U.S. patent application number 09/791783 was filed with the patent office on 2001-12-27 for impregnated composite extrusion product.
Invention is credited to Bengtsson-Riveros, Annmarie, Farnsworth, John T., Geromini, Osvaldo, Heck, Ernst, Pfaller, Werner.
Application Number | 20010055636 09/791783 |
Document ID | / |
Family ID | 26153121 |
Filed Date | 2001-12-27 |
United States Patent
Application |
20010055636 |
Kind Code |
A1 |
Geromini, Osvaldo ; et
al. |
December 27, 2001 |
Impregnated composite extrusion product
Abstract
A composite consumable food product in the form of a section of
an extruded strand of a first foodstuff impregnated into a second
foodstuff. Prior to extrusion of the strand in a twin screw
extruder, the first foodstuff is a liquid or a pasty consumable
substance, such as a syrup, while the second foodstuff is a
plasticized consumable substance, such as a cereal base. The first
and second foodstuffs are preferably processed in separate sections
of the extruder before a taste or flavor perceptible amount of the
first foodstuff is introduced into and uniformly mixed with the
second foodstuff prior to extrusion through a die. The resultant
extruded strand is typically cut into sections to obtain the final
product.
Inventors: |
Geromini, Osvaldo; (Orbe,
CH) ; Pfaller, Werner; (Orbe, CH) ;
Bengtsson-Riveros, Annmarie; (Chexbres, CH) ; Heck,
Ernst; (Vufflens-La-Ville, CH) ; Farnsworth, John
T.; (St. Joseph, MO) |
Correspondence
Address: |
WINSTON & STRAWN
200 PARK AVENUE
NEW YORK
NY
10166-4193
US
|
Family ID: |
26153121 |
Appl. No.: |
09/791783 |
Filed: |
February 26, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09791783 |
Feb 26, 2001 |
|
|
|
09667441 |
Sep 22, 2000 |
|
|
|
6268007 |
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Current U.S.
Class: |
426/89 ;
426/92 |
Current CPC
Class: |
A23L 7/17 20160801; A21C
11/163 20130101; A23L 7/191 20160801; A23L 7/122 20160801; A23P
30/25 20160801 |
Class at
Publication: |
426/89 ;
426/92 |
International
Class: |
A23L 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 22, 1999 |
EP |
991186792.2 |
Claims
What is claimed is:
1. A composite consumable food product in the form of a section of
an extruded strand of a first foodstuff impregnated throughout with
a second foodstuff, wherein, prior to the extrusion of the strand,
the first foodstuff is a liquid or a pasty consumable substance and
the second foodstuff is a plasticized consumable substance, and the
first foodstuff is present in a flavor or taste perceptible
amount.
2. The composite consumable product of claim 1, wherein the first
and second foodstuffs are present in a weight ratio of about 1:99
and 1:2.
3. The composite consumable product of claim 1, wherein the first
foodstuff is a syrup and the second foodstuff is a cereal base.
4. The composite consumable product of claim 1, wherein the
composite consumable food product has a moisture content of less
than about 15 percent.
5. The composite consumable product of claim 1, wherein the second
foodstuff comprises wheat, barley, maize, rice flour, semolina, or
mixtures thereof and water.
6. The composite consumable product of claim 5, wherein the second
foodstuff further comprises one or more additional additives
selected from the group consisting starch, sugar, fat or oil, a
source of plant fiber, non-fatty milk solids from milk, vitamins,
antioxidants, trace elements, flavorings, colorings, and mixtures
thereof.
7. The composite consumable product of claim 6, wherein the starch
comprises wheat, barley, rice, tapioca, potato, maize, or mixtures
thereof.
8. The composite consumable product of claim 6, wherein the sugar
comprises sucrose, fructose, glucose, or mixtures thereof.
9. The composite consumable product of claim 1, wherein the first
foodstuff comprises sugar, honey, water, or mixtures thereof.
10. The composite consumable product of claim 9, wherein the first
foodstuff further comprises milk powder, fruit or vegetable pulp or
concentrate, cocoa powder, colorings, flavors, vitamins, trace
elements, salt, spices, oils, materials or microorganisms with
probiotic or prebiotic properties; functional plant extracts, or
mixtures thereof.
11. The composite consumable product of claim 9, wherein the sugar
comprises sucrose, fructose, dextrose, raw cane sugar, or mixtures
thereof.
12. The composite consumable product of claim 1, wherein the first
foodstuff comprises protein hydrolysate and fat.
13. The composite consumable product of claim 12, wherein the first
foodstuff further comprises colorings, flavorings, vitamins, trace
elements, and mixtures thereof.
14. The composite consumable product of claim 1, wherein the first
foodstuff comprises minced meat, tomato sauce, cheese, almonds,
hazelnuts, chocolate, jam, and mixtures thereof.
15. The composite consumable product of claim 14, wherein the
consumable substance further comprises milk powder, fruit pulp,
vegetable pulp or concentrate, cocoa powder, colorings, vitamins,
trace elements, flavorings, salt, spices, oils, microorganisms with
probiotic or prebiotic properties; functional plant extracts, and
mixtures thereof.
