Preparing centerfilled food product

A tubular centerfilled food product having a rigid, friable, thermoplastic baked outer shell and a core of edible filling material is produced by a continuous, straight-through process. A semi-liquid batter having a relatively high content of mono- and/or disaccharides is carried between a pair of spaced-apart moving heated surfaces and baked to form a continuous, elongated flat thermoplastic sheet having a controlled thickness. The continuous thermoplastic sheet while warm and pliable is rolled around its longitudinal axis to form a continuous tube having a closed longitudinal, non-overlapping seam. As the baked sheet is rolled around its longitudinal axis, an edible filling material is injected into the core of the continuous tube as it is formed. The filled tube is cooled until the outer shell becomes rigid and is then cut into pieces of a desired length.

BACKGROUND OF THE INVENTION 
This invention relates to a novel centerfilled food product and to the 
process for its production. More particularly, the invention is directed 
to the production of a tubular centerfilled food product, having a rigid, 
friable, thermoplastic baked outer shell and a core of edible material 
surrounded by the shell, by a continuous, straight-through process. 
A number of methods have been used heretofore to provide cylindrical 
centerfilled food products. Such prior methods frequently have involved 
extruding a mixture of a farinaceous material and water through a 
restricted orifice into a tubular configuration, under conditions such 
that the tubular product is puffed or expanded as it emerges from the 
orifice. The tubular product is cut to length and cooled, and a desired 
filling is injected into the core of the puffed tubular body. Such methods 
suffer from the disadvantage that a number of separate steps are involved, 
each requiring separate handling of the fragile expanded tubular product. 
Also, because of the high temperatures and pressures to which the mix is 
subjected in the extruder, the ingredients which may be used in the mix 
are limited. For example, if the mix has a sugar content of above about 
10%, the product tends to scorch or burn during extrusion. As a result, 
such expanded, extruded products must have a shell which consists 
essentially of cereal, and accordingly has a high starch content. Since 
the starch is gelatinized during extrusion, the shell portion of such 
extruded products is permanently rigid in nature. Moreover, since the 
puffed tubular body has a relatively high moisture content, usually 
between about 20%-25%, after extrusion, it must be dried before a desired 
filling can be injected into the core. 
Another procedure which has been disclosed heretofore involves mounting a 
plurality of cylindrical molds on an endless conveyor, each of the molds 
having a rod extending horizontally into its interior. A dough is filled 
into the mold, and the mold carried into an oven for baking. The baked 
dough tubes are then stripped from the rods and held in a suitable manner 
to permit filling. This procedure also suffers from the disadvantage that 
separate shell forming and filling steps are required, each requiring 
separate handling of the product. 
It is readily apparent that a process for making baked centerfilled food 
products in which the shell is filled simultaneously with its formation 
would be desirable for it would reduce the number of handling steps 
involved. Heretofore the only procedure disclosed for such a simultaneous 
shell forming and filling operation involves a co-extrusion operation in 
which a shell of cereal dough is extruded around a core of a filling 
material. However, as noted above, due to the temperatures and pressures 
to which materials are exposed in the extruder, the ingredients which can 
be used in such a co-extrusion operation are restricted to thereby limit 
the type of products produced. In addition, since the puffed tubular body 
must be dried after extrusion, only filling materials which are not 
adversely affected by such drying temperatures may be used in such a 
co-extrusion process. 
SUMMARY OF THE INVENTION 
Briefly, the product of the present invention is a baked, centerfilled 
product which comprises a rigid tubular thermoplastic shell of baked 
comestible material having a bulk density of above 30 lbs. per cu. ft. and 
a closed longitudinal, non-overlapping or butted seam, and a core of 
edible material having a low water activity such as confectionary creme, 
fruit paste, meat paste and the like, surrounded by the tubular shell. 
The method of this invention involves baking a continuous layer of a 
semi-liquid batter mixture having a relatively high content of mono-and/or 
disaccharides to a relatively low moisture content to form a continuous 
ribbon or sheet having a controlled thickness, the continuous sheet being 
thermoplastic while at a temperature of about 210.degree. F. and above, 
due to its high content of mono-and/or disaccharides. The continuous baked 
sheet, while warm and pliable, is rolled around its longitudinal axis 
until the edges of the sheet are butted together to form a continuous tube 
having a closed longitudinal, non-overlapping seam. A viscous edible 
filling material which has a low water activity is continuously injected 
or otherwise deposited into the core of the continuous baked tube, as the 
tube is formed, to fill the core, and the centerfilled tube is cooled. 
Upon cooling, the baked outer shell becomes rigid, crisp and friable so 
that it retains its tubular shape without opening of the closed butted 
seam. However, because of the thermoplastic character of the tubular 
shell, it becomes flexible and pliable upon reapplication of heat. The 
cooled, centerfilled tubular product is then cut into pieces of desired 
lengths. 
The product of the present invention is produced using apparatus which 
includes a pair of opposed heated moving surfaces for baking a layer of a 
semi-liquid batter into a continuous strip or sheet having a substantially 
uniform controlled thickness. Tube forming means positioned adjacent the 
heating means receives the continuous sheet of baked material discharged 
from the heating means while the baked sheet is still in a plastic or 
pliable state. The tube forming means is adapted to roll the continuous 
sheet around its longitudinal axis until the edges of the sheet are butted 
together to thereby form a continuous tube having a longitudinal, butted 
or non-overlapping seam. A filling tube extends axially into the tube 
forming means at the inlet end thereof for filling the core of the 
continuous tube with an edible material. The centerfilled tube is retained 
in the tube forming means until the baked outer shell has cooled 
sufficiently to become rigid and friable. A cutter is positioned adjacent 
the discharge end of the tube forming means for cutting the continuous 
centerfilled tube into pieces of desired lengths.

