Gellan gum to improve physical stability of liquid nutritional products

Liquid, nutritionally complete formulas are disclosed with improved physical stability. The nutritionally complete formulas are pourable, yet are able to hold minerals, insoluble fiber and flavoring agents such as cocoa powder in suspension without the formation of a sediment that is not readily redispersible. The invention comprises the use of gellan gum at a concentration of between 10-500 parts per million. Although gellan gum alone is sufficient, the nutritionally complete formula may also comprise other stabilizers such as carrageenan and/or carboxymethylcellulose.

TECHNICAL FIELD 
The present invention relates to liquid formulas and more particularly to 
liquid formulas that are nutritionally complete and which have improved 
physical stability. 
BACKGROUND OF THE INVENTION 
The liquid nutritional industry is a multi-billion dollar a year business. 
Infant formulas and medical nutritionals comprise the major portion of 
this industry. "Nutritionally complete" formulas such as infant formulas 
and medical nutritionals, are required to contain significant levels of 
minerals, vitamins, protein, carbohydrates and fat to provide the required 
level of these nutrients to a human in an acceptable volume. These 
nutritionally complete formulas allow for the formula to be the sole 
source of nutrition for a human consuming same. The presence of certain 
minerals, such as calcium and phosphorus, is vitally important to the 
efficacy of the nutritional. However, the presence of these high levels of 
minerals, protein and fat cause a number of significant problems in the 
manufacture and use of these formulas. 
Nutritionally complete liquid formulas have traditionally been plagued with 
the problems of creaming and sedimentation. Creaming occurs when fat 
globules in the liquid nutritional float to the top of the product. These 
fat globules can harden and block or clog feeding tubes or nipples. In 
sedimentation, various insoluble components of the liquid nutritional 
settle to the bottom of the product container. Of particular concern is 
the sedimentation of calcium, phosphorous, fibers and flavoring powders, 
such as cocoa. Cocoa powder is especially prone to sedimentation and when 
cocoa powder sediments, it is not easily redispersed. The sedimentation of 
these elements is further aggravated when the sediment hardens into a 
cementous type of material known as "non-dispersible sediment". The 
problem with non-dispersible sediment is three fold: (1) the liquid 
nutritional is now subject to nutrient deficiency, since the 
non-dispersible sediment often refuses to go back into solution upon the 
shaking of the container; (2) the sediment will plug feeding tubes or 
nipples; and (3) the product appearance is negatively affected, for 
example, the product appears "spoiled" to the consumer. 
The liquid nutritional industry, in the past, has focused on reducing 
sedimentation through the use of stabilizers such as carrageenans and 
celluloses. While the formation of non-dispersible sediment is delayed 
through the use of the prior art stabilizer systems, it has not been 
prevented. One feature of the present invention resides in the discovery 
that gellan gum, while not preventing sedimentation, allows for the 
redispersion of the sediment upon shaking without creating a significant 
amount of non-dispersible sediment. 
Numerous stabilizing systems have been proposed to address the sediment and 
creaming problems in a nutritionally complete formula. These solutions 
however, resulted in limited success. Stabilizing systems known to date 
allow the minerals, fibers and flavoring powders to be suspended longer, 
however, they ultimately fall from solution. Typically, stabilizing 
systems or suspenders of insolubles are locust bean gum, guar gum, 
carboxymethylcellulose, lambda carrageenan, konjac flour and the like. 
These stabilizers are known as "non-gelling" or "weakly gelling" types. 
These stabilizers require fairly high addition rates (1200 ppm and higher) 
and high resulting viscosities (above 50+ cps or 0.05 Pa.multidot.s) to 
achieve acceptable levels of suspension. 
The problems associated with physical stability of nutritionally complete 
liquid formulas have been addressed through the micronization of the salts 
or minerals which are added to the liquid nutritional. Micronization is 
the comminuting of the salts and/or minerals to a particle size of about 
one .mu.m (10.sup.-6 meter or "micron") or less. It is believed that the 
reduced particle size of the salts and/or minerals will lessen their 
sedimentation. This approach is costly and any sedimentation which occurs 
is typically not able to be re-dispersed by shaking the container. 
