Abstract:
A method for creating hexahedron or cubed nut cluster having a high level of nuts or seeds. The invention is an improved process for manipulating and shaping high content nut and seed food products. In one aspect, the invention manipulates processing conditions to provide a nut slab high nut content nut slab that is conducive to slicing and cutting. In one aspect, the invention manipulates unit operation conditions so as to provide a method of slicing a high content nut slab into longitudinal strips in a continuous operation that minimizes or eliminates jamming at the cutting and/or stabbing conveyors.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention is directed towards a method for making a shaped nut cluster and more particularly to a method for making a plurality of nut-cluster hexahedrons and cubes. 
     2. Description of the Related Art 
     Snack foods are popular and convenient foods. In recent years, consumer demand has been dramatically increasing for healthy foods in general, and healthy snack foods in particular. Nuts and seeds are healthy, natural food products, but lack the sweet flavor that consumers demand. One prior art solution to providing a nut-based snack food is peanut brittle. Peanut brittle is typically made by mixing 40% to 60% raw nuts by weight with a binder solution. For example, U.S. Pat. No. 6,074,684 discloses a peanut brittle having 8 parts of peanuts to 6 parts of corn syrup and 4 parts of peanut butter to 3 parts of corn syrup by volume. Thus, before the peanut butter is added, which dilutes the amount of raw peanuts, the mixture has less than 60% by weight peanuts. Many consumers, however, are demanding even higher levels of natural food products in their snack foods. Unfortunately, it is difficult to make peanut brittle-like clusters at higher nut contents because it is difficult to form and cut the resultant mixture into squares on a commercial scale. As a result, as illustrated by U.S. Pat. No. 4,010,284, many nut clusters are simply made into irregularly shaped free formed clusters. Consequently, a need exists for a method for making a plurality of nut cluster cubes with a high nut content on a commercial scale. 
     SUMMARY OF THE INVENTION 
     The present invention is directed towards a method for making a plurality of high-nut content hexahedron-shaped clusters comprising the steps of admixing a raw food material with a binder syrup into a nut mixture such that said nut mixture comprises about 60% to about 85% of said raw material, placing said nut mixture having a controlled slab temperature on a slab conveyor moving in a longitudinal direction, compressing said nut mixture to make a nut slab with at least one compression roller, using at least one rotary slitter that comprises a rotational speed greater than a slab speed to simultaneously pull and slice said nut slab into longitudinal strips, and cutting said longitudinal strips in the transverse direction to form a plurality of hexahedron-shaped nut clusters. 
     In one aspect of the invention, the pliability of the slab is carefully controlled by adjusting the slab temperature. In one aspect, the cutting angle of the slitter is adjusted to reduce pressure at the slitter and facilitate slab movement through the slitter. In one aspect, the rotational speed of the slitter is adjusted relative to the slab speed to facilitate slab movement through the slitter. These as well as additional features and advantages of the present invention will become apparent in the following written Detailed Description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself however, as well as a preferred mode of use, 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: 
         FIG. 1  is a schematic indicating the processing steps for the present invention; and 
         FIG. 2  is a perspective view of a portion of the cutting station in accordance with one embodiment of the present invention; 
         FIG. 3   a  is an expanded linearized partial cross-sectional view of the outer circumference of the slitter in accordance with one embodiment of the present invention; 
         FIG. 3   b  is a partial end view of  FIG. 3   a ; and 
