U.S. patent application number 10/958128 was filed with the patent office on 2005-02-24 for pet food composition and method.
Invention is credited to Clark, Harry M., Cowley, Craig R., Friesen, Kim G., Schoenherr, William D..
Application Number | 20050042362 10/958128 |
Document ID | / |
Family ID | 36228205 |
Filed Date | 2005-02-24 |
United States Patent
Application |
20050042362 |
Kind Code |
A1 |
Clark, Harry M. ; et
al. |
February 24, 2005 |
Pet food composition and method
Abstract
The present invention relates to dimensionally stable low
carbohydrate pet food products and method for producing such
products. The resulting pet food products are capable of inducing
desired levels of ketosis in pets which in turn can lead to weigh
loss or weight control.
Inventors: |
Clark, Harry M.; (Topeka,
KS) ; Schoenherr, William D.; (Hoyt, KS) ;
Cowley, Craig R.; (Meriden, KS) ; Friesen, Kim
G.; (Topeka, KS) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Family ID: |
36228205 |
Appl. No.: |
10/958128 |
Filed: |
October 4, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10958128 |
Oct 4, 2004 |
|
|
|
10405742 |
Apr 2, 2003 |
|
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|
Current U.S.
Class: |
426/658 |
Current CPC
Class: |
A23K 50/40 20160501;
A23K 40/20 20160501; A23K 20/158 20160501; Y10S 426/805 20130101;
A23K 20/147 20160501; A23K 50/42 20160501; A23K 40/25 20160501 |
Class at
Publication: |
426/658 |
International
Class: |
A23K 001/00 |
Claims
What is claimed is:
1. A method of producing a dimensionally stable low carbohydrate
pet food, the method comprising: providing a pet food composition
having a low carbohydrate content based on nitrogen free extract;
of less than about 19 wt % on a dry basis; feeding the pet food
composition through an extruder equipped at an outlet end with a
high shear die assembly; advancing the pet food composition through
the die assembly at high shear; and cutting the extruded pet food
composition to the desired size whereby upon drying the composition
a low carbohydrate dimensionally stable pet food product is
obtained.
2. The method of claim 1 wherein said high shear die assembly
includes a Venturi plate.
3. The method of claim 2 wherein said Venturi plate includes a
single through hole.
4. The method of claim 3 wherein said through hole has an average
diameter of between about 0.5 to 1.25 inches.
5. The method of claim 4 wherein said through hole has an average
diameter of about 1.0 inch.
6. The method of claim 1 wherein said high shear die assembly
further comprises a first spacer plate attached on one side to said
extruder and on another side to said Venturi plate, a second spacer
plate attached to said Venturi plate along a side opposite said
first spacer plate, and a die plate including orifices for shaping
said pet food.
7. The composition formed by the method of claim 1 wherein the
dimensionally stable low carbohydrate pet food product retains
fat.
8. The composition formed by the method of claim 1 wherein the
dimensionally stable low carbohydrate pet food is coated with
fat.
9. The composition formed by the method of claim 1 wherein said low
carbohydrate content is less than about 19 wt % on a dry basis.
10. The composition formed by the method of claim 1 wherein said
dimensionally stable pet food product has a protein content in the
range of about 25 to about 70 wt %; a fat content in the range of
about 15 to about 70 wt % on a dry basis; and a carbohydrate
content based on nitrogen free extract of between about 14 wt % to
about 19 wt % all on a dry basis.
11. A dimensionally stable low carbohydrate pet food made according
to claim 1, wherein said pet food is capable of maintaining ketosis
in pets consuming said pet food.
12. A method of preparing a low carbohydrate pet food in a form of
dimensionally stable kibbles, the method comprising: providing a
pet food composition having a carbohydrate content based on
nitrogen free extract of less than about 19 wt % on a dry basis;
feeding the pet food composition through an extruder having means
for inducing high shear at an outlet end thereof; advancing the pet
food composition at high shear through a die assembly at the outlet
end to form an extrudate; cutting the extrudate to a desired size;
and drying the resulting pieces of extrudate to form dimensionally
stable kibbles.
13. The method of claim 12 wherein said means for inducing high
shear includes a Venturi plate for maintaining the pet food
composition in the extruder.