The use of a stabilizer such as carrageenan, carboxymethylcellulose and 
guar gums is well known in connection with solid food products. It must be 
appreciated that sedimentation and creaming are not nearly as much a 
problem in solid foods as they are in liquid nutritionals. In addition, 
the use of carrageenans and/or other hydrocolloids impacts the desired 
viscosity and flow characteristics of the liquid nutritional. 
Viscosity of a liquid enteral nutritional under various levels of shear 
stress is a very important characteristic. High viscosity products (those 
over 0.05 Pa.multidot.s or 50 cps) under high levels of shear stress, are 
not useful for tube feeding or through a nipple. As used herein and in the 
claims, the term "low viscosity" means a liquid nutritional product with a 
viscosity of less than about 0.05 Pa.multidot.s (50 cps) as measured by a 
Brookfield Viscometer using a #1 spindle at room temperature and at 60 
rpm. Also important is the aspect of "yield stress". Yield stress means 
that upon the application of shear (force measured in dynes/cm.sup.2), the 
product will flow in a manner that is acceptable for tube or nipple 
feeding. An aspect of the present invention is directed to the discovery 
that 10 to 500 ppm of gellan gum provides reduced sedimentation while 
maintaining actual yield stress values in the range of 0.1 to 1.0 
dynes/cm.sup.2. The term "actual yield stress" means values that are 
measured directly and not derived from a mathematical model. 
U.S. Pat. No. 5,416,077 to Hwang et al. discloses a liquid nutritional 
composition containing from 50 to 1,000 parts per million of 
iota-carrageenan and optionally, kappa-carrageenan. This patent fails to 
disclose or suggest the use of gellan gums and the unexpected results that 
can be realized through the use of gellan gum in nutritionally complete 
liquid foods. 
WO 94/24887 to Clark discloses a beverage stabilizing system which is a 
blend of gellan gum and carboxymethylcellulose. This application discloses 
that the gellan gum/carboxymethylcellulose system provides a weak, 
stabilizing gel structure suitable for beverage products. This 
application, which discloses stabilized chocolate milks and fruit juices, 
requires the combined use of gellan gum and a carboxymethylcellulose 
(CMC). Further it is stated that gellan gum alone does not provide enough 
structure to prevent settling. The beverage stabilizing blend of CMC and 
gellan gum, is disclosed as being in a weight ratio of between about 3:1 
to 20:1. 
European Patent Application 045437382 to Colegrove discloses the use of 
gellan gum fibers, produced by extrusion into a gelling salt bath, as 
wound dressings and catamenial devices. It is further disclosed that other 
gums may be coextruded with the gellan gum to produce useful fibers. 
U.S. Pat. Nos. 5,190,778 and 5,196,220 to Clare et al. discloses fermented 
malt beverages (beers) having improved foam stability and desirable lace, 
cling and clarity. It is disclosed that the beverage is stabilized by 
adding 5 to 400 ppm by weight of gellan gum. These patents do not suggest 
or disclose the use of gellan gums to overcome the problems associated 
with the sedimentation of calcium, phosphorous, insoluble fibers and 
flavoring powders, such as cocoa, in nutritionally complete liquid 
formulas. 
An article entitled "Mechanical Properties of Gellan Gels in Relation to 
Divalent Cations" by Tang et al. Journal of Food Science, Vol. 60, No. 4, 
(1995) discusses the mechanical properties of gellan gels containing 
different polymer and cation concentrations. The article states that at a 
given concentration of gellan gum, the gels were extensible below the 
critical cation level and brittle above that level. This reference fails 
to suggest or disclose a solution to the unique problems associated with 
stabilizing nutritionally complete liquid formulas or that such formulas 
would benefit from the inclusion of from 10 to 500 parts per million (ppm) 
of gellan gum. 
Hannigan in Food-Engineering, 55(1), pages 52-53 discusses gellan gum which 
is produced by controlled fermentation of Pseudomonas elodea and 
deacetylation. Gellan gum is disclosed as requiring a cation, preferably 
calcium, for gelation. Gellan gum is suggested as a replacement for 
several different commercially used gelling agents utilized in the 
manufacture of foods. Recited applications include jellies, deserts, 
retorted and ultra high temperature (UHT) processed solid foods, beverages 
and milk products (ice cream, cheese, yogurt and the like). 
