Abstract:
A system and method are provided for forming IQF shreds of mozzarella cheese into a bead form and depositing the bead on the periphery of a pizza crust for forming a pizza with a cheese stuffed rim. The IQF shreds are heated and then extruded to form the bead placed on the crust periphery via a high speed extrusion head. Heating and extrusion techniques are disclosed that work the IQF shreds into an extrudable mass or paste that, although lacking the desired stringiness quality, reconstitutes upon baking such that stringiness comparable to more expensive string mozzarella cheese is achieved.

Description:
This application claims benefit of provisional appln. Ser. No. 60/153,798 filed Sep. 14, 1999. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to a system for depositing cheese on a pizza crust and, more particularly, to a system for forming a bead of cheese on the periphery of a crust for forming a stuffed rim thereof 
     BACKGROUND OF THE INVENTION 
     Currently, precooked frozen pizzas that have a rim stuffed with cheese are made by manually placing strips of string mozzarella cheese about the periphery of the crust with the edge of the crust folded over thereon. As is apparent, the manual labor required with the making of the stuffed rims is labor intensive and limits production rates. 
     Another shortcoming of the above-described process is in the use of string cheese. First, string cheese is a relatively expensive raw material due in part to the fact that it is a perishable item which requires that it be manufactured when fresh. Another problem is that string mozzarella cheese typically is not manufactured in large quantities because of its perishable nature, e.g. shelf life of approximately 14 days. On the other hand, IQF (Individually Quick Frozen) shreds of mozzarella cheese are generally lower in price because they are frozen which allows the manufacturer to make large quantities of the cheese when their raw material costs therefor are low and slow down or temporarily cease manufacture when raw materials are at higher costs. 
     Accordingly, there is a need for an improved system and method for producing pizza crusts having cheese filled rims. Further, the system and process should be able to produce large quantities of the stuffed crusts with high production throughput while minimizing costs associated therewith. 
     SUMMARY OF THE INVENTION 
     In accordance with the invention, a system and method are provided for forming IQF shreds of mozzarella cheese into a bead form and depositing it on the periphery of a crust for a pizza. The invention heats and extrudes the IQF shreds with the extrudable mass formed into a bead for placement on the crust about the periphery thereof. The body of the cheese in its bead form lacks the desired stringiness characteristic of string mozzarella cheese. This stretchiness or string characteristic is one feature that makes string mozzarella cheese particularly well-suited for use with pizza. However, after the pizza crust including the bead of cheese is baked, it has been found that the cheese reconstitutes to provide a stringiness characteristic thereto similar to that provided by string mozzarella cheese. 
     In one form of the invention, a system is provided for forming a paste-like bead of cheese from small frozen shreds of cheese and depositing the bead on a pizza crust. The system includes a heating apparatus having a chamber for receiving the frozen cheese shreds and a tempering portion for raising the temperature of the cheese shreds for further processing. An extrusion apparatus is provided for forming the cheese shreds into an extrudable mass. The extrusion apparatus includes an advancing mechanism which drives the mass of cheese for being deposited onto the pizza crust. An extrusion head is provided for the extrusion apparatus and has at least one outlet from which the cheese exits to form and deposit the bead on the crust. Accordingly, the present system allows for use of IQF mozzarella shreds and obviates the manual labor of having workers manually place the mozzarella strings on the crust about its periphery, thus reducing raw material and labor costs associated with the process of forming cheese stuffed rims for frozen pizzas. 
