CA2088137A1

CA2088137A1 - Low oil snack chips

Info

Publication number: CA2088137A1
Application number: CA002088137A
Authority: CA
Inventors: Ronald E. Barnett; Kurt Alpha; Teresa M. Calafut
Original assignee: Borden Inc
Current assignee: Hexion Inc
Priority date: 1992-08-13
Filing date: 1993-01-26
Publication date: 1994-02-14

Abstract

ABSTRACT

The invention relates to a process for preparing a snack food chip with less than 15% oil or fat, preferably 7% to 12% oil by weight.
The process utilizes no frying, but rather the slices are dipped into with an emulsion of edible oil, water and emulsifier, then baked at a temperature of less than about 320° F in a high heat transfer environment. The slices can be potato, extruded corn masa or multigrain dough. The resulting snack food chips have good texture and flavor and contain less than 15% oil or fat. If a synthetic oil such as sucrose polyester is utilized, a baked chip product containing zero percent oil, but exhibiting acceptable taste and mouth feel, is produced.

Description

2 ~ 3 ~

TITLE: LOW OIL SNACX CHIPS

Fie]d of the Invention The invention relates to a novel process for making baked snack food chips with low oil content, and the snack food chips made by said process.

Backaround of the Invention Potato chips are among the popular snack items typically prepared by frying in hot oil until the moisture content of the product is reduced to about two percent by weight or less.
Conventional potato chip products are prepared by the basic steps of slicing peeled raw potatoes and frying them in oil at 350F for 2 to 4 minutes, or until a moisture content of approximately 1%-2%
by weight is achieved. Fried potato chips prepared using conventional methods may have an oil or fat content of from about 25 to about 45 percent by weight. The fried chips are then salted and packaged.
The oil content of potato chips is important for many reasons.
From the standpoint of good nutrition, it is desirable to maintain a low level of oil in chips. A high oil content often renders the chips greasy or oily and hence, less desirable to consumers. On the other hand, it is possible to make chips so low in oil that they lack flavor and seem harsh in texture. Consumers have come to expect and desire a mouth~eel provided by high oil content, yet the oil itself is not desired.
In recent years, a significant consumer interest has developed in weight control and reduced intake of fats and oils. Because of the high fat and oil content of conventionally prepared potato chips, a substantial portion of the total calories therein derives from the fat or oil in the product.
Chip producers generall~ are interested in making acceptable chips of lower oil contents than the 35 39 weight percent norm. A
large segment of the population, particularly those of middle age and older, is generally interested in reducing its intake of both fats and calories. Moreover, the relative and absolute si~e of this segment of the population is increasing.
In response to this consumer interest, potato chip manu~acturers have sought to produce a potato chip which retains ~he flavor and texture characteristics of conventional potato-chips, but with a significantly reduced fat or oil content.
One recent technique being investigated for reduction of fat or oil content in fried snack foods is subcritical or supercritical extraction techniques with carbon dioxide. In this technique, oil can be extracted from fried potato chips using carbon dioxide as the solvent. However, this process has limitations of expense and inconvenience.
Yuan et al., U.S 4,283,425, (issued August 11, 1981) relates to a process for preparing low fat content potato chips and 2 ~ $ 3 ~

