U.S. patent application number 09/998661 was filed with the patent office on 2002-03-21 for apparatus and method for making stackable tortilla chips.
This patent application is currently assigned to Recot, Inc.. Invention is credited to Chen, Nelson Shih-Hsun, Graham, Lawrence Alan, McNeel, Todd Charles.
Application Number | 20020034573 09/998661 |
Document ID | / |
Family ID | 23983573 |
Filed Date | 2002-03-21 |
United States Patent
Application |
20020034573 |
Kind Code |
A1 |
McNeel, Todd Charles ; et
al. |
March 21, 2002 |
Apparatus and method for making stackable tortilla chips
Abstract
An apparatus and method for making uniformly shaped snack food
chips which can be stacked for packaging, e.g., in a cylindrical
canister or a canister which conforms to the contour or perimeter
of the snack food chips. The apparatus features two-part mold
cavities in which chip preforms are restrained and transported
through hot oil to be cooked. Preferably, the mold cavities are
defined between a pair of rotating belts, one lower belt and one
upper belt, which together "encase" or "sandwich" and thereby
restrain the chips. According to the method, a continuous sheet of
dough is toasted and then proofed before being cut into individual
chip preforms. The preforms are then placed into the mold cavities
and transported through hot oil to be cooked. Vacuum transfer
rollers are used to facilitate placement of the chip preforms into
the mold cavities and extraction of the cooked chips from the mold
cavities.
Inventors: |
McNeel, Todd Charles;
(Flower Mound, TX) ; Chen, Nelson Shih-Hsun;
(Frisco, TX) ; Graham, Lawrence Alan; (Corinth,
TX) |
Correspondence
Address: |
ROTHWELL, FIGG, ERNST & MANBECK, P.C.
555 13TH STREET, N.W.
SUITE 701, EAST TOWER
WASHINGTON
DC
20004
US
|
Assignee: |
Recot, Inc.
5000 Hopyard Road, Suite 460
Pleasanton
CA
94588
|
Family ID: |
23983573 |
Appl. No.: |
09/998661 |
Filed: |
December 3, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09998661 |
Dec 3, 2001 |
|
|
|
09499042 |
Feb 7, 2000 |
|
|
|
Current U.S.
Class: |
426/549 ;
426/512; 426/808 |
Current CPC
Class: |
A23L 7/13 20160801; A21C
11/04 20130101; A21D 13/42 20170101; A47J 37/1214 20130101; A23P
30/10 20160801 |
Class at
Publication: |
426/549 ;
426/808; 426/512 |
International
Class: |
A23L 001/00 |
Claims
We claim:
1. A method of making triangular tortilla chips in a manner which
facilitates subsequent packaging in a stacked arrangement, said
method comprising: cutting triangular tortilla chip preforms from a
sheet of masa; enclosing the tortilla chip preforms in molds with a
consistent orientation; restraining the tortilla chip preforms
within said molds while cooking the tortilla chip preforms in a
cooking medium, thereby substantially maintaining the orientation
of the tortilla chip preforms while they are being cooked; and then
removing cooked tortilla chips from said molds while substantially
maintaining the orientation of the tortilla chip preforms; wherein
said consistent orientation comprises an alternating pattern of
tortilla chip preforms with base edges and apex comers of
successive tortilla chip preforms within the molds alternating
orientation, whereby said tortilla chip preforms can be placed
relatively compactly and close together within said molds so as to
minimize space therebetween.
2. The method of claim 1, further comprising packaging said cooked
tortilla chips in a generally triangular canister.
3. The method of claim 1, wherein said sheet of masa is formed by:
forming a sheet of snack food dough; toasting the sheet of snack
food dough to achieve a desired moisture content; proofing the
sheet of snack food dough such that the moisture content thereof
equilibrates; and imparting a desired texture to said sheet of
snack food dough by passing said sheet of snack food dough through
a shaping roller assembly.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to an apparatus and
method for making snack food chips. More particularly, the
invention relates in one aspect to an apparatus and method for
making curved corn-based or other snack food chips which can be
packaged neatly and compactly in a stacked arrangement, e.g., in a
canister or other sleeve-type container which preferably conforms
generally to the contour or perimeter of the snack food chips; and
in another aspect the invention relates to an apparatus and method
for making ridged or sinusoidally wavy snack food chips.