16. A composite consumable food product comprising a first
foodstuff impregnated throughout a second foodstuff, the composite
food product produced by a double extrusion process comprising:
introducing one or more first foodstuffs into a first section of a
twin screw extruder and processing the first foodstuffs in the
first section to provide a liquid or pasty consumable substance;
introducing one or more second foodstuffs into the second section
of the twin-screw extruder and processing the second foodstuffs to
provide a plasticized consumable substance, wherein the first and
second sections off the twin screw extruder are separated by a
dynamic separation device so that the first foodstuffs and the
second foodstuffs can be processed separately; introducing a flavor
or taste perceptible amount of the first foodstuff into the second
foodstuff at a location in the second section of the twin screw
extruder where the second material has been processed and
plasticized but where the first foodstuff can be uniformly mixed
with the second foodstuff to form a mixture of the second foodstuff
impregnated with the first foodstuff; and extruding the mixture to
provide an extruded strand of the composite consumable food product
with the first foodstuff impregnated throughout the second
foodstuff.
17. The composite consumable product of claim 4 in the form of
pieces formed by cutting the strand.
18. The composite consumable product of claim 4, wherein the first
and second foodstuffs are present in a weight ratio of about 1:99
and 1:2.
19. The composite consumable product of claim 4, wherein the first
foodstuff is a syrup and the second foodstuff is a cereal base.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 09/667,441, filed Sep. 22, 2000, now
pending.
FIELD OF THE INVENTION
[0002] The present invention is directed to a process and a device
for manufacturing a composite consumable product by double
extrusion.
BACKGROUND ART
[0003] EP 0,626,138 (Quaker Oats) discloses a process for
manufacturing instant cereals, wherein a mixture based on cereal
flour and water is cooked-extruded. The cooked-extruded mixture, to
which pieces of food substance have been added, is shaped into
flakes, the flakes toasted, coated with a sugar syrup to form a
film on the surface thereof, and then dried.
[0004] U.S. Pat. No. 3,764,715 (Quaker Oats) discloses a process
for manufacturing a coated instant cereal, wherein a mixture based
on cereal flour and water is prepared, the mixture is
cooked-extruded-expanded in the form of a tubular strand using an
extruder equipped with a coextrusion die comprising an annular
outlet orifice surrounding a central outlet orifice. A syrup is
injected inside the tubular strand via the central outlet orifice.
The cereal strand comprising the sugar syrup is cut into pieces at
the die face, and the pieces are then dried so that the syrup which
is present in the pieces diffuses from the inside towards the
outside to form a film of dry syrup around the pieces.
[0005] EP 0,815,729 (Socit des Produits Nestl S.A.) discloses a
process for manufacturing a foodstuff by extrusion, wherein a first
food substance to be processed is introduced into a first section
of a twin-screw extruder, a second food substance to be processed
is introduced into a second section of the twin-screw extruder
separated dynamically from the first twin screw extruder, each food
substance is processed independently in their section of the
extruder and the two masses of food substance are extruded by being
passed through at least one die and the extruded or coextruded
products are cut up.
[0006] There remains a need, however, for a process and device for
manufacturing composite consumable products that is simple and can
be well controlled. The present invention provides such a device
and process.
SUMMARY OF THE INVENTION
[0007] The invention is directed to a process for preparing a
composite consumable food product by double extrusion. The process
involves the steps of introducing one or more first foodstuffs into
a first section of a twin screw extruder and processing the first
foodstuffs in the first section to provide a liquid or pasty
consumable substance; introducing one or more second foodstuffs
into the second section of the twin-screw extruder and processing
the second foodstuffs to provide a plasticized consumable
substance, wherein the first and second sections off the twin screw
extruder are separated by a dynamic separation device so that the
first foodstuffs and the second foodstuffs can be processed
separately; extruding the plasticized consumable substance to
provide a strand of plasticized consumable substance; cutting the
strand of plasticized consumable substance into pieces; and adding
the liquid or pasty consumable substance to the plasticized
consumable substance to provide the composite consumable food
product.
[0008] The liquid or pasty consumable substance can be added to the
plasticized consumable substance by coating the liquid or pasty
consumable substance on the pieces of plasticized consumable
substance. In one embodiment the liquid or pasty consumable
substance can be coated on the plasticized consumable substance by
coextruding the pasty or liquid consumable substance and the
plasticized consumable substance through a die comprising a central
orifice and a annular orifice wherein the plasticized consumable
substance is extruded through the central orifice and the pasty or
liquid consumable substance is extruded through the annular orifice
so that the pasty or liquid consumable substance surrounds the
strand of plasticized consumable substance. In another embodiment
the liquid or pasty consumable substance is coated on the
plasticized consumable substance after the strand of plasticized
consumable substance has been cut by spraying the liquid or pasty
consumable substance on the cut pieces of plasticized consumable
substance while they are being mixed.
[0009] In another embodiment the liquid or pasty consumable
substance can also be added to the plasticized consumable substance
by coextruding the pasty or liquid consumable substance and the
plasticized consumable substance through a die comprising a central
orifice and a annular orifice wherein the pasty or liquid
consumable substance is extruded through the central orifice and
the plasticized consumable substance is extruded through the
annular orifice so that the plasticized consumable substance
surrounds the pasty or liquid consumable substance.
[0010] In yet another embodiment the liquid or pasty consumable
substance is added to the plasticized consumable substance by
injecting the liquid or pasty consumable substance into the
plasticized consumable substance while the plasticized consumable
substance is in the second section of the twin-screw extruder.
[0011] The process may further include the step of drying the
composite consumable food product. The composite consumable food
product may be dried to a moisture content of less than about 15
percent.
[0012] The second foodstuff may be wheat, barley, maize, rice
flour, semolina, or mixtures thereof and water. The second
foodstuff may further include one or more additional additives
selected from the group consisting starch, sugar, fat or oil, a
source of plant fiber, non-fatty milk solids from milk, vitamins,
antioxidants, trace elements, flavorings, colorings, and mixtures
thereof. The starch may be wheat, barley, rice, tapioca, potato,
maize, or mixtures thereof. The sugar may be sucrose, fructose,
glucose, or mixtures thereof.