products thereof. Yuan et al. discloses that a potato chip having an added fat content o~ up to about 10% by weight is prepared by coating the raw potato slice with globular protein, applying a layer of edible oil on top of the protein and subjecting the raw coated slice to microwave heating.
Dreher et al., U.S. 4,756,916, (issued July 12, 1988) relates to a process for producing low oil potato chips. Dreher et al.
discloses a process wherein potato slices are washed with an aqueous solution, coated ~t least partially with oil, blanched at a temperature of about 160 - 212F. and then baked at a high temperature of at least about 390F., but below the smoke point of the oil, to partially dry the slices. The partially dried slices are then said to be further baked in a follow-on step at a low temperature of about 290 - 320F. The method produces potato chips with an oil content of between about 10-25 weight percent.
Prosise, U.S. 4,917,909, (issued April 17, 1990) relates to low oil potato chips and the process ~or their preparation.
Prosise discloses that potato chips of the invention are made by coating potato slices with polyvinylpyrrolidone to provide the potato slices with increased resistance to oil absorption during frying. The method provides oil contents o~ 30% or more.
Barry et al., U.S. 4,933,194, (issued June 12, 1990) relates to low oil corrugated potato chips. Barry et al. claim a low fat potato chip having a ~at content of less than about 25 weight percent. The method involves frying the potato slices in frying oil at a temperature of about 171F. followed by a de-oiling and dehydrating process, after which the slices are finish dried using superheated steam.
Mancuso, et al., U.S. 3,402,049, (issued September 17, 1968) relates to a process for preparing potato chips with reduced fat content. In the process, raw potato slices are soaked in an edible fat, the excess fat is drained off the slices, and the slices are subjected to elevated air temperatures to surface-fry and dehydrate the potato slices. In-this manner, potato chips with a final fat or oil content of 20% to 30~ by weight are obtained.
Another example of low fat potato chip processing includes U. S. patent number 4,933,199, issued June 12, 1990 to Neel et al., entitled "Low Fat Potato Chip Process". This disclosure describes an optimized process for producing a low fat potato chip wherein potato slices are par-fried at a temperature between 149C and 182C (300 to 360F.) to a moisture content of from about four weight percent to about ten weight percent; the par-fried slices are exposed to superheated steam to remove surface fat from the par-fried slices, and then exposed to additional dehydrating to finish-drying the slices to less than about two weight percent moisture to yield low fat potato chips.
Additional proposals for processing low oil potato chips are known to those familiar with the art. Still, despite the numerous proposals for reducing the oil content of potato chips, low oil potato chips prepared using previously know processes often have ~ 3 ~ ~ RIF-2261 one or more drawbacks that may include undesirable texture, flavor or color characteristics and shortened shelf-life. In addition, acceptable "low oil" potato chips have not had less than 20% by weight fat or oil. Also, the previously known processes for preparing low oil potato chips generally are not economically feasible for large scale commercial potato chip production.
Accordingly, there remains a need in the art for an economical and efficient process for producing high quality potato chips having less than 15% by-weight oil content. Still another object of the present invention is to produce a potato chip of reduced calorie content which retains acceptable texture and flavor. A still further Gbject is to produce a method for preparing potato chips which eliminates undesirable deep fat frying practices.
These and other objects of the present invention will become evident to one skilled in the art from the below description of the invention and the appended claims.

SUMMARY OF THE INVENTION

In one embodiment, the invention relates to a process for the preparation of a low fat or low oil snack food, such as chips.
More specifically, the fat content of the chips from the process of the present invention is below lS% by weight, and preferably between 7% and 12~ by weight. The process comprises two steps: (1) pre-soaking slices of potatoes, corn masa or other materials in an 2 ~ J RIF-2261 oil-in-water emulsion, and (2) baking the slices to remove the water and produce chips with less total oil than the oil content of fried chips.
As used herein, the terms "low fat" and "low oil" are considered to have equivalent meaning, referring to a snack food having less than fifteen weight percent fat or oil based on the total weight of the snack food. If a synthetic fat or oil replacement is used, the weight percent of actual fat or oil on the final product is zero.
In another embodiment, the present invention relates to a method or process for providing a baked snack food with improved texture relative to conventional fried snack foods. This objective is achieved by modification of the starch structure in the snack food to change the rate of starch gelatinization.

DETAILED DESCRIPTION OF THE INVENTIOM

According to the present invention, it has now been found that an improved low oil, or essentially no oil, chip comprising potato, corn, or multigrain material can be prepared by a two step process, wherein in the first step, slices of the material are contacted with an emulsion of oil and water for a period of time sufficient to modify the subsequent starch gelatinization of the slice. Oil in water emulsions are preferred, and water in oil emulsions are also useful herein, but may add excessive oil pick-up to the final ~ RIF-2261 baked snack food. In the second step, the slices are removed from the emulsion exposure and baked under conditions of relatively low temperatures (preferably below 320F.) and high heat transfer, whereby low oil chips are produced, with improved texture relative to chips prepared from slices not exposed to the emulsion.
Thus, more specifically, the invention is directed to a process for preparing low oil, snack food chips comprising the steps of:
(a) contacting slices of a material selected from the group consisting of potato, corn masa extrudate, or multigrain dough extrudate for at least six minutes with an emulsion comprising at least one edible oil, water, and at least one emulsifier or surfactant~ wherein the oil content of the emulsion is less than about 20% by weight;
(b) and then baking the slices, whereby a snack food chip with an oil content of less than about 15% by weight is obtained.
In a preferred embodiment, the oi.1 content of the emulsion is 5% to 15% by weight. The slices may be immersed in the emulsion or otherwise contacted or coated ~or a time sufficient for adequate emulsion pick-up by the slices.
According to the present in~ention, potatoes can be sliced and soaked in the emulsion. Similarly, an extrudate of corn masa prepared from mixing corn flour and water can be sliced and exposed to the emulsion. Mixtures of grains useful in preparing a 2 ~

