GB1579266A - Potato chips from uncooked dehydrated potatoes - Google Patents

Description

(54) POTATO CHIPS FROM UNCOOKED DEHYDRATED POTATOES (71) We, THE PROCTOR & GAMBLE COMPANY, a corporation organised under the laws of the State of Ohio, United States of America, of 301 East Sixth Street, Cincinnati, Ohio 45202, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to potato chips from uncooked dehydrated potatoes.

While conventional potato chips are made by frying slices of raw potatoes, in recent years potato chip products have been made by a process which involves the steps of making a potato dough from dried potatoes and water, forming the dough into a workable coherent sheet and frying chip-like portions of the sheet to potato-chip product.

Although these products involve more expensive process steps, they are practical in that they avoid expenses associated with the procurement and storage of raw potatoes and they can have longer shelf life and more uniform texture than conventionally prepared potato chips. On the other hand, these fabricated chips often do not have as robust a flavour as do conventional potato chips.

Examples of prior art methods for making formulated potato chips from dehydrated potatoes are disclosed in: US Patent 3,396,036, 6 August 1968, to Liepa, which teaches a potato base composition which is suitable for forming into various shapes of frying to produce a fried potato product having a desirable color, appearance, flavor, and eating quality; and US Patent 3,399,062, 27 August 1968, to Willard et al., which teaches a process for producing french fried potato products from dehydrated potatoes including crushed diced, granules and flakes.

It is well known in the art that dried potatoes are generally prepared by methods which cause some degree of impairment of natural potato flavor. Thus, some prior art formulated potato products are made in whole or in part from raw potatoes. Example; of such processes are disclosed in US Patent Number 3,230,094, 18 January 1966, to Hilton; Number 3,109,739, 5 November 1963, to Hilton; Number 3,150,978, 29 September 1964, to Campfield and Number 3,493,390, 3 February 1970, to Succo. In processes wherein a food is prepared from a dough which is itself prepared from rehydrated or reconstituted dehydrated potatoes, there appears to be a loss of flavor intensity and quality due at least in part to the process of dehydrating potatoes.

It is believed that flavor loss occurs during the cooking of the potato prior to or during the process of making dehydrated potatoes such as potato flakes or potato granules.

However, the dehydration of potatoes is often necessary to facilitate their transportation and storage.

It is an object of this invention to provide a process for preparing a snack food chip made from dehydrated potatoes but having a robust, raw, earthy flavor note. It is a further object of this invention to provide a snack food chip made from a coherent workable dough which is in turn made from dehydrated potatoes. It is still a further object of this invention to provide a snack chip product having uniform texture and long shelf life and also having a flavor quality and intensity similar to that of fried potato slices.

The method of achieving these and other objects will become apparent from the following description of the invention. Unless otherwise noted, all percentages hereinafter refer to percentage by weight.

This invention relates to an economical method for preparing potato based snack food chips having a robust, raw, earthy flavor. More specifically, the present invention relates to a process for preparing potato based snack food chips having a robust, raw earthy flavor comprising the steps of preparing a potato dough, which consists essentially of water and dehydrated comminuted raw potatoes, said potatoes having been rapidly dehydrated to a moisture content of from 5 per cent. to 12 per cent. in from 10 seconds to 4 minutes, forming a sheet of said dough, and deep fat frying at least a portion of the dough sheet to a potato-based snack chip.

Potato-based snack chip products are conventionally made from a dough comprising water and commercially available dehydrated potato flakes and/or granules.

The preparation of such materials involves cooking prior to dehydration. It has been discovered, however, that formulated potato snack products having a more potato-like and earthy flavor can be prepared by departing from the use of conventionally processed dehydrated potato materials. Thus, in accordance with the present invention, formulated snack chip products are made from a dough comprising uncooked dehydrated potatoes. The dough is formed into a sheet which can be cut into pieces which are then deep fat fried. The dough is made by washing, peeling, and slicing raw potatoes which are then subjected to comminution and drum drying.