[0013] The second foodstuff can have a water content of about 14 to
23 percent to provide a plasticized consumable substance that is
expanded. The second foodstuff can also have a water content of
about 24 to 36 percent to provide a plasticized consumable
substance that is substantially non-expanded. The non-expanded
plasticized consumable substance can be rolled and toasted to
provide flakes.
[0014] The first foodstuff may be sugar, honey, water, or mixtures
thereof and may further include milk powder, fruit or vegetable
pulp or concentrate, cocoa powder, colorings, flavors, vitamins,
trace elements, salt, spices, oils, materials or microorganisms
with probiotic or prebiotic properties; functional plant extracts,
or mixtures thereof. The sugar may be sucrose, fructose, dextrose,
raw cane sugar, or mixtures thereof.
[0015] The first foodstuff may also be a protein hydrolysate and
fat and may further include colorings, flavorings, vitamins, trace
elements, and mixtures thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 diagrammatically represents a first embodiment of the
device of the invention wherein the addition device is a
coextrusion nozzle positioned directly at the outlet of the second
section of the extruder;
[0017] FIG. 2 diagrammatically represents a second embodiment of
the device of the invention wherein the addition device is at least
one spray nozzle included in a device that is separate from the
extruder and positioned after the outlet of the extruder;
[0018] FIG. 3 diagrammatically represents a third embodiment of the
device of the invention wherein the addition device is at least one
spray nozzle included in a device separate from the extruder and
positioned at the outlet of the extruder;
[0019] FIG. 4 diagrammatically represents a fourth embodiment of
the device of the invention wherein the addition device is at least
one injection opening positioned close to and upstream of the
outlet opening of the second section of the extruder;
[0020] FIG. 5 is a diagrammatic view of the vertical section of an
extruder of the device of the invention along the axis of the
left-hand screw, illustrating a representative geometry for the
screws of the device depicted in FIGS. 1-4;
[0021] FIG. 6 is a diagrammatic view of the horizontal section of
the extruder along the plane defined by the axes of the two screws,
illustrating the same representative geometry for the screws as
illustrated in FIG. 5; and
[0022] FIG. 7 represents in greater detail the embodiment of the
outlet opening for the liquid or pasty consumable substance
represented in FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] The present invention is directed to a process wherein a
liquid or pasty consumable substance is prepared in a first section
of a twin-screw extruder, a plasticizable consumable substance is
cooked-extruded in a second section of the twin-screw extruder,
separated dynamically from the first section, to provide at least
one strand of a cooked-extruded mass of the plasticized consumable
substance, which is cut into pieces, and the liquid or pasty
consumable substance is added to the pieces of the cooked-extruded
mass to provide a composite consumable product.
[0024] The present invention is also directed to a device for
carrying out the process of the invention. The device comprises a
twin-screw extruder separated into two distinct sections by a
dynamic separation device, at least one die, a cutter, and a device
for adding a liquid or pasty substance to a plasticized consumable
substance to provide a composite consumable product.
[0025] The process and device of the invention provides a
simplified and particularly well-controlled method for
manufacturing composite consumable products.
[0026] The phrase "dynamic separation device," as used herein,
means a device that effectively separates the liquid or pasty
consumable substance in the first section of a twin-screw extruder
from the plasticizable consumable substance in the second section
of the twin-screw extruder.
[0027] The phrase "consumable substance," as used herein, means a
substance that can consumed by human beings and/or a substance that
can be consumed by animals including, but not limited to, household
animals such as dogs or cats, wild animals, and animals raised for
their meat such as farm animals and cattle.
[0028] The phrase "composite consumable product," as used herein,
means a consumable product that comprises at least two separate
food stuffs that have been combined to form a single edible product
wherein one of the food foodstuffs is a platicizable consumable
substance, such as, for example a cooked cereal product, and the
other food stuff is a liquid or pasty consumable substance (as a
coating, a filling, or an impregnating component). The composite
consumable product can be, for example, a coated product, a
coextruded product with a soft interior and crunchy exterior, or a
composite product impregnated throughout its body.
[0029] The phrase "plasticizable consumable substance," as used
herein encompasses all the components introduced into the second
section of the extruder and cooked-extruded at least over a portion
of this section. The components may be added separately,
simultaneously, or successively and may also be combined together
before being added to the second section of the extruder.
[0030] The term "plasticizable," as used herein means that the
foodstuff becomes a hot plastic mass when it is subjected to the
basic cooking extruding process (i.e., mixing, compressing,
shearing by means of intermeshing screws) under high temperature
and pressure.
[0031] The phrase "liquid consumable substance" and "pasty
consumable substance," as used herein, means a substantially
flowable consumable substance, such as, for example, a free flowing
low viscosity liquid or a syrup. Liquid consumable substance are
free flowing low viscosity liquids. The pasty consumable substance
has a higher viscosity than a free flowing liquid consumable
substance and shows some resistance to flow.
[0032] Any plasticizable consumable substance from which it is
possible to produce products by cooking-extrusion including, but
not limited to, products intended for humans such as, breakfast
cereals, cereals for infants, snacks, breadcrumbs, confectionery
products, and products intended for animals such as dry pet food,
for example, may be the starting food substance for the process of
the invention. The plasticizable consumable substance can, for
example, be based on milled cereal and water and can comprise as
the major component a cereal flour or semolina. Preferably the
plasticizable consumable substance comprises wheat, barley, oats,
maize, rice flour, semolina, or a combination thereof and
water.
