REDUCED FAT FRIED SNACK FOOD

Abstract: A process for the preparation of a fried snack chip product comprises preparing a dough from at least one starch-containing ingredient and water, heating the prepared dough, the heat-treated dough having a moisture content of less than about 35 wt.%, forming discrete shapes comprising the heat-treated dough, said shapes having a moisture content of less than about 35 wt.%, and frying the treated discrete shapes to produce a fried product which has a substantially reduced level of fat.

Description: Reduced fat fried snack food The present invention relates to a fried snack food product and a process for the preparation of such fried snack product, and in which the levels of fat in the fried product are substantially reduced. Snack food products include a wide variety of edible products formed of starch-containing ingredients, which are formed into discrete shapes, and which are fried, baked or otherwise cooked to form the final products. The preforms for these food products prior to cooking may either take the form of slices of raw fresh vegetables or the like, as in the case of classic potato chips, or they may be formed from various starch-containing ingredients into a dough which is shaped into discrete preformed shapes and then cooked. Where the cooking of the snack product includes a significant frying step in a hot oil or fat, the amount of fat takeup into the final cooked product can be a concern. Given the current emphasis on the reduction of fats in the human diet for health and other reasons, extensive research presently exists and a wide variety of attempts have been made to reduce the fat content of snack and other foods and, in the case of foods which are fried, specifically to reduce the takeup of fats during the frying step. One example of a fried chip snack product is disclosed in Holm et al US Specification No. 4,931,303 (HOLM et al) . That Patent discloses the production of a fried snack chip having a bubbled aesthetically pleasing surface which, as disclosed in that Patent, is achieved by maintaining specified levels of moisture in the dough and case hardening the dough pieces prior to frying. The moisture content and case hardening combine to control the rate and amount of steam developed by the retained moisture in the dough during frying to produce the aesthetically pleasing bubbled surfaces. As disclosed in the last mentioned Specification, considerable moisture percentages of 40% or more are present in the dough pieces at the time of their introduction to the fryer in order to effect the desired levels of bubbling, appearance and texture. As is well known in the art, the presence of high moisture percentages in a dough piece which is to be fried will typically result in substantially elevated levels of fat percentages in the finished product. This is because as a general rule these high levels of moisture are replaced by the fats which are taken up during frying. Thus, it is not uncommon for fried snack products made in accordance with the aforementioned Patent to exhibit fat percentages of at least in many instances in the upper 20 wt% range, if not the 30 and 40 wt% levels as disclosed in that Patent. Given the knowledge of those skilled in the art that a reduction in the moisture percentage in the dough which is introduced to the fryer will result in a reduction of fat takeup and lower fat percentages, one skilled in the art would normally expect that all that need be done is to reduce the moisture percentages in the dough prior to frying in order to effect a substantial fat reduction in the fried product. Although such moisture reduction will in fact result in a reduction in fat takeup and fat percentage in the final product, other substantial and undesirable results accompany such simple reductions. One substantial disadvantage which arises upon substantial moisture reduction is that the dough typically becomes noncohesive. This gives rise to substantial problems in the sheeting, machining or handling of the dough. Moreover, even if the dough can be sheeted or otherwise machined, the fried end product is of inferior quality and appearance and does not display the desired aesthetic exterior surfaces or desired texture. When the moisture of the dough pieces to be fried is simply reduced to in the vicinity of the low 30 wt% range, the dough pieces become dry and do not exhibit the proper expansion or, where the process conditions are selected with the aim of obtaining a product having bubbled exterior surfaces, the proper bubbling, and the final fried product is flinty. Indeed, the aforementioned Patent confirms that where moisture levels on the order of the low 30 wt% range were attempted in the manufacture of the bubbled products described therein, the quality of the fried product is unsatisfactory. It has been discovered in the present invention that a substantial reduction in moisture content in the dough prior to frying can be accomplished so as to effect a substantial reduction in fat takeup and percentage of fat in the fried product, while at the same time the aforementioned detrimental effects on handling, appearance and quality can be avoided. The present invention permits the realisation of proper expansion of the product during frying, and absence of the undesirable flinty texture in the fried product which would otherwise occur when the moisture is simply reduced in order to reduce the fat content of the finished product, and at the same time, permits the fat content of the fried product to be substantially reduced. Further, it permits, where desired, the realization of aesthetically pleasant bubbled exterior surfaces of the fried product. The present invention involves the utilisation of a low moisture dough which is treated with heat, prior to machining and frying. It has been discovered that when the low moisture dough is so heated, it is sufficiently coherent and sticky to be readily sheeted, machined and cut. Further, the moisture is trapped sufficiently deep within the dough ingredients that it is released during