed of product movement so that the cooking time in the medium is controlled. The operation of such conventional equipment presents a number of problems and limitations. For example, oil mist from the vat as well as steam is carried away through a stack with the result that a considerable amount of oil and heat energy is lost. In fact, positive steps were taken to prevent the oil mist from re-entering the vat with the thought of minimizing contamination of the vat contents by the free fatty acids of the mist. Therefore the operating cost is increased due to the lost oil and as well as the fuel which must be consumed for the equivalent amount of heat energy lost through the stack. ~le excess oil carried away through the stack also creates an air pollution problem.
Moreover in the conventional cooking processes the presence of excess oxygen in the cooking chamber tends to degrade the frying medium and product quality. The processing methods employed with existing equipment also require a relatively high quality raw product to produce a suitable end product. In processing potato chips when potatoes with high sugar content are used the result is a dark or discolored end product. To reduce this discoloration the potato slices in many instances are blanched in hot water prior to frying to remove or reduce the sugar content. The need has therefore been recognized for food processing methods and apparatus which will provide a solution to these problems.
Objects and Summary of the Invention It is a general object of the invention to provide new and improved method and apparatus for processing chip-~ype food products such as potato chips.
3~
According to one aspect of the invention, there is provided a process for cooking a food product with a heated frying medium comprising the steps of conveying the product through a pre-treatment atmosphere of heated frying medium mist and steam in a pre-treatment zone enclosed from the surrounding atmosphere, condensing steam on the product and depositing frying medium from the pre-treatment atmosphere on the product while partially cooking the product with the latent heat of the condensing steam and with the heat of the depositing frying medium, placing the product in a heated liquid bath of the frying medium to finish cooking the product, and removing the product from the bath.
According to another aspect of the invention, there is provided in a process for cooking a food product in a bath of heated frying medium, a method for recovering frying medium which is involved as a mist from the bath including the steps o:E conveying raw :Eoocl product along a path in a pre-treatment zone which encloses heated frying medium mist and steam from the surrounding atmosphere, causing the mist to deposit on the product while also causing the steam to condense on the product for partially cooking the product in the zone, directing the partially cooked product with frying medium deposited thereon into the bath, cooking the product in the bath and removing the cooked product from the bath.
According to a furtller aspect of the invention, there is provlded a method of processing a raw food comprised of solids and water into an edible product including the steps of forming the raw food into parts, conveying the parts on a path through a pre-treatment zone with the parts being discharged at the end of the path into a bath of heated frying medium, evaporating water in ~e parts into steam, evolving a portion of the bath into a mist of frying medium, directing said steam and mist across the path of the parts ~:
in the pre-treatment zone, causing the steam and mist to respectively con-dense and deposit on the parts with the latent heat of such condensation and the heat of the depositing mist partially cooking the parts, directing the parts in the frying medium which is deposited thereon into a bath ; whereby such frying medium is conserved, cooking the parts in the bath, and ~, \ , -3-.
~ 3~
removing the coo]ced parts from the bath.
According to yet another aspect of the invention, there is provi.ded apparatus for cooking a food product with a frying medium comprising the combination o:f a vat for containing a reservoir of heated frying medium which evolves a mist of the medium, means forming a pre-treatment chamber communicating with the vat, with the chamber containing an atmosphere which includes the mist, air and steam, conveyor means for moving the product along a path through said atmosphere with the mist and steam respectively deposit-ing and condensing on the product so that the latent heat of such condensa-tion partially cooks the product, said conveyor means directing the partially cooked product into the frying medium in the vat where the product is cookecl, ancl means for removing the coolced product from the vat.
According to tlle invention, tllere i.s also provicled apparatus for processing raw edible foods such as potatoes by cooking in a frying medium, including the combination of means for slicing the food into parts, means for washing the parts, a vat for containing liquid frying medium at a temperature which evolves the medium into a mist, hood means for forming a pre-treatment chamber over the vat for containing an atmosphere of the mist, air and steam, conveyor means in the chamber for moving the washed parts ~ :
along a path through said atmosphere and into the heated medium, the conveyor means including means for controlling the speed of movement of the parts along the path at a rate which causes the parts to be in contact with the mist and steam for a dwell time which is optimum for partial cooking of the par~s, and means for controlling the speed of movement of the parts along another path in the ].iquid medium at a rate which maintains the parts in contact with the liquid medium for a time which is optimum for completion of the cooking.
The foregoing and additional objects and fea~ures of the invention ~:
will appear from the following specification in which the preferred embodiments have been set forth in detail in conjunction with the accompanying drawings.
-3a-~' ' ` .
Brief Descrip~ion of the Drawings FIG. 1 is a side elevation view of apparatus incorporating the invention.
FIG. 2A and 2B comprise a longitud;nal section view of a portion of the apparatus of FIG. 1 to an enlarged scale showing the method of operation thereof.
FIG. 3 is a cross-sectional view to an enlarged scale taken along the line 3-3 of FIG. 2A.
Description of the Preferred Embodiments In the drawings FIGS. 2A and 2B illustrate generally at 10 apparatus for carrying out the method of the invention 3~
in the processing and cooking of potato chips. While the processing of potato chips will be speciEicall~ described herein, it is understood that the invention has application for cooking other food products which can be either whole or sliced or cut into any desired shape or pa-ttern, e.g.
french fried potatoes or an extruded or prefabricated product.