The comminution step, which may be carried out by the usual methods which are well known in the art, is carried out until the potatoes have a fluid consistency and are comminuted to small particles to facilitate drying. An example of a suitable method of reducing the particle size of raw potatoes is disclosed in US Patent 3,109,739, 5 November 1963, to Hilton. The potato particles resulting from the comminution step may be either uniform or random in size. Although comminution of the potatoes may be accomplished in any apparatus which will cut or shear the potatoes into fine particles, particularly good results may be obtained by the use of an Urschel cutting mill to cut the potatoes into 3 inch slabs followed by the use of a "Waring" blender or a "Hobart (Trade Mark) VCM chopper".

To preserve flavor and color it is desirable to treat the raw potato material in a sulfite solution. Preferably, an aqueous solution containing from OS per cent. to 1 25 per cent. of sodium sulfite or sodium bisulfite is applied after slicing but before comminuting the potatoes. Usually this application is carried out by passing the potato slices through a solution of sodium sulfite or sodium bi-sulfite in such a manner that the potatoes contain from about 50 to about 500 ppm of S02 on a dry basis. While this sulfiting process has certain advantages, it is an optional part of the process of the present invention. However, it is preferred that this step be a part of the present process.

Typical whole potatoes and, accordingly, the comminuted potatoes contemplated herein usually contain from about 65 per cent. to about 85 per cent. moisture and more typically from about 70 per cent. to about 80 per cent. moisture. In accordance with the process of this invention, after comminution, the potatoes are rapidly dried or dehydrated. Because of the short time period that the potatoes are subjected to heat, there is only a minimal cooking effect on the potatoes during this step. For reasons of economy as well as surprisingly satisfactory results, the preferred drying means is a conventional drum dryer, although suitable dryers can be selected from those well known drying devices such as fluidized bed dryers, scraped wall heat exchangers, and the like.

The use of drum dryers is known in the potato industry, it having been found to have excellent utility in conventional potato flake processing.

Where a drum dryer is employed, the comminuted potatoes are fed to the top surface of the drum by conveying means.

Small diameter unheated rolls progressively apply fresh comminuted potato to portions already on the drum which are partially dried, thus building up a dense sheet.

Peripheral speed of the small rolls is the same as that of the drum, and after traveling around the circumference of the drum a doctor knife removes the dried sheet by peeling the dried sheet away from the drum Typically, a single-stage drum dryer may have from 5 to 8 small rolls placed around the circumference of the larger drum dryer which is, e.g., from about 2 to about 8 feet in diameter. The drum dryer itself is heated to temperatures within the range of from 260"F to 370"F by pressurized steam contained within the drum at pressures of from 20 to 150 psig. For optimum results the drum dryer should be rotating at a speed of from 1 to 20 rpm, and commonly from 3 to 8 rpm.

Such rotational speeds provide satisfactory residence time for the reconstituted mixture within the drying zone.

The exact time required for drying will be dependent upon the amount of heat applied to the potatoes and the desired moisture content to which the comminuted potatoes are dehydrated. If drum drying is employed, the drying time, i.e., the time the comminuted potatoes are on the roller, will be from 10 seconds to 4 minutes and preferably from 10 seconds to 30 seconds. The comminuted potatoes are dried to a moisture content of from 5 per cent. to 12 per cent. in order to be suitable for transportation and storage.

Preferably, the comminuted potatoes are dried to a moisture content of from 6 per cent. to 10 per cent.

It should be noted that if the drying means is a drum dryer, the potatoes must be comminuted to a particle size sufficiently small to facilitate uniform heat transfer to the comminuted potatoes from the surface of the drum dryer. This comminution, while it releases considerable water, causes little potato cell damage and thereby provides a raw material from which formulated potato chips can be prepared to have excellent texture and flavour.

The present invention contemplates only minimum cooking during the drying process.

In order to accomplish drying, the comminuted potatoes are heated to elevated temperatures only for a short time. For example, the potatoes may be subjected to temperatures of about 212"F for a time of up to 4 minutes. Of course, the effect of this short exposure to high temperatures is substantially different than that obtained by conventional cooking where potatoes are subjected to temperatures of 212"F for from 15 minutes to 1 hour.

In order to improve stability and texture, various stabilizers and preservatives can be present in the dehydrated comminuted potatoes or the dough made therefrom.