DETAILED DESCRIPTION OF THE INVENTION 
In accordance with the present invention, the baked outer shell portion of 
the centerfilled product of this invention is formed from a batter which 
has as its principal ingredients mono-and/or disaccharides, flour, an 
edible fat or oil, egg white and water. These ingredients are mixed to 
provide a homogeneous semi-liquid batter which is formed into a relatively 
thin continuous layer of controlled thickness and heated to form a 
continuous elongated baked sheet or ribbon having a substantially uniform, 
predetermined thickness with the baked sheet having a bulk density of 
above about 30 lbs. per cu. ft. The batter has a relatively high content 
of mono-and/or disaccharides, so that the baked sheet is thermoplastic, 
that is, it is soft and pliable when at a temperature about 210.degree. F. 
and above, but becomes hard and rigid upon cooling. However, upon each 
reapplication of heat, such as by heating to a temperature of about 
240.degree.-270.degree. F. for 3-5 minutes, the baked sheet again becomes 
pliable and flexible. It is essential that the thickness of the batter 
layer be controlled during its formation and baking so that the finished 
baked sheet will have a thickness equal to the desired thickness of the 
baked outer shell portion of the centerfilled product of this invention. 
The thickness of the baked sheet will depend on the desired shell to 
filling ratio and overall tube diameter of the product, which affects the 
texture, flavor and mouthfeel of the product, and may be in the range from 
about 1/32" to 1/4" or more, with a thickness in the range of between 
1/16" to 5/32" being preferred. 
The thickness of the baked sheet is controlled by carrying a layer of the 
semi-liquid batter between a pair of opposed heated moving surfaces which 
are vertically spaced apart a distance equal to the desired thickness of 
the baked sheet, with the heated surfaces moving in the same direction at 
the same linear speed. The batter may be retained between these moving 
heated surfaces until baking of the batter layer is completed, that is, 
until the batter layer has been baked into a continuous sheet having 
sufficient cohesion and strength to be self-supporting. Alternatively, the 
batter may be retained between the heated moving surfaces only until the 
surfaces of the batter layer have been set, so that the partially baked 
batter layer will retain this controlled thickness. The partially baked 
sheet, having a moisture content of about 15%-25% by wt. may then be 
transferred to a conventional baking means, such as a continuous band oven 
for completion of baking. 
Baking of the batter layer is completed when its moisture content has been 
reduced to about 5% or less, preferably between 2%-3%. At this moisture 
level the baked sheet is sufficiently cohesive to form a continuous 
self-supporting sheet and has sufficient tensile strength, elasticity and 
pliability to enable the baked sheet to be rolled into a tubular shape 
having a longitudinal butted seam while warm, and to become rigid, crisp 
and friable upon cooling so that when cooled it retains its tubular shape, 
that is, there is no separation or opening of the longitudinal butted 
seam. 
The temperature at which the semi-liquid batter layer is baked to form the 
continuous sheet will depend upon the formulation of the batter and the 
desired thickness of the baked sheet, but should be at least 210.degree. 
F. or above, and usually is in the range of from about 275.degree. F. to 
550.degree. F. The heated moving vertically spaced surfaces between which 
the batter layer is carried may be at the same or different temperatures. 
The time of baking will depend on the thickness of the batter layer, the 
formulation of the batter and the baking temperature, and may range from a 
few seconds to 10 minutes or more. 
In the embodiment of the invention shown in FIG. 1, the semi-liquid batter 
is prepared having a relatively high content of mono-and/or disaccharides, 
and deposited in controlled amounts on a first or lower heated endless 
belt which carries the batter as it is heated and baked to form a 
continuous baked thermoplastic sheet. A second or upper endless belt 
having a heated lower run is disposed parallel to and overlies the lower 
endless belt, with the heated opposed facing belt runs being vertically 
spaced apart so that a gap is provided between the opposed facing runs. 
The lower run of the upper belt is sufficiently proximate the upper run of 
the lower belt so as to contact the upper surface of the batter layer 
being carried on the lower belt and gauge the thickness of the batter 
layer. Thus, the facing runs of the lower and upper endless belts, which 
move in the same direction at substantially the same linear speed, are 
vertically spaced apart a distance equal to the desired thickness of the 
baked shell portion of the product of this invention, that is, about 1/32" 
to 1/4" or more. Heating units, such as radiant heaters, ribbon burners, 
and the like, are positioned adjacent the facing runs of both the upper 
and lower endless belts to heat the batter layer and bake it into a 
continuous sheet as it is carried by the lower belt. The speed of the 
belts and the baking temperature are coordinated so that the continuous 
baked sheet, at the completion of the baking step, will have a temperature 
of about 210.degree. F. or above and moisture content of no more than 
about 5% by weight, preferably between 2%-3% by weight. While a uniform 
temperature may be provided throughout this baking step, it is usually 
preferred to reduce the temperature in one or more steps as the batter 
layer is baked. This may be carried out by providing a plurality of 
heating units, which can be independently controlled in temperature, 
adjacent the facing runs of the belts. For example, at the start of the 
baking cycle, when the batter is first carried between the belts, the 
temperature is relatively high, e.g., 500.degree. F., to facilitate rapid 
setting of the surfaces of the sheet. One or more intermediate temperature 
zones having a slightly lower temperature, e.g., 450.degree. F., and a 
final heating zone at a lower temperature, e.g., 400.degree. F. are 
provided to complete baking of the batter layer and reduce the moisture 
content of the baked batter layer to no more than about 5%. 