14. The method of claim 13 wherein said Venturi plate is part of
said die assembly.
15. The method of claim 14 wherein said Venturi plate includes a
single through hole.
16. The method of claim 12 wherein the die assembly further
comprises a first spacer plate attached on one side to said
extruder and on another side to said Venturi plate, a second spacer
plate attached to said Venturi plate along a side opposite said
first spacer plate, and a die plate including orifices for shaping
said pet food.
17. The composition formed by the method of claim 1 wherein the
dimensionally stable low carbohydrate pet food product retains
fat.
18. The composition formed by the method of claim 1 wherein the
dimensionally stable low carbohydrate pet food is coated with
fat.
19. The composition found by the method of claim 1 wherein said low
carbohydrate content is less than about 19 wt % on a dry basis.
20. The composition formed by the method of claim 1 wherein said
dimensionally stable pet food product has a protein content in the
range of about 25 to about 70 wt %; a fat content in the range of
about 15 to about 70 wt % on a dry basis; and a carbohydrate
content based on nitrogen free extract of between about 14 wt % to
about 19 wt % all on a dry basis.
21. A dimensionally stable low carbohydrate pet food made according
to claim 1, wherein said pet food is capable of maintaining ketosis
in pets consuming said pet food.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 10/405,742 filed on Apr. 2, 2003. The
disclosure of the above application(s) is (are) incorporated herein
by reference.
BACKGROUND OF THE INVENTION
[0002] Dry pet foods for dogs and cats have been primarily prepared
by extrusion. A heated food mass which is sufficiently plastic to
be extruded using an ordinary screw extruder wherein expansion of
the food occurs is worked in the extruder and emerges from the
extruder usually in a strand or flat type rectangular sheet,
depending upon the die shape, and is then cut and/or shaped into
discrete particles. In this manner, dry diets utilizing kibbles, a
particular discrete particle, are prepared. These kibbles should be
dimensionally stable. That is, they retain the same shape as when
immediately prepared and then packaged. They do not spontaneously
crumble or lose fines to any great extent, even when subjected to
mild pressure. Over time the physical and dimensional stability of
the kibble is maintained.
[0003] This physical integrity of the extruded shape is at least
partially dependent upon the chemical nature of the extruded
material. When carbohydrate content is low, generally below about
19 wt % of the food composition, expansion of the food mass during
the extrusion process is significantly reduced because of the
reduced matrix formation generally obtained from the presence of
carbohydrate such as a starch or grain. The relatively low
carbohydrate, high protein, high fat food masses when extruded
under normal conditions do not expand significantly, thereby
providing a discrete particle which is not dimensionally stable.
Additionally, the discrete particle can have difficulty retaining
added fat, particularly when the fat is added to the outside of the
particle, such as by spraying. Such extruded particle is not
dimensionally stable and can not be packaged for appropriate
commercial use.
[0004] It has now been discovered that a relatively low
carbohydrate, relatively high protein and fat content pet food can
be successfully extruded into a discrete particle, which is
dimensionally stable. It has the physical attributes of typical
commercial pet foods which include much higher levels of
carbohydrate. Additionally where fat absorption can be a problem,
the article matrix is able to absorb and retain fat.
SUMMARY OF THE INVENTION
[0005] In accordance with the invention, there is a method of
producing a dimensionally stable low carbohydrate pet food.
[0006] A further aspect of the invention is the resulting
dimensionally stable low carbohydrate pet food which is capable of
inducing ketosis.
[0007] Further areas of applicability of the present invention will
become apparent from the detailed description provided hereinafter.
It should be understood that the detailed description and specific
examples, while indicating the preferred embodiment of the
invention, are intended for purposes of illustration only and are
not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The present invention will become more fully understood from
the detailed description and the accompanying drawings,
wherein:
[0009] FIG. 1 is a schematic representation of an extension device
used in the practice of the present invention; and
[0010] FIG. 2 is a schematic representation (exploded for
illustrative purposes) of a modified die assembly used in the
present invention for the manufacture of weight control
compositions.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The following description of the preferred embodiment(s) is
merely exemplary in nature and is in no way intended to limit the
invention, its application, or uses.