     In another aspect of the invention, an automated method of making pizza crusts having a rim full of cheese is provided. The automated method includes providing a crust having a peripheral region thereabout, heating small shreds of frozen mozzarella cheese, extruding the heated mozzarella cheese to a smooth paste-like body of cheese in a bead form with the body lacking stringiness, depositing the bead of cheese about the peripheral region of the crust, folding an edge of the crust over the bead of cheese, and baking the crust with the mozzarella cheese bead reconstituting so that the body has stringiness. The method uses IQF mozzarella shreds formed into a paste so it can be laid down as a bead about the crust with the body of the bead lacking the stringiness quality desired for pizza cheeses. However, after cooking, the mozzarella in the bead reconstitutes so that it has string similar to the more expensive string mozzarella cheese. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of IQF shreds of mozzarella cheese; 
     FIG. 2 is a view of string mozzarella cheese and manual placement thereof on pizza crusts; 
     FIG. 3 is a perspective view of a ribbon blender; 
     FIG. 4 is a perspective view of the ribbon blender of FIG. 3 with IQF cheese shreds therein; 
     FIG. 5 is a perspective view of an extruder including a hopper and extruder housing for receiving the IQF shreds of cheese after processing by the ribbon blender; 
     FIG. 6 is a perspective view of a passageway of the extruder including rotary drives for extruder screws shown in phantom; 
     FIG. 7 is a perspective view of a disassembled extrusion head including rotary valve members and control linkages therefor; 
     FIG. 8 is a perspective view similar to FIG. 7 showing the extrusion head assembled; 
     FIG. 9 is a perspective view of the assembled extrusion head similar to FIG. 8; 
     FIG. 10 is a perspective view of a crust forming pan for supporting six crusts for processing; 
     FIG. 11 is a perspective view of dough formed into crusts in the pan; 
     FIG. 12 is a perspective view of the extrusion heads over the crusts; 
     FIG. 13 is a perspective view of the extrusion heads depositing a bead of cheese on the crusts; 
     FIG. 14 is a perspective view of the crusts having beads of cheese thereon; 
     FIG. 15 is a perspective view of one of the beads of cheese on a single one of the crusts; 
     FIG. 16 is a perspective view of the upper flanged portion of the crusts cut therefrom; 
     FIG. 17 is a perspective view of the upstanding edge wall folded over the cheese bead; 
     FIG. 18 is a perspective view of the fold over mechanism for folding the crust wall over the cheese bead; 
     FIG. 19 is a perspective view of the crusts with the folded over wall crimped down over the cheese bead; 
     FIG. 20 is a perspective view of the crusts being dropped from the crust forming pan for further processing; and 
     FIG. 21 is a perspective view of the crust in a support pan therefor with the rims folded over the beaded cheese. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention provides a system and method that allows for the use of IQF shreds  10  (FIG. 1) of mozzarella cheese such as LMPS mozzarella to be used as the starting material in making a stuffed pizza crust  12 , and in particular, a stuffed rim  14  thereof. The use of the small frozen IQF shreds, e.g., quarter inch by quarter inch blocks, is advantageous over the prior use of string mozzarella cheese  16  (FIG. 2) in terms of costs and because frozen IQF shreds  10  can maintain their melt characteristics for long periods of time and without experiencing the negative effects of enzyme modification before the cheese ages. In addition, the present system and method as described hereinafter provides for automated depositing of the bead  18  of mozzarella cheese having a smooth paste-like consistency on the crust thus avoiding the manual labor required for having workers manually place the string cheese  16  about the crust  12  for making the stuffed rims  14  thereof. 
     Initially, the IQF shreds  10  are fed into a heating apparatus  20  in the form of a ribbon blender, as shown in FIGS. 3 and 4. The ribbon blender  20  includes a chamber  22  having a pair of laterally spaced drive shafts  24  and  26  that are driven for rotation in opposite directions therein. Two helical or auger type ribbons  28  and  30  are mounted to the drive shaft so that rotation of the shafts  24  and  26  causes the IQF shreds to travel longitudinally in the chamber  22  first in one direction as indicated by arrow  32  as driven by helical ribbon  28  and then in the opposite direction indicated by arrow  34  as driven by helical ribbon  30 . 
     The IQF cheese shreds  10  are tempered or heated in the chamber  22  via a heating portion of the ribbon blender  20  in the form of a hot water jacket  36  that is disposed about the chamber  22 . As the IQF shreds  10  traverse the length of the chamber  22  in both directions  32  and  34 , the dwell time in the chamber  22  is maximized for heat transfer from the hot water jacket  36  to raise the temperature of the IQF mozzarella shreds  10 . 
     After the IQF mozzarella shreds  10  have been tempered or heated in the ribbon blender  20 , they are transferred to an extrusion apparatus  38  as shown in FIG.  5 . 