frying at a rate and in an amount which will result in a desirable expansion of the dough pieces, a desirable texture and, where the process conditions are selected with the aim of obtaining a bubbled product, aesthetically pleasant bubbled exterior surfaces. The heat-treatment is thought to promote hydration of starch in the dough and doughs which have been heat-treated and have as a result the properties just mentioned are referred to hereinafter as "hydrated" or simply as "heat- treated" doughs. Fazzolare et al US Specification Nos. 4,834,996 and 4,873,093 disclose the cooking of starch-containing ingredients including potato ingredients in a manner that likely hydrates the ingredients to form a dough which can be machined while hot. However, those Patents purposely bake rather than fry the dough to form the final snack chip products, and therefore do not suggest a recognition that the hydrated dough may be capable of producing a fried product in which fat takeup and fat levels are substantially reduced as in the present invention. The invention provides a process for the preparation of a fried snack product comprising: preparing a dough from at least one starch- containing ingredient and water; heating the prepared dough, the heat-treated dough having a moisture content of less than about 35wt%; forming discrete shapes comprising the heat-treated dough, said discrete shapes having a moisture content of less than about 35wt%; and frying the discrete shapes to produce said fried snack product. Surprisingly, the fried snack products so obtained have expansion and textural properties which are comparable to those obtained using the same ingredients, in the same quantities except for the larger amount of water, but without use of the heat-treatment step, the desirable expansion and textural properties being present in the products of the invention in combination with a reduced fat content. The reduction in fat content, as compared with the comparable product may be substantial, for example, at least 20%, and preferably at least 25%, by weight based on the total fat content of the comparable product. Preferably, there is formed a sheet comprising said heat-treated dough, the discrete shapes being formed from the sheeted dough, for example, by cutting or stamping pieces from the sheet. Any other suitable forming method may be used instead, for example, extrusion. The process may include the step of combining the heat-treated dough with one or more further ingredients to form a second dough a substantial portion of which comprises the heat-treated dough and which has a moisture content of less than about 35 wt%, and sheeting, forming, treating and frying the second dough containing the substantial portion of the heat-treated dough to produce the fried product. The second dough advantageously includes the heat- treated dough in an amount of at least about 50 wt% of the second dough. Advantageously, the discrete shapes are subjected to a treatment step in which their moisture content is reduced, the treated shapes having a moisture content of not more than 30wt%. Such a step is particularly preferred if it is desired to obtain fried products having exterior surfaces with a controlled level of bubbling. The treatment step to reduce the moisture content may be in an oven. The moisture content of the pieces after the moisture-reducing step may advantageously be 20 wt% or more, provided of course that it does not exceed 30 wt%. Where such a treatment step is present, the fat content of the product may be especially low, for example, not more than about 20wt%. In a further aspect of the invention, the discrete shapes are fried without first being subjected to a moisture reduction step. In that case the moisture content may or may not exceed 30 wt% provided that it does not exceed 35 wt%. The fat content of the fried products may be not more than 30 wt%, that fat content representing a substantial fat reduction as compared with conventional products made by a process which is comparable except that the dough has a higher water content. In the fried products the exterior surfaces may be substantially free from bubbling. The heat-treated dough or the second dough incorporating the heat-treated dough may be passed between a pair of embossed rollers, the sheet emerging from the embossed rollers having a three-dimensional patterned configuration, and the fried pieces being of a three-dimensional patterned configuration. In that manner there may be obtained products having a three- dimensional patterned configuration, for example, corrugated products, with a relatively low fat content. Because the pieces cut from the embossed sheet will generally not be subjected to a moisture reduction step before frying, the moisture content of the pieces on entry to the fryer may be higher than in the case of pieces which have been subjected to such a moisture reduction step and, in consequence, the fat content of the fried products may be higher. The fat content of a corrugated product obtainable in accordance with the invention may nevertheless be at least 20%, and preferably 25%, by weight lower than the fat content of a corrugated product made using ingredients which, except that the amount of water is greater, are the same, whilst having comparable expansion and textural properties. Advantageously, the sheet is formed by said embossing rollers. Preferably, said embossing rollers are corrugated rollers. The heat-treated dough may be sheeted without prior incorporation of further ingredients. There may be used as a starch-containing ingredient at least one ingredient selected from the group consisting of flakes, flours, starches, ground slices, meals, granules and mixtures thereof. Advantageously, there is used at least one starch- containing ingredient selected from potato, corn and mixtures thereof. Preferably, the prepared dough comprises at least one starch-containing ingredient derived from potato. Preferably, a major proportion of the starch in the prepared dough is derived from potato. The starch-containing ingredient