Alternatively, the batter layer may be carried between the opposed 
vertically spaced heated endless belts to only partially bake the batter 
layer, that is, to heat the batter layer only to the extent that the 
surfaces of the batter layer have been set, so that the partially baked 
batter layer will retain this controlled thickness. The partially baked 
sheet, which has a moisture content of about 15%-25% by wt., may then be 
transferred to conventional baking means, such as continuous band oven or 
the like for completion of the baking step in which the moisture content 
of the sheet is reduced to 5% or below. 
In accordance with another embodiment of the invention, a layer of the 
batter may be deposited on the upper run of the upper endless belt and 
carried on the upper belt between the facing runs of the belts to gauge 
the thickness of the batter layer and at least partially bake the batter 
layer. The types and amounts of ingredients used in the batter are such 
that the baked sheet is thermoplastic, will maintain a uniform thickness, 
be sufficiently cohesive to form a continuous sheet, and have sufficient 
tensile strength, elasticity and pliability to enable the continuous baked 
sheet to be continuously rolled into a tubular shape while warm and to 
become rigid and friable upon cooling, so that the cooled tube retains its 
shape. As noted hereinabove, mono-and/or disaccharides, flour, and edible 
fat or oil, egg white and water are the principal ingredients of the 
batter. The batter has a relatively high content of mono-and/or 
disaccharides, that is, between about 15%-45% by weight, and preferably 
from about 30%-40% by weight, of the batter mix. Such a level of 
mono-and/or disaccharides in the batter provides the baked batter layer 
with a texture and structure such that it is thermoplastic, that is, the 
baked sheet is soft and pliable while at a temperature of about 
210.degree. F. and above, but becomes crisp, rigid and friable upon 
cooling. However, each time the baked layer is reheated to above about 
210.degree. F., it again becomes pliable and flexible. Suitable 
mono-and/or disaccharides which may be used include sucrose, fructose, 
dextrose, invert sugar, corn syrup solids, lactose, and the like. 
Generally, it is preferred to use cane or beet sugar in either powdered or 
granulated form as the mono-and/or disaccharide in the batter. 
The flour component may comprise from 10%-20% by weight of the batter mix, 
with amounts of between about 12% and 16% by weight being preferred. The 
flour may be derived from wheat, corn, rye, soy, barley, and the like, and 
mixtures thereof. Wheat flour is preferred. 
Any of the edible animal and vegetable fats and oils generally used in 
baked foods may be used in the batter mix, including, for example, batter, 
lard, margarine and hydrogenated vegetable oil shortenings made from oils 
such as soybean oil, cottonseed oil, corn oil, peanut oil, coconut oil, 
palm oil and the like, and mixtures thereof. The fat or oil component may 
constitute from about 5%-15% by weight of the batter mix, with amounts of 
between about 10% and 13% weight being preferred. 
Egg whites, which function as a binding material or toughener, are 
incorporated in the batter mix in either liquid, frozen or dry form (as 
egg white solids) in amounts of from about 2.5%-15% by weight of the mix. 
Water, or other aqueous liquids, is present in the batter mix in an amount 
sufficient to provide the batter with a semi-liquid consistency, generally 
constituting from about 15%-30% by weight of the batter mix. Of course, 
minor amounts of other ingredients may be incorporated in the batter mix, 
such as for example, salt, flavorings, emulsifiers, leavening agents, 
starch, lecithin and the like. The selection and quantity of such other 
ingredients will depend largely upon the character, flavor and texture 
desired for the end product. 
In preparing the batter, the ingredients, except for the fat or oil and 
emulsifier (if used) are thoroughly mixed with water until all of the dry 
ingredients are moistened. Fat or oil and emulsifier are then added to the 
mix with agitation to provide a homogeneous batter having a semi-liquid 
consistency. As noted above, the batter is deposited as a continuous layer 
on heating and conveying means which heat and bake the batter layer to 
form a continuous baked sheet having a controlled thickness. 
Generally it is preferred that the tubular centerfilled product of this 
invention have an outside diameter in the range of from about 3/8" to 1", 
depending on the intended use of the product, that is, a cookie, snack 
item, and the like. Accordingly, the baked batter layer must have a width 
at least sufficient to form a tube having the outside diameter desired in 
the finished product, when the sheet is rolled around its longitudinal 
axis and the edges of the sheet butted together. Thus, the width of the 
baked sheet which is rolled into a tube is equal to the circumference of 
the finished centerfilled product. 
When the semi-liquid batter is formed into a continuous layer and baked to 
form the continuous thermoplastic sheet, the width of the batter layer 
being baked may be controlled to provide a continuous baked sheet having a 
width such that when the baked sheet is rolled around its longitudinal 
axis and the edges of the sheet butted together, it forms a tube having 
the desired outside diameter. Alternatively, a relatively wide layer of 
batter may be formed on the heated endless belt and baked to provide a 
continuous sheet which upon completion of baking is subsequently cut into 
a plurality of continuous longitudinal strips of the desired width such as 
by passing the baked sheet through a plurality of spaced rotary or 
stationary knives disposed at or near the discharge end of the conveyor on 
which the baked sheet is carried. Thus, the baked sheet is cut into a 
plurality of continuous longitudinal strips, each of which have a width 
equal to the circumference of the finished centerfilled product. When such 
a wide batter is formed, it should have a width of no more than about 12 
inches in order to permit escape of gases generated in the sheet during 
baking without disrupting the integrity of the sheet. 