BACKGROUND OF THE INVENTION
[0002] In general, snack food chips of various varieties possess
characteristic shapes. For example, tortilla chips are one of the
more popular types of snack food products and have come to be
associated with having a triangular shape. Additionally, snack food
chips which are used for dipping, e.g., potato chips, tortilla
chips, or corn chips, preferably are curved to enhance the scooping
ability of the chip as well as to add strength to the chip.
Alternatively, chip strength may be enhanced by making the snack
food chips ridged or sinusoidally wavy.
[0003] With respect to packaging, a stacked arrangement of snack
food chips, e.g., in a cylindrical canister, has been found to be
popular for a number of reasons. Such canisters purportedly offer
some degree of protection against breakage of the snack food
product and, due to the compact nature of the stacked arrangement
of the chips, they provide greater transportability of the snack
food products, both in terms of bulk transport (i.e., large cartons
of the canisters being shipped, e.g., from the manufacturer to the
retailer) as well as the individual consumer being able to
transport a single package of chips (e.g., in a purse or in a
picnic basket). Additionally, the extended shelf life of a sealed
canister of snack food chips as compared to a bag (commonly
pillow-shaped and frequently sealed with a generally inert gas to
prevent product degradation), as well as the ability to reseal a
canister with a snap-fit-type lid once the canister has been
opened, makes a canister an attractive packaging option.
[0004] In the past, however, it has not been feasible to package a
uniform stack of snack food chips such as tortilla chips in such
canisters. This is because the conventional method of making snacks
like tortilla chips has been simply to fry a large quantity of
tortilla chips unconstrained in a fryer of cooking oil, with
paddles or other means used to submerge the chips for thorough
cooking and to move the chips through the oil. The chips are
removed continuously from the oil in a random and non-uniform
configuration. In an unconstrained environment, the chips can take
on uncontrolled variations in shape, such as by folding over on
themselves or partially bending. In addition, the lack of control
over individual chips as they exit the fryer made it essentially
impossible to package snack food chips such as tortilla chips, as
previously and commonly made, in a stacked configuration such as in
a canister or other sleeve-type container.
[0005] Additionally, in the past it has been difficult to impart
"large-scale" or "macroscopic" texture to tortilla chips, e.g., by
making them wavy. (In this context, "large-scale" or "macroscopic"
texture refers to the texture or shape of the chip overall and is
in contrast to "surface-level" texture which may be provided, e.g.,
by blistering of the surface of the chips.) This difficulty was due
primarily to the tacky nature of the corn dough or masa from which
tortilla chips traditionally are made.
SUMMARY OF THE INVENTION
[0006] The present invention provides apparatus and methodologies
for making snack food chips such as corn chips--tortilla chips in
particular and curved tortilla chips even more particularly--which
can be packaged in a stacked configuration in a canister or other
sleeve-type container which preferably conforms generally to the
contour or perimeter of the snack food chips. In particular, the
invention features a fryer apparatus which cooks the tortilla chips
by transporting them through a fryer of cooking oil while
constrained within continuous, preferably two-piece semi-closed
molds. Preferably, the apparatus includes a pair of belts which
mate to define the molds, one belt consisting of links which define
concave, lower mold cavities and the other belt consisting of links
which form convex retaining protuberances which restrain the
tortilla chips in the mold cavities. A die-cutting vacuum transfer
wheel is used to cut tortilla chip preforms (uncooked tortilla
chips) from a continuous, toasted, proofed sheet of corn masa and
place the preforms into the mold cavities in the lower belt
assembly. A vacuum transfer wheel is also provided downstream, at
the exit end of the fryer apparatus, to transfer the now-cooked
tortilla chips from the mold cavities to a take-away conveyor which
transports the tortilla chips to be seasoned, if desired, and
ultimately to a packaging station--doing so in a manner which
maintains the regular orientation of the chips that is necessary to
be able to stack them for packaging.