Gellan gums are sold by the Kelco Division of Merck & Co. under the 
KelcoGel.RTM. brand name. Gellan gums are known as multi-functional 
gelling agents for use in foods, pet foods, personal care products and 
industrial applications. Gellan gums have been approved by the U.S. Food & 
Drug Administration for use in foods and have been developed specifically 
for bakery fillings, confections, icings, frostings, glazes, jams, 
jellies, puddings and personal care products. 
Gellan gum is a high molecular weight extracellular heteropolysaccharide 
produced by fermentation of a culture of Pseudomonas elodea, ATCC 31461. 
During fermentation, oxygen, temperature and pH are strictly controlled. 
When the fermentation is complete, the gellan gum is isolated from the 
broth by alcohol extraction and dried. It is known that gellan gums form 
gels with a wide variety of cations, notably calcium (Ca 2+), magnesium 
(Mg 2+), sodium (Na+), potassium (K+) and also hydrogen ions (H+) from 
acid. These cations cause the gellan molecules to associate and form a 
gel. Calcium and magnesium are known to be much more efficient gel formers 
than sodium or potassium. 
Historically, carrageenans have been used to suspend calcium and 
phosphorous and reduce sedimentation and the compaction of the sediment. 
Products containing high levels of calcium, phosphorous, dietary fiber and 
other insoluble agents, such as cocoa powder, are especially susceptible 
to sedimentation, and the conventional stabilizing systems leave much to 
be desired. Further, the use of carrageenans has been identified as a 
bowel irritant to people consuming products that contain high levels of 
this stabilizer and certain countries around the world do not permit the 
use of carrageenans in food products. 
Thus, a need exists to improve the physical stability of nutritionally 
complete, low viscosity formulas while reducing or eliminating the use of 
carrageenans. While the liquid nutritionals of this invention are 
particularly suited for infant formulas and medical nutritionals, it is 
contemplated herein that the invention would also be useful for any liquid 
nutritional that has encountered the problems of sedimentation. 
DISCLOSURE OF THE INVENTION 
An ideal stabilizer for nutritionally complete liquid formula would exhibit 
at least the following rheological profile: (1) behave like a gel with 
high viscosity under quiescent conditions, so as to suspend insoluble 
materials such as calcium during storage; (2) "flow like water" when 
poured or tube fed (high degree of pseudoplasticity); and (3) when left 
undisturbed after shaking, reform a gel to as near the original 
characteristic as possible. This invention discloses a novel stabilizer 
for nutritionally complete formula that demonstrates these rheological 
attributes. 
There is disclosed a nutritionally complete liquid formula with improved 
physical stability, said liquid formula comprising gellan gum at a 
concentration between 10 and 500 parts per million, said concentration 
being low enough for said liquid formula to possess an actual yield stress 
value of from about 0.1 to about 1.0 dyne/cm.sup.2, yet said concentration 
being high enough to hold minerals, fibers and flavoring agents, such as 
cocoa powder, in suspension with minimum sedimentation. 
As used herein and in the claims, the term "parts per million" or "ppm" is 
based on weight. 
There is also disclosed a liquid nutritional composition comprising a 
liquid nutritional mixture containing a total solids content including 
suspended minerals at a concentration of from about 5% to about 35% by 
weight. As mentioned previously, liquid nutritionals are unique in that as 
a sole source of nutrition, they must supply all of the required dietary 
minerals to the consuming patients. Nutritionally complete formulas may 
contain from 5 to 35% by weight total solids including suspended minerals 
(i.e., calcium phosphorous and the like), more specifically 10 to 30% by 
weight total solids including suspended minerals, and even more 
specifically 15 to 25% by weight total solids including suspended dietary 
minerals. It is this high loading of minerals, in part, that causes the 
problem of sedimentation that these products experience. 
In another embodiment, the invention comprises carboxymethylcellulose, 
carrageenan and gellan gum as a stabilizer system for the nutritionally 
complete liquid formula wherein the concentration of the gellan gum is 
less than 5% by weight of the total concentration of the stabilizing 
system (gellan gum plus carrageenan plus carboxymethylcellulose). 