multigrain dough are also useful herein and the extruded or sheet multigrain dough can be sliced or stamped or otherwise cut and the resulting pi2ces exposed to the emulsion. Thus, a low oil, baked multigrain snack food can be prepared using two or more of the grains selected from corn, wheat, barley, oats, rice, rye and the like, and combinations thereof, in addition to potato and other vegetables capable of being sliced. To prepare a multigrain dough, two or more grains are combined, ground to desired flour particle size and mixed with a liquid, preferably water, to make a dough.
The potatoes useful in the present invention can include any and all types and strains known to those in the art. ~ow~r moisture content and higher concentrations of protein in the potato increase the quality of the texture and mouth feel. It has also been discovered herein that reducing the heat of gelatinization (gelatinization enthalpy) and increasing the heterogeneity of the potato starch also improves the quality of the resulting baked chip. The emulsion treatment of the present invention is believed to inhibit water diffusion into the starch granules, which would increase the crystallinity of the starch. Increasing crystallinity makes starch more difficult to gelatinize, which it is believed improves the quality of the resulting baked chip.
The potato or other slices used in the process of the present invention can be prepared by any suitable means. Slices of any size or shape may be used, but conventional size slices having a thickness of from about 0.04 inch to about 0.08 inch are preferred.

The emulsion comprises an edible oil, water and an emulsifier.
The emulsion can contain any amount of oil, but it is preferred that the oil content of the emulsion be 20% or less by weight. At 20% oil in the emulsion, chips produced by the present process exhibit 15-16% by weight oil based on 0.065 inch thickness of the potato slice. Preferably, the oil content in the emulsion is less than 20% and more preferably is ~etween 5% and 15% by weight.
The edible oil used in the emulsion can be any edible oil or edible oil substitute known to th"ose skilled in the art. These can include, for example and not by way of ~limitation, corn oil, sunflower oil, soybean oil, cottonseed oil, peanut oil, coconut oil, palm oil, rape seed oil, safflower oil, olive oil, sesame oil, vegetable oil, and mixtures thereof. By "edible oil" herein is also meant beef tallow, and other animal fats, and oils with the only proviso being emulsification capability. Also included as "oils" are friable fat substitutes, referred to herein as 'tsynthetic oil," such as OlestraN (available from The Proctor and Gamble Company), a sucrose polyester material. Many synthetic oils and fat replacers are known and will be useful herein. Slendid, available from Hercules, is a partial methyl ester of polygalaturonic acid, extracted from citrus peel. To use Slendid as a fat replacer, it is usually mixed at a level of 5% or less with water and a source of calcium to make it gel. Shear is applied as the gel forms to break it up. The resulting material can be used as-is or homogenized to become creamy. The small _ g _

