Note: Descriptions are shown in the official language in which they were submitted.
2004149
1824-416/G4
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PROCESS FOR MAKING CREAMY INSTANT_AGG OMERATED CEREAL
BACKGROUND OF THE INVENTION ~-~
Field of the Invention
This invention relates to processes for making pre- '
cooked instant cereal products, and more particularly to
processes involving the steps of extrusion, size reduction ` ~-
and agglomeration of a dry cereal blend to provide instant
cereals capable of rapidly dispersing in liquids to form a - -
creamy product for consumption.
Prior methods for preparing cereal products have ~:
been described whereby dry cereal ingredients are moistened
and heated through the use of extruders or drum drying
techniques and then dried before packaging such as described
in U.S. Patent No. 4,044,159. Other methods have been
described for production of cereal-type products that can
readily be dispersed in liquids (see, for example, U.S.
Patent Nos. 3,615,674 and 4,016,337).
None of these methods, however, teaches the process
of the present invention that produces a pre-cooked instant
cereal product of high quality consistency and taste which
may be readily dissolved in liquids without forming lumps in
less than 60 seconds, and more typically in less than 30
seconds. The novel processes of this invention are further ~ -~
advantageous because they use the efficient heat-transfer
method of an extrusion process and allow for the
intermediate addition of heat-sensitive ingredients to the
30 cereal. The resulting novel products are capable of -
yielding a high quality cereal of creamy consistency upon ;~
mixing with liquid such as milk or waterj particularly
suited for the feeding of infants. Further, the products
are capable of rapidly and instantly dissolving in liquids ~s
that allow for quick and easy preparation of a creamy
appealing product for consumption.
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SUMMARY OF THE INVENTION
The present invention relates to novel processes for ;~ r
producing pre-cooked instant agglomerated cereal capable of
being readily dissolved in liquid to give a creamy -
5 consistency. The starting dry cereal blend is moistened and -
cooked in an extruder which extrudes the cereal blend in an ~ ~ ;
expanded form. The cereal blend is then ground through a -~
mill equipped with a screen having openings of about 0.093
inches in diameter or smaller. Granules are formed by
metering the ground cereal blend into an agglomerator. The
granules are then dried to a moisture content of about 4 to
about 7%, at which time they are ready for packaging or for
combining with a desired liquid. Preferably, the cereal
blend is extruded from the extruder at a moisture content of
about 14 to about 16% and at a temperature of about 220F to
about 260F. Further, it is preerred that the cereal blend
i8 extruded from the extruder in a rope and sliced with a
blade into about 1/2 inch to about 3/4 inch in diameter
puffs which after drying have a density of about 21 g/100 ml
of product. Typically, the extruder has a diehead opening
of about 1/8 inch in diameter to about 1/4 inch in diameter.
In the agglomerating step it is preferred that the moisture
content of the extruded product be adjusted to about 14%.
The processes of the present invention have the further
advantage that heat-sensitive ingredients may be blended
into the product after the cereal blend is extruded and
before the cereal blend is metered into the agglomerator.
DETAILED DESCRIPTION
Though processes of the present invention are
particularly suited for use as infant cereals, they may be
used to produce any pre-cooked cereal-type product where
quick and easy dispersability of a cereal product into
liquid is desired. In addition, through use of the
processes of the present invention a product is produced
efficiently because intermediate products have a low
moisture content which minimizes the amount of drying time
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2004149
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required and provides an intermediate product which is
easier to grind. For the purposes of this invention, what
is intended to be defined by creamy instant cereal, is a~ ~-
cereal capable of being readily dissolved in liquid in less
than 60 seconds without leaving or forming lumps, and more
typically in less than 30 seconds with only minimal
stirring.
The starting dry cereal blend for the production of -
an instant cereal as detailed by the methods of the present
invention may include cereal grains or blends which are
capable of expanding in an extruder such as rice, wheat,
oat, corn, barley or the like, as well as mixtures thereof
and special composites such as hi-protein formulas.
Additional ingredients can include calcium phosphates, -
various proteins, various conventional minerals, vitamins,
oils and seasonings.