[0033] The plasticizable consumable substance can additionally
comprise one or more of starch, sugar, fat or oil, a source of
plant fiber, non-fatty solids from milk, or combinations thereof.
Preferably the starch is wheat, barley, rice, tapioca, potato,
maize starch, or a mixture thereof. Preferably the sugar is
sucrose, glucose, fructose or a mixture thereof. Preferably the oil
or fat is butter oil, palm kernel fat, ground nut or maize oil or
fat, or a combination thereof. Preferably the source of plant fibre
is bran. Preferably the nonfatty solids from milk is skimmed milk
powder. The plasticizable consumable substance can additionally
comprise additional additives including, but not limited to,
vitamins, trace elements, antioxidants, flavorings, colorings, and
combinations thereof. The plasticizable consumable substance can
also comprise, in particular in the case where it is more intended
for consumption by pets, leguminous flour or semolina, such as
soya, meat or fish meal, hydrolysate, tallow, or mixtures
thereof.
[0034] The components of the plasticizable consumable substance and
their respective proportions can be introduced into the second
section of the extruder either individually or as a premix.
[0035] The plasticizable consumable substance is cook-extruded in
the second section of the extruder under conditions of pressure,
shear, and temperature so that the final product has the desired
characteristics. In particular it is possible to vary the
cooking-extruding conditions so as to vary the water content and
the degree of expansion that is desired in the extruded product.
For example, it is possible to cook-extrude a plasticizable
consumable substance having a water content of between about 14 to
23% in order to obtain an expanded product. Preferably, the
expanded product exhibits an expansion coefficient of from about 2
to 10 and more preferably from between about 2 and 5. It is also
possible to cook-extrude a plasticizable consumable substance
exhibiting a water content of about 24 to 36% in order to obtain a
substantially non-expanded or only slightly expanded product. By
substantially non-expanded is meant that the volume of the
extrudate does not increase more than a few percent after exiting
the extruder and has an expansion coefficient of less than about 2.
The non-expanded or only slightly expanded product, which has been
cut up, can be converted into flakes by rolling and toasting, for
example. One of ordinary skill in the art may readily determine the
cooking-extruding conditions to obtain specific characteristics in
the extruded product.
[0036] The liquid or pasty consumable substance is prepared in the
first section of the extruder with stirring and at an appropriate
temperature so that the ingredients are well mixed and to assure
that the mixture has good fluidity so that it can be pumped.
Conditions may be chosen to avoid or, if appropriate, promote
reaction between components of the liquid or pasty consumable
substance. The reactions may be enzymatic or nonenzymatic
reactions.
[0037] The resulting liquid or pasty consumable substance can be
added in various ways to the cooked-extruded plasticizable
consumable substance. In particular by coating the plasticizable
consumable substance, coextrusion of the plasticizable consumable
substance and the liquid or pasty consumable substance, or
impregnating the plasticizable consumable substance throughout with
the liquid or pasty consumable substance.
[0038] The liquid consumable substance for coating is prepared in
the form of a syrup. When the liquid consumable substance is
intended for human consumption it preferably comprises sugar,
honey, water, or mixtures thereof. The liquid consumable substance
may further comprise additional components, including, but not
limited to milk powder, fruit or vegetable pulp or concentrate,
cocoa powder, colorings, flavors, vitamins, trace elements, salt,
spices, oils, or mixtures thereof. In addition, materials or
microorganisms with probiotic or prebiotic properties; functional
plant extracts, such as guarana, ginseng, acerola, rosehip, cola,
and garcinia extracts, indeed even procyanidol oligomers (P.C.O.)
such as can be extracted from grape or strawberry seeds, can
advantageously be added to the syrup.
[0039] Preferably the sugar is sucrose, fructose, dextrose, raw
cane sugar, or a mixture thereof.
[0040] When the liquid consumable substance for coating is intended
for animals it preferably comprises protein hydrolysate, vegetable
extract, water, and mixtures thereof. In addition, it may further
comprise one or more additional components, such as colorings,
flavorings, vitamins, trace elements, and mixtures thereof.
[0041] A pasty consumable substance, intended for human
consumption, preferably comprises minced meat, tomato sauces and or
cheese (for savory products), almonds, hazelnuts, chocolate or jam
(for sweet products), and mixtures thereof. The pasty consumable
substance may further comprise one or more additional components,
including but not limited to milk powder, fruit or vegetable pulp
or concentrate, cocoa powder, colorings, vitamins, trace elements,
flavorings, salt, spices, oils, and mixtures thereof. In addition,
materials or microorganisms with probiotic or prebiotic properties;
functional plant extracts, such as guarana, ginseng, acerola,
rosehip, cola or garcinia extracts; indeed even procyanidol
oligomers (P.C.O.) such as can be extracted from grape or
strawberry seeds can advantageously be added to the pasty
consumable substance.
[0042] A pasty consumable substance intended for pets preferably
comprises protein hydrolysate and fat. Preferably the fat is
tallow, molasses, or a mixture thereof. The pasty consumable
substance may further comprise one or more additional components,
including, but not limited to, colorings, flavorings, vitamins,
trace elements, and mixtures thereof.
[0043] The pieces of cooked-extruded plasticizable consumable
substance can be coated before or after they are cut up at the
outlet of the extruder. To coat the cooked-extruded plasticizable
consumable substance before they are cut up at the outlet of the
extruder the cooked-extruded plasticizable consumable substance and
the liquid or pasty consumable substance is coextruded through a
die comprising an annular outlet orifice surrounding a central
outlet orifice. A strand of cooked-extruded plasticizable
consumable substance is extruded through the central orifice and
the liquid or pasty consumable substance is distributed through the
annular orifice around the cooked-extruded strand.