3 ~

stable pieces of gel simulate the behavior of an emulsified fat and, being soft and deformable, give the gel a fat-like mouth feel.
Stellar, available from A.E. Staley, is made by a process that modifies largely insoluble starch granules by acid depolymerizing the amorphous amylopectin portion to yield fragments with an average molecular weight about one-tenth that of potato maltodextrin or tapioca dextr~n. Under high shear or pressure, the particles absorb water and immediately form a particle gel that is similar to shortenin~.
Simplesse is a protein-based fat replacer available from NutraSweet.
Rhone-Poulenc and Quaker Oats have developed Oatrim, produced by the enzymatic treatment of oat flour and oat bran. It is believed that Oatrim's high beta-glucan content gives a creamier taste and texture than other fat replacers.
National Starch and Chemical has produced a line of fat replacers called N-Lite based on chemically modlfied maltodextrin.
Thus, N-Lite B, N-Lite~D, N-Lite F, N-Lite LP and N-Oil are synthetic fat materials which should be useful in the present invention.
FMC has produced fat replacers including hydrocolloids, Nutricol konjac flour, and Avicel microcrystalline cellulose, which it is believed will also be useful in the present inventio~.
Pfizer's Litesse is a polydextrose useful as a fat replacer, and Lita, based on zein, is a microparticulated protein from corn 2 ~ g ~ ~ 3 ~ RIF-2261 Kraft has developed a microparticulated protein-based fat replacer called Trailblazer. Procter and Gamble has developed caprenin, a reduced-calorie fat with functional properties similar to cocoa butter. Arco Chemical has produced esterified propoxylated glycerols (EPG) which are naturally occurring fats with propylene glycol inserted between the glycerol and fatty acid segments.
Frito-Lay has produced dialkyl dihexadecylmalonate, a noncaloric fatty alcohol ester of malonic and alkylmalonic acids.
Thus, synthetic and natural fats, lard, oils, etc. commonly used in frying or other food-related processing can be used in the emulsions of the present invention. Food grade triglycerides, in general, are also useful herein.as edible oils. The oil or oils can be of varying degree of hydrogenation or saturation, however, it is preferred for dietary reasons that the oil be at least partially unsaturated. In a more preferred embodiment, the oil is unhydrogenated or with a low level of saturation. Canola oil can produce off-flavors, thus more preferred oils useful herein include olive oil and corn oil.
The edible oil used in the emulsion can supply a flavor to the final product, or depending on the oil chosen, can be essentially flavorless. One purpose for the edible oil on the final chip product, albeit at a low level, is to provide a mouth feel which is acceptable to the consumer. While the present invention can produce chips from slices of 0.065 inches with less than 1% by weight oil on the final product by using less than 1~ weight ~ a $ ~ RIF-2261 percent oil in the emulsion, the chips resulting from soaking in such a low-oil emulsion followed by baking lack the familiar potato chip mouth feel generally preferred by consumers~ Emulsion pick-up on ths snack food slice is a function of surface area. Thus, reducing the slice thickness increases the oil pick-up based on weight because of increased area/mass ratio. It is desirable in the present invention to maintain most or all of the oil on the surface of the chip. This is achieved by baking at the lower temperatures (i.e., below 320 F~ of the present invention.
In one embodiment of the present invention, it is desirable to use as at least part of the edible oil in the emulsion an oil which has previously been used for frying snack foods. The pre-used oil can be employed in the emulsion as-is or in admixture with unused oil. Using pre-used oil in the emulsion alone or mixed with new oil or synthetic oil adds flavors to the resulting baked snack food resembling the desirable flavor of a fried food but without the high oil content. In fact, mixing new and used corn oil at a 1~1 weight ratio yielded baked chips of t:he best quality in terms of taste, however pre-used oil can result in shortened shelf life of the resulting baked snack food chip.
Thus, in order to achieve more of a fried flavor and to mask possible o flavors due to the presence of the emulsifiers used in the low fat baking process of the present invention, corn oil previously used commercially to fry potato chips was used in the present invention. The resulting baked chips exhibited a desirable 2 ~ 3 ~ RIF-2261 fried-like flavor while maintaining the total oil content of the baked chip below 15% by weight, and preferably about 7% to 12% by weight.
One advantage of the present invention is the ability to use canola oil or olive oil which cannot be used for conventional frying of potato chips because of the poor temperature stability of these oils. However, hecause the present invention does not fry, these oils can be utilized alone or in combination with each other, or with other natural or synthetic oils.
- ~ particular advantage of the present invention is the ability to use emulsions of synthetic fats or oils to soak the slices of potato, corn masa or multigrain dough, whereby upon baking, a snack food chip is produced with essentially zero fat or oil, and yet has an acceptable taste and mouth feel. By emulsifying Olestra~, for example, according to the present invention, a solution can be prepared for soaking potato or other slices.