When the continuous batter layer has been baked to the desired extent, i.e. 
until its moisture content has been reduced to about 5% or less, the 
resulting continuous sheet while still warm and pliable, is formed into a 
continuous tube having a longitudinal, non-overlapping or butted seam. 
Thus, the baked sheet, having a desired width, is transferred onto a 
flexible, deformable, forming conveyor belt which has its feed end located 
adjacent the discharge end of the endless belt on which the sheet is 
carried during its baking, and moves in the same direction and at the same 
linear speed as the endless baking belt. This forming conveyor belt 
carries the baked dough sheet, while warm and pliable, through a closed 
forming tube in which the continuous baked sheet is formed into a 
continuous cylindrical tube. As this belt, which is flexible and 
deformable, enters the forming tube, the lateral edges of the flat belt 
are progressively raised and the belt progressively curved until the edges 
of the belt meet to form a closed cylindrical tube. The pliable, 
thermoplastic baked sheet which is carried on the flexible forming belt 
conforms in shape to the shape of the belt and is also formed into a 
closed cylindrical tube with the longitudinal edges of the sheet butted 
together to provide the tube with a non-overlapping longitudinal seam. 
The baked sheet has a moisture content of no more than about 5% and a 
temperature of at least about 210.degree. F. when it is carried into the 
forming tube and formed into a tubular shape, so that the baked sheet will 
be sufficiently pliable to be formed into a closed cylindrical tube 
without cracking of the sidewalls of the tube and will have sufficient 
cohesion and strength to hold together. 
The cylindrical tube thus formed is confined until it has cooled to an 
extent to become sufficiently rigid to retain its tubular shape without 
opening or separation of the longitudinal seam, this is, until the baked 
batter has cooled to a temperature below about 200.degree. F., preferably 
between about 95.degree.-100.degree. F. or below. Because of its 
relatively high mono-and/or disaccharide content, and the fact that the 
thickness of the sheet is restricted during baking, the baked batter is 
rigid, crisp and friable at such temperatures, so that upon cooling, the 
closed cylindrical tube retains its shape with no separation or opening of 
the closed longitudinal seam. In order to facilitate cooling of the baked 
batter tube, the forming tube through which the baked sheet is carried, is 
surrounded by a cooling jacket through which a refrigerant, such as cold 
water or glycol, is circulated. 
An edible filling material is continuously deposited into the center of the 
baked tube as it is carried through the forming tube to fill the core of 
the tube. While the nature of the filling material may vary depending on 
the intended use of the product, it is generally preferred to use a 
viscous material such as confectionary creme, fruit paste, meat paste, 
cheese paste, and the like, which has a visocity such that it is 
sufficiently fluid to be pumpable when warm but upon cooling will be 
sufficiently stiff and firm to be retained within the baked tubular shell. 
However, it is important that the filling material have a water activity 
(Aw) of no more than 0.2. Since the baked tube in which the filling is 
deposited has a relatively high mono-and/or disaccharide content, it is 
hygroscopic. If the filling material has a water activity of higher than 
0.2, moisture from the filling would be readily absorbed by the tubular 
shell, causing the shell to become soft and soggy rather than being rigid, 
crisp and friable, and causing the longitudinal seam of the shell to open 
up. When such a viscous filling material having a low water activity is 
used, it is injected into the baked tubular shell at a point after the 
baked strip is rolled into tubular shape and the edges of the baked strip 
are butted together. This gives the baked material an opportunity to cool 
somewhat before the introduction of the filling, thereby eliminating 
problems which may arise relating to melting or thermal degradation of 
heat sensitive fillings. It also reduces the risk of filling material 
escaping from the tubular shell. This is accomplished by pumping the 
filling material through a center filling tube which extends axially into 
the forming tube at the inlet end thereof to a point beyond that at which 
the edges of the baked strip are butted together to form a closed 
cylindrical tube. The filling material is introduced into the center of 
the cylindrical tubular shell at a velocity substantially equal to the 
velocity at which the tubular shell is carried through the forming tube, 
so that the center filling is continuous and uniform within the shell. 
Other edible filling materials such as, for example, dry granular powders 
and solid materials, may be filled into the core of the baked tube by 
suitable means. 
According to an embodiment of the invention, a confectionary creme having a 
maximum water activity of 0.2 is filled into the center of a continuous, 
baked tube to provide a cylindrical, centerfilled cookie product. Such a 
filling material contains as its principal ingredients between about 
20%-50% by weight of a sugar, such as granulated sugar, powdered sugar, 
brown sugar, dextrose, corn syrup solids, and the like, and combinations 
thereof, and between about 20%-40% by weight of an edible animal or 
vegetable fat or oil, such as butter, lard, hydrogenated vegetable oil 
shortenings, and the like, and combinations thereof. Minor amounts of 
other ingredients, such as salt, flavoring, antioxidant, emulsifiers, and 
the like, may be included, if desired. In a preferred embodiment, a 
proteinaceous material is included in the sugar-fat mix to provide a 
protein fortified cookie product. Preferably, non-fat dry milk solids are 
incorporated in the sugar-fat mix in amounts up to about 40% by weight of 
the mix, usually between 10%-40% by weight. Other suitable protein source 
materials may also be used, such as, for example, sodium caseinate, 
calcium caseinate, vegetable protein isolates, and the like. Vitamins, 
minerals and other nutrients may also be included if desired. In preparing 
such a filling mix, the shortening and emulsifier are melted and cooled to 
a temperature of about 100.degree.-110.degree. F. The cooled fat mixture 
is then combined with a blend of the dry ingredients (such as powdered 
sugar, nonfat milk solids, salts, etc.) in a mixer equipped with suitable 
agitating means until the texture is creamy and uniform. The mix then is 
pumped by a metering pump through an overrun control device that whips the 
filling mix until it becomes slightly stiff and has an overrun which may 
range from 0%-100%. The mix is then pumped through a filling tube which 
extends axially into the forming tube at the inlet end thereof to 
continuously deposit the filling in the baked tubular shell at a point 
after the tubular shell has been formed. 