         FIG. 4  is a perspective view of a nut cluster made in accordance with one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The hexahedron-shaped nut clusters of the present invention are prepared using nuts and a binder syrup. As used herein, the term “hexahedron-shaped nut cluster” is defined as a shaped nut-cluster having six sides and encompasses cubes and quadrates having sides with equal or unequal areas.  FIG. 1  is a flowchart indicating the processing steps for the present invention. In one embodiment, nuts  110 , binder syrup  128 , and optionally seeds  130  at an elevated temperature, defined as a temperature above ambient, are placed into a continuous mixer  200  which extrudes the mixture onto a slabbing conveyor  300  where the mixture is compressed and cut into nut cubes on the cutting conveyor  400 . The nut cubes are then routed to a cooling conveyor  500  and are then routed to packaging  600 . 
     The mixture, consisting of all process streams  116   128   130  entering the mixer  200  preferably comprises between about 60% and about 85% and more preferably between about 65% and about 85% and most preferably between about 77% and about 82% of raw food material by weight of the total mixture entering the mixer  200 . As used herein, “raw food material” is defined as raw or roasted nuts or seeds. In one embodiment, whole nuts or seeds are used as opposed to chopped or cut nuts or seeds. The nuts used in the present invention can be selected from one or more nuts including, but not limited to, peanuts, cashews, almonds, walnut, pecan, chestnut, macadamia, pistachio, hazelnuts/filberts, brazil nuts and pine nuts. Further, the seeds used in this invention can be selected from one or more seeds including, but not limited to, sesame seeds, sunflower seeds, pumpkin seeds, flax seed, poppy seeds, and squash seeds. In one embodiment, the raw food material comprises about 1% to about 20% seeds. The combinations and ratios of nuts to seeds is specific to the nuts used, and optimized for consumer preferences, considering processability, supply and economics. As used herein, “nut mixture” is defined as a raw food material that has been admixed with a binder syrup and the term nut mixture is intended to encompass raw food mixtures having only seeds and no nuts admixed with a binder syrup as well as raw food mixtures having only nuts and no seeds admixed with a binder syrup. 
     In one embodiment nuts are roasted  112  in an oven operating at an oven temperature of between about 250° F. and about 300° F. and more preferably between about 265° F. and about 280° F. for between about 5 and about 15 minutes and more preferably for about 10 minutes. In one embodiment, nuts having a native moisture content of between about 3% and about 7% by weight are roasted  112  to a moisture content of about 0.5% to about 4% by weight and most preferably about 2% moisture by weight. The nuts, having an elevated temperature, can then be added directly to the mixer  200 . 
     In an alternative embodiment, pre-roasted nuts can be used. If nuts  116  at ambient temperature are mixed with the binder syrup  128  having an elevated temperature leaving the evaporator  126  in the mixer  200 , the nuts  116  may quickly lower the temperature of the syrup, the syrup may not flow properly and proper mixing and coverage of the binder syrup and the nuts or seeds may not occur. Consequently, if pre-roasted nuts or unroasted nuts are used it is preferred that the nuts be preheated  114  to a nut temperature that is sufficient to prevent substantial cooling of the nut mixture in the mixer  200 . In one embodiment, the nuts  116  entering the mixer  200  comprise an elevated nut temperature of between about 180° F. and about 200° F. In one embodiment, the temperature of the nut mixture in the mixer is between about 200° F. and about 250° F. and more preferably between about 21° F. and about 240° F. and most preferably between about 220° F. and about 235° F. 
     The composition of binder syrup ingredients  120  for one formulation is shown in Table 1. In addition, various acceptable ranges of binder syrup ingredients  120  are also shown. As indicated below, binder syrup ingredients comprise a base syrup such as corn syrup, brown rice syrup or rice malt, or honey; a sugar such as evaporated cane juice or sucrose, optionally sea salt, and optionally water. Artificial sweeteners and sugar alcohols can also be used. 
     
