Abstract:
A continuous process for making a pita chip or other similar products using a continuous pressing step that occurs shortly after a continuous oven initial cooking step. Applicants&#39; invention produces a final product with characteristics of a traditionally cooked pita chip using equipment that provides for significant increases in manufacturing throughput. The use of a continuous oven with the relatively concurrent pressing step allows for the production of a flat chip piece on a continuous product line.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    The present invention relates to a method for making a pita chip or crisp and other such products in a continuous sheeting operation. Specifically, the process involves cutting a sheeted dough into longitudinal strips, cooking these longitudinal strips to form tubes, and pressing these tubes with a nub press prior to cutting and finish cooking. 
         [0003]    2. Description of Related Art 
         [0004]    Pita bread is a type of flatbread typically a round pocket bread, believed to have originated in the Middle East. The baking process typically involves forming, by rolling, a flat dough disk that is baked in a hot oven, usually in excess of 500° F., on a flat support surface. The “pocket” inside the finished loaf is created during cooking when the outside layers of the bread are seared, thus forming a cap that impedes the release of steam from the interior of the bread. This trapped steam puffs up the dough in the middle of the bread forming a pocket. As the bread cools and flattens, a pocket is left in the middle that can be later stuffed for making sandwiches and the like. 
         [0005]    Pita “chips” or “crisps” (these two terms are used interchangeably herein) can be made by cutting or chopping pita bread loaves into chip sized pieces. Making individual round pita bread loaves and cutting each loaf into chip sized pieces can be time consuming and is not conducive to an efficient, continuous operation. One prior art approach to this issue involves pressing a dough ball between two hot plates to form the pita loaf and then cutting the loaf into smaller chip sizes. This approach is referred to as a dough ball press method followed by chopping of the bread loaves. The dough ball press method is not particularly efficient and has not demonstrated desirable throughput rates on continuous or semi-continuous product lines. 
         [0006]    One attempt at developing a continuous process that makes pita chips or crisps more efficiently than the dough ball press method can be found in U.S. Pat. No. 6,291,002 entitled “Method for Preparing Elongated Pita Bread” issued on Sep. 18, 2001, to inventor George Goglanian (the “Goglanian Patent”). The Goglanian Patent describes a process whereby dough is sheeted and then cut longitudinally into continuous strips. These strips are run through an oven, thereby producing a tube-shaped bread product. A tube shape, however, is not conducive to making into a flat chip, because cutting the resultant tube would yield shorter tube segments as opposed to flat chips. Consequently, the Goglanian Patent teaches cutting this tube along its longitudinal edges into two sections, a top section and a bottom section. When these sections are cut into chip shapes, the sections fall away from each other, thus making chips of both the top and the bottom of the tube. 
         [0007]    The process described in the Goglanian Patent produces a pita chip or crisp with only one side having the characteristic pita bread exterior texture. The other side of the chip comprises the interior of the cooked tube and, therefore, presents a different texture than the outside surface. Further the Goglanian Patent requires the cutting step that separates the top half of the tube from the bottom half of the tube. This step requires special cutting equipment and leads to product loss during the cutting itself. While the Goglanian Patent can produce a chip from flatbread, it does not produce the pita chip similar to one made by chopping or cutting a round pita bread loaf. 
         [0008]    Consequently, a need exists for a continuous pita chip process, along with the accompanying equipment, that can efficiently produce a pita chip having the exterior pita texture on both sides of the chip such that it resembles a pita chip made by cutting a traditional pita bread loaf. Such process should be capable of throughput rates typical of sheeter lines and, preferably, use equipment which provides for a minimal plant footprint. 
       SUMMARY OF THE INVENTION 
       [0009]    In a preferred embodiment the invention mixes raw ingredients to produce a sheetable dough. In one embodiment, the dough is then subjected to a low stress sheeting step followed by a proofing step. After the dough is proofed it is cut, for example into longitudinal strips, and then proceeds continuously to a pita oven for cooking. Shortly after exiting the oven the cooked dough, now in a tube shape, is run through a nub press, which in a preferred embodiment is a pin roller. After this pressing step, the product is allowed to cool, is cut into chip shaped pieces, and is further cooked and seasoned prior to packaging. 
         [0010]    The invention provides for a continuous process that produces a pita chip or crisp that resembles a pita chip made by cutting a traditional pita bread loaf into chips. Yet, such process provides for substantially increased throughput and minimal plant footprint. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred embodiment, further objectives and advantages thereof, will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein: 
           [0012]      FIG. 1  is flowchart of Applicants&#39; method for making pita chips; 
           [0013]      FIG. 2  illustrates cooked dough tubes exiting a pita oven as a part of Applicants&#39; method; 
           [0014]      FIG. 3  is a perspective view of a portion of one of the dough tubes of  FIG. 2 ; 
           [0015]      FIG. 4  is a perspective view of a chip produced by Applicants&#39; invention; 
           [0016]      FIG. 5  is a schematic of one embodiment of Applicants&#39; oven and press combination; and 