[0012] The pet foods included are those useful primarily for dogs
and cats. These foods are high in protein and fat and contain a
relatively small amount of carbohydrate as compared to protein and
fat. The resulting pet foods are dry as opposed to a wet chunk
and/or gravy. Protein levels are a minimum of about 25, 30, or 40
wt % of the overall composition with a maximum of about 50, 60 or
70 wt % of the composition. The fat content is a minimum of about
15, 20, 25 or 30 wt % and not to exceed about 70, 60, 50 or 45 wt
%. The carbohydrate content based on nitrogen free extract, "NFE",
is a minimum of zero, 5 or 7 with a maximum of about 22, 15 or 10
wt %. All numbers are on a dry matter basis. When the term diet is
used, this refers not only to a food product which provides most,
if not all, the nutrition for a pet but also refers to such items
as a snack, treat or supplement and the like.
[0013] The protein can come from any source but because of the
relatively low carbohydrate level, a protein source with low
carbohydrates is particularly preferred. Examples of such protein
sources are animal sources such as pork protein isolate and veal
protein isolate and the like as well as vegetable sources such as
soy protein isolate, corn gluten meal and the like.
[0014] The fat source can be any source, which provides fat to the
pet food. Examples of such sources are beef tallow, poultry fat,
soybean oil, canola oil, sunflower oil, fish oil, lard and choice
white grease. The fat can be incorporated completely within the pet
food, deposited on the outside of the food or a mixture of the two
methods. Generally, fat on the exterior of the food brings about an
increase in palatability to the pet.
[0015] Very little, if any, carbohydrate is initially present in
the food. The carbohydrate can enter the food as part of another
source such as protein but also can be present through specifically
added carbohydrate sources such as starches and grains. Examples of
such carbohydrate sources include a starch such as corn starch or
wheat starch or mixtures thereof and a grain which can be greater
than 50% starch such as corn, sorghum, barley, wheat, rice and the
like as well as mixtures thereof. A specific carbohydrate source
such as a starch, however, is not necessary.
[0016] The preparation of a dry extruded pet food with the very low
quantity of carbohydrate therein, with discrete particles which are
dimensionally stable is not readily accomplished. By "dimensionally
stable" it is meant that the resulting extruded product when
sufficiently dried has physical integrity i.e., not readily losing
its shape or shedding significant amounts of fines, particularly
when the food is in discrete particles such as kibbles, bits and
the like in a bag filled with the materials. Additionally, such a
food often does not readily retain its fat content in a cohesive
manner, particularly when the fat is deposited on the exterior of
the discrete particle. Non-adherence can be visually observed.
These problems are further accentuated by using a high quantity of
protein. Protein isolates, which are generally used when there is a
high protein content, particularly the vegetable isolates, make it
even more difficult to successfully extrude a dry pet food having
discrete particles which are dimensionally stable.
[0017] Utilizing a standard single screw extruder with a
preconditioner, under standard operating conditions dimensionally
stable discrete particles of the pet food described herein were not
obtainable. After much work, it was found that increasing the shear
in the extruder created an extruded pet food which was processed
into discrete particles which were dimensionally stable even with
the relatively low levels of carbohydrate described herein. The
increased shear produces a pet food discrete particle, which is
generally of a higher density than the discrete particle produced
under normal shear processing conditions. Increased shear during
the processing can be produced by various means such as for example
using cut flight screws, lobe locks, steam locks, and straight
ribbed liners.
[0018] Another means for increasing the shear of the pet food
compositions described herein is through the use of a metal Venturi
plate which covers or essentially covers the cross section of the
extruder. The Venturi plate which contains a limited number of
through-holes, preferably a single through-hole, increases shear by
restricting extrudate flow in the extruder barrel. The discrete
particles prepared by passing through the Venturi plate generally
of a greater density than particles produced without such an
apparatus. They are dimensionally stable in that they resist
crumbling and do not form a significant level of fines after
preparation.
[0019] By utilizing a Venturi plate in the extrusion process to
increase shear certain processing problems are addressed. First,
the formulation is designed to be low in starch which limits the
cohesive nature of an extruded product and hence its ability to
form discrete particles in the absence of increased shear.
