Abstract:
Visually distinct, flaked Ready-to-Eat (“R-T-E”) cereal products with varied texture and thickness are produced by forming a cereal dough and forcing the same through an extrusion die assembly including various spaced openings which establish a plurality of dough streams which are merged prior to reaching a die outlet. Directly at the die outlet, a resulting dough extrudate is sliced by a cutter unit to form dough discs which are then dried and cooled, during which the discs curl and form cereal flakes having varying textures defined, at least in part, by distinct sets of surface bumps. The number and configuration of the bumps can be altered by changing the number, shape and/or position of the various spaced openings of the die assembly, while the thicknesses of the resulting cereal flakes can be varied by just altering an operational speed of the cutter unit.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a divisional of U.S. patent application Ser. No. 13/372,977 filed Feb. 14, 2012 entitled “Method and Apparatus for Making Cereal Flakes”, pending. The entire contents of this application are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The invention relates to food products and, more particularly, to a method and apparatus for making cereal flakes. In particular, the invention relates to the making of flakes for ready-to-eat breakfast cereals by extruding and cutting cooked cereal dough. 
         [0003]    A wide variety of food products are prepared from cooked cereal doughs, especially ready-to-eat (“RTE”) or breakfast cereals, as well as a variety of snack products. Generally in the preparation of the cooked cereal dough, cereal or farinaceous ingredients, such as various cereal flours, are first admixed with other dry ingredients such as salt, minerals, starch, sugars, to form a dry blend of ingredients and then is further blended with various liquid ingredients, including water, heated and worked to gelatinize or cook the starch fraction of the cereal ingredients and other starchy materials. A wide variety of blending, cooking and working apparatuses and techniques are well known. 
         [0004]    More recently, the preparation of a cooked cereal dough using a cooker extruder, especially a twin screw extruder, has become commonplace. The cooked cereal doughs so prepared can be processed to form finished products of various size, textures and shapes. Typically, a post, cooked cereal dough formation step involves forming suitably sized and shaped individual pieces and drying to form finished cereal base pieces, such as shreds, flakes, biscuits or puffs. Thereafter, the finished dried cereal base pieces can have a topical coating applied to provide desired taste and texture attributes. For instance, in the preparation of a breakfast cereal, the topical coating can include a sugar coating. 
         [0005]    Of particular interest to the invention is the making of flake-type ready-to-eat (RTE) cereal products. A typical production arrangement is illustrated in  FIG. 1  wherein various ingredients, such as a grain-based ingredient, syrup and water  2 ,  4  and  6  are blended together and cooked in an initial extruder  15  to form a cooked cereal dough  18 . The cereal dough  18  can undergo additional cooking, if desired, in a downstream cooking vessel  22 , prior to being formed into individual pellets  28  in a pelletizer  32 . The pellets  28  are then dried in a dryer  36  to establish dried pellets  40 . Thereafter, the dried pellets  40 , which can also be otherwise conditioned, are converted into thin wet flakes  44  in a flaking or flake forming step wherein the pellets are directed through flaking roller  48 . Thereafter, the wet thin flakes  44  are dried and optionally puffed at  52  and/or toasted at  56  prior to reaching a final cooling zone  58  to produce a final flaked cereal product  60 . 
         [0006]    Although very effective, this method of producing cereal flakes includes numerous steps, each having associated manufacturing structure. To minimize this structure, it has also been proposed to form cereal flakes by forcing extruded cereal dough through a slotted die and, after extruding a desired length of the dough, the extrudate is cut and dried as represented by U.S. Patent Application Publication 2010/0055282. Although minimizing the structure needed to produce flakes, this arrangement has various disadvantages, in particular the inability to readily vary thicknesses of the flakes. With this known art in mind, there is seen to exist a need in the art for an apparatus and method to produce cereal flakes with minimal structure while still being able to readily vary flake thickness. 
       SUMMARY OF THE INVENTION 
       [0007]    The invention pertains to the formation of cereal flakes, particularly visually distinct, flaked Ready-to-Eat (“R-T-E”) cereal products with varied texture and thickness produced by forming a cereal dough within a cooker extruder and forcing the same through an extrusion die assembly including at least one die port establishing various spaced openings to create a plurality of dough streams which are merged in a convergence zone prior to reaching a die outlet. Directly at the die outlet, a resulting dough extrudate is sliced by a cutter unit to form dough discs which curl and form cereal flakes having varying textures defined, at least in part, by distinct sets of surface bumps and then are dried and cooled. The number and configuration of the bumps can be altered by changing the number, shape and/or position of the various spaced openings of the die assembly, while the thicknesses of the resulting cereal flakes can be varied by just altering an operational speed of the cutter unit. 