[0007] In other aspects, the invention features methodologies which
enable form-frying of tortilla chips in semi-closed, constrained
molds in regular order so as to produce uniformly shaped chips that
can be stacked for packaging. Thus, in one methodological aspect,
the invention features placing tortilla chip preforms into a first
mold section; constraining the tortilla chip preforms in the first
mold section by enclosing them in the mold using a mating second
mold section and immersing the tortilla chip preforms in hot oil to
cook them. The tortilla chip preforms are loaded into the molds in
a regular or uniform arrangement, and they are removed from the
molds and processed subsequent to their being fried while
maintaining the regular or uniform arrangement. This permits them
to be stacked for packaging. Preferably, the tortilla chips are
transported through the hot oil, e.g., by means of a belt
configuration. This permits the tortilla chips to be cooked on a
continuous basis instead of on a batch basis (which also is deemed
to be within the scope of the invention).
[0008] In another methodological aspect, the invention features a
departure from conventional pre-processing of tortilla chips, in
which conventional pre-processing corn masa is first cut into the
raw tortilla chip preforms which are then toasted and proofed to
bring the moisture content of the preforms to a required level
before they are cooked in oil. According to this aspect of the
invention, the corn masa is sheeted then toasted and proofed before
being cut into the individual tortilla chip preforms and cooked,
e.g., in enclosed molds. This order of the process steps is used in
particular when the tortilla chips are to be packaged in a uniform,
stacked arrangement because it was found that uniform orientation
of the tortilla chip preforms--which is necessary in order to be
able to transfer the tortilla chip preforms repeatedly and reliably
into the molds and then subsequently to be able to stack and
package the cooked chips--could not be maintained if the tortilla
chip preforms were cut from the relatively sticky or tacky corn
masa sheet before being toasted and proofed. Thus, to a relatively
large extent, toasting and proofing the corn masa sheet before
die-cutting the tortilla chip preforms is the step which enables
stackable tortilla chips to be manufactured efficiently and on a
commercially viable scale.
[0009] Additionally, toasting and proofing the sheet of masa makes
it feasible to provide, on a commercially viable scale,
"macroscopic" texture to the tortilla chips, e.g., by passing the
sheet of masa through one or more corrugated rollers, check
rollers, embossing rollers, waffle cut rollers, or other forming
step after it has been toasted and proofed and before it is die-cut
to produce the chip preforms. Again, it is the reduction in
stickiness or tackiness occasioned by toasting and proofing that
renders this processing step commercially feasible. When so shaping
the chip preforms, it may be desirable to forego the subsequent
molding of the chip preforms (by, for example, frying them in mold
cavities as described above); in that case, the chip preforms could
be baked or fried unrestrained, in a manner as is known in the
art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The invention will now be described in greater detail in
connection with the drawings, in which:
[0011] FIG. 1 is diagrammatic, side elevation view depicting
tortilla chip-making apparatus according to the invention;
[0012] FIG. 2 is a perspective view illustrating the lower, mold
cavity conveyor assembly in the circled region labeled 2 in FIG.
1;
[0013] FIG. 3 is a diagrammatic, face-on view showing the end
portion of the links of the lower and upper belt assemblies shown
in FIG. 1 making mating engagement;
[0014] FIG. 4 is a diagrammatic section view along the lines 4-4 in
FIG. 3;
[0015] FIG. 5 is a diagrammatic, face-on view similar to FIG. 3 and
illustrating construction of the lower and upper belt assemblies on
a commercial production scale;
[0016] FIG. 6 is a diagrammatic, side elevation view depicting the
upstream, die-cutting vacuum transfer assembly shown in FIG. 1;
[0017] FIG. 7 is a plan view showing the die-cutting ring of FIG. 6
in "unrolled" or "unwrapped" fashion;
[0018] FIG. 8 is a diagrammatic, side elevation view illustrating
the downstream vacuum transfer assembly shown in FIG. 1;
[0019] FIG. 9 is a diagrammatic, side elevation view similar to
that of FIG. 1 showing an alternate embodiment of the
invention;
[0020] FIGS. 10 and 11 are perspective views illustrating
alternative lower, mold cavity conveyor assemblies used to produce
chips according to the invention with alternative large-scale
curvature configurations; and
[0021] FIGS. 12a-12c are cross-sectional views illustrating cooked
snack food chips packaged in canisters which conform generally to
the contours or perimeters of the chips.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0022] An installation 10 for making stackable tortilla chips
according to the invention is shown in FIG. 1. In general, the
installation has two major sub-installations: pre-processing
apparatus 12 and the tortilla chip frying apparatus 14.