Apparatus lO includes an elongate, upwardly open vessel or vat ll supported on a frame 12 above a suita~le foundation 13. The vat is adapted to contain a reservoir 15 of heated cooking or frying medium. The frying medium can be any suit-able animal fat or vegeta~le oil, either fully or partially hydrogenated, such as cottonseed oil, soy bean oil, olive oil, peanut oil, palm oil and blends of the foregoing fats and oils. The oil is heated ~y means of an external heat exchanger, not shown, which can be heated by suitable means such as steam or by a burner using a fuel, e.g. gas or fuel oil. The heated frying medium from the heat exchanger is forced by a suitable pump, not shown, through piping 14 into the upstream end of the vat, with return oil flowing back to the heat exchanger through a conduit connected with ou-tlet 16 at the downstream end of the vat. The hottom wall of the vat inclines downwardly toward the downstream end to assist the flow of oil~ The oil is pumped to flow along the vat at a rate which is preferably in the range of 50 to 90 fpm.
An elongate dome-shaped hood 17 is mounted above the vat to define a pre-heat chamber or zone 18. The hood is supported by pairs of vertically extending hoist jacks l9, 20 mounted at their lower or head ends to the frame 12 and at their upper or rod ends to brackets 22, 23 attached to opposite sides of the hood. The jacks are actuated ~y .
~9~
suitable mechanical means, not shown, to raise and lower the hood for purposes of inspection and maintenance within the chamber. A pair of cylindrical vent stacks 24, 25 are mounted at opposite ends oE the hood for exhausting waste steam and oil mist and air from the chamber, and the vent stacks con-nect with a common stack 26 which can feed into a vent scrubber, as required. Control dampers 28 and 29 are pivotally mounted in the lower ends of each stack for selectively controlling the rate of exhaust flow.
The raw product is fed into apparatus 10 by an endless conveyor 32 which inclines upwardly within a housing 33 from a slice washer tank 34. The washer tank in turn receives the sliced parts from a slicing machine 36 and feeder-hopper 37.
The slices 30 are moved ~rom the washer tank upwardly thxough an opening 43 in hood 17,intP the pre-heat or pre-treatment zone l8. ~- ~
Conveyor means is provlded within pre-heat chamber 18 ;
for moving the product slices 30 along a path over the vat and through an atmosphere of steam and the oil mist rising upwardly at 38 from the heated fr~ing medium. The steam is evaporated from heating of the raw po-tato slices, which are comprised of approximately 80% water and 20% solids.
The conveyor means includes an upper horizontal endless conveyor 39 formed of a perforate belt such as open mesh or flat wire construction. Conveyor 39 is driven by a roller 40 mounted transversely across the downstream end of the hood. Roller 40 in turn is driven by the preferred electric motor 41 in a direction to move the upper run and the pro- `
duct along a path 42 toward the downstream end of the hood.
Conveyor 39 is trained around an idler roller 44 positioned ~3~
to receive the washed slices which drop by gravity from the discharge end of feed conveyor 32~ The side maxgins of the upper and lower runs of conve~or 39 are supported by means of angle irons 46, 47 secured to frames 48, 49 which are mounted within the pre-heat chamber abo~te the vat.
l'he product drops from the discharge end of con~eyor 39 onto the upper run of a lower horizontal endless conveyor 51 which is also formed of a perforate belt, such as open mesh or flat wire. The lower conveyor is dri~en by a roller 52 which is powered by motor 41 in a dire~tion to carry the product along a path 53 through the atmosphere back toward the upstream end of the hood. The discharge end of lower conveyor 51 is trained around an idler roller 54 and the side maryins of the upper and ~ower runs of this conveyor are supported by anyle irons 56, 57 secured to frames 48 and 49.
Suitable motor speed control means 58 is provided to selectively control the speeds of the two conveyors so that the dwell time duriny which the product is in contact with the oil mist and steam atmosphere within chamer 18 is optimum for the desired amount of dwell time prior to immersion in the vat oil. This dwell time i5 dependent upon factors such as the type o~ product, the frying medium employed, and the temperature within the pre-heat zone. For example, where the product is potato chips in a pre-heat atmosphere where the steam is superheated to a temperature in the ran~e of 26Q-295~ then the dwell time preferabl~
is in the range of 2Q to 40 seconds. To obtain this dwell time the conveyor speed is therefore dependent upon the combined length of the runs of the two conveyors. Thus in --7~
8~
this example where a dwell time of 30 seconds is desired and the combined conveyor run length is 30 Et. the conveyor speed would prefera~ly be on the order of 60 fpm., The partially pre-cooked product dro~s from the dis-S charge end of lower conveyor 51 and falls through the path 60 into the upstream end of vat 11 where it is immersed in the bath of heated oil. The product floats in the oil and is advanced along the path 61 by the flow of oil being pumped through the vat. The rate of movement of the product in the bath is controlled by paddle wheel means so that an .