Secondly, the balance of the formulation is generally vegetable
based protein which is by nature very difficult to extrude and
cook. By increasing shear a dimensionally stable product optionally
including a significant level of vegetable based protein is
possible.
[0020] In preparing the low carbohydrate pet food by the method of
the present invention, a mixture of carbohydrates, protein, fats
and sufficient vitamins and minerals selected to yield a low
carbohydrate dimensionally stable pet food is mixed and
preconditioned or moisturized within a preconditioner or mixing
cylinder wherein the ingredients are contacted with steam and
moisture. The moisturized mixture is then introduced into the
barrel of an extruder, which can be either a single or twin screw
type extruder, which cooks the mixture to yield an extruded
product. The extruder barrel is provided with at least one helical
screw which axially rotates to advance the material through the
extruder barrel.
[0021] Preferred processing conditions involve initially
preconditioning dry food ingredients to uniformly moisturize and
precook materials and form an at least partially sterilized mixture
for passage into the apparatus of the present invention. In this
connection, preconditioning of this type normally involves
injection of water and/or steam with intense mixing.
Advantageously, the moisture level of the initial ingredients
ranges from about 10-14% by weight, and, after preconditioning,
this moisture level is typically elevated to a level of from about
20-30% by weight, and more preferably from about 20-25% by weight,
MCWB (moisture content, wet basis).
[0022] In terms of temperature, it is preferred to elevate the
temperature of the mixture in the preconditioner to a level of from
about 160-210.degree. F., and more preferably from about
190-205.degree. F. The residence time of the mixture within the
preconditioner will depend upon the equipment selected and the
degree of mixing desired; generally speaking, however, the average
residence time of the food mixture in the preconditioner should be
from about 0.5-8 minutes, and more preferably from about 4-7
minutes.
[0023] After preconditioning, the food mixture is fed into the
extruder barrel and is conveyed by the screw toward the outlet end
of the barrel. The temperature of the food mixture within the
barrel is generally maintained at about 165-240.degree. F., and
preferably from about 180-240.degree. F.
[0024] During passage through the extruder, the food mixture is
subjected to increasing amounts of shear and pressure. The maximum
pressure conditions achieved in the extruder barrel generally
ranges from about 250-500 psi. The screw rpm (revolutions per
minute) generally ranges from about 250-500 rpm. Also during such
passage, moisture may be added directly to the food material
passing through the barrel, in the form of injected water and/or
steam.
[0025] The food mixture exiting the extruder barrel outlet passes
directly into the die assembly of the present invention, whereupon
the mixture is forced outwardly as a strand through the orifices of
the die plate in a state of laminar flow. The extrudate strand is
then sliced into appropriate sized pieces by rotating knives or
other suitable cutting means. The moisture level of the sliced
pieces is-from about 15-25% by weight, and more preferably from
about 18-22% by weight.
[0026] Turning now to FIGS. 1-2, in FIG. 1 the extrusion apparatus
10 includes an extruder 12 having a barrel 14 with an inlet 16
located below the outlet of a preconditioner 18; the extruder 12
also having an outlet 20 to which is affixed a die assembly 22.
Hopper 11 is provided to premix the ingredients prior to
preconditioning. The barrel 14 as depicted in FIG. 1 comprises
seven barrel sections 24, 25, 26, 27, 28, 29, 30, although the
number of barrels may vary without departing from the principles of
the present invention. The barrel sections are interconnected to
provide an elongated bore through the barrel 14 of the extruder 12.
A material advancing screw (not shown) is received in the bore of
the barrel and is intermeshed along the majority of the length of
the extruder barrel 14 and terminate at outlet 20. The screw feeds
the food mixture to and through the die assembly 22 at an
appropriate velocity and in a state of laminar flow. Extrusion
apparatus 10 of the type illustrated in FIG. 1 is available from
the Wenger Manufacturing Company such as the Wenger X-135. The
pre-conditioner 18 shown in FIG. 1 is also manufactured by the
Wenger Manufacturing Company.