[0023] The pre-processing apparatus 12 includes sheeting apparatus
16, toasting oven 18, proofing oven 20, and conveyor apparatus 22,
23. The sheeting apparatus 16 may be conventional, or it may be
configured to produce whole sheets of masa using an ultrasonic
scraper to separate the sheet from the rollers, as described in
co-pending U.S. patent application Ser. No. 09/418,495, filed Oct.
15, 1999 and entitled "Ultrasonic Full-Width Sheeter." The toasting
oven 18, proofing oven 20, and conveyor apparatus 22, 23 are
generally conventional. A transfer assembly 24 is located between
the pre-processing apparatus 12 and the fryer apparatus 14.
[0024] The primary components of the tortilla chip frying apparatus
14 include a lower, mold cavity belt assembly 26; a cooperating or
mating upper, mold plate belt assembly 28; and an oil pan assembly
30, all housed within housing 32. A downstream transfer assembly 34
transfers the cooked tortilla chips from the mold cavities of the
lower belt assembly 26 to a take-away conveyor 36, which transports
the tortilla chips downstream for post-processing (which includes
light re-oiling and seasoning, if desired) and subsequent
packaging. (Apparatus which may be used to package tortilla chips
produced using the apparatus and methods of the present invention
is disclosed in co-pending U.S. patent application Ser. No.
09/326,682, filed Jun. 7, 1999 and entitled "Apparatus and Method
for Stacking Tortilla Chips.")
[0025] The construction of the lower and upper belt assemblies 26
and 28 is illustrated in greater detail in FIGS. 2-5. As
illustrated in FIG. 2, which is a close-up view of the circled
portion of the lower, mold cavity belt assembly 26 at the point
where the belt assembly begins to drop down into hot oil contained
within the oil pan 30, the lower, mold cavity belt assembly is
composed of a number of transversely extending mold cavity "links"
40 which are connected together to form the continuous belt 26. The
mold cavities 42 are formed as continuous, longitudinally extending
(in terms of the running direction of the belt assembly, indicated
by arrow 46), trough-shaped depressions. The mold cavities 42 are
curved about longitudinally extending axes 44 but, locally, are
relatively straight or non-curved in the longitudinal direction. In
other words, the only longitudinal curvature is attributable to the
belt flexing, and that curvature is essentially absent over the
length of the portion of the belt disposed within the oil pan.)
[0026] The links 40 of the belt assembly 26 are each constructed
with a number of individual mold cavity elements 47. The mold
cavity elements are formed from perforated, preferably
electro-polished stainless steel (to prevent the masa from
sticking), on the order of 0.25 inch (6.35 mm) thick, that is bent
into a "lazy M" configuration, and the mold cavity elements are
fastened together in side-by-side fashion as shown more clearly in
FIG. 3. The perforations should be large enough to allow hot oil to
reach the product to cook it and for steam to escape.
[0027] FIG. 3 also illustrates the construction of the upper, mold
plate belt assembly 28, which mates with the lower, mold cavity
belt assembly 26. The mold plate assembly 28 is also comprised of a
series of links 50 which are connected together to form the
continuous belt 28. Similar to the links 40, the links 50 are
constructed from convex, arch-shaped mold plate elements 52, which
are fastened together in side-by-side fashion by the parallel leg
portions 54 thereof. Like the mold cavity elements 47, the
arch-shaped mold plate elements 52 preferably are fabricated from
perforated, electro-polished stainless steel on the order of 0.25
inch (6.35 mm) thick.