The continuous filled tube, after being cooled to a temperature below 
200.degree. F. is carried from the forming tube by the forming belt and is 
subsequently cut into pieces of desired length, say from about 1-3 inches, 
by any suitable cutting means such as a reciprocating knife, rotary 
cutting blade, high speed saw, guillotine knife, water knife, and the 
like, and packaged in suitable moisture-impermeable packaging material. 
The ratio by weight of the filling material to the baked dough shell in 
the finished product may range from about 0.33-1.5:1, depending on the 
nature and intended use of the product. The product has a relatively high 
bulk density, on the order of about 10-50 lbs. per cu. ft., and has a 
water activity (Aw) of about 0.1-0.40. 
Referring now more particularly to the drawings, the apparatus of the 
present invention includes a general frame 10 serving as a support and 
mounting for a baking unit 11, tube forming and filling means 12 and 
cutting means 14. 
The baking unit 11 comprises a lower endless conveyor belt 15 adapted to 
receive a semi-liquid batter and carry a layer of batter as it is baked 
into a continuous sheet, an upper endless belt 16 disposed parallel to and 
vertically spaced a predetermined distance above lower conveyor belt 15 to 
gauge the thickness of the batter layer, and heating means 31 and 32 
disposed adjacent the facing runs of lower and upper belts 15 and 16 
respectively to bake the batter layer as it is carried on the lower belt. 
As shown in FIG. 2, lower endless conveyor belt 15 having a substantially 
horizontal upper run 25, extends longitudinally along the frame and 
extends around idler pulley 20 and drive pulley 21 at the feeding and 
discharge ends respectively of conveyor belt 15. Pulleys 20 and 21 are 
freely rotatable about shafts 22 and 23 which are horizontal and parallel 
to one another, the shafts being mounted in bearings (not shown) secured 
to the frame. Lower conveyor belt 15 preferably comprises an imperforate 
stainless steel band for suitable rigidity, although other suitable 
materials may be used. 
Upper endless belt 16 having a substantially horizontal lower run 24 is 
disposed above conveyor belt 15, parallel thereto, with the lower run 24 
of belt 16 being uniformly vertically spaced above the upper run 25 of the 
conveyor belt 15 a distance equal to the desired thickness of the baked 
shell portion of the product of this invention, generally a distance of 
between about 1/32" to 1/4". Upper endless belt 16 extends around idler 
pulley 26 and drive pulley 27 which are mounted for rotation about 
horizontal shafts 28 and 29 respectively which are parallel to one another 
and mounted in bearings (not shown) secured to the frame. 
As shown in FIG. 2, upper endless belt 16, which is made of the same 
material as the lower belt, overlies a substantial portion of lower 
conveyor belt 15, with the feed end of upper belt 16 being longitudinally 
spaced a short distance from the feed end of the lower conveyor belt. 
Disposed above the endless conveyor belt 15, intermediate the feed end of 
lower conveyor belt 15 and the feed end of upper belt 16 is nozzle 30 
adapted to deposit a uniform predetermined amount of semi-liquid batter on 
the upper run 25 of conveyor belt 15. Feeding means (not shown) associated 
with nozzle 30, cooperate with the nozzle to deposit a continuous layer of 
the semi-liquid batter onto the upper run of belt 15 with the batter layer 
having a thickness at least equal to the desired thickness of the baked 
shell portion of the product of this invention. 
Thus the upper run 25 of belt 15 and lower run 24 of belt 16 are axially 
aligned and vertically spaced apart to provide a gap therebetween, with 
the layer of semi-liquid batter being carried on the lower belt 15 into 
the gap to thereby gauge the thickness of the batter layer. Lower run 24 
of belt 16 is sufficiently proximate to upper run 25 of belt 15 to contact 
the upper surface of the batter layer being carried on upper run 25. 
One or more heating units 31 and 32 are mounted adjacent both facing belt 
runs 24 and 25 substantially the entire length of the facing belt runs. 
The heating units are adapted to heat the batter layer disposed between 
the facing runs and bake it into a continuous elongated sheet. Preferably 
a number of independently controlled heating units are mounted adjacent 
the facing runs 24 and 25, so that several temperature zones are provided 
over the length of the facing runs. However, in any given temperature 
zone, the heating units adjacent the upper and lower facing belt runs 
should be substantially the same temperature. Any suitable heating means 
capable of heating the batter layer to a temperature of between about 
275.degree. F.-550.degree. F. may be used, such as for example, gas 
burners, electrical heating coils, resistance heating elements, and the 
like. 
Lower and upper endless belts 15 and 16 are driven by motor means 33 to 
move in the same direction at the same linear speed. Drive chain 35 
connects the motor 33 to the main drive shaft 36 mounted in speed 
reduction means 34. Drive chain 37 connects the drive pulley 27 of the 
upper endless belt 16 and drive pulley 21 of the lower endless conveyor 15 
with the main drive shaft 36 through idler sprockets 38a, 38b, and 38c, so 
that the upper belt 16 moves in the same direction as and uniformly with 
the lower conveyor belt 15 in the direction indicated by the arrows. 