[0027] In preparing the pet food product of the present invention,
the ingredients are first mixed in a mixer such as a ribbon mixer
and fed to hopper 11. The mixed ingredients are metered into the
preconditioner 18, at a rate between 200 and 300 lbs./min. and is
further mixed with water which is introduced into the
preconditioner at a rate of 10 to 40 lbs./min. The temperature of
the mixture is raised from ambient to 170.degree. to 210.degree. F.
by the injection of steam into the preconditioner 18 at the rate of
10 to 40 lbs./min. Total residence time in the preconditioner 18
generally ranges from 0.5 to 3.5 minutes.
[0028] Once the mixture of the ingredients and water is introduced
into the extruder barrel 14, the mixture is advanced along the
length of the barrel 14 by axial rotation of the screws. The
mixture is sequentially advanced through the extruder and finally
through the die assembly 22.
[0029] The die assembly 22 as shown in FIG. 2 consists of Venturi
plate 36 and a die plate 37 mounted in clamped parallel engagement
between first and second spacer plates 34 and 35. These plates are
mounted on the outlet end 20 of the extruder barrel 14 by a
plurality of bolts (not shown) which extend through bolt receiving
holes, designated generally by the numeral 38, formed on the
peripheral faces 40, 41, 42 and 43 of the aforementioned
plates.
[0030] The first spacer plate 34 shown in FIG. 2 has an annular
opening 44 which extends through the plate 34 and corresponds in
diameter to the annular opening 45 of the second spacer plate 35.
The diameter of the annular openings 44 and 45 of the spacer plates
34 and 35 is generally about 3.5 to about 4.5 inches and preferably
about 3.75 to 4.25 inches. While the foregoing sizes are
appropriate for certain extruder models, it should be understood
that the size and process parameters will vary depending on the
extruder model employed.
[0031] The annular opening 44 of the first spacer plate 34 is of
sufficient length along the axis of extrusion to stabilize and
streamline, i.e., impart a more smoother flow to, the plasticized
food mixture stream being advanced therethrough causing the fibrous
material in the food mixture to be compressed to a dense, randomly
structured, plastic state. Typically the spacer plate 34 has a
length of about 0.25 to about 1.0 inch, preferably about 0.35 to
about 0.75 inch to provide for such food stream stabilization.
[0032] The Venturi plate 36 which is clamped between first spacer
plate 34 and second spacer plate 35 is comprised of a limited
number of through-holes generally designated by the numeral 48
which are cut into and extended through the core 46 of plate 36.
The diameter of core 46 of the Venturi plate 36 corresponds to the
diameter of the annular openings 44 and 45 of the spacer plates 34
and 35.
[0033] Under certain embodiments, a single through-hole 48 is
employed. The through-hole is of sufficient length along the axis
of extrusion to separate and align the food structure in a
preliminary pieced laminar configuration as the food mixture is
advanced therethrough under pressure. An appropriate length of the
through-hole 48 to achieve this preliminary alignment in the pet
food mixture flowing therethrough is about 0.25 to 1.0 inches and
preferably about 0.3 to 0.7 inches. The size and limited number of
through holes cause the pet food composition to remain in the
extruder longer thus increasing the amount of shear on the
composition. With this increased shear dimensionally stable
discrete particles are prepared with less than about 19.0 wt %
carbohydrate on a dry basis. Breakage rates of the discrete
particles processed through a die assembly including the Venturi
plate appear to be on the order of less than 1% versus from 2.5 to
9% for the die assembly described in U.S. Pat. No 5,500,239.
[0034] The annular opening 45 of the spacer plate 35 is of
sufficient length along the axis of extrusion to allow the
individual pieces to reform under pressure and present a mass to
the orifices generally designated by the numeral 49 cut into the
core 50 of the die plate 37.
[0035] The die orifices 49 of the die plate 37 are sufficient
length along the axis of extrusion to promote the final alignment
of the material in the food product mixture. An appropriate length
of orifice 49 to promote alignment in the food product extrudate is
about 0.5 to about 1.5 inches and preferably about 0.66 to about
1.0 inches. The die orifices which are substantially round as shown
have a diameter of about 0.5 to 1.25 inches, preferably about 1.0
inch.