may advantageously include low leach, low peel potato flakes. The prepared dough may be heated to a temperature of, for example, up to 90°C. The prepared dough may advantageously be heated to a temperature lower than the gelatinization temperature of ungelatinized starch in the starch-containing ingredient or ingredients. The preferred maximum temperature may vary according to the ingredients of the mixture and, in particular, according to the type(s) of starch present but, in general, it will be advantageous for the prepared dough to be heated to a temperature of not exceeding 80°C, preferably not exceeding 70°C, and more preferably not exceeding 65°C. The prepared dough is advantageously heated to a temperature of at least 105"F (40°C) , preferably at least 120°F (49°C) and more preferably to a temperature greater than 125°F (52°C), for not more than one minute. The heating temperature and time may be so selected that any ungelatinized starch therein is not substantially gelatinized. The dough may be at substantially ambient temperature during sheeting. Preferably, the heating of the prepared dough is accomplished by exposing the prepared dough to steam. Advantageously, the fat content of the fried product is not more than about 20 wt%. The invention further provides a process for the preparation of a fried snack chip product having a controlled level of bubbling on the exterior surface and a substantially reduced level of fat comprising: preparing a dough from at least one starch- containing ingredient and water; heating the prepared dough to a temperature and for a time sufficient to substantially hydrate the dough, the hydrated dough having a moisture content of less than about 35 wt%; sheeting the hydrated dough; forming the sheeted dough into discrete shapes; treating the discrete shapes if necessary to further reduce the moisture content of the shapes to less than about 30 wt%; and frying the treated discrete shapes to produce said fried product. Where the moisture contents of doughs are referred to herein they may be determined by any suitable method. For example, the amount of moisture may be determined by ascertaining the loss in weight on drying a sample in an oven in air at atmospheric pressure to constant weight (for example, at 131°C) . It has been found that, for practical purposes, a Sartorius IR moisture meter (with an operating temperature of 135°C) is useful for giving a reasonably accurate guide to the moisture content. Fat contents referred to herein may be determined by any suitable method, for example, by the Soxtec method, in which the product is crushed, a 2g portion of the crushed product is mixed with acid-washed sand and finely ground using a glass rod, and then extracted for 15 minutes using 30ml boiling di-ethyl ether in a preweighed dry aluminium Soxtec cup, the Soxtec cup is dried between 100"C and 105°C to constant weight, and the fat content is calculated from the increase in the weight of the Soxtec cup. Four preferred embodiments of process in accordance with the invention will now be described in detail with reference to the accompanying drawings, of which: Figure 1: is a schematic diagram showing the process steps of first and second embodiments of the invention in each of which a moisture-reduction step is included; and Figure 2: is a schematic diagram showing third and fourth embodiments, which are suitable for manufacture of a corrugated product. In the preferred embodiments of the present invention, a dough is prepared from at least one and preferably several starch-containing ingredients and water. The amount of water utilised in the preparation of this dough, whether it be water added per se or water which is part of any one or more of the several ingredients, is reduced from the levels of water typically employed in the dough formulations of the prior art. Referring now to Fig. 1 of the drawings, the dry ingredients for the dough are added to a cooker mixer 10, preferably followed by the addition of the liquid ingredients. The dry ingredients may include one or more starch-containing ingredients in the form of flakes, flours, starches, ground slices, meals, granules or mixtures thereof. The starch-containing ingredients may be from any one or more of a wide variety of vegetable bases including for example potato, corn, wheat, buckwheat, rice, barley, rye, sorghum and mixtures thereof. Potato and/or corn ingredients are principally preferred. Other dry ingredients may also be included as are conventional in doughs, such as salt and the like. The liquid ingredients may include any one of a number of conventional liquid ingredients, such as glycerol monooleates and the like, and will also include the water. Once the ingredients have been added to the cooker mixer 10, the cooker mixer 10 is closed and steam is injected into the ingredients in the cooker mixer through a steam line 12. The injected steam assists with mixing the ingredients and to elevate their temperature for the purpose of promoting hydration of the ingredients, as will be described in further detail to follow. Mixing in the cooker mixer 10 is also be assisted by a mechanical mixer 14, as depicted in the drawing. By way of example, the cooker mixer 10 may be a Stephan T.C. 850 cooker having a trapezoid mechanical kneading element 14, Part No. 8187 of Stephan Machinery Company, with a mixing speed of up to 600 rpm. Steam is admitted to the cooker mixer until the temperature of the ingredients exceeds 120°F (49°C) for less than one minute, for example about 50 seconds. At this temperature and time, it has been found that the dough in the cooker mixer will substantially hydrate without substantially gelatinizing any previously ungelatinized starch in the ingredients. In the alternative to steam, some or all of the water which is added to form the dough may be hot water which exceeds 120°F (49°C), and preferably is about 150°F (65°C). Preferably the hydrated dough in the cooker mixer 10 will have a moisture content following heating and hydration of less than about 35 wt%, and more preferably