There is also disclosed a liquid, nutritionally complete food with reduced 
sedimentation, said liquid food comprising gellan gum and carrageenan in a 
weight ratio of gellan gum to carrageenan of at least 1:4, said gellan gum 
being of a concentration between 10 and 500 parts per million and said 
liquid food having a viscosity of less than 0.05 Pa.multidot.s (50 cp). In 
a more preferred embodiment, the weigh ratio of gellan gum to carrageenan 
is at least 1:5 and the viscosity is less than 0.04 Pa.multidot.s (40 cp). 
Preferably, the liquid nutritional in accordance with this invention uses 
only gellan gum as the stabilizer. The gellan gum is preferably at a 
concentration between 10 and 500 parts per million, more preferably 
between 20 and 400 parts per million and most preferably between 50 and 
100 ppm. 
There is also disclosed a liquid nutritional composition comprising a 
liquid nutritional mixture containing suspended minerals and having a 
total solid content, including suspended minerals, in the range from about 
5 to about 35% by weight and a stabilizing system consisting of gellan gum 
that is present in the liquid nutritional composition at a concentration 
in the range of 10 to 500 parts per million. 
There is also disclosed a method of preparing a liquid nutritional 
composition comprising the steps of: (a) preparing a liquid nutritional 
mixture comprising: (i) suspended minerals and wherein said nutritional 
mixture contains total solids, including suspended minerals, in the range 
from about 10% to about 35% by weight; and (ii) gellan gum; (b) subjecting 
the mixture to aseptic processing; and (c) aseptically packaging the 
liquid nutritional composition so that the composition is essentially 
devoid of sedimentation. 
There is further disclosed a liquid nutritional comprising (a) a protein 
system consisting of, by weight, about 50 to 90% of a protein hydrolysate 
and not more than about 50% of one or more intact proteins; (b) a fat 
source; (c) a carbohydrate system; and (4) a stabilizer system comprising 
gellan gum at a concentration of from 175 to 350 ppm. 
There is also disclosed a process for the incorporation of gellan gum into 
a nutritionally complete liquid formula comprising the steps of (a) 
forming a dispersion of (i) gellan gums in water; or (ii) gellan gum and 
sugar in water; (b) admixing a sequesterant to the dispersion formed in 
step (a) to form a solution; and (c) admixing additional components to 
form a nutritionally complete liquid formula. 
There is still further disclosed a liquid nutritional composition wherein 
the composition has a caloric content in the range from about 500 calories 
per liter to about 2000 calories per liter and wherein the liquid 
nutritional composition has a caloric distribution of about 10 to 20% 
protein, 25 to 40% fat and 40 to 60% carbohydrate. 
Another aspect of the invention provides for a nutritionally complete 
liquid formula possessing an actual yield stress (the stress above which 
flow begins) of approximately 0.1 to 1.0 dyne per square cm. Yield stress 
refers to a minimum shear stress or force that must be applied to a 
quiescent fluid to initiate flow deformation. One aspect of the present 
invention relates to the discovery that use of gellan gum produces 
nutritionally complete liquid formulas having a yield stress. As used 
herein and in the claims, the term "actual yield stress" means the yield 
stress of a quiescent sample as measured by physical measurements and not 
a yield stress that is derived from a mathematical model. The advantage of 
having a yield stress is that the nutritional product will not move (flow) 
until a force is applied. Thus, minerals will not sediment or fall due to 
the gel structure, however, once force is applied to the product (through 
pouring, shaking or pumping), the gel structure easily breaks and thus 
provides for a free flowing liquid. Examples of materials having a yield 
stress are ketchup, mustard, toothpaste, mayonnaise and various polymer 
solutions. One aspect of the invention resides in a nutritionally complete 
liquid formula which is shear thinning, such that the product is freely 
flowing at shear rates at which the product is poured or consumed. It is 
believed that a weak three-dimensional network forms through interaction 
of the gellan gum and the components of the liquid nutritional. This 
network maintains product emulsion and suspension stability. 
There is disclosed a nutritionally complete liquid formula with improved 
physical stability containing at least one material selected from the 
group comprising dietary fibers, soy polysaccharides and cocoa powder. 
This liquid formula contains a stabilizing system which comprises gellan 
gum at a concentration between 175 and 350 parts per million and wherein 
the concentration is low enough for the liquid formula to possess a yield 
stress of about 0.1 to about 1.0 dyne per square centimeter. 