[0036] Upon discharge from the orifices 49 the pet food is cut to
an appropriate length. While the die orifices are shown as being
round, the die orifice shape may change as a function changes in
the pet food formulation. The die orifices 49 may each have a
specific shape which is the desired shape for the fiber striated
pet food product.
[0037] Preferably, die orifices 49 which are circular in shape have
die inserts inserted into them. Die inserts function to provide the
desired shape to the product. By use of die inserts, die plate 37
need not be made specific for each particular shape desired, but,
rather, die inserts can be produced for each particular shape. When
a different shape than the one currently being produced is desired,
die inserts can then be replaced, thereby eliminating the need for
the replacement of die plate 37.
[0038] Die plate 37 preferably further comprises flange 51 which
can be used to secure die plate 37 the outlet 20. Flange 51 most
preferably has holes which correspond to the holes in complementary
flanges on plates 34, 35 and 36 and the outlet 20. Bolts (not
shown) or other conventional securing means can be disposed through
the holes in die flange 51 and the corresponding holes of the other
plates to secure die plate 37 to the die outlet.
[0039] The size of the food product formed by the orifices 49 of
die plate 37 is dictated by a desire to obtain a high degree of
dimensional stability, among other factors. Generally, it has been
found that food pieces that the pet food pieces can be too large
for comfortable consumption especially by smaller pets. On the
other hand pieces which are too small may not convey the visual
image desired in a pet food having visually distinct regions. For
example, pet food pieces having a length of about 5.7 to 7.3
millimeter, a width of about 6.5 to 7.5 millimeters and a thickness
of about 6.5 to 7.5 millimeters appear to be preferred by cats.
[0040] The components of the die assembly 22 can be made of any
material providing the required structural integrity and sanitary
characteristics such as a metal like stainless steel. Other
characteristics which should be present in the material include
thermal stability and corrosion resistance and approval from the
United States Food and Drug Administration or other such agency for
contact with food products is also beneficial.
[0041] The extrudate 33 as it is discharged from the orifices 49 of
the die plate 37 is formed into food pieces by a slicing means (not
shown) such as a rotating knife assembly which functions to slice
the extrudate streams as they are discharged from the orifices 49
to form the product of this invention.
[0042] By flowing the food ingredient mixture through the die
assembly 22 in accordance with the practice of the present
invention at a velocity of about 12 to about 20 inches per second
(in./sec.) a condition resembling laminar flow is created in the
extrudate. As the food ingredient mixture passes through the barrel
sections 24, 25, 26, 27, 28, 29, and 30, it is mixed, cooked and
subjected to barrel temperatures in the range of about 100.degree.
to about 250.degree. F., preferably about 170.degree. to about
210.degree. F. The food mixture is flowed through the die assembly
22 at a temperature of about 240.degree. to about 320.degree. F.
Total residence time in the die assembly 22 is about 0.10 to about
0.35 seconds.
[0043] The pet food composition extrudate as it leaves the die
assembly 22 has a moisture content between about 15 and about 30%
by weight and preferably about 17 to about 24% by weight. The
extrudate may swell upon exiting the die assembly 22 due to
flashing of moisture to steam. The extrudate is cut into
appropriate lengths to form pieces and then placed in an oven at
190.degree. to 230.degree. F. for 15 to 30 minutes to dry to about
7 to about 9% moisture. Following the dryer, the dried products
otherwise referred to herein as kibble, are screened to remove
fines and the products and are coated with additional liquid (fat)
and dry ingredients designed to meet nutritional targets and to
improve animal acceptability (palatability).
[0044] Below are two examples of an attempt to prepare a
dimensionally stable discrete particle as well as a successful
example. In all of the examples, a standard Wenger X 135 extruder
was employed. It was equipped with an Acrison feeder and a DDC-7
preconditioning cylinder.
COMPARATIVE EXAMPLE 1
[0045] A pet food comprising 62 wt % corn gluten meal, 24 wt %
poultry meal, 11 wt % soy isolate and 3 wt % minerals and vitamins
had the following nutrient composition, with carbohydrates
expressed in terms of NFE:
1 Protein 59.6% Fat 22.0% Fiber 0.85% Carbohydrate (NFE) 11.5%
[0046] This formula was produced without the Venturi plate. The
kibble was brittle. 10 to 25% of the dried kibble broke and was
therefore unacceptable for sale. This product would not have been
strong enough to withstand the harsh handling from the cooler to
the packaging line. Fat absorption was a problem, as 2 to 10% of
the fat would not stay within the kibble.