about 31 to 33 wt%. The hydrated dough may be introduced either directly to the sheeting operation without further processing or ingredient supplementation, as depicted by the dotted line 16 in the drawing (the process in that case being referred to below as the "first embodiment") , or it may be introduced to a second mixer 20, as depicted by the solid line 18 in the drawing, for further processing and ingredient supplementation (the process including that step being referred to below as the "second embodiment") . All or some of the hydrated dough from any cooker mixer batch may also be held for use at a later time either in the direct introduction to the sheeting operation or to the mixer 20. Where the hydrated dough is discharged to the mixer 20 for further processing or supplementation, additional dry and liquid ingredients are preferably mixed with the hydrated dough to form a second dough for sheeting. The dry and liquid ingredients which are further added in the mixer 20 are preferably of the same general nature and kind as previously described or they may be different. Moreover, unused dough web from further downstream in the process may be also returned and reclaimed by addition to the mixer 20. Thus, it is preferred to incorporate the mixer 20, as shown in the drawing, rather than to simply pass unsupplemented hydrated dough directly to the sheeting operation not only because the additional mixer 20 provides the ability to reclaim scrap web cuttings, but also facilitates adjustments in the dough formulation and provides flexibility in the commercial production. However, it will be understood that the mixer 20 may be eliminated and the hydrated dough may be delivered from the cooker mixer 10 directly to the sheeting operation without the sacrifice of the purposes of the invention. Where the mixer 20 is employed in the process, it is preferred that the second dough which is formed in the mixer 20 comprises in substantial portion hydrated dough which was formed in the cooker mixer 10, and preferably at least about 50 wt% to two thirds or more of the hydrated dough. The proportional amount of hydrated dough may depend to some extent upon the amount of web being recycled. The moisture percentage of this second dough after formulation is also preferably about the same as that of the hydrated dough, e.g. less than about 35 wt%, and more preferably about 31 to 33 wt%. As previously mentioned, either the hydrated dough as such is delivered to the sheeting line, as depicted by the dotted line 16 in the drawing, or the second dough which includes in major portion hydrated dough is delivered, as depicted in the drawing by the solid line 22. Whichever dough is delivered, it is conveyed along a sheeting conveyor 24 and between a plurality of spaced sheeting rolls, two sets of which are shown in Fig. 1 as rolls 26 and 28. These rolls sheet the dough to a desired thickness. Although two sets of sheeting rolls are shown in the drawing, it will be appreciated that a fewer or greater number of sheeting rolls may be employed as needed to achieve the final desired thickness of the dough sheet. The thickness of the sheeted dough upon completion of sheeting is preferably a thickness which results in a dough weight of about 15 to 18g for 10 discs having 2 inch (50mm) diameters. The temperature of the dough as introduced to the sheeting line is of no particular importance. It may be at either a somewhat elevated temperature or it may be at ambient temperature. The latter is likely where the dough has been held for some period of time after formulation prior to introduction to the sheeting line. The dough sheet is next cut by a cutter 30 to form discrete pieces 32 which may take any one of many different shapes, including circles, ovals, irregular shapes and the like. Discrete pieces of various different shapes and sizes are preferred in the present invention so that the final fried chip snack product, as packaged, will present the impression of a wide ranging number of random sizes and shapes. As shown in the drawing, the cutter 30 may take the form of any one of a wide variety of cutters employed in the industry for forming discrete dough pieces, such as the rotary cutter shown. It will also be appreciated that more than one cutter may be employed, if desired. After cutting, the discrete pieces 32 are conveyed along a conveyor 34 to an oven 36. The oven 36 may be either a single or multitemperature zone oven. One purpose of the oven 36 is to create a moisture differential as discussed in the aforementioned US Patent No. 4,931,303. Another purpose is to further treat the discrete pieces 32 to further reduce, if necessary, the moisture content of the pieces preferably to less than about 30 wt%, and more preferably to of the order of 22 to 26 wt% . Upon leaving the oven, the lowered moisture dough pieces 32A are conveyed by the conveyor 38 to the fryer 40 where they will be cooked to produce the final fried chip product. From the fryer, the discrete fried chips 32B are conveyed to and through a seasoning station 42, if desired, and thereafter are packaged as shown. As indicated above, in the first and second embodiments described with reference to Fig. 1, the process conditions are such that a moisture differential is created in the pieces before they are fried. The object of creating that moisture differential is to cause bubbling to occur during frying and thus to obtain a product with bubbling on its exterior surface. The fried snack chip food pieces obtained according to the methods of the first and second embodiments preferably have, as packaged, a substantial portion of their exterior surfaces covered with noticeable bubbles, most of which withstand breakage during normal packaging and handling. Some of the bubbles may be broken, but broken bubbles are in the substantial minority. There may be some cupped pieces, but the presence of such cup shaped pieces is nominal. The fried chips are slightly expanded from the frying and have a golden mottled appearance with few pillows, rips or tears. The texture is