For example, sulfite and/or antioxidants such as BHA (butylated hydroxyanisole) and BHT (butylated hydroxytoluene) can be added to help prevent discoloration.

It is contemplated that the dough will be formed into a coherent workable dough sheet which is suitable for shaping, cutting and frying to provide snack chips. The total moisture content of the dough (including the moisture content of the dehydrated comminuted potatoes) is preferably from 30 per cent. to 50 per cent. to provide a dough which can be easily rolled into thin sheets.

While sheeting may be accomplished by extruding, slicing or stamping, it is most easily accomplished by a roll milling operation. In this process the dough is passed through a roller mill to provide a dough sheet. One pass through a roller mill is usually sufficient to provide a coherent workable dough sheet but additional roller milling may be used if it is required to form a good dough sheet. It has been found preferable to employ only the minimum number of roller mill passes both to have the most efficient process and to preserve flavor.

Sheet thickness is a matter of practical importance. Generally, very thin sheets will give a less intense potato flavor because the increased work input necessary to form thin sheets causes greater ceilular impairment.

Conversely, the thicker the sheet the more intense is the potato flavour. However, very thick sheets result in a fried chip of poor eating quality because uneven frying often occurs resulting in chips burned at the edges and raw in the center. Preferred sheet thicknesses are from 005 inches to 040 inches and most preferred sheet thicknesses are from 010 inches to 030 inches.

An important factor which affects both the ability to prepare workable, coherent dough and the eating qualities of the chips fried from the dough is the lipid content of the dough. The lipid content can be increased (when desired) to a higher level by the addition of a suitable amount of fatty substances such as, for example, mono-, diand triglycerides of fatty acids such as monopalmitin, monostearin, monoolein, dipalmitin, and tripalmitin, partial fatty acid esters of glycols such as propylene glycol monostearate and monobehenic and mixtures thereof.

After the dough is prepared in the form of a sheet, at least a portion of the sheet is fried in hot frying fat. The sizes and shapes of the chips into which the dough can be formed are endlessly variable. The dough sheet can be cut into individual chip-like portions for frying to a potato chip product. Alternatively an entire sheet or strip of potato dough can be fried and then cut into chip-sized snack portions. A conventional potato chip made from a slice of raw potato can be closely duplicated by the present invention by passing the dough between spaced mill rolls to form a sheet of dough and then cutting the dough sheet into elliptical pieces having the approximate size and shape of sliced potatoes and frying each piece in a conventional chip frying apparatus. Preferably apparatus such as that described in U.S.

Patent 3,576,647, 27 April 1971, to Liepa is used to produce uniformly shaped chips. In order to provide potato chips of the present invention which have a surface conformation and shape similar to conventional chips made by frying thin slices of raw potatoes, it is preferred that the frying be performed with the chips constrained between a pair of closely fitting similarly configured shaping molds which have apertures to permit the hot frying fat to come into intimate contact with the dough. The aforementioned U.S.

Patent 3,576,647 describes one form of suitable shaping molds.

An alternative method of forming chips from the dough sheet whereby the dough sheet or strip is continuously passed through a deep fat fryer and thereafter cut into individual snack portions can also be employed. Preferably, a continuous ribbon of dough cut in "paper doll" fashion to provide a plurality of individual oval chip portions joined to one another by a narrow interconnecting portion will be employed.

After frying of the sheet and emergence of the continuous ribbon from the fryer, individual chips will be obtained by fracturing the fried chips across the narrow interconnecting portions. A suitable method is more fully described in US Patent 3,935,322, issued 27 January 1976 to Weiss et al.

Although the dough formulations herein described are particularly suited for preparing molded chips by constraining them during the frying operation, it is not necessary that the frying be performed with the dough in a constrained condition and satisfactory chips can be produced by passing unconstrained cut dough pieces through hot frying fat.

Generally, frying in hot vegetable oil is conducted at temperatures of from 275"F to 400"F for from 5 seconds to 60 seconds, with from 7 to 15 seconds being preferred.