There is also disclosed a method for the reduction of sedimentation in a 
nutritionally complete liquid formula. This method comprises the steps of 
(1) hydrating gellan gum in a buffered system; (2) combining the hydrated 
gellan gum with a slurry selected from a protein slurry, a carbohydrate 
slurry, a fat slurry and mixtures thereof, to form a gellan gum slurry; 
and (3) combining the gellan gum slurry with one or more slurries and/or 
premixes to result in a nutritionally complete liquid formula containing 
total solids in the range from about 10% to about 35% by weight and 
wherein the nutritionally complete liquid formula has a yield stress of 
about 0.1 to about 1.0 dyne per square centimeter. 
The nutritional industry has expended a substantial effort to solve the 
problems uniquely encountered with medical and infant nutritional 
products. The problems encountered by these nutritionally complete liquid 
formulas are unique. Other foods such as yogurt, are not required to 
deliver all or a substantial portion of the vitamins, minerals, fats and 
proteins required for the average human. Thus, a solution to the problems 
of sedimentation and creaming would fulfill a long-felt need in this very 
specific industry. 
Other aspects and advantages of the present invention will become apparent 
from the following description, examples and the appended claims. 
DETAILED DESCRIPTION OF THE INVENTION 
The primary structure of gellan gum consists of a linear tetrasaccharide 
repeat structure. Each repeating unit comprising four (4) sugar units of 
1,3-.beta.-D-glucose; 1, 4-.beta.-D-glucuronic acid; 1,4-.beta.-D-glucose 
and 1,4-.alpha.-L-rhamnose. The molecular weight of gellan gums can range 
from about 4.times.10.sup.5 to about 6.times.10.sup.5 daltons. These gums 
are supplied as free-flowing powders containing about 10 to 15% water by 
weight. 
The term "gellan gum" as used herein and in the claims, means a high 
molecular weight extracellular heteropolysaccharide produced by 
fermentation of the organism Pseudomonas elodea. When fermentation of 
Pseudomonas elodea is complete, the viscous broth is pasteurized to kill 
viable cells prior to recovery of the gum. Direct recovery from the broth 
yields the gum in its native or high acyl form. Recovery after deacylation 
by treatment with alkali, produces the gum in its low acyl form. The acyl 
groups are known to influence gel characteristics. 
Three (3) forms of gellan gums are presently available from the Kelco 
Division of Merck & Co., San Diego, Calif. The first form is K9A50 which 
is a non-clarified form of gellan gum for industrial use. The second form 
is KelcoGel.RTM. gellan gums for food and industrial products. The third 
form is Gelrite.RTM. gellan gums for microbial media, plant tissue culture 
and pharmaceutical applications. In a preferred embodiment of the 
invention, the KelcoGel.RTM. form of gellan gum is marketed under the 
names: KelcoGel.RTM., KelcoGel F.RTM., KelcoGel BF.BF-10.RTM., KelcoGel 
JJ.RTM., KelcoGel IF.RTM., and KelcoGel CF.CF-10.RTM.. The most preferred 
gellan gum is KelcoGel F.RTM.. Many solid foods utilize gellan gums, for 
example in pie fillings, jellies, jams, yogurts and the like. As a result 
of the inventors' endeavors, it has been discovered that superior results 
can be achieved when a nutritionally complete liquid formula contains 
mostly, if not solely, gellan gum. If iota-carrageenan is present then the 
ratio of gellan gum to carrageenan must be greater than or equal to a 
weight ratio of 1:4. 
Representative of the carrageenans useful in this invention is 
iota-carrageenan which is sold under the name Viscarin.RTM. SA-359 by FMC 
Corporation. Viscarin.RTM. SA-359 is a relatively weak gelling 
carrageenan. Those skilled in this art will appreciate that numerous 
suppliers can provide the various forms of the gellan gum and carrageenan 
that are useful in the present invention. 
The addition of the gellan gum stabilizer system to the nutritional product 
can occur at any point when conventional stabilizers have been added, for 
example, in the protein slurry, the carbohydrate slurry, the fat slurry or 
at the end of manufacture (just prior to packaging). It has been 
determined from trial and error, that the preferred place of gellan gum 
addition is to the carbohydrate/mineral slurry. Medical nutritionals are 
typically made through the combination of various prepared slurries and 
premixes. It is important to note that the gellan gum should be fully 
hydrated in a buffered system (i.e., sodium citrate) prior to any addition 
of mineral cations, such as calcium. The presence of cations, at 
relatively low concentrations, for example 0.004% by weight, increases the 
temperature at which the gellan gum hydrates. Proper hydration of the 
gellan gum prior to exposure to cations provides for the proper level of 
yield stress that results in the unique properties of gellan gum in a 
nutritionally complete liquid formula. 