The dry cereal blend ingredients are first moistened
and cooked in an extruder where water or another suitable
wetting agent is added to evenly adjust the moisture content
20 of the dry cereal blend to about 14% to about 22%, ;~ ;
preferably to about 16% to about 20%, and most preferably to
about 18% to about 20%. If desired, the cereal blend may be
moistened to the moisture contents described above prior to
its entry into an extruder, but adjusting the moisture
content through the use of an extruder is the preferred
method. It has been found to be particularly advantageous
to utilize a twin screw type of extruder having a plurality
of jacketed zones that can be either heated (or cooled)
individually.
The extruder is further advantageously equipped with
a cutting device, pressure-sensing gauge and a thermocouple. ~ -
The pressure gauge and thermocouple are placed immediately
preceding the die so that the processing pressure and -
temperature can be readily ascertained. The jacketed -
35 heating zones provide heat to the product by conduction and ~ ~
further heat is imputed to the product by the friction ~-
developed with the rotating screw. The heat imputed from
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the extruder surfaces to the product and accomplishes the
desired cooking.
The extruder is advantageously provided with a
cutter blade for attachment and controlled periodic rotation
along the outer surface of the extruder head to cut the
extruded material into short segments as it leaves the
extruder such that the segments may be readily dried and
fitted into a mill for grinding. ~;
Any configuration of shaped opening can be provided -~
in the extruder die with openings ranging from about 1/16
inch to about 3/4 inch in diameter, the desired size
depending upon the composition of the dry cereal blend used
since the expansion of different grains varies as they are
extruded. For a blend which contains primarily rice flour,
for instance, an opening of about 1/8 inch to about l/4 inch
in diameter is preferred, a diameter of 5/32 inch is most
preferred. The cereal blend thus preferably exits the ~'
extruder in a rope of about 1/2 inch to about 3/4 inch in
diameter and pieces are cut to yield puffs with such
diameters.
The cereal product should be processed through the
extruder so that the moisture content of the extruded
product is about 12% to about 20%, preferably about 14% to
about 16%, and most preferably about 15%. The temperature ~-
of the product being extruded should be 160F to 340F,
preferably about 200F to about 340F, most preferably about i~
220F to about 260F.
The extruded cereal product is then allowed to dry
to a total product moisture content of between about 7% to ~ `~
30 about 10%, preferably to about 7% by any of the conventional -
methods well-known in the art. The dried product is then ,~
ground to give a fine powder-like particle size. Typically
it is ground in a mill with a screen having openings of
about 0.093 inches in diameter or smaller, preferably about ~ `
0.093 inches to about 0.033 inches in diameter, most ~-~
preferably 0.050 inches in diameter.
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Once the extruded cereal product has been ground to
a smaller particle size, it may be blended with other
ingredients if desired, particularly heat sensitive
ingredients whose taste, color, nutritional value etc. would
be decreased through the heat process of the extruder.
Examples of products which could be added include milk -
products and other protein sources, flavors, minerals,
fruit, sugars, and vitamins or the like.
The dried extruded product (including any additional :
blended ingredients, if desired) is then passed through an
agglomerator (an apparatus well-known in the field), which ~ ;
evenly applies moisture to the dried product to bring the .-
moisture content of the product up to about 14% while i~
creating small granules of the product. This agglomerating
process should allow some binding of the particles together
to create granules which, once dried, will more readily mix
with liquid. This may be advantageously accomplished by
using a disc pelletizer type of agglomerator (Teledyne ;~
Readco, York, PA; Sprout-Bauer, Muncie, PA). The pan onto '
which the extruded product is dropped is angled at, for
instance, about a 50 angle. The pan is rotated at a speed
to allow the dried particles to pass through a spray of
water and as the particles bind due to the addition of the ~`
water they drop off the pan as small wet agglomerates or
granule8. Granule size can be ad~usted by controlling the
di8c speed, disc angle, total feed rate, position of the
water and dry cereal in relation to the face of the disc. ~ ;i ;
Other agglomerators such as a fluidized bed-type
agglomerator (Glatt, West Germany) or high-speed mixer
agglomerator (Bepex s Tripleflex Vertical Agglomerator,
Bepex, Minneapolis, MN) may also be used.