hard, crisp and slightly crackly, but may be slightly spongy, and the chips fracture into discrete particles upon chewing. Fig. 2 shows schematically the process steps of two alternative processes (third and fourth embodiments of the invention) for making a corrugated fried snack product. In most respects, the process steps of the third embodiment are the same as those of the first embodiment mentioned above and the process steps of the fourth embodiment are the same as those of the second embodiment mentioned above, and where in Fig. 2 there are used reference numerals already used in Fig. 1, they have the same meaning as in Fig. 1. In the third embodiment. the hydrated dough may be sheeted without further processing or ingredient supplementation. Instead, in the fourth embodiment, the hydrated dough is combined with further ingredients, and/or with unused dough web from further downstream in the process in the second mixer 20 to obtain a second dough. The moisture content of the dough to be fed to the sheeting line (that is, the hydrated dough or the second dough as the case may be) is preferably not more than about 35wt%. The dough is conveyed along the sheeting conveyor 24 and between a pair of corrugated rollers 26' which are spaced from one another and arranged to form the dough into a sheet having a corrugated configuration. The rollers are corrugated in an axial direction, that is, they have circumferentially extending ridges and/or grooves. Corrugated rollers of a suitable configuration are described, for example, in our earlier European Specification No. 0 496 161 A. The sheet emerging from the rollers has ridges and grooves which extend along the direction of travel of the sheet. The thickness of the sheeted dough is preferably a thickness which results in a dough weight in the range of about 15 to 22g for 10 discs having 2 inch (50mm) diameters. If desired, the corrugated rollers 26' may be preceded by a pair of sheeting rollers, the dough then being fed to the corrugated rollers in the form of a sheet. In that case, it is preferred so to arrange the corrugated rollers that, in addition to imparting a corrugated configuration to the sheet, they reduce the thickness of the sheet. In that case, the thickness of the sheet immediately before it is acted upon by the corrugated rollers will preferably be such that the dough weight is greater than 22g, for example, in the range of about 22 to 33g for 10 discs having 2 inch (50mm) diameters. Pieces are cut from the sheet in the manner described in relation to Fig. 1, the pieces preferably being of circular or oval configuration. The pieces 32' are conveyed along conveyor 34 to a fryer 40 where they are cooked to produce the final fried snack product. From the fryer, the discrete fried corrugated snacks 32B are conveyed to and through seasoning station 42, if desired, and thereafter are packaged. The fried snack products obtained according to the methods of the third and fourth embodiments may have higher fat contents than those made in accordance with the first and second embodiments, in which the hydrated pieces are subjected to a moisture-reducing step in an oven before frying. Nevertheless, the corrugated products obtained may have comparable expansion and textural properties with previously known corrugated products made using a recipe which is the same except that the amount of added water is greater, whilst having a fat content which is 75% or less of the fat content in those previously known products. An important aspect of the present invention is that the fat content of the fried snack products is substantially reduced from the fat levels which result from the practice of the prior art processes, such as the processes disclosed in the aforementioned US Patent No. 4,931,303. In fact, in the case of certain products including products having a controlled level of bubbling, the fat content may be reduced in the present invention to as little as 15 wt%. This ability to substantially reduce the fat content without detrimental effect to the appearance and texture of the produce is surprising in the present invention in view of the detrimental results which are experienced when the moisture content of the dough pieces is simply reduced prior to frying as previously discussed. In the present invention the surprising discovery has been made that the moisture content of the dough, in fact, can be substantially reduced without detrimental effect to the appearance and texture, if at least a substantial portion of the dough is hydrated as described before frying. It is not entirely certain as to the exact mechanism by which such enhanced hydration permits the requisite moisture reduction without the accompanying negative textural and appearance results in the fried product. However, it is believed that with the enhanced level of hydration the reduced level of remaining water that is still present is forced deeply into the starch-containing dough ingredients. This water is sufficient to permit the dough to become cohesive and sticky after heating so that it can be sheeted and otherwise machined. However, the water which has been forced deeply into the dough ingredients is not easily released in the treating oven but is released in a sufficiently controlled manner upon frying to permit the proper controlled expansion and, where the process conditions are selected to promote bubbling, proper controlled bubbling of the chip during frying. Such controlled expansion and bubbling does not otherwise occur where the water is rapidly released as in a dough which is not deeply hydrated as in the present invention. The following examples are illustrative of doughs, processes and fried snack chips food products which incorporate the principles of the present invention. Example 1 In this Example, the hydrated dough is introduced directly to the sheeting line. A dough is prepared having the following ingredients: Wt% of In redients Douαh LL/LP* Potato Flakes 49.35 Water 26.16 Degerminated White Corn Flour 12.35 Potato Starch 3.95 Coarse Ground Untoasted Slices 