         [0008]    Additional objects, features and advantages of the invention will become more readily apparent from the following detailed description of the invention wherein like reference numeral refer to corresponding parts in the several views. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  schematically illustrates a flow process employed in connection with the making of cereal flakes in accordance with a known prior art arrangement. 
           [0010]      FIG. 2  is a schematic of a flow process employed in accordance with the invention to make cereal flakes. 
           [0011]      FIG. 3  is a partial perspective view of a die plate employed in making cereal flakes in accordance with the flow process of  FIG. 2 . 
           [0012]      FIG. 4  is an enlarged, partial cross-sectional view of a portion of the die plate of  FIG. 3 , showing a stage in the formation of the cereal flakes. 
           [0013]      FIG. 5  is an enlarged view of a cereal flake constructed in accordance with the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]    The invention relates to an apparatus and a method for making flaked ready-to-eat (R-T-E) cereal products, along with a uniquely structured cereal flake produced thereby. More specifically, with initial reference to  FIG. 2 , the apparatus of the invention is generally indicated at  75 . As shown, apparatus  75  includes a cooker extruder  78  into which various cereal ingredients  81 - 83  are supplied to form a cooked cereal dough. At this point, it should be noted that cereal ingredients  81 - 83  may take the form of a wide range of cereal components suitable for cooking and extrusion. By way of example, ingredient  81  constitutes a dry, processed starchy cereal ingredient,  82  constitutes a syrup and ingredient  83  constitutes water. The cereal ingredient  81  can be formed with appropriately sized particles of whole grains supplied by any of the major cereal grains including wheat, corn (maize), oats, barley, rye, rice, and mixtures thereof. In one form, the cereal ingredient  81  has only fine particles so as to constitute a cereal flour. The cereal ingredient  81  can comprise from about 40 to 99% (dry basis) of the cooked cereal dough. Better results in terms of organoleptic attributes and reductions in R-T-E cereal piece frangibility are obtained when the cereal ingredient(s) comprises about 75 to 95% of the cooked cereal dough composition. The dry ingredients can also include various minor ingredients or additives, such as sugar(s), salt and mineral salts, e.g., trisodium phosphate, and starches which can conveniently be pre-blended with ingredient  81 . Ingredient  82  can actually be constituted by various liquid ingredients, such as corn (maize) or malt syrups or the like. The amount of moisture from ingredients  82  and  83  will depend on various factors, including the particular cereal ingredients, cooking temperature and working techniques employed. The moisture content of the cooked cereal dough typically ranges from about 20-30% before exiting cooker extruder  78 . If desired, the cereal dough can additionally comprise about 0.1 to about 20% (dry weight) by weight sugar(s) or, synonymously herein, nutritive carbohydrate sweetening agents, particularly about 0.5% to 5%. Such materials are also well known in the R-T-E cereal art. Useful herein as the sugar component is sucrose. However, the sugar(s) component can additionally comprise conventional fructose, maltose, dextrose, honey, fruit juice solids, brown sugar, and the like. In addition to providing desirable sweetness, the sugar component additionally beneficially affects the cereal color and texture. Conveniently, the sweeteners can be added in with the starchy ingredient  81  or the syrup ingredient  82 . 
         [0015]    If desired, the cereal dough composition can additionally include a variety of materials designed to improve the aesthetic, organoleptic or nutritional qualities of the cereal. These adjuvant materials can include vitamin and/or mineral fortification, colors, flavors, high potency sweetener(s), and mixtures thereof. The precise ingredient concentration in the cereal composition can certainly vary. Generally, however, such materials can each comprise about 0.01% to about 2% dry weight of the cereal composition. One especially useful material is common salt. 
         [0016]    Although not shown, cooker extruder  78  can be defined by an Archimedes-type single or twin screw extruder which is driven by a motor  86  linked through a communication line  88  to a CPU  90 . In a particular form, the screw extruder is equipped with a screw configuration designed to minimize imparting shear to the cooked cereal mixture. Both single and twin screw extruders are widely known in the art and suitable for the control of shear. As will become more fully evident below, the use of cooker extruder  78  has the advantage of enabling a continuous process. When taken in conjunction with other aspects of the invention, an overall minimization of manufacturing components and required space is achieved. In addition, the use of a continuous process can have advantages with respect to processing of large volumes, as well as lowering costs for larger volume production. 