           [0017]      FIGS. 6   a ,  6   b , and  6   c  illustrate a preferred embodiment nub press pin roller of Applicants&#39; invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Referring to  FIG. 1 , Applicants&#39; process starts with sheeting of a dough during a sheeting step  102 . In a preferred embodiment, this sheeting step  102  is a low-stress sheeting operation, typically involving two or more sheeter roller pairs, such that the thickness of the sheet is gradually reduced, thereby limiting the work imparted to the dough by the sheeters. In one embodiment, the dough sheet is sheeted  102  to a final thickness of approximately 0.0625 ( 1/16) inches to 0.1875 ( 3/16) inches. This dough sheet then continues down a conveyor system through a proofing step  104 , typically involving a proofer box or proofer. 
         [0019]    A proofer is a type of food processing equipment that allows the dough to rise in a relatively warm and humid environment for a period of time before further processing. Proofing relaxes the stress in the dough and lets the yeast work. A proofer box is a chamber that is humidity and temperature controlled, for example at around 90° F. and about 50% relative humidity. The proofing time using Applicants&#39; invention varies between zero minutes to twenty minutes, depending upon the amount of flour in the dough, the amount of yeast in the dough, and the preferred texture of the end product. For example, a softer textured product requires a longer proofing time than a harder textured product. 
         [0020]    After exiting the proofer at the proofing step  104 , the dough continues down a conveyor through a continuous cutter at a cutting step  106 . In a preferred embodiment, this cutter cuts the dough into continuous longitudinal flat strips. However, the cutter can also make shapes other than longitudinal flat strips, such as longitudinal hexagonal shapes and longitudinal round shapes. In an alternative embodiment, the cutting step  106  can occur prior to the proofing step  104 . 
         [0021]    The continuous longitudinal strips formed by the cutting step  106  continue along a conveyor and are spread apart by a spreading conveyor in order to input small gaps between the strips prior to entering a continuous pita oven where it is cooked during a cooking step  108 . These small gaps assure that the strip doesn&#39;t join back together during cooking  108 . In a preferred embodiment, the pita oven is a two zone oven set at 850° F. and 575° F. for zones 1 and 2, respectively, for a dwell time, in a preferred embodiment, of between six and thirty seconds, depending on product thickness and heat intensity. During this cooking step  108 , the longitudinal strips puff up, thereby forming a cavity in the center of each strip, as can be seen in  FIG. 3 , resulting in tube-like longitudinal strips (or hollow ropes) exiting the pita oven, as can be seen in  FIG. 2 . 
         [0022]    Returning to  FIG. 1 , after the cooking step  108 , these longitudinal tubes can be subjected to an optional cooling step  110  varying from zero seconds to fifteen seconds depending on the line speed required to achieve the desired texture and shape of the end product. For example, eliminating the cooling step  110  results in a harder product than conducting a cooling step  110  of up to fifteen seconds. 
         [0023]    After the cooling step  110 , the longitudinal tubes are subjected to a pressing step  112 . In a preferred embodiment, this involves a nub press or pin roller, as will be described in more detail in reference to  FIGS. 6   a ,  6   b , and  6   c . This pin roller presses the interior surfaces of the tube together. Because this pressing step  112  occurs very shortly after the cooking step  108 , the dough inside the longitudinal tube is still somewhat pliable and tacky. Consequently, the pressing step  112  generally flattens the tube such that the inner surfaces of the pocket adhere in places, thereby forming a relatively flat, double layered product resembling a standard pita flatbread in its cross-section, but without the completely open pocket. 
         [0024]    After the pressing step  112  this now generally flattened longitudinal strip is subjected to a second cooling step  114  that varies in time from zero to thirty seconds, depending on the cooling conditions and desired end product, prior to cutting into snack size pieces. 
         [0025]    If a single layered pita chip resembling that described in relation to the Goglanian Patent is desired, the flattened tube is next subjected to a splitting step  116 . This splitting step  116  separates the flattened tube into a top and bottom strip. This step  116  is listed as optional, as the preferred embodiment maintains the upper and lower portions in contact to thus later form a food piece having two layers. 
         [0026]    The flattened longitudinal strip is next cut in a cutting step  118  by, for example, a cutting roller that forms individual chip-sized pieces, such as is illustrated in reference to  FIG. 4 . Finally, and again in reference to  FIG. 1 , these individual pieces are finish cooked and seasoned  120  prior to packaging. 
         [0027]    Each of the individual steps described in general with reference to  FIG. 1  will now be described in more specific detail in relation to a preferred embodiment of Applicants&#39; invention. 
         [0028]    Table 1 below shows the dough formula used to produce a pita chip in accordance with this preferred embodiment. 
         [0000]                                TABLE 1                       Ingredient   Weight Percentage                           Wheat Flour   30-62           Whole Wheat Flour    0-31           White Whole Wheat Flour   1-2           Sugar   1-2           Salt   0-2           Oat Fiber   0-1           Yeast   1           Actual water   32-34                        
The raw ingredients listed in Table 1 are first fixed mixed to hydration in order to form a pliable dough. This can be done, for example, by a triple roller horizontal bar mixer. A typical mix time is between two and six minutes to a dough temperature of about 82° F. to 90° F.
 