     The extrusion apparatus  38  includes a hopper  40  which funnels and feeds the tempered IQF mozzarella shreds  10  into a passageway  42  in the housing  43  of the extruder  38  below the hopper  10 , as shown in FIG.  6 . The passageway  42  redirects the tempered IQF mozzarella shreds  10  in a generally horizontal direction via an advancing mechanism, generally designated  44 . The advancing mechanism  44  includes a pair of rotatable couplings  46  and  48  for rotating extruder screws,  50  and  52 , shown in phantom. 
     The screws  50  and  52  extend parallel to each other and are rotated in the same direction so that the IQF mozzarella shreds  10  are advanced from one end of the passageway  42  downstream to extrusion heads  54 . The screws  46  and  48  are sized relative to the passageway  42  and rotated at a speed such that the IQF mozzarella shreds  10  are worked into an extrudable mass. It is important that the extrusion be tailored so that the working of the IQF mozzarella shreds  10  does not release oil therefrom and generate oiling off problems, as are known to be undesirable in the pizza making art. It has been found that generating a pressure of approximately 300 to 400 psi in the extruder  38  is sufficient to create an extrudable mass of the cheese without generating oiling off problems. To this end, a control is provided which senses a maximum pressure that cannot be exceeded before the control will act to shut off the drive for the extruder screws  50  and  52 . 
     FIGS. 7-9 depict an extrusion head  54  which communicates with the extruder passageway  42 . In the illustrated and preferred form, the extruder head  54  has an inverted V-shape including an inlet  56  from which a pair of tubular arms  58  and  60  are branched having respective outlets  62  and  64  at ends distal from the inlet  56 . 
     The extrusion heads  54  are preferably mounted so that their inlets  56  are disposed above the center of the pizza crust  12  so that rotating the extrusion head  54  via a drive deposits the bead  18  having a smooth, paste-like consistency about a peripheral region  66  of the crust  12 . As noted, the body of cheese in the bead form lacks the desired stringiness characteristic for pizza cheese. The distance between the outlets  62  and  64  substantially matches that of the diameter of the predetermined position on the crust peripheral region  66  at which the substantially circular bead  18  is to be deposited. Referring to FIGS. 12-14, the extrusion head  54  is rotatably coupled to the extruder  38  so that the head  54  can be rotated 180 degrees in one direction while it deposits the bead  18  with each arm  58  and  60  depositing one half of the circular pattern for the bead  18 , and then being rotated back with the outlets  62  and  64  closed to its starting position for the next crust  12 . As shown in FIG. 11, a crust forming pan  68  is provided with six openings  70  in which the pizza crust is initially formed. Accordingly, in the preferred and illustrated form six extrusion heads  54  are coupled to the extruder  38  and are simultaneously rotated by a drive including a motor and a belt for rotating the rotatable couplings between the extrusion heads  56  and the extruder  38 . In this fashion, extremely high production rates can be obtained with the system and method of the present invention. In this regard, approximately one-hundred crusts per minute having beads  18  of mozzarella cheese deposited thereon can be made. 
     As can be seen in FIGS. 7-9, the ends of the arms  58  and  60  distal from the inlet  56  include respective valve housings  72  and  74  having cylindrical throughbores  76  and  78  that are oriented transverse to the length of the arms  58  and  60 . The bores  76  and  78  are adapted to receive rotary valve members  80  and  82  therein. The valve members  80  and  82  have a cylindrical body with a T-shaped cutout extending transversely therethough. More specifically, the T-shaped cutout includes a slotted inlet end  84  from which a central passageway  86  extends to an outlet end  88 . Accordingly, the slotted inlet end  84  extends for a greater extent along the circumference of the cylindrical body of the rotary valve members  80  and  82  than the outlet end  88  thereof. In this manner, as the rotary valve members  80  and  82  are rotated between open and closed positions in their respective housings  72  and  74  as will be described more fully hereinafter, the elongated or slotted inlet end  84  stays in communication with the passageway through the tubular arms  58  and  60  and thus the passageway  42  of the extruder  38  whether in the opened or closed positions. This provides advantages in terms of the starting and stopping of the depositing of the bead  18  as the slug of cheese in the rotary valve members  80  and  82  remains, in effect, connected to the extrudable mass in the head  54  and extruder  38  so that discontinuities or other deformities that may be created in the circular pattern of the bead  18  at the starting and stopping points of the depositing of the bead  18  by the extruder head arms  58  and  60  are minimized. 