Any edible cooking oil or shortening is a suitable medium for frying the chips. The principal factor which influences the frying time is the color of the fried chips which is primarily a function of the reducing sugar content of the dehydrated potatoes. Other factors which affect chip color are the thickness of the chip, the temperature of the frying oil, and the type of oil used. The process of this invention can tolerate the use of high reducing sugar content potatoes.

Potatoes for making potato chips generally contain up to about 0.5 per cent. by weight on a dry basis of reducing sugar; however, a substantial amount of potatoes often referred to as high sugar potatoes contain from greater than 4 per cent. to about 3 per cent. or even higher reducing sugar on a dry weight basis. These high sugar potatoes are not suitable for use in conventional potato chip processing because the chip is fully browned during frying before any crispness is obtained. In addition, the long fry time needed to develop crispness will result in a burnt chip. Where high sugar potatoes are used in the process of the present invention, the result is a properly browned crisp chip of good flavor having a distinct retained sweetness flavor note.

The chips resulting from the use of the present process steps have an intense, earthy potato flavor similar to that of potato chips formed from fried slices of raw potatoes.

It will be apparent to one skilled in the art that various other ingredients can be included in the dough prepared according to the present invention. For example, emulsifiers, flavor imparting substances, colorings, preservatives, antioxidants and the like can be added but are not necessary.

The following example is offered to further illustrate but not limit the present invention.

Example A supply of Russet Burbank potatoes is washed, peeled, inspected and finish-peeled by hand. The potatoes are sliced into -1- inch slices in an Urschel cutting mill and passed through a 0 10 per cent. solution of sodium bisulfite. Then the potato slices are comminuted in a Waring blender until they have a fluid consistency. Thereafter the comminuted raw potatoes, which are estimated to have a water content of approximately 80 per cent., are dried by means of a pilot plant drum dryer to a moisture content of about 7 per cent. The drum steam pressure was 100 psig (340"F) and the drum was rotating at about 2k rpm. The estimated residence time of the comminuted raw potatoes on the drum surface is 20 seconds.

Five hundred g. of the dried, raw comminuted potatoes are later mixed with 320 g.

of water and 14 g. of monoglyceride emulsifier in a conventional mixer. This mixture is then passed once through a roll mill to provide a sheet of approximately 015 inches in thickness. The sheet is then cut into elliptical ovals which are fried in hot 3300F vegetable oil for about 15 seconds.

Thereafter the resulting chip product was examined and found to have a raw earthy flavor note similar to the flavor note characteristic of fresh potato chips made from raw slices of potato in a conventional potato chip process.

WHAT WE CLAIM IS: 1. A process for preparing potato based snack food chips having a robust, raw, earthy flavor comprising the steps of preparing a potato dough consisting essentially of water and dehydrated, comminuted raw potatoes, said potatoes having been rapidly dehydrated to a moisture content of from 5 per cent. to 12 per cent. in from 10 seconds to 4 minutes; forming a sheet of said dough; and deep fat frying at least a portion of said dough sheet to a potato-based snack food chip.

2. The process of Claim 1 wherein said comminuted raw potatoes are rapidly dehydrated by means of a drum dryer having a roll surface temperature of from 260"F to 370 F.

3. The process of Claim 2 wherein the drum dryer is rotating at a speed of from 1 to 20 revolutions per minute.

4. The process of Claim 3 wherein said comminuted raw potatoes are dried to a moisture content of from 6 per cent. to 10 per cent. and then rehydrated to form said potato dough.

5. The process of Claim 4 wherein the raw comminuted potatoes are dehydrated in from 10 seconds to 30 seconds.

6. The process of Claim 5 wherein the dough has a moisture content of from 30 per cent. to 50 per cent.

7. The process of Claim 6 wherein the dough is formed into a sheet by means of a roll mill.

8. The process of Claim 1 wherein the sheet of dough is cut into individual chip-like portions and the individual portions are fried to potato chips.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (10)