         [0017]    Apparatus  75  also includes a cold forming unit  94  having an outlet  97  at which is mounted an extrusion die  100 . At this point, although cooker extruder  78  and cold forming unit  94  are described as separate components of apparatus  75 , it should be recognized that cooker extruder  78  and cold forming unit  94  can be integrated so as to define a single unit as represented in  FIG. 2 . Mounted directly adjacent cold forming unit  94  is a cutter unit  104  including a hub  107  which rotatably supports a plurality of cutter arms  109  having secured thereto respective blades  111 . Cutter unit  104  includes a motor  105  for driving rotatable cutter arms  109 , with motor  105  being linked through a communication line  117  to CPU  90 . Certainly, various types and configurations for cutter unit  104  can be employed. One particular embodiment employs a cutter unit having a central axis aligned with the center of extrusion die  100 , i.e., the cutter unit and die  100  have a common central axis. In addition, the cutter unit has an outside diameter that is similar in size to the outside diameter of the die  100 . With this arrangement, all of the blades  111  are in substantial contact with a frontal die surface at all times. At this point it should just be noted that various types of cutter units could be employed, with one particular arrangement being set forth in more detail in U.S. Pat. No. 6,767,198 which is incorporated herein in its entirety by reference. 
         [0018]    In operation, ingredients  81 - 83  are introduced into cooker extruder  78  of apparatus  75  and blended to form a cereal mix which is cooked and mechanically worked in order to form a cereal dough. Through activation of motor  86 , the cereal dough is directed through cold forming unit  94  and through extrusion die  100  in the form of an extrudate. Timed with the ejection of the extrudate, cutter arms  109  of cutter unit  104  rotate so as to slice the extrudate directly at outlet  97  to form dough discs  122  (also see  FIG. 4 ). Dough discs  122  are transferred by a conveyor  125  through a drying zone  126 , such as a toasting zone, and then through the same or another conveyor  130  to a cooling zone  132 . Upon exiting cooling zone  132 , dough discs  122  have been transformed into cereal flakes, such as that indicated at  135 . By way of example, the toasting can be practiced at about 185° C. (365° F.) for about 10-30 seconds to toast the cereal flakes  135 . The toasted flakes are dried to about 2-5% moisture. Cooling zone  132  can be used to establish a temperature of about 21-32° C. (70-90° F.) to arrest the toasting and to bring the toasted flakes to near ambient temperatures. 
         [0019]    As shown in  FIG. 2 , each cereal flake  135  includes a lower body portion  139 , side portions  141  and a peripheral edge portion  143 . Based on being dried and cooled, cereal flake  135  is curled and, based on the particular structure of extrusion die  100  as will be discussed more fully below, cereal flake  135  is uniquely formed with a first set of bumps  146  in lower body portion  139  and a second side of spaced bumps  149  in side portions  141 . The flake thickness is also highly variable across individual pieces due to the production method employed and can range from, for example, about 0.1 to about 3 mm. Moreover, the cereal flakes  135  generally have at least some degree of curl rather than being highly planar. As a result, a quantity of such flakes will have a bulk density ranging from about 270-480 g/liter (170-300 g/100 3 inch), particularly about 350 g/liter (220 g/100 3 inch). If desired, cereal flakes  135  can be fabricated into presweetened R-T-E cereals such as by the topical application of a conventional sweetener coating. In other variations, an oil topical coating optionally with salt and/or flavors is applied to form finished dried snack products. In still another variation, the topical coating can additionally include particulates to provide added visual appeal. Finally, the finished dried R-T-E cereal can be packaged and distributed in conventional form. 
         [0020]      FIG. 3  illustrates a particular configuration for extrusion die  100 . As shown, extrusion die  100  includes a die head  155  having a central opening  158  and one or more adjacent apertures  160 , with opening  158  and aperture  160  being utilized for mounting purposes, including a distribution cone (not shown) and potentially an in-line cutter unit  104 . More importantly, die head  155  is provided with a plurality of spaced extrudate ports  164 . More specifically, with reference to both  FIGS. 3 and 4 , die head  155  includes a main body  169  which leads to a peripheral flange portion  171 . Main body  169  includes a substantially planar front surface  174  which is formed with an outer beveled edge  176 . Each of the plurality of extrudate ports  164  is formed within main body  169  and includes a first diametric portion  180  which leads to a second, reduced diametric portion  183 . With this arrangement, an internal ledge  186  is defined between first and second diametric portions  180  and  183 . 