According to one embodiment of the invention, a vertically disposed endless 
belt 40, made of the same material as conveyor belt 15, is mounted 
adjacent both edges of the lower conveyor belt 15 at the feeding end 
thereof to confine the semi-liquid batter and thereby control the width of 
the semi-liquid batter on the lower conveyor belt. Thus, the vertical 
belts 40 extend from a point forward of nozzle 30 to a point where the 
semi-liquid batter has been baked sufficiently that it is no longer 
flowable. Each vertical belt extends around an idler pulley 41 and a drive 
pulley 42 which are freely rotatable about vertical shafts 43 and 44 
respectively, the shafts being mounted in bearings attached to the frame. 
Drive chain 53 connects drive pulley 42 with the main drive shaft 36 so 
that the vertical endless belts 40 move in the same direction and at the 
same linear speed as lower and upper horizontal endless belts 15 and 16. 
In this embodiment, both lower and upper belts 15 and 16 have a width 
substantially equal to the desired circumference of the tubular shell 
portion of the product of this invention. Since the vertical endless belts 
40 confine the edges of the batter layer, the baked batter layer will also 
have a width substantially equal to the desired circumference of the 
tubular shell. 
If desired, endless belts 15 and 16, and the batter layer carried 
therebetween, may have a width substantially greater than the desired 
circumference of the tubular shell. In such event, a plurality of suitable 
cutting means, such as stationary or rolling knives (not shown) are 
provided at or near the discharge end of the baking means to cut the 
continuous wide baked sheet into continuous strips having a width 
substantially equal to the desired circumference of the tubular shell. 
The lower and upper endless belts 15 and 16 may both have a length 
sufficient that the batter layer is completely baked (i.e., it has a 
moisture content of no more than 5%) when the batter layer reaches the 
discharge end of lower conveyor 15. Alternatively, the lower heated run 24 
of upper endless belt 16 may overlie lower endless belt 15 only adjacent 
to the feed end of the lower belt a distance sufficient to gauge the 
thickness and heat the batter layer until it has become set, so that the 
batter layer will retain its set thickness. Thereafter, the batter layer 
may be heated only on the lower endless belt 15 or may be transferred to 
other conventional baking means such as a continuous band oven for 
completion of baking of the batter layer. 
Located adjacent the discharge end of the lower endless conveyor 15 is the 
feed end of tube forming and filling means 12 which is adapted to receive 
the continuous baked batter sheet from conveyor belt 15. The tube forming 
and filling means 12 comprises a deformable, flexible endless conveyor 
belt 45 made of canvas, cotton, filled dacron or other suitable flexible 
and deformable material, arranged so as to have a substantially horizontal 
upper run 46 which is axially aligned and substantially co-planar with 
upper run 25 of endless conveyor belt 15. Thus, deformable endless belt 45 
is disposed end to end in longitudinal line with endless conveyor 15, the 
deformable belt 45 having a feed end located adjacent the discharge end of 
lower endless conveyor 15 and adapted to receive from the lower endless 
conveyor the continuous baked sheet, with the baked sheet being 
transferred onto the upper run 46 thereof. Deformable endless belt 45 
extends around idler pulley 47 and drive pulley 48 at the feed and 
discharge ends respectively. Pulleys 47 and 48 are rotatably mounted in 
bearings (not shown) mounted on the frame. Drive chain 49 connects the 
drive pulley 48 of flexible conveyor belt 45 with the drive pulley 21 of 
lower endless conveyor belt 15 so that the flexible conveyor belt 45 moves 
in the same direction and at the same linear speed as lower endless 
conveyor belt 15. 
The upper run 46 of flexible belt 45, which carries the continuous baked 
sheet, passes through tubular member 50, which has a converging guide 51 
at the inlet thereof, and through guide ring 52 which is secured to the 
frame 10 intermediate the discharge end of tubular member 50 and drive 
pulley 48. Tubular member 50 is surrounded by a cooling jacket through 
which a refrigerant such as cool water, glycol, and the like is circulated 
through inlet 55 and outlet 56. Tubular member 50 has a bore extending 
therethrough, the bore having a diameter which is substantially equal to 
the desired outside diameter of the centerfilled product of this 
invention, plus twice the thickness of the flexible belt, and may be in 
the range of from about 3/8" to 1". Flexible conveyor belt 45 has a width 
which is substantially equal to the circumference of the shell portion of 
the product of this invention. As the flexible conveyor belt 45 moves 
through converging guide member 51 into the tubular member 50, the lateral 
edges of the flat belt are progressively raised and the belt progressively 
curved until the edges of the belt meet to form a closed cylindrical tube 
at a point adjacent the inlet end of the tubular member. The belt is 
retained in this tubular configuration until the belt moves through guide 
ring 52. The continuous baked thermoplastic sheet which is carried on belt 
45 has a width substantially equal to the width of deformable belt 45. The 
baked sheet, as it is carried into tubular member 50, is at a temperature 
of about 210.degree. F. or above so that it is flexible and pliable so 
that it conforms in shape to the shape of belt 45. Accordingly, as the 
baked sheet is carried by the flexible conveyor belt 45 through converging 
guide 51 into tubular member 50, the lateral edges of the sheet are 
progressively raised and curved until the edges of the sheet are butted 
together to form a closed cylindrical tube having a longitudinal butted or 
non-overlapping seam. As the cylindrical tube formed from the baked sheet 
is carried through tubular member 50 it is cooled to an extent that it 
becomes rigid and friable so that as the continuous baked tube is carried 
beyond guide ring 52 it is sufficiently rigid to retain its tubular shape 
without opening or separation of the longitudinal seam. 