optimum cooking time within the oil is achieved before removal by an upwardly inclinded endless convey~r 62 mounted at the downstream end of the vat. The paddle wheel means comprises a~plurality of wheels 63, 6~ spaced apart along the length of the vat and rotatably mounted on transverse axles which are conjointly rotated in a counterclockwise directions, as viewed in FIG. 1, by a suitable motor, not shown. Each of the wheels carries a plurality of transversely extending blades or paddles 66, 67 which turn downwardly below the surface of the oil so as to continually dunk or immerse the product while at the same time restraining forward movement of the product at the selected rate. The rotational speed of the paddles varies according to the length of the vat to achieve the desired cooking time. For example, where ,the product is sliced potato chips and where the vat length is on the order of 24 feet then the paddle wheels are ~otated at a speed to achieve an immersed cooking time in the oil on the order of 2 minutes and 7 seconds. This cooking time ls substan-tial.ly less than ~he cooking time of from 2 minutes 20 seconds 3~
to 2 minutes 25 seconds of conventional cooking apparatus.This reduction in cooking time which is achieved by the invention permits a relatively higher throughput capacity.
The product which moves away from ~he tail-end paddle S wheel 64 floats with the oil into contact with the lower run of a submerger conveyor 68 wh.ich is operated to advance the product downs-tream onto the upper run of inclined take-away conveyor 62. Conveyor 62 is operated to carry the product upwardly from the bath.
A flapper or baffle 70 hangs down from the lower end of hood 69 to limit the size of the opening above the oil and thereby limit air entry into the pre-heat zone.
The product falls downwardly from conveyor 62 onto the upper run of a horizontal transfer conveyor 71 mounted below salter apparatus 72, which can be provided as re~uired.
The salter apparatus dispenses salt downwardly onto the product carried ~cross by the transfer conveyor, and the product thereafter is directed to a fu.rther conveyor, not shown, for packaying.
The use and operation of the invention will be explained throuyh a specific example in which the food prcduct is potato chips. The frying medium selected for this example is cottonseed oil heated to a témperature of 375F in an external heat exchanger and pumped through conduit 14 into vat 11 to flow at a speed of 50 fpm. The paddle wheels are conjointly rotated at a speed of 1.75 rpm.
The raw potatoes are.sliced in slicer 36, washed and rinsed in tank 34, and then deposited onto the upper run of feed con~eyor 32. At this time the slices are at a ~emperature in the range of 50-80F. The product then a~
drops onto the upper run of conveyor 39 which moves it along -the first path 42. The product drops down onto the upper run of lower conve~Jor 51 which moves it along the return path 53 and subsequently clischarges it into the heated oil of the vat. The hot oil with steam and air evolves into a mist which rises upwardly through the openings in the conveyors. The oil mist contacts and deposits on the slices, and the steam also condenses on the ~ `
slices. The latent heat of condensation in the ste~m is transferred to the -product which begins to cook. As the slices move along the conveyor they are heated to a temperature sufficient to vaporize a portion of their con lQ -tained water into steam for subsequent condensation on the incoming slices.
The steam in the a,tmosphere within the chamber below the pair of conveyors is superheated to a temperature on the order of 260-295F, ana the temper ature of the effluent discharging through the stacks is on the order of 190F.
The increased moisture within the pre-treatment atmosphere reduces the amount of available oxygen so that the degree of oxidation and degradation o~ oil and product during the cooking cycle is reduced.
Oil which adheres to the product in -the pre-heat atmosphere remains on the product until it reaches the oil bath. Thus this amount of oil is re-covered since it is not carried away through the stacks. ; ;~
The slices falling into the oil bath float as they are carried downstream by the moving oil. The -speed of the paddle wheels 63, 6~ is less than the oil flow rate so that the paddle wheels restrain the product move-ment to achieve a cooking time wi-thin -the vat of 2 minutes and 7 seconds. At the same time the downward movemen-t of the paddle blades continually dunk or immerse the slices for uniform contact wi-th the oil. The slices are then directed rearwardly by submerged conveyor 68 onto take-away conveyor 62 which deposits -the slices on con~eyor 71 of the salter. The potato chips are then conveyed away for packaging.
.. ".... .
One specific example of the processing of potato chips by -the foregoing method and apparatus produced the following operating data and --1 0 ~
~ .
, ~. , , . ,, :
measurements. Ihe apparatus with applicant's invention provided a product throughput capacity of approximately 12% greater than equipment not employing the invention. The oil disappearance ~as approximately 5-1/2% less with applicant's invention. The vent stack ternperature was 190F as compared to a stack temperature of 265F with equipment not employing the invention. Measurement of the stack effluent showed that there was ~.5% less oil vapor in the stack using applicant's invention as compared to equipment not employing the invention. Applicant's invention also reduced the cooking time in the oil by 9.3% ancl reduces the free fatty acid content of the oil bath by substantially ~0%. The reduction of free fatty acid content in the produck, it will be understood, gives a longer shelf life.
Although in the configuration disclosed the pre-cooking unit and the pre-treatment zone is located above the cooking vat, it is contemplated that the princlples of the invention embrace a construction wherein the pre-cooking unit is separate component from the cooker. Further, a single run conveyor system may be used in the pre-treatment zone.
While the foregoing embodiments are at present considered to be preferred it is understood that numerous variations and modifications may be made therein by those skilled in the art and it is intended to cover in the appended claims all such variations and modifications as fall within the true spirit and scope of the invention. `
..~
, . . ,, . . .
.
Backgro~md of the Invention This invention relates in general to food processing, and in particular relates to the cooking of food products.