[0028] The mold cavity element-supporting structure of each of the
links 40 is fabricated from sheet metal such as stainless steel. It
is formed so as to have a flat, transversely extending support
member 60 with slots 64 therein through which the legs 48 of the
mold cavity elements extend, with the elements being secured
thereto by appropriate retaining means 68, and downturned front and
rear flanges 69, 71 (hidden in FIG. 3). The support member 60
extends laterally to the very end of the link assembly, beyond the
flanges 69, 71. Mounting brackets 72 are attached to the lateral
ends of the support member 60 and have bearing assemblies 76 which
support and guide the lower belt assembly in appropriately
configured tracks installed within the housing 32 (not shown).
[0029] The links 50 of the upper, mold plate belt assembly 28 have
a two-part configuration which allows the arch-shaped mold plate
elements 52 to "float" somewhat relative to the mold cavity
elements as the belts merge together. As shown in greater detail in
FIG. 4, the links 50 each include a stainless steel upper bracket
member 70 and a stainless steel lower, mold plate element-support
bracket member 62 which fits within the flanges 73 of the upper
bracket member 70. (The amount of space between the upturned
flanges 63 of the lower, mold plate element-supporting bracket
member 62 is slightly exaggerated for clarity purposes. The
clearance should be large enough to permit a slight amount of
rotation of the lower bracket member 62 relative to the upper
bracket member 70, about an axis extending transversely to the belt
direction, but should be small enough to prevent significant
fore-and-aft shifting of the lower bracket member 62 relative to
the upper bracket member 70.) The lower, mold plate-supporting
bracket 62 is supported by pins 65 which are secured to the
upturned flanges 63 and which slide vertically within slots 67
formed within the down-turned flanges 73 of the upper bracket
member 70.
[0030] Similar to the configuration of the lower links 40, the
cross-member 75 between the flanges 73 extends laterally beyond the
ends of the flanges, and mounting brackets 74 are attached thereto.
The mounting brackets 74 have bearing assemblies 78, which support
and guide the upper belt assembly in appropriately configured
tracks within the housing 32 (not shown).
[0031] As described in more detail below, and as is shown in FIG.
1, the construction and arrangement of the lower and upper mold
element belt assemblies is such that the links 50 of the upper,
mold plate belt assembly merge with the links 40 of the lower, mold
cavity belt assembly as the two belt assemblies rotate. Together,
the mold cavity elements 47 and the mold plate elements 52 define a
small, longitudinally extending space 80 between them (FIG. 3), and
the tortilla chip preforms are restrained within these spaces 80.
In other words, the spaces 80 form longitudinally continuous,
semi-closed mold cavities that maintain the tortilla chip preforms
in uniform arrangement as they are cooked in the hot oil (which is
critical to being able to stack them subsequently for
packaging).
[0032] To ensure proper positioning of the mold elements relative
to each other, both in terms of their distance apart from each
other and in terms of their relative lateral positioning, a male
centering pin 82 is provided on one of the link members and a
female centering trough 84, which cooperates with the centering pin
82, is provided on the other of the link members. Proper vertical
and lateral positioning of the mold elements is important because
having them too close together prevents the masa from expanding as
it cooks and can mash the masa into the perforations in the mold
elements, thereby preventing subsequent removal of the tortilla
chips from the mold assembly; and having them too far apart will
allow the tortilla chips to move around within the mold cavities
defined by the gap 80, resulting in loss of process control.
[0033] Although FIG. 2 depicts (schematically) just four mold
cavity elements 47 across the width of the belt assembly 26, it
will be appreciated that for operation on a commercial scale, the
link assemblies 26 and 28 may be on the order of sixty-five inches
across or more (i.e., laterally or transverse to the traveling
direction of the belt), with as many as twenty or more mold cavity
elements and mold plate elements per link 40, 50. Preferably, links
of such width are constructed with a number of subassemblies, e.g.,
40a-40d and 50a-50d, as illustrated in FIG. 5. Each subassembly
consists of a number of mold cavity elements or mold plate
elements, with a set of centering pins 82 and centering troughs 84
as well as a pair of guide pins 65 and slots 67 for each paired
subassembly. This permits the mold plate elements of each
subassembly to find their proper positioning more easily than would
be the case if all the mold elements on a given link member 40 or
50 (e.g., all twenty, as shown in FIG. 4) were linked together such
that all twenty would have to move up and down or side-to-side
together.