         [0021]    In each of the plurality of extrudate ports  164 , extrusion die  100  receives a die insert assembly  190 . Although die insert assembly  190  could be formed as a single piece, in accordance with one form of the invention, die insert assembly  190  includes a die sleeve  193  defined by a substantially smooth, cylindrical main body  195  which defines a die convergence zone from which extends a peripheral flange  197 . Die sleeve  193  is inserted into a respective one of the plurality of extrudate ports  164  such that peripheral flange  197  abuts internal ledge  186  while an outermost exposed surface  200  of die sleeve  193  is substantially flush with front surface  174 . Upstream of die sleeve  193  is a breaker plate  205  formed with a plurality of geometric openings  207 . Each of the plurality of geometric openings  207  actually extend entirely through breaker plate  205  and are exposed to the convergence zone. That is, an outermost radial portion (not separately labeled) of breaker plate  205  abuts peripheral flange  197  and each of the plurality of geometric openings  207  are arrange radially inward of this abutment region. 
         [0022]    With this arrangement, the formed, homogeneous blended cereal dough is directed to extrusion die  100  wherein a portion of the cooked cereal dough enters a respective one of the plurality of extrudate ports  164 , and then is divided into a plurality of extrudate streams upon being forced through the plurality of geometric openings  207 . Thereafter, the plurality of extrudate streams are merged and fused within the convergence zone defined by main cylindrical body  195  to form a single extrudate stream which exits extrusion die  100  with an outer surface that is substantially parallel to front surface  174 , while also being of uniform thickness. At the same time, CPU  90  controls the operation of motor  115  in order to rotate cutter arms  109  such that a cutting edge  210  of a respective blade  111  slices the emerging extrudate  214  into dough discs  122  having a uniform thickness. 
         [0023]    With this overall arrangement, it should be readily apparent that the additional structures previously employed in the prior art to include at least a pelletizer, pellet dryer and flaking roll, such as described with respect to  FIG. 1  and set forth in U.S. Pat. No. 7,413,760 which is incorporated herein in its entirety by reference, are avoided. In addition to advantageously reducing the number of stages and structure needed to form cereal flakes, apparatus  75  of the invention establishes uniquely configured cereal flakes  135  as represented in  FIGS. 2 and 5 . That is, through the use of the plurality of geometric openings  207  in breaker plate  205 , a controlled flow of cereal dough is established which emerges from extrusion die  100  with a face that is uniform, i.e., neither substantially concave or convex, until cut to create a cereal flake  135  having varying density regions throughout its body which are interconnected. Due to the fusing of dough after breaker plate  205 , in the formation of each cereal flake  135 , bumps are formed in these regions and the bumps can take various configurations. In particular, it has been surprisingly found that, in lower body portion  139 , the first set of bumps  146  establish a generally flower-like pattern through interconnected, generally trapezoidal-shaped undulations as clearly shown in  FIG. 5 . On the other hand, in side portions  141 , the second set of bumps  149  are generally more circular, oval or oblong. Certainly, the particular configurations of first and second sets of bumps  146  and  149  can be varied by altering the geometric shapes of the plurality of geometric openings  207 , such that the circular configuration merely represents one embodiment of the invention. 
         [0024]    With this arrangement, it should be advantageously apparent that the rate at which the extrudate  214  exits extrusion die  100  and the speed at which cutter unit  104  is operated could be used to determine the thickness of each flake disc  122 . However, the timing employed in cooker extruder  78  and cold forming unit  94  in the formation of the cereal dough is desirably maintained substantially constant for dough consistency. Therefore, in accordance with the invention, the thickness of each cereal flake is readily varied by just altering the speed of operation of motor  115  through CPU  90 . For exemplary purposes, the dough discs  122  formed can have a thickness ranging from say 375-750 micrometers (“μm”) (≈0.0175-0.030 inch). Extrusion die  100  is shown with various extrudate ports  164 , the number of which can vary from one to many more depending on the size of front surface  174 . Most importantly, it should be understood that each extrudate port  164  receives a corresponding die insert assembly  190  and each die insert assembly  190  creates a separate dough disc  122 . As shown, a single action of one cutting arm  109  can produce numerous dough discs  122  and, correspondingly, numerous cereal flakes  135 . In addition, the number, size and/or geometric shape of each opening  207  can be varied to establish another uniquely configured cereal flake  135 . For instance, one other particularly advantageous shape for openings  207  is oval. The finished cereal flakes  135  would typically be packaged in a sealed bag which is arranged inside an outer carton. In any case, the cereal flakes  135  can be packaged alone or in combination with other cereal particulates, such as dried fruit, marbits, nuts, clusters of agglomerated grains, granola and/or the like. The cereal flakes  135  are also suitable as an additive to a packaged snack mix including other cereal pieces, pretzels, dried fruit, chocolate pieces, nuts and the like. 
         [0025]    With the above in mind, it should be readily apparent that the invention has been described with reference to certain embodiments of the invention and that various changes and/or modifications can be made to the invention without departing from the spirit thereof. Instead, the invention is only intended to be limited by the scope of the following claims.