[0044] The pieces can also be coated after they have been cut up.
In this embodiment provision is made to spray the liquid consumable
substance onto the cut-up pieces while they are being mixed or
tumbled.
[0045] In another embodiment the liquid or pasty consumable
substance is encapsulated by coextruding the liquid or pasty
consumable substance and the cooked-extruded substance through a
die comprising an annular outlet orifice surrounding a central
outlet orifice. The cooked-extruded substance is extruded as a
strand or rope through the annular orifice and the liquid or pasty
consumable substance is extruded through the central orifice to
provide a rope or strand having the liquid or pasty consumable
substance inside the cooked-extruded strand.
[0046] The cooked-extruded strand can also be impregnated with the
liquid or pasty consumable substance throughout the strand by
injecting the liquid or pasty consumable material into the second
section of the extruder. Preferably the liquid or pasty consumable
material is injected close to the outlet of the second section of
the extruder but sufficiently upstream for it to be well mixed with
the mass of plasticized consumable substance to be extruded before
the mass is extruded. Advantageously the cooked-extruded strand is
cut into pieces directly at the outlet of the second section of the
extruder.
[0047] Optionally, the composite product resulting pieces can be
dehydrated to a residual water content of less than about 15%,
preferably less than about 10% and more preferably less than about
5%.
[0048] The device for carrying out the process according to the
present invention comprises a twin-screw extruder separated into
two distinct sections by a dynamic separation device, at least one
die, a cutter, and a device for adding a liquid or pasty
substance.
[0049] The dynamic separation device can be a blocking region
wherein the twin screw has a reverse pitch and can also comprise
cones positioned head-to-tail, i.e., one cone, for example the cone
on the first screw of the has its broad part downstream, and the
second cone, i.e., on the second screw has its broad part
upstream.
[0050] The outlet opening of the first section of the extruder can
entirely cover the outlet region of the twin-screw device and which
overlaps, on either side, onto a compression region and onto a
dynamic separation region as depicted in FIG. 7.
[0051] In one embodiment the outlet region comprises one or more
bilobes on one screw and a collar on the other screw, the collar
facing the outlet opening.
[0052] The outlet opening of the second section can be provided
along the axis or on the side of the downstream end of the
extruder, for example.
[0053] The outlet opening of the first section can be connected via
a pipe to at least one coextrusion die provided at the outlet of
the second section of the extruder. In another embodiment the
outlet opening of the first section is connected to at least one
spray nozzle provided in a device separate from the extruder. In
yet another embodiment the outlet opening of the first section can
be connected to at least one injection opening provided in the
barrel of the extruder, preferably it is connected close to the
outlet opening of the second section.
[0054] The outlet opening of the second section can emerge directly
onto the die. The die can be an extrusion or coextrusion die
through which the substance processed in the second section is
extruded or pressed under the pressure exerted by the twin-screw
device. The die can comprise one or more extrusion pipes emerging
into one or more outlet orifices provided on a front wall of the
die.
[0055] The cutter may be in the form of a multi-blade rotary
cutter, preferably comprising 2-16 blades, rotating against the
outlet orifice or orifices of the die, i.e., against the front wall
of the die.
[0056] The addition device for adding the pasty or liquid substance
is positioned at the outlet of the second section of the extruder
in the form of at least one coextrusion die. In another embodiment
the addition device for adding the pasty or liquid substance is
positioned close to the outlet opening of the second section,
upstream of the outlet opening, in the form of at least one
injection opening provided in the barrel of the extruder. In yet
another embodiment the addition device for adding the pasty or
liquid consumable substance is positioned at the outlet or after
the outlet of the extruder in the form of at least one spray nozzle
included in a device separate from the extruder.
[0057] The addition device can be separate from the extruder and
can be a hollow cylindrical drum rotating about a generally
horizontal axis that includes, in its upper part or its side part,
at least one spray nozzle capable of spraying a liquid consumable
substance over the extruded plasticized consumable substance while
it is mixed or tumbled in the cylinder. A preferred addition device
of this type is a rotary cylindrical drum, having a first open part
that surrounds the die of the extruder and the cutter, and a second
non-open part that extends downstream of the cutter and having, in
its upper part or in a side part, at least one spray nozzle capable
of spraying a liquid consumable substance directly over the pieces
of product ejected by the cutter. In this preferred embodiment, the
cutter can advantageously be driven by a hydraulic motor which is
smaller in size than a conventional electric motor.
[0058] A drying device may also be provided. For example, the dryer
may be a hot-air drying tunnel.
[0059] A feed device for each section of the extruder can be in the
form of one or more feed openings provided in the barrel of the
twin-screw device, starting from the upstream end of the extruder
for the first section and, for the second section, starting from a
transportation region following the blocking region of the
twin-screw device.
[0060] The geometry of the screws can varied for each section of
the extruder to provide the desired properties in the the
plasticizable consumable substance or the liquid or pasty
consumable substance that is processed. The geometry of the screws
may be readily determined by one of ordinary skill in the art.
[0061] It is possible in particular to provide successive and/or
alternating transporting, transporting-mixing-dissolving,
compressing-dissolving, or mixing-dissolving regions on the first
section and successive and/or alternating transporting, compacting,
compressing, kneading or mixing regions on the second section, of
the extruder. In order to define these various regions, it is
possible, for example, to vary the pitch and the handedness of the
screws, the empty space defined in by the respective diameters of
the shafts and the flights of the screws, or the insertion of
bilobes of various shapes. It is also possible to divide each
section of the extruder into several independent subdivisions, the
temperature of which can be individually adjusted by circulating a
cooling or heating fluid.