     The cylindrical rotary valve members  80  and  82  are sealed in the bores  76  and  78  of their respective housing  72  and  74  by way of annular O-ring seals  90  mounted about either end thereof. The valve members  80  and  82  are provided with an extension portion  130  which projects out from the housing, as best seen in FIGS. 8 and 9. The extension portion  130  has an annular groove  132  formed thereabout and into which a hook member  134  pivotally mounted to each of the housings  72  and  74  is received to prevent the valve members  80  and  82  from sliding laterally out from the housing bores  76  and  78 . 
     For shifting the rotary valve members  80  and  82  between their opened and closed positions, control linkages, generally designated  94  are provided. The linkages  94  can include a power cylinder such as pneumatic cylinder  96  having a piston rod  98  connected at its distal end to a link plate  100 . The plate  100  is attached to the piston rod  98  at one end and to the rotary valve member  80  at its other end so that as the piston rod  98  is extended and retracted by operation of pressurized air through lines  102  and  104 , the plate  100  will rotate the valve member  80  so that its outlet end  88  is in registry with the outlet  62  of the valve housing  72  with the valve member  80  in its open position or rotated so that the valve member outlet end  88  is sealed by a wall of the housing  72  in its closed position. A rod  106  is attached at one of its ends to the plate  100  intermediate the attachments of the plate  100  to the piston rod  98  and rotary valve member  80  with the rod  106  attached at its other end to a link plate  108  which, in turn, is attached to the other rotary valve member  82 . In this manner, extension and retraction of the piston rod  98  rotates both the valve members  80  and  82  in a synchronized manner so that both are opened and closed at the same time. 
     As previously mentioned, the preferred crust forming pan  68  has six openings  70  having generally vertical annular walls  110  bounding the openings  70  with slots  112  spaced equidistantly about the circumference of the walls  110 , as best seen in FIG.  10 . Dough is tamped into the openings  70  and supported by a bottom pan plate  113  therein to form initial crusts having an upstanding edge wall  114  about the peripheral region  66  of the crust and an upper flanged portion  116  projecting radially out from the top of the wall  114 . The extrusion heads  54  deposit the beads  18  in a substantially circular pattern about the peripheral region  66  generally between the bottom of the crust  12  and the edge wall  114 , as best seen in FIGS. 12-15. 
     Thereafter, the upper flange portion  116  is cut so as to be severed from the remainder of the crust  12 , as shown in FIG.  16 . The upstanding edge wall  114  is then folded over the bead  18  of mozzarella cheese, as can be seen in FIG.  17 . For this purpose, several pivotal knock-down members  118  associated with each of the slots  112  is mounted to a platen  120 . When the crust arrives at the fold-over station of FIGS. 17 and 18, the platen  120  is raised and the knock-down members  118  are pivoted through their slots  112  to engage the outer side of the upstanding edge wall  114  for folding it down over the circular bead  18  of cheese on the crust peripheral region  66 . 
     After the edge wall  114  has been folded over as described, it is crimped (FIG. 19) to form the cheese stuffed rim  14  of the pizza crust  12 . The support plate  113  for the crust  12  then drops away from the crust forming pan  68  (FIG. 20) for further processing, such as proofing and baking. 
     As has been stated, it has been found that after the crust  12  including the cheese bead  18  has been baked, the body of the cheese in the bead reconstitutes with the desired stringiness characteristic. It had been assumed that the mozzarella cheese after working as through an extrusion process would not obtain this quality and instead it was expected that cheese melts and/or processed cheeses would have to be used in the present application. However, it has been found that with careful design and selection of the equipment and the operating conditions thereof as specified herein, the cheese stuffed rim  12  can be formed by an automated process and using lower cost IQF shreds  10  as the starting material while achieving commercially satisfactory results in terms of the texture and stringiness characteristics of the cheese. 
     While there have been illustrated and described particular embodiments of the present invention, it will be appreciated that numerous changes and modifications will occur to those skilled in the art, and it is intended in the appended claims to cover all those changes and modifications which fall within the true spirit and scope of the present invention.