[0034] Furthermore, in terms of the apparatus of the invention,
details of the upstream transfer assembly 24 and the downstream
transfer assembly 34 are illustrated in FIGS. 6-8. As illustrated
in FIGS. 6 and 7, the upstream transfer assembly 24 is configured
to cut the corn masa sheet into individual tortilla chip preforms
and to deposit the preforms into the mold cavities of the lower,
mold cavity belt assembly 26. To this end, the upstream transfer
assembly 24 includes an anvil roller 110 and a die-cutting, vacuum
transfer roller 112. The transfer roller has a die-cutting outer
ring 114 which is mounted on a support ring 116, which support ring
rotates around a central vacuum/pressure drum 118. The support ring
is perforated or ducted to permit suction/over-pressurizatio- n
forces to act through it.
[0035] The die-cutting outer ring 114 is constructed with a cutting
pattern as shown in FIG. 7. (A few rows of perforations/ducts 119
in the support ring 116 are also shown in FIG. 7; it will be
appreciated that the perforations/ducts 119 are present around the
entire circumference of the support ring 116.) As a result of this
pattern, the die-cutting outer ring 114 cuts the masa sheet into
tortilla chip preforms which will be deposited into the channel
shaped mold cavities of the lower belt assembly in alternating
fashion, as illustrated in FIG. 2. In other words, if the chip
preforms are deemed to be curved about the longitudinal axes 44 of
the mold cavities, and the edges 122 of the preforms that extend
parallel to the longitudinal axes are deemed to be the base edges B
and the opposing, upturned comers of the tortilla chip preforms are
deemed to be the apex corners A, the tortilla chip preforms will be
arranged with the base edges B and the apex corners A of successive
chips arranged left-right-left-right and right-left-right-left,
respectively.
[0036] The central vacuum/pressure drum 118 is constructed with
internal chambers and/or manifolds such that constant suction is
drawn within region 120, and constant over-pressure is created
within region 122. As the die-cutting ring rotates while making
bearing contact against anvil roller 110, the die-cutting ring cuts
a sheet of masa into the individual tortilla chip preforms. The
preforms adhere to the assembly 112 by suction, as indicated by the
inwardly pointing arrows in the vacuum chamber 120. As the
die-cutting ring 114 continues to rotate and the tortilla chip
preforms pass by over-pressure region 122, they are blown (or
"air-peeled") off of the vacuum transfer roller 112 and down into
the mold cavities of the belt assembly 126, in the alternating
arrangement shown in FIG. 2.
[0037] Finally, with respect to the upstream transfer assembly 24,
a doctor blade 126 is provided to lift the masa sheet from the
conveyor apparatus 23 and help guide it onto the anvil roller 110
for die-cutting.
[0038] The downstream transfer assembly 34 is illustrated in FIG.
8. The transfer assembly 34 includes a pick-off ring 130 which
rotates about stationary vacuum/pressure drum 132. The pick-off
ring 130 has pick-off pads 134 distributed around its circumference
to lift cooked tortilla chips out of the mold cavities at the
downstream end of the belt assembly 26, as at 136 (see FIG. 1). The
pick-off pads 134 are perforated and made out of material such as
silicone, and are supported on the pick-off ring 130 by pad stands
138, which have air passageways passing through them. Like the
vacuum/pressure drum 118, the vacuum/pressure drum 132 has internal
manifolds and/or chambers which create constant under-pressure in
suction region 140 and constant over-pressure in region 142, which
causes the cooked tortilla chips to be suctioned against the
pick-off pads 134 and then released down onto the take-away
seasoning conveyor 36.
[0039] The transfer wheel assembly 34 may be supported by pivot
strut 136, which is attached to the housing 32 (see FIG. 1). The
pivot attachment permits the roller to be swung away from the hot
fryer belt when the system is not in operation.