The emulsion is prepared by any known emulsification :
technique. This emulsification can include, for example, various sh~ar procedures. A preferred emulsification technique is paddle wheel agitation, but various techniques including homogenization are also effective.
Emulsifiers are sur~ace-active agents which are mainly noted for their ability to promote the formation, and improve the stability, of emulsions. The unifying characteristic of emulsifiers is the presence of a hydrophilic group (dissolving in 2~S ~ 3 ;) RIF-2261 aqueous solutions) and a lipophilic group (dissolving in lipids) on the same molecule. It is not necessary that the hydrophilic and lipophilic groups have equal effectiveness, and usually one or the other dominates the actions of the emulsifier. Emulsifiers having HLB values of from about 4 to about 20 have been useful in preparing emulsions of the present invention, but this range is not a limitation herein, and HLB's of 21 are effective. Some emulsifiers are known to form complexes with starch, and particularly amylose.
Mono- and diglycerides are emulsifiers which consist of fatty acids chemically combined either 1 or 2 on a glycerol residue. The ~mcombined -OH groups on the glycerol moiety provide the hydrophilic portion of the molecules. Monoglycerides exhibit much more of a starch-complexing reaction than do diglycerides.
In the present invention the preferred level of emulsifier or emulsifiers in the emulsion is from about 0.04 to 10.35 weight percent. Anionic, cationic and nonionic emulsifiers are useful in the present invention, if they stabilize the oil and water emulsion used to coat the slices before baking. Known phosphate lipid emulsifi~rs are also useful herein.
The preferred emulsifiers useful in the emulsions are food grade surfactants or emulsifiers, such as Dimodan and Panodan available from Grinstead Products (Industrial Airport, Kansas). In one embodiment, these are used simultaneously at levels of, for example, 0.61~ by weight Dimodan and 0.08% by weight Panodan, in an ~ 9 ~ 3 i aqueous emulsion comprising 10% by weight oil, such as canola oil or corn oil. Dimodan is a distilled monoglyceride made from refined hydrogenated soybean oil. It is made up of stearic acid (85%-90%) and palmitic acid (10-15~). It has a melting point of approximately 72C (162F.). Panodan is a diacetyl tartaric acid ester of mono-diglycerides made from edible, refined vegetable fat.
It is a solid powder with a melting point of approx mately 45C
(113F). The emulsifier can also be selected from gum arabic, sodium stearoyl lactylate, sodium caseinate, stearic acid, gum ghatti, lecithin, monoglycerides, diglycerides, and sorbitan monostearate. Lecithin, having a relatively low HLB of 4.2 will be useful herein, as is sodium stearoyl-2-lactylate, which has an HLB
of 21Ø
In one embodiment of the process of the present invention, potato slices are soaked at ambient (room) temperature in the emulsion for a period of time sufficient to modify the starch gelatinization of the slice so that on subsequent baking a chip is obtained which exhibits texture and crispiness like that of a traditional fried chip but with very low oil content. A mere pre-soak of a potato slice in water or a short term dip in the emulsion does not produce the desired conventional texture and mouth feel.
Elevating the temperature of the emulsion used to soak the potato slicPs to 85-90 C does not accelerate the desired texture change, , and in fact, gives a less desirable, though acceptable, potato chip product. Therefore, room temperature or at least ambient ~ $ ~ 7 RIF-2261 temperature for the emulsion is preferred. It has been determined that the soak step in the emulsion must proceed at least about six minutes, with the optimal time being ten minutes but can be as long as several hours. On small batch scale, the emulsion preparation step can be achieved by adding the emulsifier(s) and room temperature oil to water with agitation. If the emulsifier is a solid or is not very soluble in water, the water can be warmed to facilitate emulsification. On production scale, it is preferable to add the ~imodan and Panodan emulsifiers to warm (70 C) oil and then add this agitated mixture to warm water. It is desirable to allow the emulsion to cool to room temperature before soakin~ the chips. It is interesting to note that longer soak times generally do not result in increased oil pick-up, however, as the temperature of the emulsion is reduced, the oil pick-up increases. Thus, it is believed, but the inventors do not wish to be limited to the theory, that the oil and/or the emulsifier(s) topically coat the slices thereby preventing further oil pick-up. The emulsion applies a uniform layer of oil, water and emulsifier which wets the entire surface of the slice, a phenomenon which cannot be accomplished by sprayin~ with or dipping in oil alone. Thus, the emulsion provid~s a surprisin~ and unexpected benefit in the present invention. When slices which have been dipped in oil alone rather than emulsion are baked, the surface texture and color are non-uniform due to incomplete coating (poor wetting) of the 2 ~ ~ .S ~ 3 ~