Many food products such as potato chips and french fries are conventionally cooked by ;mmersion in a vat of heated frying medium. In one method for processing potato chips paddle wheels are rotated in the vat for controlling the speed of product movement so that the cooking time in the medium is controlled. The operation of such conventional equipment presents a number of problems and limitations. For example, oil mist from the vat as well as steam is carried away through a stack with the result that a considerable amount of oil and heat energy is lost. In fact, positive steps were taken to prevent the oil mist from re-entering the vat with the thought of minimizing contamination of the vat contents by the free fatty acids of the mist. Therefore the operating cost is increased due to the lost oil and as well as the fuel which must be consumed for the equivalent amount of heat energy lost through the stack. ~le excess oil carried away through the stack also creates an air pollution problem.
Moreover in the conventional cooking processes the presence of excess oxygen in the cooking chamber tends to degrade the frying medium and product quality. The processing methods employed with existing equipment also require a relatively high quality raw product to produce a suitable end product. In processing potato chips when potatoes with high sugar content are used the result is a dark or discolored end product. To reduce this discoloration the potato slices in many instances are blanched in hot water prior to frying to remove or reduce the sugar content. The need has therefore been recognized for food processing methods and apparatus which will provide a solution to these problems.
Objects and Summary of the Invention It is a general object of the invention to provide new and improved method and apparatus for processing chip-~ype food products such as potato chips.
3~
According to one aspect of the invention, there is provided a process for cooking a food product with a heated frying medium comprising the steps of conveying the product through a pre-treatment atmosphere of heated frying medium mist and steam in a pre-treatment zone enclosed from the surrounding atmosphere, condensing steam on the product and depositing frying medium from the pre-treatment atmosphere on the product while partially cooking the product with the latent heat of the condensing steam and with the heat of the depositing frying medium, placing the product in a heated liquid bath of the frying medium to finish cooking the product, and removing the product from the bath.
According to another aspect of the invention, there is provided in a process for cooking a food product in a bath of heated frying medium, a method for recovering frying medium which is involved as a mist from the bath including the steps o:E conveying raw :Eoocl product along a path in a pre-treatment zone which encloses heated frying medium mist and steam from the surrounding atmosphere, causing the mist to deposit on the product while also causing the steam to condense on the product for partially cooking the product in the zone, directing the partially cooked product with frying medium deposited thereon into the bath, cooking the product in the bath and removing the cooked product from the bath.
According to a furtller aspect of the invention, there is provlded a method of processing a raw food comprised of solids and water into an edible product including the steps of forming the raw food into parts, conveying the parts on a path through a pre-treatment zone with the parts being discharged at the end of the path into a bath of heated frying medium, evaporating water in ~e parts into steam, evolving a portion of the bath into a mist of frying medium, directing said steam and mist across the path of the parts ~:
in the pre-treatment zone, causing the steam and mist to respectively con-dense and deposit on the parts with the latent heat of such condensation and the heat of the depositing mist partially cooking the parts, directing the parts in the frying medium which is deposited thereon into a bath ; whereby such frying medium is conserved, cooking the parts in the bath, and ~, \ , -3-.
~ 3~
removing the coo]ced parts from the bath.
According to yet another aspect of the invention, there is provi.ded apparatus for cooking a food product with a frying medium comprising the combination o:f a vat for containing a reservoir of heated frying medium which evolves a mist of the medium, means forming a pre-treatment chamber communicating with the vat, with the chamber containing an atmosphere which includes the mist, air and steam, conveyor means for moving the product along a path through said atmosphere with the mist and steam respectively deposit-ing and condensing on the product so that the latent heat of such condensa-tion partially cooks the product, said conveyor means directing the partially cooked product into the frying medium in the vat where the product is cookecl, ancl means for removing the coolced product from the vat.
According to tlle invention, tllere i.s also provicled apparatus for processing raw edible foods such as potatoes by cooking in a frying medium, including the combination of means for slicing the food into parts, means for washing the parts, a vat for containing liquid frying medium at a temperature which evolves the medium into a mist, hood means for forming a pre-treatment chamber over the vat for containing an atmosphere of the mist, air and steam, conveyor means in the chamber for moving the washed parts ~ :
along a path through said atmosphere and into the heated medium, the conveyor means including means for controlling the speed of movement of the parts along the path at a rate which causes the parts to be in contact with the mist and steam for a dwell time which is optimum for partial cooking of the par~s, and means for controlling the speed of movement of the parts along another path in the ].iquid medium at a rate which maintains the parts in contact with the liquid medium for a time which is optimum for completion of the cooking.
The foregoing and additional objects and fea~ures of the invention ~:
will appear from the following specification in which the preferred embodiments have been set forth in detail in conjunction with the accompanying drawings.
-3a-~' ' ` .
Brief Descrip~ion of the Drawings FIG. 1 is a side elevation view of apparatus incorporating the invention.
FIG. 2A and 2B comprise a longitud;nal section view of a portion of the apparatus of FIG. 1 to an enlarged scale showing the method of operation thereof.
FIG. 3 is a cross-sectional view to an enlarged scale taken along the line 3-3 of FIG. 2A.