       
         
               
             
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Ingredients for Binder Syrup For a Nut Cluster 
               
             
          
           
               
                   
                 Ingredient 
                 Formula wt. % 
                 Range % 
               
               
                   
                   
               
               
                   
                 Base Syrup 
                 62% 
                 40–70% 
               
               
                   
                 Sugar 
                 34% 
                 10–50% 
               
               
                   
                 Sea Salt 
                  2% 
                  0–10% 
               
               
                   
                 Water 
                  2% 
                 0–5% 
               
               
                   
                   
               
             
          
         
       
     
     In one embodiment, the binder syrup ingredients are mixed in a syrup batch mixing tank  122  or other suitable mixer and heated to an elevated temperature. The elevated temperature should be sufficiently high to solubilize the sugars, but not so high as to induce carmelization of the sugar. Elevated temperatures can also impact viscosity and texture characteristics of the sugars in the binder syrup. In one embodiment, a binder syrup ingredient temperature of between about 170° F. and about 200° F. and more preferably between about 175° F. and about 185° F. is sufficient. In one embodiment, the binder syrup ingredient mixture in the mixer  122  comprises a brix of about 76°. The binder syrup ingredient mixture can then be routed to a continuous syrup use tank  124  where the elevated temperature of the binder syrup is maintained. The continuous syrup use tank  124  permits the process to be run in a continuous fashion by accepting batches from the mixer  122  while continuously pumping the binder syrup ingredient mixture to the evaporator  126 . The evaporator  126  removes the moisture to make a binder syrup  128 . The amount of heat input into the evaporator  126  can be adjusted such that the exit temperature of the binder syrup  128  is between about 240° F. and about 290° F. and more preferably between about 250° F. and about 280° F. and most preferably about 255° F. to about 275° F. At higher binder syrup  128  exit temperatures of about 280° F. and about 290° F. the viscosity of the syrup is high and begins to approach a threshold temperature where caramelization and scorching of the sugars in the binder syrup can occur. At temperatures lower than about 240° F., there is too much moisture in the binder syrup  128  and the finished product will be very chewy and sticky and processing at the slitter  450  becomes difficult. The temperature range of the binder syrup  128  exiting the evaporator  126  is also important to permit a relatively low mass of binder syrup  128  to effectively bind a relatively high mass of nuts/seeds together. Because the evaporator  126  removes most of the water, the binder syrup  128  exiting the evaporator  126  comprises a moisture content less than about 5% and preferably between about 1% and about 3% and most preferably about 2%. The nuts and/or seeds and the binder syrup is then routed into a heated continuous mixer such as a low shear single screw former  200  to form a nut mixture. The composition of the resultant nut mixture for one formulation is shown in Table 2. In addition, various acceptable ingredients in ranges are presented as well. 
     
       
         
               
             
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 Ingredients for Nut Cluster 
               
             
          
           
               
                   
                 Ingredient 
                 Formula wt. % 
                 Range wt. % 
               
               
                   
                   
               
               
                   
                 Nuts 
                 76% 
                 0%–90% 
               
               
                   
                 Seeds 
                  2% 
                 0%–90% 
               
               
                   
                 Brown Rice Syrup 
                 14% 
                    0–20% 
               
               
                   
                 Evaporated Cane Juice 
                  7% 
                    0–20% 
               
               
                   
                 Sea Salt 
                 0.5%  
                    0–3%  
               
               
                   
                 Water 
                 0.5%  
                    0–3%  
               
               
                   
                   
               
             
          
         
       