surface. In addition, the texture of such baked products is very poor, with sharp, gritty, and hard pieces.
According to the present invention, the slices which have been soaked in the emulsion for at least six mlnutes are then baked rather than fried. Baking is continued until a desirable dryness, crispiness and mouth feel is obtained. The preferred moisture content after baking is below 2~ by weight. The baking is preferably at relatively low temperatures, i.e, below 320F. A
more preferred baking temperature range is from about 280F to 320F. Higher baking temperatures can be used but thesa allow oil and emulsifier penetration into the chip, providing an inferior flavor and texture. Thus, lower temperature profiles provide an internal matrix in the potato which is relatively impermeable to the oil and the emulsifier. This is desirable for producing a low oil chip since if the oil remains on the surface, the chip will have better organolPptic properties without excessive oil pickup.
It has been discovered that it is also desirable to have high heat transfer in the baking process, whereby a chip with good texture and flavor is obtained. Low levels of heat transfer produce poor chip texture. Microwave cooking is also useful in the present invention for baking the chip.
Thus, a preferred baking cycle for the soaked potato slices is 6 to 15 minutes at about 320F. The toasting or baking ovens useful for the baking step of the present invention can be any conventional, heated-air oven known to those skilled in the art.

2 3 13 3 ~ ? 7 Thus, for example, a Wolverine oven, manufactured by Jetzone, of Methuen, Massachusetts; was used to supply the high blast of heated air for baking the chips. Also useful in the present invention would be known fluidized bed heaters, drying/baking columns or tunnels, and the like. However, other ovens are also useful in the baking step.
The chips resulting from the baking preferably have 7-12% by weight oil, but by varying the slice thickness and the oil content in the emulsion, the oil in the resulting chips can range from about 1% (for natural oils and zero percent for synthetic substitutes) up to about 15% by weight. At about 14% oil by weight on the chip, approximately 30% of the calories in the product result from fat. Thus, at the preferred 7-12% by weight oil content, the chip product will have less than 30% of its calories derived from fat, a dietary goal commonly suggested.

. . .
The present invention also provides a method for providing a snack food with improved texture and mouth feel. This is achieved by changing the rate and/or degree of starch gelatinization which occurs in the baking process for the snack food of the present invention. During baking, gelatinization begins at temperatures o~
about 60 C and above. Starch gelatinization is endothermic, meaning the starch takes in heat to undergo the gelatinization transition. ~he temperature (T1) of the onset of the gelatinization endotherm can be measured and used as an indicator of starch modification. Gelatinization enthalpies (-Htg starch) - 18 ~