Description of the Preferred Embodiments In the drawings FIGS. 2A and 2B illustrate generally at 10 apparatus for carrying out the method of the invention 3~
in the processing and cooking of potato chips. While the processing of potato chips will be speciEicall~ described herein, it is understood that the invention has application for cooking other food products which can be either whole or sliced or cut into any desired shape or pa-ttern, e.g.
french fried potatoes or an extruded or prefabricated product.
Apparatus lO includes an elongate, upwardly open vessel or vat ll supported on a frame 12 above a suita~le foundation 13. The vat is adapted to contain a reservoir 15 of heated cooking or frying medium. The frying medium can be any suit-able animal fat or vegeta~le oil, either fully or partially hydrogenated, such as cottonseed oil, soy bean oil, olive oil, peanut oil, palm oil and blends of the foregoing fats and oils. The oil is heated ~y means of an external heat exchanger, not shown, which can be heated by suitable means such as steam or by a burner using a fuel, e.g. gas or fuel oil. The heated frying medium from the heat exchanger is forced by a suitable pump, not shown, through piping 14 into the upstream end of the vat, with return oil flowing back to the heat exchanger through a conduit connected with ou-tlet 16 at the downstream end of the vat. The hottom wall of the vat inclines downwardly toward the downstream end to assist the flow of oil~ The oil is pumped to flow along the vat at a rate which is preferably in the range of 50 to 90 fpm.
An elongate dome-shaped hood 17 is mounted above the vat to define a pre-heat chamber or zone 18. The hood is supported by pairs of vertically extending hoist jacks l9, 20 mounted at their lower or head ends to the frame 12 and at their upper or rod ends to brackets 22, 23 attached to opposite sides of the hood. The jacks are actuated ~y .
~9~
suitable mechanical means, not shown, to raise and lower the hood for purposes of inspection and maintenance within the chamber. A pair of cylindrical vent stacks 24, 25 are mounted at opposite ends oE the hood for exhausting waste steam and oil mist and air from the chamber, and the vent stacks con-nect with a common stack 26 which can feed into a vent scrubber, as required. Control dampers 28 and 29 are pivotally mounted in the lower ends of each stack for selectively controlling the rate of exhaust flow.
The raw product is fed into apparatus 10 by an endless conveyor 32 which inclines upwardly within a housing 33 from a slice washer tank 34. The washer tank in turn receives the sliced parts from a slicing machine 36 and feeder-hopper 37.
The slices 30 are moved ~rom the washer tank upwardly thxough an opening 43 in hood 17,intP the pre-heat or pre-treatment zone l8. ~- ~
Conveyor means is provlded within pre-heat chamber 18 ;
for moving the product slices 30 along a path over the vat and through an atmosphere of steam and the oil mist rising upwardly at 38 from the heated fr~ing medium. The steam is evaporated from heating of the raw po-tato slices, which are comprised of approximately 80% water and 20% solids.
The conveyor means includes an upper horizontal endless conveyor 39 formed of a perforate belt such as open mesh or flat wire construction. Conveyor 39 is driven by a roller 40 mounted transversely across the downstream end of the hood. Roller 40 in turn is driven by the preferred electric motor 41 in a direction to move the upper run and the pro- `
duct along a path 42 toward the downstream end of the hood.
Conveyor 39 is trained around an idler roller 44 positioned ~3~
to receive the washed slices which drop by gravity from the discharge end of feed conveyor 32~ The side maxgins of the upper and lower runs of conve~or 39 are supported by means of angle irons 46, 47 secured to frames 48, 49 which are mounted within the pre-heat chamber abo~te the vat.
l'he product drops from the discharge end of con~eyor 39 onto the upper run of a lower horizontal endless conveyor 51 which is also formed of a perforate belt, such as open mesh or flat wire. The lower conveyor is dri~en by a roller 52 which is powered by motor 41 in a dire~tion to carry the product along a path 53 through the atmosphere back toward the upstream end of the hood. The discharge end of lower conveyor 51 is trained around an idler roller 54 and the side maryins of the upper and ~ower runs of this conveyor are supported by anyle irons 56, 57 secured to frames 48 and 49.
Suitable motor speed control means 58 is provided to selectively control the speeds of the two conveyors so that the dwell time duriny which the product is in contact with the oil mist and steam atmosphere within chamer 18 is optimum for the desired amount of dwell time prior to immersion in the vat oil. This dwell time i5 dependent upon factors such as the type o~ product, the frying medium employed, and the temperature within the pre-heat zone. For example, where the product is potato chips in a pre-heat atmosphere where the steam is superheated to a temperature in the ran~e of 26Q-295~ then the dwell time preferabl~
is in the range of 2Q to 40 seconds. To obtain this dwell time the conveyor speed is therefore dependent upon the combined length of the runs of the two conveyors. Thus in --7~
8~
this example where a dwell time of 30 seconds is desired and the combined conveyor run length is 30 Et. the conveyor speed would prefera~ly be on the order of 60 fpm., The partially pre-cooked product dro~s from the dis-S charge end of lower conveyor 51 and falls through the path 60 into the upstream end of vat 11 where it is immersed in the bath of heated oil. The product floats in the oil and is advanced along the path 61 by the flow of oil being pumped through the vat. The rate of movement of the product in the bath is controlled by paddle wheel means so that an .