[0062] Finally, the mechanical energy needed to prepare the liquid
or pasty consumable substance, to process the plasticizable
consumable substance, to distribute or spray the liquid or pasty
consumable substance, and to extrude the processed substance can be
supplied by a single means for driving the screws of the twin-screw
device. The mechanical energy may be provided, for example by an
electric motor. In order to ensure that the processed plasticizable
consumable substance passes through the die, the motor can be
assisted or the load on it can be lightened using a
positive-displacement pump, such as a gear pump, connected upstream
of the die.
[0063] More precise control of the spraying and the injection of
the liquid or pasty consumable substance can be provided by
connecting a positive-displacement pump between the outlet of the
first section of the extruder and the spray nozzle, the coextrusion
die, or the injection opening.
[0064] The device according to the invention is described below in
greater detail with reference to the appended Figures. FIG. 1
illustrates an embodiment wherein the device comprises a twin-screw
extruder separated into two distinct sections 1 and 2 by a dynamic
separation device 3, at least one die 4, cutter 5, 6, an addition
device 7, 8, and a drying device (not represented). The twin-screw
device is driven by a motor 9 and is enclosed in a jacketed barrel
subdivided into seven compartments i-vii, in each of which can be
circulated a cooling or heating fluid. In this embodiment of the
device the components of the liquid or pasty consumable substance A
are introduced into the first section 1 through a feed device
comprising at least one feed opening 10 provided in the first
compartment i of the barrel. The liquid or pasty consumable
substance prepared in the first section 1 exits from this section
via an outlet opening 11 provided in compartment iv of the barrel
at the dynamic separation device 3. The opening 11 is connected to
the die 4 via a pipe 12 which optionally passes through a
positive-displacement pump 13 that makes it possible to inject the
liquid or pasty consumable substance into an extrusion pipe 16
emerging into an annular or central outlet orifice 8.
[0065] A plasticizable consumable substance B is introduced into
the second section 2 through a feed device comprising at least one
feed opening 14 provided in the fifth compartment v of the barrel,
downstream of the dynamic separation device 3. The mass of
substance B processed in the second section 2 is pressed through an
extrusion pipe 15 emerging into a central or annular outlet orifice
7.
[0066] In this first embodiment, the addition device is positioned
at the outlet of the second section of the extruder in the form of
a coextrusion die comprising the two extrusion pipes 15 and 16
emerging respectively into the central or annular orifice 7 and
into the annular or central orifice 8. If the strand of plasticized
consumable substance is extruded through the central orifice and a
liquid or pasty consumable substance is distributed through the
annular orifice the liquid pasty consumable substance surrounds the
extruded strand. If the strand of plasticized consumable substance
is extruded through the annular orifice and a liquid or pasty
consumable substance is distributed through the central orifice
then the liquid pasty consumable material is surrounded by the
plasticized consumable substance. The resulting strand of composite
product is cut up into pieces using the cutter 5. Preferably the
cutter 5 is a rotary cutter that rotates against the outlet
orifices of the die 4 and is driven by an electric motor 6. The
resulting cut pieces can subsequently be dried, if appropriate, in
a drying device (not represented).
[0067] In the embodiment represented in FIG. 2, the device is
analogous to that represented in FIG. 1, except that it comprises
an addition device 17 positioned after the outlet of the extruder
in the form of at least one spray nozzle included in a device
separate from the extruder. The embodiment illustrated in FIG. 2
further comprises a drying device 18. The separate addition device
17 is in the form of a hollow cylindrical drum rotating about a
substantially horizontal axis and having at least one spray nozzle
(not represented) in its upper part or its side part capable of
spraying the liquid consumable substance over the product to be
coated while the product to be coated is mixed or tumbled in the
cylinder 17. In this second embodiment of the device, a liquid
consumable substance A is prepared in the first section and is
injected into the spray nozzle via the pipe 12. A plasticizable
consumable substance B is processed in the second section 2 and is
pressed through at least one extrusion pipe 15 of the die emerging
onto at least one outlet orifice 7. The resulting cooked-extruded
strand plasticizable consumable substance B is cut up into pieces
by cutting means (not represented) and the pieces are introduced or
transported into the addition device 17 in order to be coated with
the liquid consumable product sprayed over them by the spray nozzle
(not represented). The coated pieces are subsequently dried in the
drying device 18. The drying device 18 may be, for example, a hot
air dryer.
[0068] The embodiment illustrated in FIG. 3 is analogous to that
illustrated in FIG. 1, except that it comprises an addition device
30, 31 provided at the outlet of the extruder in the form of at
least one spray nozzle included in a device separate from the
extruder and that it additionally comprises a drying device 18. In
this embodiment a liquid consumable substance A is prepared in the
first section 1 and is injected into at least one spray nozzle 31
via the pipe 12. A plasticizable consumable substance B is
processed in the second section 2 and is pressed through at least
one extrusion pipe 15 of the die emerging onto at least one outlet
orifice 7. The resulting cooked-extruded strand of plasticizable
consumable substance B is cut into pieces by cutter 5 attached to
the die 4. Preferably the cutter 5 is a rotary cutter that rotates
against the outlet orifices of the die 4 and is driven by a
hydraulic motor 6. The addition device comprises at least one spray
nozzle 31 provided in a rotary cylindrical drum 30 having a first
open part 32 that surrounds the cutting means 5, motor 6, and die 4
and a second non-open part that extends downstream of the cutting
means.