3.40 White Corn Meal 3.40 Corn/Cottonseed Oil Blend 0.39 Flour Salt 0.27 Glycerol Monooleate 0.68 Baked Potato Flour 0.05 TOTAL 100.00% *LL/LP - low leach (not much free starch removed) , low peel. The dry ingredients are blended and then added to a Stephan T.C. 850 Cooker Mixer. The liquid ingredients are then added while mixing, and mixing is continued. A valve in the steamline 22, as depicted in the drawing, is then opened to introduce steam to the ingredients in the cooker mixer 10 to mix the ingredients and heat them. The mechanical mixer is also activated. The steam shuts off automatically when the temperature in the cooker mixer 10 reaches about 128°F (53°C). The temperature peaks in the mixture at between about 135°F to 145'F (57°C to 63°C). The ingredients are held at peak temperature for about 50 seconds after which the pressure is bled off from the cooker mixer 10 and a vacuum pump (not shown) is energised which will drop the temperature of the ingredients in the cooker mixer again to about 128°F (53°C) or less. At this point the dough in the cooker mixer 10 has been hydrated, but preferably without any substantial gelatinization of any of the starches which have not already been gelatinized in the starch-containing ingredients. In this Example the hydrated dough from the cooker mixer is introduced directly to the sheeting line as shown by dotted line 16 in Fig. 1. Sheeting is accomplished with a single reduction process that sheets the hydrated dough to a thickness such that 10 discs 2 inches (50mm) in diameter cut from the sheet will weigh approximately 16 to 17g. The dough moisture in the hydrated sheeted dough is about 31 to 33 wt% . The sheeted dough then proceeds to a roller cutter in which various discrete but different shapes are cut from the sheet. These discretely cut pieces 32, as depicted in Fig. 1, are then conveyed by the conveyor 34 to an oven 36. Prior to entry into the oven, the dough moisture of the pieces is still between about 31 to 33 wt%. The oven is maintained at about 750°F (4OCC) and the residence time of the pieces 32 in the oven is from about 16 to 20 seconds. Thus, the moisture content of the pieces will be further reduced to from about 22 to 26 wt%, and preferably about 24 wt%. The pieces 32A upon exiting the oven are conveyed by the conveyor 38 to the fryer 40. The oil inlet temperature to the fryer is maintained at between about 320 to 330°F (160 to 166°C), the oil outlet temperature between about 308 to 316°F (153 to 158°), and the total fry time is about 35 to 45 seconds. The fried pieces 32b leave the fryer and are seasoned in a transitube without the addition of any further oil spray. The fried seasoned product is then packaged. The fried chip snack product as packaged has a fat content within the range of about 15 to 18 wt%, and typically about 16.5 wt%. The conditions (specified above) in the oven 36 are such that a moisture differential is created, the piece thus having outer layers of relatively low moisture content enclosing an inner region of higher moisture content and, as a result, the fried snack pieces of this Example have a bubbled appearance. The fried snack chip product pieces as packaged have a substantial portion of their exterior surfaces covered with noticeable bubbles most of which withstand breaking during normal packaging and handling. Some of the bubbles are broken, but the broken bubbles are relatively rare. There are some cup shaped pieces, but the presence of such cup shaped pieces is nominal. The chips are slightly expanded from the frying and have a golden mottled appearance with few pillows, rips or tears. The texture is rather hard, crisp and slightly crackly, and the chips fracture into discrete particles upon chewing. Example 2 In this Example, the hydrated dough is used as a component of a second final dough, the latter of which is sheeted. A batch of dry preblended ingredients as follows is added to the cooker mixer 10 of the kind described in Example 1: wt% of Ingredients Preblend LL/LP Potato Flakes 66. .99 White Corn Flour 25. .03 Potato Starch 7. ,98 TOTAL 100. .00% 5.29 pounds (2.40kg) of glycerol monooleate and 172.01 pounds (78.02kg) of water at ambient 70°F (21°C) temperature are added to 477.7 pounds (216.68kg) of this dry preblend, to form a total of 655 pounds (297.1kg) of ingredients in the cooker mixer 10. These ingredients are then hydrated in the cooker mixer 10, following the procedure set forth in Example 1, to form a batch of hydrated dough. Upon completion of the hydration, 403.26 pounds (182.92kg) of the hydrated batch of dough is delivered, as depicted by line 18 in the drawing, from the cooker mixer 10 to the mixer 20 which is a Stephan T.K. 850 Mixer. Any hydrated dough which is not added to the mixer 20 and which remains is saved for another batch. After the addition of the hydrated batch of dough to the mixer 20, the following additional ingredients are also added to the hydrated batch in mixer 20 in order to formulate a second and final batch of dough for sheeting: Ingredients Wt ribs) Wt fkσ. LL/LP Potato Flakes 97.03 44.01 Coarse Ground Untoasted Slices 20.28 9.20 White Corn Meal 20.28 9.20 Flour Salt 1.61 0.73 Baked Potato Flour 0.32 0.14 Corn/Cottonseed Oil Blend 2.33 1.06 Glycerol Monooleate 0.77 0.35 Water 50.00 22.68 TOTAL* 595.88 270.29 * Without recycled web, but including 403.26 pounds (182.92kg) of hydrated dough. Additionally, up to about 25 wt% of this second dough batch may include recycled dough web which remains after the web is cut into the discrete pieces 32. This scrap web (193.35 ± 15 pounds) (87.70 ± 7kg) is added to the mixer 20 to provide a total batch weight of about 789.23 pounds (357.99kg) . The dry ingredients and then the scrap web are first added to the hydrated dough in mixer 20, and these are all mixed for about 20 seconds. The oil and glycerol monooleate blend is then added, followed by the water while mixing, and the entire second and final dough batch is mixed for a total of about 105 seconds. The second and final dough from mixer 20 is then introduced, as