         [0029]    Once the dough is formed, it is fed into a sheeter. The preferred sheeter utilizes three sets of sheeting rollers in order to progressively sheet  102  to a thinner sheet thickness while imparting a minimum amount of work into the dough during the process. A final sheet thickness of between 1/16 inch and 3/16 inch is preferred given the ingredients for the dough listed in Table 1. 
         [0030]    The proofing step  104  is a continuous step that mimics the static resting of the dough in an environment with a constant temperature and humidity. This is accomplished by the use of a proofer box such as a continuous proofer with humidity and temperature control, which is a cascading multi-tier proofer designed to process a continuous dough sheet. Preferably, the proofer box used with Applicants&#39; invention is maintained at a temperature of between 75° F. and 95° F. and a humidity level of between 45% and 65%. More preferably, the temperature inside the proofer is about 85° F. and about 55% humidity. The dwell time during the proofing step  106  is adjusted depending on the composition of the dough admix and the preferred texture of the end product. In relation to the dough composition disclosed in  FIG. 1 , the dwell time in the proofer preferably ranges between one minute and fifteen minutes. Applicants most preferred embodiment using the dough described in Table 1 involves a proofing step at 85° F. and 55% humidity for a period of about eight minutes. 
         [0031]    After exiting the proofer, the dough is subjected to a cutting step  106 , preferably cut into longitudinal strips that are 1.25 inches wide. As noted previously, the cutting step  106  can optionally occur prior to the proofing step  104 . After the cutting  106 , the longitudinal strips are slightly separated by a spreading conveyor in order to maintain some distance between each longitudinal strip as they proceed through the next step, the cooking step  108 . A gap of 0.125 inches is accomplished by the spreading conveyor in a preferred embodiment, but other distances are acceptable as long as the strips are not touching each other at their lateral edges. 
         [0032]    Referring again to the dough made by the ingredients listed in Table 1, Applicants&#39; preferred embodiment involves a continuous infrared oven with radiant, connective and conductive heat from both the top and bottom sides of the product conveyor. It is preferred to subject the dough made by the ingredients of Table 1 to a temperature of greater than 500° F. for a dwell time during the cooking step  108  of less than one minute. Doing so sears the exterior of the longitudinal dough strips causing capping layers on the exterior of the strips and a continuous cavity to form inside the strips. This makes the dough strips into partially-cooked bread tubes or hollow ropes. This can best be understood with reference to  FIGS. 2 and 3 . In a preferred embodiment a two zone oven is used with temperature settings of 850° F. and 575° F. in zones 1 and 2, respectively, for a dwell time of between ten and fifteen seconds or, more preferably, about 12.7 seconds. 
         [0033]    It should be noted that the cooking step  108  is only a partial cooking of the dough. In a preferred embodiment, the dough enters the oven at 42% water by weight and exits the oven at 32% water by weight, thereby reducing the moisture level of the dough during the cooking step  108  by less than 11%. The strips as they exit the oven are still pliable and somewhat tacky on the inside. 
         [0034]    Referring to  FIG. 2 , several of these bread tubes  220  are shown exiting the oven  250  immediately after the cooking step by way of a conveyor  252 . A perspective view of a cross-sectional portion of one of these tubes  220  is shown in  FIG. 3  as a tube piece  320 . By viewing the piece  320  in cross-section, it can be seen that a cavity has formed between the upper layer  322  and the lower layer  324 . Also shown is one of the lateral edges  326 . 
         [0035]    Returning to  FIG. 1 , Applicants&#39; method can incorporate an optional cooling step  110  depending on the environmental temperature and line speed. If a tube  220  is pressed together while the product is too hot, the interior cavity can be joined back together, so to speak, making the finished product harder. The cooler the product before pressing, the less bonding spots and the softer the finished product. 
         [0036]    It should be noted that the cooling step  110  is, in any event, relatively short such that the partially cooked bread tubes are not allowed to set up or harden in the shape illustrated by both  FIGS. 2 and 3 . Instead, the tubes are either immediately or within a short period of time after the cooking step  108 , and certainly no more than 15 seconds thereafter, subjected to the pressing step  112 . It is preferred that the internal temperature of the dough tube at the time of the pressing step  112  should be at least 140° F. and preferably of between 140° F. and 210° F. The purpose of this pressing step  112  is to collapse the tube and reform these continuous ropes into flat longitudinal strips. This is accomplished, in a preferred embodiment, by a device referred to as a nub press or pin roller. A nub press is a flat plate having protrusions or nubs that is periodically pressed onto the passing partially cooked bread tubes. A more preferable embodiment uses a pin roller such as illustrated in  FIG. 6 . A pin roller is a cylindrical roller with protruding pins. Ideally, and as it is illustrated in  FIG. 5 , this pin roller  562  is located in close proximity to the exit of the pita oven  550  such that the bread ropes or tubes that exit the oven  550  on the conveyor belt  552  are shortly thereafter subjected to the previously described pressing step. This pressing step, in a preferred embodiment, occurs continuously with the tubes proceeding along the conveyor  522  to be pressed between the pin roller  562  and a support plate  564 . Thereafter, the flattened strips continue along the direction indicated on the conveyor  552  to the next processing step. 