[0069] FIG. 4 illustrates yet another embodiment of the device of
the invention. The embodiment illustrated in FIG. 4 is analogous to
that illustrated in FIG. 1, except that it comprises an addition
device provided upstream of the outlet of the extruder, in the form
of at least one injection opening 33 in the barrel of the extruder.
Preferably the at least one injection opening 33 is in the middle
of the final compartment vii of the second section 2. In this
embodiment a pasty consumable substance A is prepared in the first
section 1 and is injected into the second section 2, preferably
close to the outlet of section 2, but sufficiently upstream for it
to be well mixed with a plasticizable consumable substance B
processed in section 2 before the plasticizable consumable
substance B is passed through at least one extrusion pipe 15 of the
die emerging onto at least one outlet orifice 7. The resulting
composite strand is cut into pieces by cutter 5. Preferably the
cutter 5 is a rotary cutter that rotates against the outlet
orifices of the die 4 and is driven by an electric motor 6. The
resulting cut pieces can subsequently be dried, if appropriate, in
a drying device (not represented).
[0070] FIGS. 5 and 6 diagrammatically illustrates a representative
geometry of the screws used in the device of the invention. The
screws illustrated in FIGS. 5 and 6 can be used without distinction
in each of the devices illustrated in FIGS. 1 to 4. In section 1,
the screws successively exhibit a transporting region 19 (200/100),
a transporting-mixing-dissolving region 20 (100/66), a
compressing-dissolving region 21 (200/33), a mixing-dissolving
region 22 (140/various bilobes), a compressing-dissolving region 21
(100/33), a mixing-dissolving region 22 (150/various bilobes), a
compressing-dissolving region 21 (100/33), a syrup outlet region 23
(two 15 mm bilobes on one screw, one 30 mm collar on the other
screw), and a dynamic separating region 3 (30 mm cones, 50/-25,
100/-50).
[0071] In the section 2, the screws successively exhibit a
transporting region 19 (200/100), a transporting region 20
(100/66), a compressing region 21 (100/33), a compressing region 24
(100/50), a compressing region 21 (200/33), a kneading region 25
(100/-33), and a compressing region 26 (100/35).
[0072] In the above description of the screws, the figures in
brackets give the length of the region and the length of the pitch
in mm for screws with a diameter of 88 mm and a distance between
axes of 72 mm. The device in this instance is a Clextral BC-72
twin-screw extruder.
[0073] The illustrated geometry is given by way of example only and
the device of the invention is not limited to screws with these
dimensions. For example, other extruder models, in particular the
BC-45 model (screw with a diameter of 55 mm and distance between
axes of 45 mm) or the BC-92 model (screw with a diameter of 115 mm
and a distance between axes of 92 mm) of the same series, may be
used.
[0074] Preferably, the screw pitches are double, except for the
reverse pitch of the blocking region, which is preferably
single.
[0075] In contrast to the reverse pitch of the kneading region 25,
which exhibits on its perimeter notches for the passage of the
processed mass, the reverse pitch of the blocking region 3 does not
exhibit any notches so that blocking region 3 is as efficient as
possible in its role as dynamic separation device.
[0076] As is seen in more detail in FIG. 7, the outlet opening 11
of the first section 1 of the extruder has an axial oblong shape,
in this instance in the shape of a figure eight, covering the
entire length of the outlet region 23 (facing the collar) and
overlapping onto the compression region 21 and the separation
region 3 (facing the cones).
EXAMPLES
[0077] The invention is further defined by reference to the
following examples describing in detail the process and device of
the present invention. The examples are representative, and they
should not be construed to limit the scope of the invention. All
percentages and parts are by weight, unless otherwise
indicated.
Example 1
[0078] Use is made of a device as illustrated in FIGS. 2 or 3 and
5-7, using a Clextral BC-72 type twin-screw extruder with a screw
diameter of 88 mm and a screw length of 2100 mm. The addition
device is a hollow cylindrical drum provided after the outlet of
the extruder that rotates about a substantially horizontal axis and
exhibits, in its upper part, three twin-fluid nozzles having an
internal diameter of 2.5 mm. Alternatively, the addition device is
a partially open rotary cylindrical drum that surrounds the die of
the extruder and the cutter having, in a side part, a horizontal
row of five spray nozzles, the furthest upstream spray nozzle being
positioned at the cutter. The drying device is a hot air drying
tunnel.
[0079] The syrup was prepared in the first section of the extruder
by dissolving therein 60 kg/h of caster sugar in 13 kg/h of water.
The temperature of the syrup or sugar solution is brought to
76.degree. C. within the first section of the extruder.
[0080] To prepare the cereal base in the second section of the
extruder, the following components are mixed therein (kg/h):
1 Maize semolina 84.0 Wheat flour 11.4 Sucrose 4.8 Sodium chloride
1.2 Calcium carbonate 0.6 Oatmeal 6.0 Wheat starch 12.0 Palm kernel
fat 10.0 Water 13.0
[0081] The cereal base was prepared by combining the powders to
form a dry-mixture. The dry mixture, the fat, and water are then
subsequently mixed and the resulting mixture is then processed,
i.e., it is cooked-extruded at 150.degree. C. under 155 bar
pressure with the screws of the extruder rotating at 218 rpm. The
resulting thermoplastic mass is extruded through a die in the form
of a front plate pierced with four cylindrical pipes each emerging
onto a circular outlet orifice with a diameter of 5 mm. The
resulting extruded-expanded cylindrical strands are immediately cut
using a four-blade cutter rotating at 6000 rpm against the front
wall of the die, the cutter being driven by a conventional electric
motor (in the case where the addition device is positioned after
the outlet of the extruder) or by a hydraulic motor integral with
the die (in the case where the addition device is positioned at the
die). The resulting expanded cereal pellets had a diameter of
approximately 10 mm. The pellets were coated by spraying them with
the syrup while mixing or tumbling them, the syrup being sprayed
under the effect of a stream of air ejected from the nozzle at a
pressure of 1.8 bar. The cereal pellets were dried with air at
113.degree. C. to a residual water content of less than 3%. The
final product was pellets of a light and crunchy sugar-coated
breakfast cereal.