2 3 ~ ~ ~ 3 ~ RIF--2261 and onset temperatures were determined for various potatoes by differential scanning calorimetry (DSC), using 55+ 0.5 mg samples of ground-up potato hermetically sealed in stainless steel pans and heating at a rate of 10 C/minute.
DSC was also performed on potato starch which was soaked overnight as 30% by weight in water or 28% by weight in a corn oil/water emulsion. A foamy film formed on the surface of the starch/emulsion system and the film was also tested by DSC. This foamy film is believed to have been formed from partial de-emulsification due to creaming caused by, it is believed, starch interacting with the emulsifier molecules, whereby the original starch structure was modified. DSC analysis simulates subsequent baking temperature exposures of 60 C or greater whereby gelatinization begins.
The results of the DSC analysis of the potato starch/emulsion indicated that two types of starch structures were present; the original starch structure and a structure modified as a result of interaction with the emulsion of oil, water and emulsifier.
For both potato starch/water and potato starch/emulsion systems, gelatinization enthalpies generally decreased as onset temperatures increased. Thus, a potato starchlwater system exhibited an average onset gelatinization temperature (T1) of 62.2 C and an average gelatinization enthalpy, ~H/g starch, of 16.3. The potato starch/emulsion system exhibited an average onset gelatinization temperature of about 62~ C and an average 2 ~ 3 ~ RIF-2261 gelatinization enthalpy of 11.1. The DSC also generates a peak gelatinization temperature (T2) for each sample. Enthalpy values divided by the difference between T2 and Tl (-H/T2-Tl) indicate that the gelatinization of the starch in the emulsion system is more heterogeneous than the starch water system without emulsifier. In a wider endotherm peak, the starch gelatinizes over a broader temperature range, another indication that the starch structure may be more heterogeneous or disordered. Low gelatinization enthalpy values may result from low amounts of starch in the sample or from regions that are very difflcult to gelatinize. Starch heterogeneit~ may be caused by stronger hydrogen bonds or slower water diffusion in some starch regions compared to others. Table I
indicates the results of taste tests on various brands of potato starch after gelatinization.
Table 1 Gelatinization Enthalpies (~H/g starch) and Temperatures of Gelatinization Onset (~
Potato Sensorv Test Tl, C ~H/g Starch Monona 7.8 70.69 12.33 Norwis 7.0 6~.75 13.50 Kanona 7.0 68.31 15.00 Norchip 6.0 66.64 15.50 Atlantic 5.2 67.64 16.30 Snowden 3.8 67.66 14.16 Sensory data from six taste testers were obtained on potato chips made from the emulsion and baking procedure. The results shown in Table 1 indicated that a lower gelatinization enthalpy and wider endotherm temperature range in the baking process claimed ~a3,3~r~l herein are both associated with better textured chips. As discussed above, a mixture of emulsifiers, such as Dimodan and Panodan, is particularly effective in producing desirable baked chips, presumably because the mixture of emulsifiers induces a wider endotherm range within which the starch gelatinizes to produce a better textured chip.
Example 1 Oil Dipped (Control) Potato slices, approximately 0.065 inches thick, were dipped in corn oil, peanut oil, or sunflower oil for approximately 2 seconds and then blotted on paper towels to remove excess oil. The slices were then baked at 250 F for 10 minutes, then at 360 F for approximately 20 minutes, or until the resulting chips began to brown~ Analysis of the final chips indicated residual oils content of corn oil 4.59 wgt %, peanut oil 7.79 wgt %, and sunflower oil 10.65%. Texture was unacceptably hard.
Example 2 Gum arabic was dissolved in water at 11~ by weight and allowed to stand without heating for one hour. To the solution was added 10% by weight corn oil and the mixture emulsified on a high speed paddle mixer, then heated to 70 C. Potato slices (0.065 inches) were soaked in the emulsion for 10 minutes at 70 C and the slices then transferred to a toaster oven and baked at 475 F then lowered to 350 F for final browning. Texture was improved over Example 1 and flavor remained acceptable.

2a33~3 l RIF-2261 Exam~le 3 An aqueous solution of Dimodan (0.61% by weight) and Panodan (0.08% by weight) was prepared and heated to 70 C. With high speed mixing, corn oil was added to make a 10% oil in water emulsion, which was mixed for 10 minutes. Sliced potatoes were then soaked in the warm emulsion for 10 minutes and baked as in Example 2. The flavor of the resulting chip was good and the texture showed improvement over Example 2. The emulsion remained stable at room temperature and at 70 C.
Example 4 An emulsion was prepared as in Example 3 using 0.61% by weight Dimodan and 0.08% by weight Panodan. The emulsion was allowed to cool to room temperature and potato slices were soaked therein for lO minutes then baked in a Stein oven at 320 to 325 F until brown.
The resulting chips had excellent taste and texture and had about 7% oil by weight.
Although the invention has been described with reference to certain embodiments thereof, it will be understood that changes and modifications may be made which are within the skill of the art. Moreover, the scope of the invention shall include all modifications and variations that fall within the spirit or scope of the attached claims.

.

Claims

THAT WHICH IS CLAIMED IS:

1. A process for preparing low oil snack food comprising the steps of :

(a) contacting slices of material selected from the group consisting of potatoes, extruded corn masa, and multigrain dough for at least six minutes with an emulsion comprising at least one edible oil, water and at least one emulsifier, wherein the oil content of the emulsion is less than about 20% by weight; and then (b) baking the slices, whereby a snack food with an oil content of less than about 15% by weight is obtained.