Once the wet agglomeration process is completed, the
wet granules are dried in any one of the many driers, such
as fluidized bed driers or vibrating bed ovens, which are - ~'~
typically used in the field in connection with
agglomerators. The wet granules are dried briefly at low
heat, for example, about 180F until the moisture content is i~ ~
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reduced to about 7% by total weight or until the dried
product has a density of about 19 g to about 24 g/100 ml of
product, preferably about 19 g to about 21 g/100 ml of
product, most preferably 21 g/100 ml of product. The
5 agglomerates are screened to remove oversized material. ~ ~
Undersized material may be recycled back to the ~;
agglomeration step. The preferred product is that which is
capable of passing through an 8 mesh sieve but not capable
of passing through a 20 mesh sieve, although a broader range
10 is also useful. All mesh sizes referred to herein are ~-
according to the U.S. Bureau of Standards. ;~`
To further illustrate the invention, the following
example is provided. It should be understood that the
particular details of the example are not to be regarded as ~ . -
limitations as they may be varied as will be understood by
one skilled in this art. `
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Example~
The following components were mixed to create a dry
cereal blend~
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InaredientsWeiqht(lbs) ~ ~
rice flour 133.00 ; ~ - ,
~oy oil 2.67
vitamins & minerals 2.71
The cereal blend was metered at a uniform rate to a
twin screw MPF-50 extruder manufactured by Baker Perkins
(Grand Rapids, MI) which adjusted the moisture content of
the cereal blend with water so that when entering the barrel
of the extruder the cereal blend had a moisture content of ;~
about 18%. The extruder was equipped and set with the -
following screw profile: ~ -
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2004~'19
1/4" spacer
9" feedscrew -
6 - 30 degree forward paddles
3ll feedscrew
2" single pitch (S.P.) feedscrew
1 paddle
6" single lead ~;
3" feedscrew
3" single lead
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The diehead was a twin hole die of 5/32 inches. The barrel ~ ~ -
length had a ratio of 15:1 (length/diameter of. screw). The
feed rate was 200 lb/hr, the pump setting was 5.9 and the
motor had a screw speed of 400 rpm. The meter load was 70%. :
15 Steam introduction into 5 heating zones of the extruder was
such that zone 1 was 60F, zone 2 was 125F, zones 3,4 and 5 ~ -~
were 180F. The moist blend was forced out of the die under
a pressure of 1450 lbs/in2, at a temperature of 237F and a
moisture content of 15%. ~ ~ ;
The extruded product was found to have expanded, on
an average to about 1/2 to 3/4 inches in diameter with a ~-~
moisture content of about 15%. The product was cut into
puffs and allowed to cool. The puffs were dried in ambient
air to a crisp ball. The dried product was then milled
25 through a Fitzpatrick Model D comminuting lB (0.050 inch) ;~
~creen (Fitzpatrick Company, Chicago, IL) at slow speed.
Density of the ground cereal was 31 g/100 ml. At this point
the moisture content of the product was 7%.
The milled cereal was then agglomerated with a
30 Sprout-Bauer 16 inch disc pelletizer. The disc was operated
at a feed rate of 60 lbs/hr, a disc speed of 3.5 rpm, and a
ban angle of 50. Water was sprayed onto the disc and the -
cereal. Small spherical granules were formed as the cereal
was brought to a moisture content of about 14%.
The wet agglomerates or granules were dried in a hot
laboratory air upflow tray drier oven at 180F for 15
minutes. The dried product had a density of 21 g/100 ml.
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It was passed through a series of sieves for sizing as
follows:
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Sieve Size (U.S. Std.) y~ Retention of Granules
10 mesh 3
14 mesh 5
20 mesh 32 - ~
30 mesh 35 ~ ;
on pan 24
The cereal retained by the 20 mesh sieve and larger pore `
size sieves was collected for use as the instant cereal.
The resulting cereal mixed instantly in water in
less than 30 seconds without lumping. Water adsorption was
100 ml/20 g cereal.
Although the foregoing invention has been described
in some detail by way of illustration and example for
purposes of clarity of understanding, it will be appreciated
that certain changes and modifications may be practiced
within the ~cope of the invention as limited only by the
scope of the appended claims.
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