     
     The nut mixture at this point is transferred onto a slabbing conveyor  300  where the mixture is compressed between a lower endless steel belt  302  and an upper endless cotton belt  310  surrounding a plurality of compression or tamping rollers  320 . The nut mixture is compressed to a slab thickness  330  of between about ½-inch and about 1-inch and more preferably of between about ⅝-inches and about ¾ inches and most preferably about 0.7 inches for a cube-shaped embodiment. The nut mixture partially cools as it is rolled out. The nut mixture must be at a temperature such that the resultant nut slab is set up enough that it is sufficiently rigid to maintain shape while the nut slab it is being slit and cut, yet not too pliable. If the nut slab is too pliable, the slab becomes difficult to cut resulting in undesirable backpressure. The backpressure causes the slab to move back on itself which can cause jamming at the slabbing and cutting conveyors. If the nut slab is too hard, on the other hand, it becomes too difficult to slit. In one embodiment, the temperature of the slabbing conveyor  300  is controlled by a water bath adjacent to the lower stainless steel belt  302  and ensures a controlled slab temperature just prior to cutting by the rotary slitter  450  of between about 120° F. and about 180° F. and more preferably between about 135° F. and about 145° F. The nut slab is next routed to a cutting station  400  where the nut slab is sliced in the longitudinal direction by a rotary slitter  450  to divide the continuous slab into continuous longitudinal strips or multiple lanes of product. 
       FIG. 2  is a perspective view of a portion of the cutting station  400  in accordance with one embodiment of the present invention. When used in the Figures, the same numerals designate the same or similar parts. Referring to  FIGS. 1 and 2 , a plate  410  is used upstream of the slitter to help guide the slab  305  and keep it from buckling as a result of backpressure at the slitter  450 . The plate  410  can be held in place by a transverse or other suitable support bar  412  that is held in place by a suitable mounting member  414 . In one embodiment, the plate  410  comprises an expanded ultra high molecular weight polyethylene (EUHMWPE), or other non-stick coated metal. As shown in  FIG. 2  multiple slitters  450  can be placed in parallel across the width of the slab spaced apart as desired to produce multiple longitudinal strips  470 . In one embodiment, the plate  410  optionally surrounds at least a portion of the slitter blade by providing a channel  452  in spaced relation to a slitter  450  to permit the slitter to engage the slab  305 . In one embodiment, the rotary slitters  450  are spaced in parallel apart about 0.75 inches to cover the width of the band and produce longitudinal strips  470  of about 0.75 inches in width. Of course, these numbers are purely for purposes of illustration and not limitation. 
     Slitting a high nut content slab so as to provide a clean, effective cut to reduce waste while keeping the product in a forward motion is very difficult. This can be especially true if whole nuts or seeds are used. As discussed above, one important factor to ensure proper pliability of the slab is that the slab temperature must be carefully controlled. Additionally, in one embodiment, the design of the slitter also plays an important role in providing a clean effective longitudinal cut. Consequently, a rotary slitter having a plurality of serrated blades about the outer circumference  458  can be used in accordance with one or more embodiments of the present invention. 
       FIG. 3   a  is an expanded partial cross-sectional, linearized view of the outer circumference  458  of the slitter in accordance with one embodiment of the present invention. In one embodiment, the serrated or scalloped blade comprises a plurality of high points  460  about the outer circumference  458 . In one embodiment, the high points  460  are separated by an arcuate trough  464  having a radius of curvature of between about 1/10 inches and about ¼ inches and more preferably about ⅛ inches. In one embodiment, the distance  462  between the high points  460  is between about 1/10 inches and about ¼ inches and more preferably about ⅛ inches. In one embodiment, the arcuate trough  464  comprises an amplitude of between about 0.010 and about 0.020 and more preferably about 0.015 inches. 
       FIG. 3   b  is a partial end view of  FIG. 3   a . In one embodiment, the bottom tip  466  of the scallop comprises a bottom angle  467  of between about 0 and about 10 degrees from vertical and more preferably comprises a bottom angle  467  of about 5 degrees. 
     In one embodiment, the high point  460  comprises a high point angle  461  of between about 0 degrees and about 20 degrees and more preferably about 10 degrees. In one embodiment, the slitter comprises about 450 high points  460  about the outer circumference  458 . Again such number is provided purely for purposes of illustration. 
     In one embodiment, a single rotary slitter  450  in series can be utilized, as depicted in  FIG. 1  to provide the longitudinal cut to the nut slab. In one embodiment, the rotary slitter  450  station comprises two or more slitters in series. For example, a first slitter in series following the slabbing conveyor perforates a portion of the slab, e.g., between about 25% and about 75% and more preferably about 50% of the slab thickness and a second slitter finishes the slit and nearly contacting or contacting the lower conveyor belt  402 . 
     In one embodiment, the outer circumference  458  of the rotary slitter  450  rotates a speed sufficient such that the slitter exerts a pulling motion on the slab and ensures the slab continues to move in the forward direction (e.g. left to right as depicted in  FIG. 1 ). Consequently, in one embodiment, the slitter comprises a rotational speed greater than the slab speed. In one embodiment, the slitter simultaneously pulls and slices the nut slab into longitudinal strips. 