Filling tube 58 extends axially into the tubular member 50 to a point 
beyond that at which the edges of the baked sheet are butted together to 
form the cylindrical tube, for continuously introducing a viscous edible 
filling material into the center portion of the tube. The filling 
material, which has an overrun of about 30%-100%, is pumped from metering 
cylinder 59 through the filling tube 58 into the center of the cylindrical 
baked tube at a velocity substantially equal to the velocity at which the 
baked tube is carried through tubular member 50 so that the center filling 
is continuous and uniform and completely fills the core of the baked tube. 
As the center-filled tube is carried through tubular member 50 it is 
cooled sufficiently that the filling material becomes firm and is retained 
within the tubular shell. 
As the continuous center-filled tubular product is discharged from flexible 
conveyor belt 45 it is cut into pieces of desired length by suitable 
cutting means 14 provided at the discharge end of belt 45, and the cut 
pieces packaged in any suitable manner in moisture-impermeable packaging 
material. 
As seen in FIGS. 5 and 6, the product of this invention comprises a rigid, 
tubular baked shell 64 which surrounds and encases a core 65 of edible 
material, the tubular shell having a longitudinal, non-overlapping butted 
seam 66. 
The invention will be disclosed with more particularity in the following 
examples, which are intended to illustrate the present invention. 
EXAMPLE I 
A tubular centerfilled food product was made in accordance with the process 
disclosed hereinabove and using the apparatus shown in the accompanying 
drawings. A semi-liquid batter was prepared from the following 
ingredients: 
______________________________________ 
Percent 
by wt. 
______________________________________ 
Sugar 35.5 
Wheat Flour 13.5 
Shortening 11.5 
Cocoa 9.0 
Egg white solids 3.4 
Pregelatinized corn starch 
2.5 
Leavening 1.6 
Salt 0.5 
Emulsifier 0.5 
Water 22.0 
100.0 
______________________________________ 
In preparing the batter the dry ingredients were thoroughly mixed and the 
water added to the mix. The emulsifier and shortening were then added with 
agitation to form the batter. 
The semi-liquid batter was deposited as a continuous layer on the upper 
heated run of a lower, imperforate stainless steel endless belt 13/4" 
wide. A vertical, imperforate stainless steel belt, approximately 1" wide, 
was provided adjacent both lateral edges of the lower endless belt to 
contain the semi-liquid batter on the lower belt. An upper imperforate 
stainless steel endless belt, also 13/4" wide, was disposed above the 
lower endless belt with the lower run of the upper belt being vertically 
spaced 1/8" above the upper run of the lower endless belt. The batter 
layer was carried on the lower endless belt into the gap between the 
facing belt runs to provide the batter layer with a uniform thickness of 
1/8". Heating units disposed adjacent the facing belt runs heated the 
batter layer to a temperature of about 400.degree.-500.degree. F. as it 
was carried on the lower endless belt, with the batter layer being 
retained between the heated belt runs until the moisture content of the 
batter layer was reduced to about 3%. 
The continuous baked sheet, 13/4" wide.times.1/8" thick, was transferred 
from the lower endless belt to a flexible dacron endless belt, also 13/4" 
in width, disposed end to end in longitudinal line with the lower endless 
belt, and carried on the flexible endless belt through a forming tube 
having an internal diameter of 9/16". The baked sheet carried on the 
flexible belt had a temperature of above 210.degree. F. as it entered the 
forming tube. As it was carried through the forming tube, the lateral 
edges of the baked sheet were progressively raised and curved until the 
edges were butted together to form a continuous tube having a longitudinal 
non-overlapping seam. 
An edible filling material was prepared from the following ingredients: 
______________________________________ 
Percent 
by wt. 
______________________________________ 
Sugar 40.0 
Shortening 30.0 
Non-fat dry milk 20.0 
Butterfat 7.5 
Emulsifier 2.2 
Salt 0.2 
Flavor, antioxidant 
0.1 
100.0 
______________________________________ 
In preparing the filling, the dry ingredients were thoroughly mixed and 
added to a mixture of fat and emulsifier, which was at a temperature of 
about 100.degree.-110.degree. F. The resulting mix was whipped until it 
became slightly stiff. The filling was then pumped through a filling tube 
which extended axially into the forming tube at the inlet end thereof to 
continuously deposit the filling material into the core of the tube of 
baked batter, with the filling being injected at a point after the edges 
of the baked sheet had been butted together. The filled tube was retained 
in the forming tube until the temperature of the shell was reduced to 
below 150.degree. F. so that the shell was rigid and friable. 
The cooled filled tube was then carried on the flexible belt from the 
forming tube to cutting means which cut the continuous filled tube into 
pieces about 3" in length. 
The centerfilled product thus produced had an outside diameter of about 
9/16" with a baked shell thickness of 1/8". The filling material 
completely filled the core of the tube. There was no opening or separation 
of the longitudinal butted seam of the cooled shell. 
EXAMPLE II 
This example illustrates the production of a sweet bakery centerfilled 
product in accordance with the process of the present invention, in which 
a high level of disaccharides is included in the batter. Thus a 
semi-liquid batter was prepared from the following ingredients: 
______________________________________ 
Percent 
by wt. 
______________________________________ 
sucrose or lactose 37.6 
wheat flour 10.0 
cocoa 8.2 
margarine 7.1 
egg white solids 5.2 
vital wheat gluten 4.8 
pregelatinized corn starch 
3.6 
leavening 2.0 
emulsifier 1.0 
salt 0.5 
water 20.0 
100.0 
______________________________________ 
In preparing the batter, the dry ingredients were thoroughly mixed and the 
water added to the mix. The emulsifier and margarine were then added with 
agitation to form the batter. 