optimum cooking time within the oil is achieved before removal by an upwardly inclinded endless convey~r 62 mounted at the downstream end of the vat. The paddle wheel means comprises a~plurality of wheels 63, 6~ spaced apart along the length of the vat and rotatably mounted on transverse axles which are conjointly rotated in a counterclockwise directions, as viewed in FIG. 1, by a suitable motor, not shown. Each of the wheels carries a plurality of transversely extending blades or paddles 66, 67 which turn downwardly below the surface of the oil so as to continually dunk or immerse the product while at the same time restraining forward movement of the product at the selected rate. The rotational speed of the paddles varies according to the length of the vat to achieve the desired cooking time. For example, where ,the product is sliced potato chips and where the vat length is on the order of 24 feet then the paddle wheels are ~otated at a speed to achieve an immersed cooking time in the oil on the order of 2 minutes and 7 seconds. This cooking time ls substan-tial.ly less than ~he cooking time of from 2 minutes 20 seconds 3~
to 2 minutes 25 seconds of conventional cooking apparatus.This reduction in cooking time which is achieved by the invention permits a relatively higher throughput capacity.
The product which moves away from ~he tail-end paddle S wheel 64 floats with the oil into contact with the lower run of a submerger conveyor 68 wh.ich is operated to advance the product downs-tream onto the upper run of inclined take-away conveyor 62. Conveyor 62 is operated to carry the product upwardly from the bath.
A flapper or baffle 70 hangs down from the lower end of hood 69 to limit the size of the opening above the oil and thereby limit air entry into the pre-heat zone.
The product falls downwardly from conveyor 62 onto the upper run of a horizontal transfer conveyor 71 mounted below salter apparatus 72, which can be provided as re~uired.
The salter apparatus dispenses salt downwardly onto the product carried ~cross by the transfer conveyor, and the product thereafter is directed to a fu.rther conveyor, not shown, for packaying.
The use and operation of the invention will be explained throuyh a specific example in which the food prcduct is potato chips. The frying medium selected for this example is cottonseed oil heated to a témperature of 375F in an external heat exchanger and pumped through conduit 14 into vat 11 to flow at a speed of 50 fpm. The paddle wheels are conjointly rotated at a speed of 1.75 rpm.
The raw potatoes are.sliced in slicer 36, washed and rinsed in tank 34, and then deposited onto the upper run of feed con~eyor 32. At this time the slices are at a ~emperature in the range of 50-80F. The product then a~
drops onto the upper run of conveyor 39 which moves it along -the first path 42. The product drops down onto the upper run of lower conve~Jor 51 which moves it along the return path 53 and subsequently clischarges it into the heated oil of the vat. The hot oil with steam and air evolves into a mist which rises upwardly through the openings in the conveyors. The oil mist contacts and deposits on the slices, and the steam also condenses on the ~ `
slices. The latent heat of condensation in the ste~m is transferred to the -product which begins to cook. As the slices move along the conveyor they are heated to a temperature sufficient to vaporize a portion of their con lQ -tained water into steam for subsequent condensation on the incoming slices.
The steam in the a,tmosphere within the chamber below the pair of conveyors is superheated to a temperature on the order of 260-295F, ana the temper ature of the effluent discharging through the stacks is on the order of 190F.
The increased moisture within the pre-treatment atmosphere reduces the amount of available oxygen so that the degree of oxidation and degradation o~ oil and product during the cooking cycle is reduced.
Oil which adheres to the product in -the pre-heat atmosphere remains on the product until it reaches the oil bath. Thus this amount of oil is re-covered since it is not carried away through the stacks. ; ;~
The slices falling into the oil bath float as they are carried downstream by the moving oil. The -speed of the paddle wheels 63, 6~ is less than the oil flow rate so that the paddle wheels restrain the product move-ment to achieve a cooking time wi-thin -the vat of 2 minutes and 7 seconds. At the same time the downward movemen-t of the paddle blades continually dunk or immerse the slices for uniform contact wi-th the oil. The slices are then directed rearwardly by submerged conveyor 68 onto take-away conveyor 62 which deposits -the slices on con~eyor 71 of the salter. The potato chips are then conveyed away for packaging.
.. ".... .
One specific example of the processing of potato chips by -the foregoing method and apparatus produced the following operating data and --1 0 ~
~ .
, ~. , , . ,, :
measurements. Ihe apparatus with applicant's invention provided a product throughput capacity of approximately 12% greater than equipment not employing the invention. The oil disappearance ~as approximately 5-1/2% less with applicant's invention. The vent stack ternperature was 190F as compared to a stack temperature of 265F with equipment not employing the invention. Measurement of the stack effluent showed that there was ~.5% less oil vapor in the stack using applicant's invention as compared to equipment not employing the invention. Applicant's invention also reduced the cooking time in the oil by 9.3% ancl reduces the free fatty acid content of the oil bath by substantially ~0%. The reduction of free fatty acid content in the produck, it will be understood, gives a longer shelf life.
Although in the configuration disclosed the pre-cooking unit and the pre-treatment zone is located above the cooking vat, it is contemplated that the princlples of the invention embrace a construction wherein the pre-cooking unit is separate component from the cooker. Further, a single run conveyor system may be used in the pre-treatment zone.
While the foregoing embodiments are at present considered to be preferred it is understood that numerous variations and modifications may be made therein by those skilled in the art and it is intended to cover in the appended claims all such variations and modifications as fall within the true spirit and scope of the invention. `
..~
, . . ,, . . .