2. The process of claim 1 wherein the oil content of the emulsion is 5% to 15% by weight.

3. The process of claim 1 wherein the edible oil is selected from the group consisting of corn oil, canola oil, sunflower oil, soybean oil, cottonseed oil, peanut oil, coconut oil, palm oil, rape seed oil, safflower oil, olive oil, sesame oil, vegetable oil, lard, beef tallow, animal fat, triglycerides, and mixtures thereof.

4. The process of claim 1 wherein the edible oil is a synthetic oil.

5. The process of claim l wherein the edible oil is a mixture comprising new and used oils.

6. The process of claim 4 wherein the synthetic oil is selected from the group consisting of a sucrose polyester, a synthetic fat substitute pectin-based material, a microparticularized protein corn-based fat substitute, esterified propoxylated glycol, dialkyl dihexadecylmalonate, partial methyl ester of polygalaturonic acid, microcrystalline cellulose, and polydextrose.

7. The process of claim 1 wherein the edible oil comprises corn oil and is present in the emulsion at 5% to 15% by weight.

8. The process of claim 1 wherein the edible oil comprises canola oil and is present in the emulsion at 5% to 15% by weight.

9. The process of claim 1 wherein the emulsifier is present in the emulsion at from 0.04 to 10.35 weight percent.

10. The process of claim 1 wherein the emulsifier is selected from the group consisting of gum arabic, lecithin, sodium lactylate, sodium caseinate, stearic acid, gum ghatti, mono-and di-glycerides, and sorbitan monostearate.

11. The process of claim 1 wherein the emulsifier comprises a monoglyceride made from refined hydrogenated soybean oil containing stearic acid and palmitic acid.

12. The process of claim 1 wherein the emulsifier comprises a diacetyl tartaric acid ester of mono-diglycerides made from vegetable fat.

13. The process of claim 1 wherein the baking is at a temperature of less than 320°F.

14. The process of claim 1 wherein the baking is conducted for a time sufficient to reduce the moisture content of the chips to below about 2% by weight.

15. The process of claim 1 wherein the slices are baked in a hot air oven with high heat transfer capacity.

16. The process of claim 1 wherein the slices are baked in a microwave oven.

17. The process of claim l wherein the slices are soaked in the emulsion.

18. A snack food produced by the process of claim 1.

19. The snack food chip of claim 18 wherein the slice is a potato slice.

20. A slice of material selected from the group consisting of potato, corn masa, and multigrain dough, which has been contacted with an emulsion comprising at least one edible oil, water, and at least one emulsifier.

21. The sliced material of claim 20 wherein the material is a multigrain dough which comprises two or more of the grains wheat, corn, barley, oats, rice, and rye.

22. A snack food which has been baked and not fried which exhibits an oil content of 7% to 12% by weight, and a moisture content of below about 2% by weight.

23. A baked snack food chip which has an oil content of less than 15% by weight and which also contains at least one emulsifier or surfactant.

24. A snack food chip produced by the process of claim 4.

25. The snack food chip of claim 23 which exhibits an oil content less than 1% by weight.

26. A baked potato chip which exhibits an oil content of less than 15% by weight, further comprising an emulsifier, and less than 2% moisture by weight.

27. A process for reducing the gelatinization enthalpy of starch in a snack food comprising:
contacting slices of a material selected from the group consisting of potatoes, corn masa, and multigrain dough with an emulsion comprising at least one edible natural or synthetic oil, water, and at least one emulsifier under process conditions of time and temperature sufficient to modify the sliced material's starch structure so as to decrease its gelatinization enthalpy during subsequent baking, relative to the gelatinization enthalpy of its starch not contacted with the emulsion.

28. The process of claim 27 wherein the process conditions include soaking the slices in the emulsion for six minutes to ten hours, and at a temperature of from room temperature to 90° c.

29. The process of claim 27 wherein the slices are soaked for six to ten minutes in an oil-in-water emulsion at a temperature of about 25° C.

30. A process for increasing the heterogeneity of starch gelatinization in slices of a material selected from the group consisting of potatoes, corn masa, and multigrain dough used for making snack food chip comprising:
contacting the slices with an emulsion comprising at least one edible natural or synthetic oil, water, and at least one emulsifier under process conditions of time and temperature sufficient to modify the slice's starch structure so as to increase the heterogeneity of its gelatinization after subsequent baking, relative to the heterogeneity of starch gelatinization not contacted with the emulsion.