The resulting semi-liquid batter was deposited as a continuous layer on the 
upper heated run of an upper oven-quality iron endless belt 26" wide. Two 
strips of batter, each 12" wide, were deposited on each half of the upper 
endless belt. A lower oven-quality iron endless belt, 28" wide, was 
disposed below the upper endless belt, with the lower run of the upper 
belt being parallel to and vertically spaced 1/8" above the upper run of 
the lower endless belt. The batter layer was carried on the upper endless 
belt into the gap between the facing belt runs to provide the batter layer 
with a uniform thickness of 1/8". Heating units disposed adjacent the 
facing belt runs heated the batter layer to a temperature of about 
250.degree.-350.degree. F. as it was carried on the lower endless belt, 
with the batter layer being retained between the heated belt runs to only 
partially bake the batter layers, that is, until the moisture content of 
the batter layers was reduced to about 15-25%. 
The two continuous baked sheets, each 12" wide.times.1/8" thick, were then 
transferred from the lower endless belt to a continuous band oven belt and 
baked until a moisture level of less than 5% is achieved. After baking, 
the 12" strips of baked product were cut and trimmed into continuous 
longitudinal strips each being 13/4" wide. Each of the baked longitudinal 
strips thus formed was transferred to a flexible endless belt and formed 
into a continuous tube using the same procedure described in Example I. 
An edible filling material was prepared from the following ingredients: 
______________________________________ 
Percent 
by wt. 
______________________________________ 
sucrose 52.3 
shortening 20.0 
nonfat dry milk 18.7 
butterfat 7.4 
emulsifier 1.3 
salt 0.2 
flavor, antioxidant 
0.1 
100.0 
______________________________________ 
In preparing the filling, the dry ingredients were thoroughly blended and 
added to a mixture of fat and emulsifier, which was at a temperature of 
about 120.degree.-165.degree. F. The resulting mix was whipped until it 
became slightly stiff. The filling was then pumped through a filling tube 
which extended axially into the forming tube at the inlet end thereof to a 
point beyond which the edges of the longitudinal strips were butted 
together, to continuously deposit the filling material into the core of 
the tube of baked batter. The filled tube was retained in the forming tube 
until the temperature of the shell was reduced to below 150.degree. F. so 
that the shell was rigid and friable. 
The cooled filled tube was then carried on the flexible belt from the 
forming tube to cutting means which cut the continuous filled tube into 
pieces about 3" in length. 
EXAMPLE III 
The same process is followed as in Example II, except that the semi-liquid 
batter was prepared from the following ingredients, in which mono-and 
disaccharides are used to provide a thermoplastic baked sheet and produce 
a non-sweet, snack food centerfilled product. 
______________________________________ 
Percent 
by wt. 
______________________________________ 
wheat flour 16.90 
margarine 7.20 
dextrose 6.60 
corn syrup solids 6.60 
lactose 6.60 
malto-dextrin 6.60 
vital wheat gluten 6.00 
egg white solids 5.50 
malt powder 3.90 
pregelatinized corn starch 
3.50 
leavening 2.50 
salt 1.00 
emulsifier 0.60 
water 26.50 
100.0 
______________________________________ 
EXAMPLE IV 
The same process is followed as in Example II, except that the semi-liquid 
batter was prepared from the following ingredients, in which 
monosaccharides were used to provide a thermoplastic baked sheet and 
produce a non-sweet, snack food centerfilled product: 
______________________________________ 
Percent 
by wt. 
______________________________________ 
dextrose 26.40 
wheat flour 16.83 
margarine 7.20 
vital wheat gluten 6.00 
egg white solids 5.50 
malt powder 3.90 
pregelatinized corn starch 
3.50 
leavening 2.50 
salt 1.00 
emulsifier 0.67 
water 26.50 
100.00 
______________________________________ 
The non-sweet snack food product produced in Examples III and IV were 
filled with an edible filling material which included the following 
ingredients: 
______________________________________ 
Percent 
by wt. 
______________________________________ 
dehydrated meat 30.00 
shortening 23.00 
pregelatinized corn starch 
9.00 
potato starch 9.00 
malto-dextrin 9.00 
corn syrup solids 9.00 
butterfat 8.50 
emulsifiers 1.30 
spices 1.00 
flavor, antioxidant 
0.20 
100.00 
______________________________________ 
The dry ingredients were combined with approximately 30% of the formula 
weight of shortening which was at a temperature of 120.degree.-150.degree. 
F. This mixture was processed to reduce its particle size, followed by 
heating to a temperature of 100.degree.-125.degree. F. The resulting 
mixture was then processed and injected into the continuous tubular shells 
using the same procedure described in Example II. 
The centerfilled products produced in Examples II-IV had an outside 
diameter of about 9/16" with a baked shell thickness of 1/8". The baked 
shell portion of the products produced in Examples II-IV each had a bulk 
density of about 36 lbs. per cu. ft. The filling material used in these 
examples had a water activity of no more than 0.2, and completely filled 
the core of the tube. There were no openings or separations of the 
longitudinal butted seam of the cooled shell. 
While the invention has been described and illustrated with reference to a 
particular preferred embodiment, it is to be understood that this is only 
illustrative and not intended to limit the scope of the invention. Rather, 
the invention encompasses modifications, variations and rearrangements of 
parts which fall within the scope of the appended claims.