depicted by line 22 in the drawing, to the sheeting line. That dough, as sheeted, has the moisture content as set forth in Example 1, and the sheeting, cutting, treating in the oven 36, frying equipment, conditions and remaining steps as well as the nature, appearance and texture of the fried chip snack product are the same as set forth in Example 1. Examples 3 and 4 In these Examples, the hydrated dough is introduced directly to the sheeting line. Two doughs are prepared respectively as follows: Wt% of Ingredients Doucrh Ex. 3 EX. 4 LL/LP Potato Flakes 35.79 35.79 Water 28.22 28.38 Degerminated White Corn Flour 18.05 18.05 Potato Starch 3.87 3.87 Wheat Flour (Pretzel Flour) 6.30 Rice Flour 6.14 White Corn Meal 7.00 7.00 Corn/Cottonseed Oil Blend 0.23 0.23 Flour Salt 0.40 0.40 Glycerol Monooleate 0.07 0.07 Baked Potato Flour 0.07 0.07 TOTAL 100.00 100.00 The dry ingredients are blended and added to a Stephan T.C. 850 Cooker Mixer. The liquid ingredients are then added while mixing, and mixing is continued. The dough is hydrated using water heated prior to introducing it to the cooker mixer. The water is heated to 150°F (65°C), is added to the dry ingredients over 15 seconds while mixing, and the mixing is continued for 180 seconds, thus hydrating the dough. The hydrated dough from cooker mixer 10 is then introduced, as depicted by line 16 in the drawing, to the sheeting line. That dough, as sheeted, has the moisture content as set forth in Example 1, and the sheeting, cutting, treating in the oven 36, frying equipment, conditions and remaining steps are also the same as set forth in Example 1. The nature, appearance and texture of the fried chip snack product are the same as set forth in Example 1, except that the product containing the wheat is somewhat darker and has some wheat flavour, and the product containing the rice is somewhat harder and crisper and has some rice flavour. Example 5 In this Example, the hydrated dough is introduced directly to the sheeting line, and the oven treatment step of Examples 1 to 4 is omitted. A dough is prepared having the following ingredients: Wt% of Ingredients Dough LL/LP Potato Flakes 69.30 Potato Starch 3.70 Glycerol Monooleate 0.09 Vegetable Oil 0.24 Flour Salt 0.35 Water 26.30 TOTAL 100.00% The dry ingredients are blended and then added to a Stephan UMM/SK44E cooker mixer. The liquid ingredients are then added while mixing and mixing is continued. Steam is introduced into the ingredients in the cooker mixer 10, with the mechanical mixer activated. The steam pressure is set at 1.9 bar. Steam injection is ceased after 45 seconds, when the temperature of the ingredients in the cooker mixer 10 reaches about 128°F (53°C). Mixing is continued for 30 seconds, by which time the temperature reaches from 138 to 142°F (59 to 61°C). The ingredients are held at peak temperature for about one minute after which a vacuum pump is ene: gised for a period of 4 h minutes, during which water is evaporated from the mixture leaving a dough moisture content of from 32 to 34% by weight, based on the total weight of the dough (as measured using a Sartorius IR moisture meter) . The temperature of the ingredients in the cooker mixer reduces during the evaporation step to 128°F (53°C) or less. At this point the dough in the cooker mixer 10 has become sufficiently coherent and sticky to be readily sheeted, machined and cut, but preferably without any substantial gelatinization of any of the starches which have not already been gelatinized in the starch containing ingredients. In this Example the hydrated dough from the cooker mixer is introduced directly to the sheeting line as shown by dotted line 16 in Fig. 2. Sheeting is accomplished by passing the dough between a pair of corrugated rollers, which are arranged to form the hydrated dough into a sheet of a thickness such that 10 discs of diameter 2 inches (50mm) cut from the sheet weigh approximately 18 to 21gms. The moisture content of the hydrated sheet remains substantially the same as that of the unsheeted dough after the evaporation step, that is, about 32 to 34% by weight, based on the total weight of the dough. The sheeted dough then proceeds to a roller cutter in which various discrete but different shapes are cut from the sheet. These discretely cut pieces 32, as depicted in the drawing, are then conveyed by the conveyor 34 to the fryer 40. Thus, the pieces are not subjected to a case hardening treatment before frying. The pieces are fried in oil at a temperature of 329°F (165°C) for about 35 to 50 seconds, the pieces being held in baskets in a Valentine batch fryer. On completion of the frying time, the baskets of fried product are removed from the fryer and shaken to remove free oil present on the surface of the product. The moisture content at the end of the frying time is from 1 to 2% by weight, based on the total weight of the fried pieces. The moisture content of the fried pieces is determined by an oven method, in which the previously weighed pieces are dried in air at atmospheric pressure in an oven at 104°C for four hours, and the dried product is re-weighed. The fried product may be seasoned and packaged. The fried rippled snack product pieces, when packaged, have a fat content of from 26 to 31% by weight, based on the total weight of the pieces. Without use of the heat-treatment of the dough according to the invention, if the ingredients used remain the same in all respects except for the amount of water, a dough moisture content of from 43 to 45% is required in order to obtain a rippled fried product having the desirable expansion and textural properties. On frying pieces cut from sheets of such a dough, products with a fat content of 39 to 42% by weight are obtained. Thus, the process of this Example enables a reduction of more than 25% or more in fat content to be obtained. It will be understood that the preferred embodiments of the present invention which have been described are merely illustrative of the principles of the present invention. Numerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention.