         [0037]    Referring now to  FIGS. 6   a ,  6   b , and  6   c , a pin roller  662  is illustrated.  FIG. 6   a  shows a perspective view in elevation of the pin roller  662 . The pin roller  662  is mounted on a shaft  670 . The pin roller  662  consists of a curved surface interspersed with raised pins  682 . The pin roller  662  illustrated has an overall tube length  672  of 20.0 inches or 508 mm. Referring to  FIG. 6   b , which is a side view of the pin roller  662  mounted on the shaft  670 , the height or outside diameter  676  of the tube  662  (not taking into account the pins  682 ) is 5.229 inches or 133 mm. Taking into account the pins  682 , the over diameter  674  of the pin roller  662  is 5.729 inches or 146 mm. In the embodiment illustrated, the height of each individual pin  682  from the tube surface of the pin roller  662  is 0.250 inches or about 6 mm. Further, the roller is spaced from the conveyor surface such that the end of the pins  682  are 1/16 inch away from the conveyor surface at the closest point. 
         [0038]      FIG. 6   c  is a cut away section of the pin roller surface flattened in order to illustrate the relative distance between the pins  682  and the pattern used. It can be seen that the pins  682  are arranged in a triangular pattern resulting in a series of vertical and horizontal rows.  FIG. 6   c  is oriented such that the horizontal rows of pins  682  are parallel to the shaft  670  and the vertical row of pins  682  are perpendicular to the shaft  670 . The vertical distance  688  between pins  682  in vertical rows is 1.0 inches or 25 mm, while the vertical distance  680  as between pins  682  in adjacent vertical rows is 0.50 inches or 13 mm. The horizontal distance  684  between adjacent vertical rows is 0.866 inches or 22 mm, while the horizontal distance  686  between two vertical rows separated by a third vertical row is 1.7320 inches or 44 mm. The roller  662  depicted, therefore, is 23 pins wide and 18 pins around. Each pin  682  has a spherical radius of 0.188 inches. 
         [0039]    The pins  682  illustrated in  FIGS. 6   a ,  6   b , and  6   c  provide for points of increased pressure along the bread tube during the pressing step. For a dough thickness out of the sheeter of about 3/32 inch, a press gap of 1/16 inch is preferred in order to impart the desired structure for a pita chip end product. The pressing with a nub press or pin roller of such configuration is preferable because it allows for a continuous process, providing controlled contact or press points without completely flattening the strips, which in turn contributes to the textural characteristics of the end product. The triangular pattern center of 1 inch is optimized for the thickness of the product to manage the span between the attachment points to minimize breakage. This varies depending on product thickness and strength. 
         [0040]    Returning again to  FIG. 1 , after the pressing step  112  is accomplished, the now flattened and partially cooked strips continue along a conveyor and are allowed to cool, typically in ambient conditions, for between 12 minutes and 20 minutes. Referring again to the dough formulation listed in Table 1, is it preferable for the formation of a pita chip that the dough be allowed to cool at this cooling step  114  for approximately 15 minutes. 
         [0041]    If it is desirable to produce a pita chip wherein one side of the chip is characteristic of the outside surface of a pita and the other side of the chip is characteristic of the inside surface of the pita pocket, Applicants&#39; invention can optionally employ a splitting step  116  that involves splitting the piece along its lateral edges. This can be done, by example, with a modified band saw typically used for cutting bread. In a preferred embodiment, however, the flattened strips proceed to a cutting step  118 , typically involving a cutting roller, that can cut the strips into chip sized shapes, such as rectangular shapes or triangular shapes. A rectangular shaped chip is illustrated in  FIG. 4 , which shows a pita chip  420  with an upper surface  422 , a lower surface  424 , and two lateral edges  426 ,  428 . It can be seen that this end product  420  exhibits an undulating exterior surface. The interior surface also maintains variations in the distance between the two distinct layers of the chip  120  produced by the process, such that in places the layers are physically connected and in other are separated slightly by small pockets of between 0.5 mm and 2.0 mm in height, for example. 
         [0042]    After cutting the strips to form the chips  420  shown in  FIG. 4 , the chips  420  are finished cooked and seasoned. This finish cooking can involve convection baking, hot air drying, microwave cooking, frying, or other finish cook methods known in the art in order to lower the end product moisture level to a desired end point. In a preferred embodiment, the moisture level is lowered to between 3% and 1% by weight. Thereafter, the finished product is packaged by methods known in the art. 
         [0043]    Table 2 below shows the composition of a finished product in accordance with one embodiment of Applicants&#39; invention. The ingredients are listed by weight percentage of the finished crisp. 
         [0000]    
       