[0040] The apparatus described above operates as follows. Cooked
and soaked corn is fed into the sheeting apparatus 16. The corn is
wet-milled by the apparatus to form a sheet of masa which, for
commercial production intended to produce on the order of three
thousand pounds of tortilla chips per hour, is on the order of five
feet wide. The masa sheet is deposited onto conveyor apparatus 22,
which is fabricated from metal mesh (i.e., the belt is made from
"breathable" material). The masa sheet, transported by the conveyor
apparatus 22, makes a single pass through toasting oven 18, which
has infrared burners above the sheet of masa and open flame burners
below the belt. The length of the toasting oven is set so that the
masa sheet passes through the toasting oven in approximately twenty
seconds, and the burners are controlled such that the temperature
inside the oven is on the order of 600.degree. F. The masa
residence time and oven temperature essentially are sufficient to
"crust over" the masa, i.e., to sear the outside while leaving the
interior with a substantial amount of moisture. (This internal
moisture will cause the chips to blister when they are fried, which
gives the chips a preferred texture.)
[0041] Once it exits the toasting oven 18, the masa sheet
transitions to conveyor apparatus 23 and enters proofing oven 20.
The conveyor apparatus 23 may be made from a plastic mesh material.
The proofing oven 20 is maintained at on the order of 200.degree.
F., with a relative humidity of approximately 80% maintained by
steam injection. The length of the proofing oven is set to achieve
a twenty to thirty second dwell time of the masa. This allows the
moisture content to equilibrate throughout the sheet of masa, which
makes the masa more pliable and facilitates subsequent handling of
the tortilla chip preforms when they are cut from the masa sheet,
but without making them so pliable as to be unworkable. The masa
sheet enters the toasting oven 18 at a moisture content on the
order of 50% by weight, and exits the toasting oven and enters the
proofing oven at approximately 35% moisture by weight; the moisture
content of the masa sheet remains essentially the same as it
travels through the proofing oven, but the moisture content and
distribution essentially equilibrate, as noted above. (The overall
system is designed to deliver a desired level of product
through-put, which will determine the frier apparatus dimensions
and operating speed; the line speed of the frier apparatus dictates
the line speed of the conveyor apparatus 22 and 23 (so as to match
belt speeds), which therefore dictates toasting and proofing oven
lengths to achieve the desired masa dwell times.)
[0042] Once the sheet of masa exits the proofing oven 20, it is
removed from the conveyor apparatus 23 and guided onto the anvil
roller 110 (FIG. 6) by doctor blade 126. As the sheet of masa
enters the nip formed between the anvil roller 110 and the
die-cutting transfer roller 112, the sheet of masa is cut into the
individual tortilla chip preforms 121, which are deposited into the
mold cavities provided by the mold cavity elements 47, as shown in
FIG. 2.
[0043] (Although the above-described processing sequence is
preferred for the reasons explained in the Summary of the
Invention, there may be instances in which it is desirable to
die-cut the masa sheet before toasting and proofing the preforms.
In such instances, the speed of processing should be reduced
sufficiently to permit a system operator to ensure that proper
orientation of the chip preforms is maintained to facilitate
subsequent stacking and packaging of the cooked chips.)
[0044] The belt assembly 26 transports the tortilla chip preforms
121 in the direction indicated by arrow 46 (FIG. 2). At
approximately the portion of the assembly which is circled in FIG.
1 and shown in greater detail in FIG. 2, the belt assembly 26
passes over the upper edge 160 of the oil pan assembly 30 and down
into a pool of hot oil which is contained within the oil pan
assembly 30. (Hot oil is continuously pumped into and out of the
oil pan assembly via inlet and outlet 162 and 164, respectively,
and is filtered to maintain oil quality.) At approximately the same
location, the links 50 of the upper mold plate belt assembly come
down into engagement with the links 40 of the lower belt assembly
26 to confine the tortilla chip preforms within the gap 80 formed
therebetween. The lower and upper mold belt assemblies rotate at
the same speed and transport the tortilla chip preforms through the
hot oil contained within the oil pan 30. The oil is maintained at a
temperature on the order of 350.degree. F., and the tortilla chips
are maintained within the hot oil for on the order of thirty-five
to forty seconds so as to achieve a moisture content of
approximately 1.5% by weight and an oil content of approximately
30% by weight.