**WARNING** start of CLMS field may overlap end of DESC **. constrained condition and satisfactory chips can be produced by passing unconstrained cut dough pieces through hot frying fat. Generally, frying in hot vegetable oil is conducted at temperatures of from 275"F to 400"F for from 5 seconds to 60 seconds, with from 7 to 15 seconds being preferred. Any edible cooking oil or shortening is a suitable medium for frying the chips. The principal factor which influences the frying time is the color of the fried chips which is primarily a function of the reducing sugar content of the dehydrated potatoes. Other factors which affect chip color are the thickness of the chip, the temperature of the frying oil, and the type of oil used. The process of this invention can tolerate the use of high reducing sugar content potatoes. Potatoes for making potato chips generally contain up to about 0.5 per cent. by weight on a dry basis of reducing sugar; however, a substantial amount of potatoes often referred to as high sugar potatoes contain from greater than 4 per cent. to about 3 per cent. or even higher reducing sugar on a dry weight basis. These high sugar potatoes are not suitable for use in conventional potato chip processing because the chip is fully browned during frying before any crispness is obtained. In addition, the long fry time needed to develop crispness will result in a burnt chip. Where high sugar potatoes are used in the process of the present invention, the result is a properly browned crisp chip of good flavor having a distinct retained sweetness flavor note. The chips resulting from the use of the present process steps have an intense, earthy potato flavor similar to that of potato chips formed from fried slices of raw potatoes. It will be apparent to one skilled in the art that various other ingredients can be included in the dough prepared according to the present invention. For example, emulsifiers, flavor imparting substances, colorings, preservatives, antioxidants and the like can be added but are not necessary. The following example is offered to further illustrate but not limit the present invention. Example A supply of Russet Burbank potatoes is washed, peeled, inspected and finish-peeled by hand. The potatoes are sliced into -1- inch slices in an Urschel cutting mill and passed through a 0 10 per cent. solution of sodium bisulfite. Then the potato slices are comminuted in a Waring blender until they have a fluid consistency. Thereafter the comminuted raw potatoes, which are estimated to have a water content of approximately 80 per cent., are dried by means of a pilot plant drum dryer to a moisture content of about 7 per cent. The drum steam pressure was 100 psig (340"F) and the drum was rotating at about 2k rpm. The estimated residence time of the comminuted raw potatoes on the drum surface is 20 seconds. Five hundred g. of the dried, raw comminuted potatoes are later mixed with 320 g. of water and 14 g. of monoglyceride emulsifier in a conventional mixer. This mixture is then passed once through a roll mill to provide a sheet of approximately 015 inches in thickness. The sheet is then cut into elliptical ovals which are fried in hot 3300F vegetable oil for about 15 seconds. Thereafter the resulting chip product was examined and found to have a raw earthy flavor note similar to the flavor note characteristic of fresh potato chips made from raw slices of potato in a conventional potato chip process. WHAT WE CLAIM IS:

1. A process for preparing potato based snack food chips having a robust, raw, earthy flavor comprising the steps of preparing a potato dough consisting essentially of water and dehydrated, comminuted raw potatoes, said potatoes having been rapidly dehydrated to a moisture content of from 5 per cent. to 12 per cent. in from 10 seconds to 4 minutes; forming a sheet of said dough; and deep fat frying at least a portion of said dough sheet to a potato-based snack food chip.

2. The process of Claim 1 wherein said comminuted raw potatoes are rapidly dehydrated by means of a drum dryer having a roll surface temperature of from 260"F to 370 F.

3. The process of Claim 2 wherein the drum dryer is rotating at a speed of from 1 to 20 revolutions per minute.

4. The process of Claim 3 wherein said comminuted raw potatoes are dried to a moisture content of from 6 per cent. to 10 per cent. and then rehydrated to form said potato dough.

5. The process of Claim 4 wherein the raw comminuted potatoes are dehydrated in from 10 seconds to 30 seconds.

6. The process of Claim 5 wherein the dough has a moisture content of from 30 per cent. to 50 per cent.

7. The process of Claim 6 wherein the dough is formed into a sheet by means of a roll mill.

8. The process of Claim 1 wherein the sheet of dough is cut into individual chip-like portions and the individual portions are fried to potato chips.

9. A process according to Claim 1, when

carried out substantially as described in the Example.

10. Potato based snack food chips when produced by the process of any of the foregoing claims.