Example 2
[0082] A composite pet food with a soft interior and a crunchy
exterior was prepared using the device illustrated in FIG. 1. In
order to prepare a pasty consumable substance for the soft interior
of the pet food the following components, in the following
proportions (given as % by weight), were introduced into the first
section of a twin-screw device (Clextral BC-72 type), and
continuously mixed therein:
2 Meat protein hydrolysate 40 Lecithin 0.5 Chicken fat 45 Molasses
10.5 Dye 3 Vitamins and trace elements 1
[0083] In the first section, the screws had a length to diameter
ratio of 9:1 (for a total length to diameter ratio of 20:1) and
were composed of a transportation screw and mixing bilobe elements.
The temperature of the barrel was maintained at approximately
49.degree. C.
[0084] To prepare a plasticizable consumable substance, i.e., the
cereal base for the crunchy exterior, in the second section of the
twin-screw device, the following components were introduced
therein, mixed therein, and continuously processed therein in the
following proportions (given as % by weight):
3 Milled wheat 45 Milled maize 24 Chicken meal 13 Soya flour 13
Vitamins 1 Trace elements 0.5 Tallow 3.5
[0085] In the second section, the screws had a length to diameter
ratio of 10:1 and were composed of a double-pitch screw element for
transportation, a reverse pitch element for compression and
shearing, and a trapezoidal single thread element for expulsion or
pressing. The temperature of the barrel was maintained at
approximately 120.degree. C.
[0086] The consistency of the pasty substance for the soft interior
was adjusted in the first section so that it was just capable of
being pumped through the die and so that it would rapidly set as a
solid after exiting from the die.
[0087] The food substance, plasticized and heated under the effect
of the pressure, shear, and temperature in the second section,
greatly expanded on exiting from the die and formed a shell which
became solid and crusty during cooling and drying.
[0088] The pasty substance and the cereal base were coextruded at
respective throughputs such that the ratio by weight of the soft
interior to the crunchy exterior of the composite product was
40%:60%.
[0089] The activity of the water in the soft interior and that in
the crunchy exterior were adjusted so that the interior remained
soft and the exterior remains crunchy during a storage period of at
least six months.
Example 3
[0090] A composite food which was impregnated throughout its body
was prepared using a device as illustrated in FIG. 4.
[0091] To prepare an impregnating syrup in the first section of the
twin-screw device (Clextral BC-72 type), mackerel flesh, an enzyme
for its digestion, sucrose, and molasses were introduced therein
and continuously mixed therein in the following proportions (given
in % by weight):
4 Mackerel flesh emulsion 80 Enzyme 0.5 Sucrose 10 Molasses 9.5
[0092] In the first section, the screws had a length to diameter
ratio of 9:1 (for a total length to diameter ratio of 20:1) and
were composed of a transportation screw and mixing bilobe elements.
The rotational speed of the screws was chosen such that the
mackerel flesh was minced. The temperature of the barrel was
maintained at 120.degree. C.
[0093] In order to prepare the plasticizable consumable substance,
i.e., the cereal base, the following components were introduced
into the second section of the twin-screw device, mixed therein,
and processed therein continuously in the following proportions
(given as % by weight):
5 Wheat 45 Maize 15 Chicken meal 17 Soya 14.3 Vitamins 1 Trace
elements 0.5 Dye 3 Tallow 4.2
[0094] In the second section, the screws had a length to diameter
ratio of 10:1 and were composed of a double-pitch screw element for
transportation, a reverse pitch element for compression and
shearing, and a trapezoidal single thread element for expulsion or
pressing. The temperature of the barrel was maintained at
approximately 120.degree. C.
[0095] The impregnating syrup prepared in the first section was
injected into the second section close to the outlet of the second
section but sufficiently upstream for the syrup to be well mixed
with (i.e., uniformly distributed in) the cereal base before it is
extruded. The ratio by weight of the syrup to the cereal base in
the composite product was 10%:90%. The resulting composite product
had an appetizing mackerel flavor and was pleasant to eat, both for
humans and for pets.
[0096] In the preceding example, the syrup to cereal weight ratio
was 10:90, but the invention is operable over a wide range of syrup
to cereal ratios. Of course, the minimum amount of syrup would be
that which provides a perceptible flavor or taste to the extruded
product. Generally, this ratio can be between about 1:99 and 1:2.
Preferably, the syrup-cereal ratio is between about 3:97 and 1:4,
and most preferably between about 1:20 to 1:17. In relative weight
percent, based on the total amount of syrup and cereal, the amount
of syrup is between 1 to 35% by weight, preferably between about 3
to 25% by weight, and most preferably between about 5 and 15% by
weight. While syrup is mentioned as a first preferred component, it
should be recognized that the relative weight ratios apply to any
of the first and second components described herein.
* * * * *