[0045] As the now-cooked tortilla chips ramp up out of the oil pan
at the opposite, downstream end thereof, oil will drain from the
chips and the mold cavities will open as the links 50 of the upper,
mold plate belt assembly 28 rotate away from the links 40 of the
lower, mold cavity belt assembly 26, e.g., as at 168. Preferably,
the chips are sprayed from below by a high-pressure spray of oil or
even just a burst of high-pressure air at 170. This helps ensure
subsequent separation from and removal of the cooked tortilla chips
from the cavity elements 47.
[0046] The downstream transfer assembly 34 picks up the tortilla
chips at the downstream end of the conveyor 26 by sucking them up
against the transfer pads 134, and then deposits them by slight
blowing onto take-away seasoning conveyor 36 to be seasoned and
then packaged. It will be appreciated that the tortilla chips are
placed onto the take-away conveyor 36 in substantially the same
orientation shown in FIG. 2, i.e., arranged with their axes of
curvature essentially aligned and with their base edges and apex
corners arranged in alternating fashion. This uniform orientation
is critical for the subsequent stacking and packaging
operations.
[0047] Finally, as noted above in the Summary of the Invention and
as illustrated in FIG. 9 (in which the same reference numerals are
used to describe components that are the same as described above),
toasting and proofing the entire sheet of masa before die-cutting
it facilitates imparting "macroscopic" texture to the chips (e.g.,
by making them ridged or sinusoidally wavy or even "waffle cut") by
passing the toasted and proofed sheet of masa through one or more
contoured or corrugated shaping rollers 200 or sets thereof. The
shaped sheet of masa would then be die-cut using die-cutting
rollers 202. In this embodiment of the invention, the shape
imparted to the chips by passing the masa sheet through the shaping
rollers may be all the shape that is desired to be imparted to the
chips. In that case, the subsequent step of placing the die-cut
chip preforms into molds, which imparts other shape characteristics
to the chips, may be foregone; the chips would then be cooked to a
desired final state by unrestrained frying, baking or other
conventional means which will be known to those having skill in the
art.
[0048] Although the invention has been described in detail above,
it will be appreciated that numerous modifications to and
departures from the illustrative embodiments will occur to those
having skill in the art. For example, whereas the tortilla chips
are described above as being curved about an axis extending
parallel to one of the edges of the chip, they alternatively may be
curved about an axis extending from one corner of the chip to the
opposite edge of the chip (i.e., a bisector of the chip). Tortilla
chips with such a curvature configuration could be made by shaping
the chip preforms on hump-shaped, perforated mold surfaces and
restraining the chip preforms with mating concave mold cavities
(not shown), as illustrated in FIG. 10. Alternatively, the chip
preforms could be given large-scale waviness by shaping them on
sinusoidally wavy mold elements, as illustrated in FIG. 11.
[0049] Moreover, the apparatus and method may be practiced using
corn meal rather than corn masa to produce tortilla chips having
different taste characteristics. The process parameters (toasting
time and temperature, proofing time and temperature, and cooking
time and temperature) would have to be adjusted accordingly.
Additionally, chips other than tortilla chips can be made using the
invention, which alternative chips may be triangular or have other
shapes such as ovals, squares, rectangles, other polygons, etc.
Moreover, it is preferable that the shape of the canister in which
the chips are packaged conform generally to the contour or
perimeter of the chips, as illustrated in FIGS. 12a-12c. For
example, cooked tortilla chips 221 would be packaged in generally
triangular canisters 321; cooked fabricated potato crisps 221'
(which customarily are oval or elliptical) would be packaged in
oval or elliptical canisters 321'; cooked hexagonal snack food
chips 321" would be packaged in hexagonal canisters 321"; etc.
These and other modifications are deemed to be within the scope of
the following claims.
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