     In one embodiment, the slab adhesion to the upper belt and/or the lower belt is increased, e.g. the upper or lower belt is made stickier to help prevent the slab from sliding backwards. Either or both belts can be made stickier by coating the belts with binder syrup. 
     In one embodiment, the slitter comprises a diameter sized so as to provide a cutting angle that provides a clean, effective cut. In one embodiment, the slitter comprises a diameter of between about 5 and about 30 inches and more preferably between about 8 inches and about 10 inches. 
     In one embodiment, the slitter  450  comprises a plurality of indentations  456  to a clean, effective cut minimize the fines. In one embodiment, the slitter  450  comprises an electrolysis nickel coating to minimize sticking to the nut slab  305 . 
     In one embodiment, the rotary slitter comprises a blade gap  454  of less than about 0.3 inches and in one embodiment less than about 0.03 inches. Such blade gap  454  advantageously provides a longitudinal cut while minimizing backpressure. 
     Referring back to  FIG. 2 , the longitudinal strips  470  are then cut into hexahedron-shaped nut clusters  490  by a guillotine cutter  480  or other suitable cutter cutting in the transverse direction. In one embodiment (not shown), a rotary cutter cutting in the transverse direction can be used in place of the guillotine cutter. Such embodiment can provide a trapezoidal type hexahedron shaped nut cluster. The nut clusters are cooled  500  to less than about 100° F. or ambient temperature by methods well known in the art and sent to a packaging step  600 . 
       FIG. 4  is a perspective view of a high nut content cubed nut cluster  490  made in accordance with one embodiment of the invention. As shown, the nut cluster comprises well-defined edges resembling a cube and also whole, rather than crushed nuts. 
     EXAMPLE 
     Binder syrup ingredients comprising about 640 pounds of brown rice syrup, about 347 pounds of evaporated can juice, about 196 pounds of water and about 29 pounds of sea salt were mixed together and heated to about 180° F. in a syrup batch mixing tank. The binder syrup ingredients were transferred to a continuous syrup use tank where the temperature of about 180° F. was maintained. The binder syrup ingredients were then pumped to an evaporator where the moisture was removed thereby producing about 250 pounds of binder syrup having a solids content of about 98%. An evaporator available from a manufacturer such as Design Tools and Gauges of Birkenhead, England can be used. This binder syrup was fed into the feed hopper of a steam jacketed continuous mixer. 
     Nuts, previously roasted at oven temperature of about 270° F. for about 12 minutes in a Nut Roaster available from Wolverwine, Proctor and Schwartz, of Merrimac, Massachussetts. The roasted nuts were then fed to a pre-heater at a nut temperature of about 200° F. at a rate of about 975 pounds per hour and then fed into the hopper with the about 250 pounds per hour of binder syrup and about 25 pounds per hour of sesame seeds and the ingredients were mixed together in the continuous mixer to make a nut mixture. Pre-heaters and evaporators available from available from a manufacturer such as Design Tools and Gauges of Birkenhead, England can be used 
     The nut mixture was then transferred onto a slabbing conveyor where about 1200 pounds per hour of the nut mixture was made into a nut slab having a width of about 35 inches and having a thickness of about 0.7 inches (18 mm) where it cooled to a temperature of about 140° F. Slabbing conveyors can be obtained from manufacturers such as Sandvik Process Systems of Totowa, N.J. The nut slab moving at a line speed of about 12 feet per minute was then slit into 35 longitudinal strips having about ¾-inch widths by 50 slitters operating in parallel. Each slitter comprised an outer diameter of about 9 inches and independently rotated at a speed of about 170 RPM to ensure the slitter exerted a pulling force in the forward direction on the slab. A transverse cut made by a guillotine cutter operating at about 192 cuts per minute made a plurality of nut cubes, each nut cube weighing about 4.5 grams and having a longitudinal length of about 0.75 inches, a height of about 0.7 inches and a width of about 0.75 inches. Thus, in accordance with one embodiment, the present invention is able to manufacture large scale quantities, e.g., about 1200 pounds per hour of a bite-sized nut cluster cube. 
     There are numerous advantages provided by the instant invention. First, the instant invention discloses a novel method for making a cubed, high content nut cluster. The invention provides a novel way to cut a high nut content mixture. Finally, the instant invention provides a method for economically making large quantities of a cubed, high content nut clusters whereby the nuts maintain their traditional and expected texture, appearance and flavor. 
     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. For example, the dimensions may be changed to increase or decrease the overall size of the nut pieces; the shapes of the nut pieces may be changed; and the nut piece composition may be varied to adjust the texture and flavor of the final product, and to accommodate various flavor combinations and/or inclusions. Further, the means for cutting the product need not be one particular type, but could include any number of commonly available cutting devices. Different thicknesses of the final product may be desired. The overall intent of this invention is to create a cube shaped nut-cluster having a high nut content that can be manufactured in an efficient manner.