It has been discovered that the utilization of low concentrations of gellan 
gum in nutritionally complete liquid formulas, results in the formation of 
a relatively weak three-dimensional network that effectively holds the 
minerals as well as the fat globules in the nutritional matrix. By holding 
the minerals in this weak three-dimensional network, the result is reduced 
sedimentation, creaming and sagging. 
The specific concentrations of the gellan gum may range from 10 to 500 
parts per million depending upon the specific type, nature of the product 
matrix and addition of other stabilizers. Certain rheological properties 
are necessary for a liquid nutritional product. For example, the products 
possess a yield stress (a stress above which flow begins) such that the 
yield stress exceeds about 0.1 dyne per sq cm and is preferably below 1.0 
dyne per square cm. In comparison, water has a yield stress value of about 
0.0. In addition, the gellan gum allows the liquid nutritional to be quite 
shear thinning, such that it is free flowing at shear rates at which the 
product is poured or consumed.

EXAMPLE I 
Gellan Gum in a Medical Nutritional 
Nutrition is an important consideration for the patient with respiratory 
insufficiency. The incidence of malnutrition is high in patients with 
chronic respiratory disease and those hospitalized with respiratory 
failure. Patients on mechanical ventilatory support are often administered 
medical nutritionals that are directed to the specific needs of a patient 
with respiratory insufficiency. 
Pulmocare.RTM. is a nutritional product which is distributed commercially 
by the Ross Products Division of Abbott Laboratories, Columbus, Ohio. 
Pulmocare.RTM. is a high fat, low carbohydrate enteral formula designed to 
meet the total dietary needs of pulmonary patients. This medical 
nutritional may be consumed as a supplement to a regular diet, or more 
often, tube fed to patients on long term ventilatory support. 
To evaluate the effectiveness of the use of gellan gum in accordance with 
this invention, a Pulmocare.RTM. type medical nutritional was prepared 
with and without a stabilizing system. The base formula was prepared in a 
manner similar to that described in U.S. Pat. No. 5,223,285, which is 
incorporated herein by reference, except that no stabilizing system was 
added. This product serves as the Control in this Example. The 
Experimental product contained 75 ppm KelcoGel F.RTM. gellan gum supplied 
from the Kelco Division of Merck & Co. 
The Control and Experimental were filled into 0.23 kg (8 ounce) glass 
bottles or metal cans, closed and sterilized in an agitating retort 
cooker. The Control and Experimental samples after sterilization were 
placed in quiescent storage for six months. 
After the 6 months of storage, the samples were evaluated for sediment, 
viscosity, bound sediment and unbound sediment. Sedimentation is a 
phenomenon of product phase separation wherein mineral particles, 
denatured proteins and the like, which are insoluble, fall to the bottom 
of the product container and form a layer. As the product ages, the 
sediment may further settle and pack and progressively become less 
dispersible. 
Upon shaking, the sediment either remains on the bottom of the product 
container or becomes dislodged and resuspended (sometimes in pieces) 
depending on the dispersibility of the sediment. Those resuspended 
sediment particles or flakes may quickly fall out of suspension within a 
few minutes of quiescent standing. The sediment, which can be redispersed 
upon shaking but quickly settles again as particles or flakes upon 
standing, is called the "unbound" sediment. The sediment which remains on 
the bottom of the product container is called the "bound" sediment. The 
presence of "bound" and "unbound" sediment is highly undesirable as their 
presence adversely affects product functionality, organoleptic properties 
and nutritional quality. 
The "bound" and "unbound" sediment tests used to evaluate the present 
invention, were performed by first pouring the entire shaken sample into a 
sediment testing container to separate the two types of sediment and then 
each sediment was visually rated according to rating scales, as described 
below. 
The rating scale for the "bound" sediment was based on the fraction of the 
bottom of the original product container actually covered by the sediment. 