COMPARATIVE EXAMPLE 2
[0047] A pet food comprising 51 wt % corn gluten meal, 29 wt %
poultry meal, 12 wt % pork protein isolate, 2 wt % dry egg and 5 wt
% vitamins, minerals, and other nutrients had the following
nutrient composition:
2 Protein 59.0% Fat 25.0% Fiber 0.85% Carbohydrate (NFE) 9.80%
[0048] This formula was produced without the Venturi plate. The
kibble was brittle and was greater than 10% broken. Fat absorption
was an issue, as 2 to 5% of the fat did not bind to the matrix.
EXAMPLE 1
[0049] The same pet food as in Comparative Example 2 was produced
under the same operating conditions but was processed with the
presence of a Benturi plate (Wenger Part No. 28299-3) with a 0.35
inch opening and a total diameter of 5.65 inches. A strong kibble
was produced with less than 5% fines. The kibble did not have a fat
absorption issue since less than 1% of the total fat was lost from
the product.
[0050] As noted above, in addition to methods for producing a
dimensionally stable low carbohydrate pet food, the composition has
been found to induce ketosis which leads to weight loss. Over the
course of a 28 day study, the efficacy of four dry formulations as
set forth in the Table I with varying levels of carbohydrate NFE
(14.2, 16.9, 18.6, and 21.6%) for inducing dietary ketosis in
thirty-two obese cats during weight loss was evaluated. As
demonstrated in Table II below, the foods were effective for weight
loss in the obese cats in that, they lost an average of 0.243 kg of
weight at a rate of 1.00% of initial body weight per week. On days
0, 14 and 28 of the study, serum levels of beta-hydroxybutyrate
(BHBA) were analyzed. Cats fed the dry foods were mildly ketotic at
the initiation of the study and they maintained the ketosis on day
14 of the experiment when compared with the initial values. The
BHBA levels at the completion of the study remained elevated when
compared with the levels at the initiation of the study for cats
fed dry foods containing less than 21.6% carbohydrate on an NFE
basis. This study demonstrated that obese cats fed a high protein,
low carbohydrate, moderate fiber dry food lost weight at effective
levels and dietary ketosis was maintained when dietary NFE levels
were at or below about 19.0%. Cats fed dry foods with NFE level of
21.6% were not able to maintain ketosis at the completion of the
28-day study as demonstrated in Table II below. All foods were
considered safe based on the lack of change in serum chemistry
parameters.
3 TABLE I Formulation No. 1 2 3 4 NFE 14.2% 16.9% 18.6% 21.6%
Animal protein 30.85 30.08 30.05 25.03 Vegetable protein 30.84
28.72 27.84 24.83 Starch 7.44 10.21 11.1 18.21 Meat or soy isolate
7.68 7.68 7.68 7.68 Cellulose 7.12 7.12 7.12 7.12 Animal fat 13.44
13.56 13.58 14.24 Minerals 1.29 1.29 1.29 1.54 Vitamins 1.34 1.34
1.34 1.34
[0051]
4TABLE II Effect of Food on Weigh Loss in Obese Cats Weight %
Weight Formula Change, change/ Number Kg week Formulation 1 -0.17
-0.70 Formulation 2 -0.22 -0.90 Formulation 3 -0.26 -1.04
Formulation 4 -0.32 -1.26
[0052]
5TABLE III Effect of Food on BHBA in Obese Cats Over Time Formula
Number Day 0 Day 14 Day 28 Formulation 1 1.17 1.24 0.94 Formulation
2 0.81 0.73 0.80 Formulation 3 1.01 1.12 0.78 Formulation 4 0.38
0.87 0.47
[0053] The description of the invention is merely exemplary in
nature and, thus, variations that do not depart from the gist of
the invention are intended to be within the scope of the invention.
Such variations are not to be regarded as a departure from the
spirit and scope of the invention.
* * * * *