         
               
               
               
             
               
               
               
             
           
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                 Finished Product Composition 
                 Percentage 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Wheat Flour 
                 73.3 
               
               
                   
                 Salt 
                 2.4 
               
               
                   
                 Sugar 
                 1.8 
               
               
                   
                 Yeast 
                 2.8 
               
               
                   
                 Oat Fiber 
                 0.9 
               
               
                   
                 Vegetable Oil 
                 17.4 
               
               
                   
                 Water 
                 1.4 
               
               
                   
                   
               
             
          
         
       
     
         [0044]    It should be noted that the entire process described as Applicants&#39; preferred embodiment involves the continuous movement of the dough or product starting from the sheeting step through the finish cooking and seasoning step. The process is intended to take place using conveyors along with equipment that accommodates the continuous operation of each of the steps described. This allows for the continuous production of a flat bread type product without the need for the use of the dough ball and hot press equipment used in prior art. Equipment used in this continuous process is said to be ‘in communication,” because dough and/or product moves continuously from one piece of equipment (such as sheeter, proofer, oven, press, etc.) to the next piece of equipment. 
         [0045]    Further, while Applicants&#39; invention has been described with reference to a pita chip embodiment, the processing steps and equipment used with Applicants&#39; invention and described herein are equally adaptable for producing any number of types of flat bread products on a continuous processing line, including crackers. Adjustments can be made to the initial dough composition and various processing parameters, including cooling times, oven temperatures, dwell times at various stages, and temperature and humidity during the proofing stage, to produce flat bread products of varying types and consistencies. For example, a differential speed in conveyors of 2:1 can be used between the proofing step and oven to create a cracker like texture in the final product by stretching the dough before cooking. It should be understood that Applicants&#39; invention can substitute for the prior art dough ball and hot press method and equipment in order to produce any type of flat bread, such as the East Indian Naan bread, previously made by prior art methods but with the efficiencies and throughput of a continuous process. 
         [0046]    While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.