.
Claims (20)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for cooking a food product with a heated frying medium comprising the steps of conveying the product through a pre-treatment at-mosphere of heated frying medium mist and steam in a pre-treatment zone en-closed from the surrounding atmosphere, condensing steam on the product and depositing frying medium from the pre-treatment atmosphere on the product while partially cooking the product with the latent heat of the condensing steam and with the heat of the depositing frying medium, placing the product in a heated liquid bath of the frying medium to finish cooking the product, and removing the product from the bath.
2. A process as in Claim 1 in which the frying medium in the liquid bath is evolved into the mist and such mist is directed into the pre-treat-ment zone for contact and deposit on the product.
3. A process as in Claim 2 in which the product is moved through the pre-treatment zone in a path above the bath, and frying medium mist from the bath is directed upwardly through the path into contact with the product.
4. A process as in Claim 3 in which the partially cooked product is discharged from the end of the path in the pre-treatment zone and is immersed in the bath, and said cooking step is carried out by moving the immersed product along another path in the bath.
5. A process as in Claim 1 in which the food product comprises a potato subdivided into a chip-like shape.
6. A process as in Claim 5 in which the potato product is placed in said atmosphere of the pre-treatment zone for a dwell time in the range of substantially 20 to 40 seconds.
7. A process as in Claim 6 in which the frying medium in the bath is at a temperature in the range of substantially 300°F to 400°F and the potato product is placed in the bath for a time of at least substantially two minutes.
8. In a process for cooking a food product in a bath of heated frying medium, a method for recovering frying medium which is involved as a mist from the bath including the steps of conveying raw food product along a path in a pre-treatment zone which encloses heated frying medium mist and steam from the surrounding atmosphere, causing the mist to deposit on the product while also causing the steam to condense on the product for partially cooking the product in the zone, directing the partially cooked product with frying medium deposited thereon into the bath, cooking the product in the bath and removing the cooked product from the bath.
9. A method as in Claim 8 in which the raw food product is partially comprised of water, including the steps of vaporizing the water of the prod-uct into steam, and condensing the steam on the raw product with the latent heat of condensation of the steam contributing to partially cook the product.
10. A method as in Claim 9 in which the product comprises a sliced potato.
11. A method of processing a raw food comprised of solids and water into an edible product including the steps of forming the raw food into parts, con-veying the parts on a path through a pre-treatment zone with the parts being discharged at the end of the path into a bath of heated frying medium, evap-orating water in the parts into steam, evolving a portion of the bath into a mist of frying medium, directing said steam and mist across the path of the parts in the pre-treatment zone, causing the steam and mist to respectively condense and deposit on the parts with the latent heat of such condensation and the heat of the depositing mist partially cooking the parts, directing the parts in the frying medium which is deposited thereon into a bath whereby such frying medium is conserved, cooking the parts in the bath, and removing the cooked parts from the bath.
12. A method as in Claim 11 in which the parts are conveyed along the path through the pre-treatment zone at a controlled rate to maintain the parts in contact with said mist for a predetermined dwell time which is optimum for partially cooking the parts prior to discharge into the bath.
13. A method as in Claim 12 in which the raw food comprises sliced potatoes, and the potatoes are conveyed along the path at a rate which causes said dwell time to be in the range of 20 to 40 seconds.
Apparatus for cooking a food product with a frying medium comprising the combination of a vat for containing a reservoir of heated frying medium which evolves a mist of the medium, means forming a pre-treatment chamber communicating with the vat, with the chamber containing an atmosphere which includes the mist, air and steam, conveyor means for moving the product along a path through said atmosphere with the mist and steam respectively depositing and condensing on the product so that the latent heat of such condensation partially cooks the product, said conveyor means directing the partially cooked product into the frying medium in the vat where the product is cooked, and means for removing the cooked product from the vat.
15. Apparatus as in Claim 14 which includes stack means for directing excess mist and steam away from the pre-treatment chamber.
16. Apparatus as in Claim 14 in which the pre-treatment chamber means comprises a hood disposed over the vat with mist evolved from the reservoir rising directly upwardly into the hood, and the conveyor means is disposed within the hood.
17. Apparatus as in Claim 16 in which the conveyor means comprises elongate endless perforate belt means extending horizontally over the vat with the rising mist passing through the belt for contact with the product.
18. Apparatus as in Claim 16 in which the vat is horizontally elongate, and the conveyor means comprises a horizontally disposed upper conveyor driven to move the product along a path extending over and lengthwise of the vat, together with a horizontally disposed lower conveyor positioned in the chamber between the upper conveyor and the vat, with one end of the lower conveyor positioned below the discharge end of the upper conveyor for receiving products therefrom, and with the lower con-veyor being driven to move the product along another path extending over and lengthwise of the vat for discharge of the product into the heated frying medium.
19. Apparatus as in Claim 18 in which the conveyor means includes speed control means for selectively controll-ing the rate of movement of the product through the pre-treatment chamber for controlling the dwell time of the pro-duct in the atmosphere whereby the degree of partial cooking and amount of frying medium condensation is made optimum.