Claims: Claims 1. A process for the preparation of a fried snack product comprising: preparing a dough from at least one starch- containing ingredient and water; heating the prepared dough, the heat-treated dough having a moisture content of less than about 35wt%; forming discrete shapes comprising the heat-treated dough, said shapes having a moisture content of less than about 35wt%; and frying the discrete shapes to produce said fried snack product. 2. A process as claimed in claim 1, wherein there is formed a sheet comprising the heat-treated dough, the discrete shapes being formed from the sheeted dough. 3. A process as claimed claim 2, wherein the heat-treated dough is combined with one or more further ingredients to form a second dough a substantial portion of which comprises said heat-treated dough and which has a moisture content of not more than about 35 wt%; and said second dough is sheeted, formed, treated and fried to produce the fried product. 4. A process as claimed in claim 3, wherein said second dough includes said heat-treated dough in an amount of at least about 50 wt% of said second dough. 5. A process as claimed in any one of claims 1 to 4, wherein the discrete shapes are subjected to a treatment step in which their moisture content is reduced, the treated pieces having a moisture content of not more than 30wt%. 6. A process as claimed in claim 5, wherein the treatment step to reduce the moisture content is in an oven. 7. A process as claimed in claim 5 or claim 6, wherein the fat content of said fried product is not more than about 20wt%. 8. A process as claimed in claim 2, wherein the heat-treated dough or the second dough incorporating the heat-treated dough is passed between a pair of embossed rollers, the sheet emerging from the embossed rollers having a three-dimensional patterned configuration, and the fried pieces are of a three-dimensional patterned configuration. 9. A process as claimed in claim 8, wherein the sheet is formed by said embossing rollers. 10. A process as claimed in claim 8 or claim 9, in which said embossing rollers are corrugated rollers. 11. A process as claimed in any one of claims 2 to 10, wherein the heat-treated dough is sheeted without prior incorporation of further ingredients. 12. A process as claimed in any one of claims 2 to 11, wherein the dough is at substantially ambient temperature during sheeting. 13. A process as claimed in any one of claims 1 to 12, wherein there is used at least one starch-containing ingredient from the group consisting of flakes, flours, starches, ground slices, meals, granules, and mixtures thereof. 14. A process as claimed in any one of claims 1 to 13, wherein there is used at least one starch-containing ingredient from the group consisting of potato, corn and mixtures thereof. 15. A process as claimed in any one of claims 1 to 14, wherein there is used as a said starch-containing ingredient low leach, low peel potato flakes. 16. A process as claimed in any one of claims 1 to 15, wherein the prepared dough is heated to a temperature of at least 120°F (49°C) for less than one minute. 17. A process as claimed in any one of claims 1 to 16, wherein the prepared dough is heated to a temperature of not more than 90°C. 18. A process as claimed in any one of claims 1 to 16, wherein the heating temperature and time are so selected that any previously ungelatinized starch therein is not substantially gelatinized. 19. A process as claimed in any one of claims 1 to 18, wherein the heating of the prepared dough is accomplished by exposing the prepared dough to steam. 20. A process as claimed in any one of claims 1 to 18, wherein the heating of the prepared dough is effected by combining heated water with the other ingredients. 21. A process for the preparation of a fried snack chip product having a controlled level of bubbling on the exterior surface and a substantially reduced level of fat comprising: preparing a dough from at least one starch- containing ingredient and water; heating the prepared dough to a temperature and for a time sufficient to substantially hydrate the dough, the hydrated dough having a moisture content of not more than about 35 wt%; sheeting the hydrated dough; forming the sheeted dough into discrete shapes; treating the discrete shapes if necessary to further reduce the moisture content of the shapes to not more than about 30 wt%; and frying the treated discrete shapes to produce said fried product. 22. A process for preparation of a fried snack product substantially as described herein with reference to, and as illustrated by, Fig. 1 or Fig. 2 herein. 23. A reduced fat fried chip product produced in accordance with the process of any of claims 1 to 21.

Inventors: AVASHIA SANJIV, CLOW ANDREW EDWARD CRISPIAN, AVASHIA, SANJIV, CLOW, ANDREW, EDWARD, CRISPIAN
Applicants: UNITED BISCUITS LTD, UNITED BISCUITS (UK) LIMITED
Application year: 1996
Main classification: A23L1
IPC codes: A23L1