20. Apparatus for processing raw edible foods such as potatoes by cooking in a frying medium, including the com-bination of means for slicing the food into parts, means for washing the parts, a vat for containing liquid frying medium at a temperature which evolves the medium into a mist, hood means for forming a pre-treatment chamber over the vat for containing an atmosphere of the mist, air and steam, conveyor means in the chamber for moving the washed parts along a path through said atmosphere and into the heated medium, the conveyor means including means for controlling the speed of movement of the parts along the path at a rate which causes the parts to be in contact with the mist and steam for a dwell time which is optimum for partial cooking of the parts, and means for controlling the speed of movement of the parts along another path in the liquid medium at a rate which maintains the parts in contact with the liquid medium for a time which is optimum for completion of the cooking.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US69827676A | 1976-06-21 | 1976-06-21 | |
| US698,276 | 1976-06-21 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1093894A true CA1093894A (en) | 1981-01-20 |
Family
ID=24804594
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA278,968A Expired CA1093894A (en) | 1976-06-21 | 1977-05-24 | Method and apparatus for processing food products |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPS6017496B2 (en) |
| AU (1) | AU506470B2 (en) |
| CA (1) | CA1093894A (en) |
| DE (1) | DE2724280A1 (en) |
| FR (1) | FR2355459A1 (en) |
| GB (1) | GB1523700A (en) |
| NL (1) | NL7706774A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112205436A (en) * | 2020-09-27 | 2021-01-12 | 湖南省嘉品嘉味生物科技有限公司 | High-temperature frying equipment for food processing |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2368250A1 (en) * | 1976-10-21 | 1978-05-19 | Rossignol Louis | Precooking plant for food prods. partic. quenelles - holds prods. under hot water until cooked |
| US4269861A (en) * | 1979-02-21 | 1981-05-26 | Heat And Control, Inc. | Process for preparing french fried potatoes and apparatus |
| US4392420A (en) * | 1981-01-05 | 1983-07-12 | Heat & Control, Inc. | Recirculating hot oil cooking apparatus |
| WO1987006445A1 (en) * | 1986-04-23 | 1987-11-05 | Peter Martin Vos | Cooking apparatus |
| ATE91601T1 (en) * | 1987-10-07 | 1993-08-15 | Gooding Int Ltd | METHOD AND APPARATUS FOR PREPARING AND COOKING EDIBLE PRODUCTS. |
| US5188859A (en) * | 1990-10-25 | 1993-02-23 | The Procter & Gamble Company | Low fat snack |
| DE102007037605A1 (en) | 2007-08-07 | 2009-02-12 | Mars Incorporated | Method and device for drying a material |
| DE102009014737A1 (en) * | 2009-03-25 | 2010-10-07 | Mars, Incorporated | Process and preparation for frying foodstuffs |
| US8651016B2 (en) * | 2011-05-02 | 2014-02-18 | Heat And Control, Inc. | Unitized vacuum fryer |
| DE102012100498B4 (en) * | 2012-01-23 | 2015-01-22 | Chuan Yang Foods Machine Co., Ltd. | Frying machine with conveying function |
| JP6213953B2 (en) * | 2013-07-16 | 2017-10-18 | 有限会社タテック工業 | Immersion processing equipment |
| IT201600069848A1 (en) * | 2015-07-09 | 2018-01-05 | Tna Australia Pty Ltd | Fryer. |
| CN114651841B (en) * | 2022-04-06 | 2023-07-25 | 凌航食品(山东)有限公司 | Automatic change food processing production line |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1279955A (en) * | 1960-10-17 | 1961-12-29 | Machine for frying thin strips of potatoes or dough made from corn or wheat flour | |
| US3085498A (en) * | 1962-01-18 | 1963-04-16 | Falla Fernando | Frying kitchen utensil |
| US3681084A (en) * | 1970-07-24 | 1972-08-01 | Cornnuts Inc | Method of producing a potato snack product |
| DD99303A1 (en) * | 1972-05-17 | 1973-08-13 |
-
1977
- 1977-05-23 GB GB21630/77A patent/GB1523700A/en not_active Expired
- 1977-05-24 CA CA278,968A patent/CA1093894A/en not_active Expired
- 1977-05-28 DE DE19772724280 patent/DE2724280A1/en not_active Ceased
- 1977-06-20 FR FR7718880A patent/FR2355459A1/en active Granted
- 1977-06-20 AU AU26248/77A patent/AU506470B2/en not_active Expired
- 1977-06-20 JP JP52073164A patent/JPS6017496B2/en not_active Expired
- 1977-06-20 NL NL7706774A patent/NL7706774A/en not_active Application Discontinuation
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112205436A (en) * | 2020-09-27 | 2021-01-12 | 湖南省嘉品嘉味生物科技有限公司 | High-temperature frying equipment for food processing |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS52156942A (en) | 1977-12-27 |
| AU506470B2 (en) | 1980-01-03 |
| NL7706774A (en) | 1977-12-23 |
| DE2724280A1 (en) | 1977-12-29 |
| FR2355459A1 (en) | 1978-01-20 |
| JPS6017496B2 (en) | 1985-05-02 |
| AU2624877A (en) | 1979-01-04 |
| FR2355459B1 (en) | 1984-04-06 |
| GB1523700A (en) | 1978-09-06 |
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Legal Events
| Date | Code | Title | Description |
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| MKEX | Expiry |