A numerical value from 1 to 6 was assigned based on the coverage of the 
bottom of the container by the bound sediment. 
The rating scale for the "unbound" sediment was based on the size and the 
distribution density of the sediment particles or flakes which resettled 
to the bottom of the sediment testing container within the first two 
minutes of quiescent standing after sample transfer. The distribution 
density of the unbound sediment particles or flakes was also measured. In 
the rating of the unbound sediment, a numerical value from 1 to 6 was used 
to indicate the level of the particle distribution density. In addition, a 
capitalized letter from A to F was used to indicate the size range of the 
largest unbound sediment particle or flake. Both numerical and alphabetic 
ratings were used together for the determination of the unbound sediment. 
The distribution of bound and unbound sediments in a sample are affected by 
the degree of shaking the sample receives. Therefore, a machine was used 
for uniform shaking the samples to obtain reproducible results. 
______________________________________ 
Rating 
Description 
______________________________________ 
RATING SCALE FOR BOUND SEDIMENTATION 
1 No sediment is present. 
2 Up to 1/8 of the bottom of the contain is covered with sediment. 
3 More than 1/8 and up to 1/4 of the bottom of the container is 
covered with sediment. 
4 More than 1/4 and up to 1/2 of the bottom of the container is 
covered with sediment. 
5 The bottom of the container is more than 1/2, but less than 
tottally, covered with sediment. 
6 The bottom of the container is totally covered with sediment. 
RATING SCALE FOR UNBOUND SEDIMENTATION 
1 No sediment particles or flakes are present. 
2 Less than 2.0 A-C sediment particles or flakes per square 
centimeter, but not more than six C particles overall, are 
present. 
3 From 2.0 to 3.9 A-D sediment particles or flakes per square 
centimeter, but not more than two D particles overall, 
are present. 
4 From 4.0 to 7.9 A-E sediment particles or flakes per square 
centimeter, but not more than two E particles overall, 
are present. 
5 From 8.0 to 12 A-F sediment particles or flakes per square 
centimeter, but not more than two F particles overall, 
are present. 
6 More than 12 sediment particles or flakes per square centimeter, 
or more than two F particles overall, are present; or the 
container 
bottom is totally covered by the sediment within the first two 
minutes of quiescent standing after the sample transfer. 
______________________________________ 
The size ranges are deflned as: A = 0.2-1.0 mm B = 1.1-2.0 mm C = 3.1-4.0 
mm D = 4.1-10.0 mm E = 10.1-20.0 mm F &gt; 20.0 mm 
Samples were mechanically shaken and each container was placed on its side 
in a horizontal position. The sample container remained in that position 
until it was opened for the liquid transfer in the next step. The time 
span between the shaking and the transfer of the sample liquid did not 
exceed 3.5 minutes. 
The container was opened by removing the entire lid and the liquid 
immediately poured into a suitable sized cylindrical sediment testing 
container. The emptied original sample container was inverted and placed 
on a towel, or equivalent, to drain out and absorb any residual fluid to 
facilitate the subsequent bound sediment rating. 
The cylindrical testing container containing the liquid sample was allowed 
to stand quiescently for a minimum of two minutes after the sample 
transfer to allow the dislodged and resuspended sediment particles or 
flakes to fall down to the bottom of the container for the subsequent 
unbound sediment rating. 
The bound sediment which remains adhered to the bottom of the original 
sample container was then visually rated by estimating the fraction of the 
sample container bottom actually covered by the bound sediment and the 
rating number was assigned. 
The unbound sediment on the bottom of the cylindrical sediment testing 
container was rated between two minutes and one hour of quiescent standing 
after the sample transfer. Through the use of a template to measure area, 
proper lighting and the sediment testing container, the number of unbound 
sediment particles or flakes larger than 0.2 mm in size (within a grid of 
the template) were counted. An average number of particles per grid (or 
per cm) were calculated and used to determine the unbound sediment rating. 
Viscosities were determined on a Brookfield viscometer using a RV #1 
spindle at room temperature. 
The results of the physical stability investigation conducted at 0 time and 
6 months is set forth in Table I. 
TABLE I 
______________________________________ 
Physical Stability Results 
0 and 6 month data 
Viscosity 
Sediment Pa .multidot. s .times. 
Bound Unbound 
Liquid+ 10.sup.3 Sediment Sediment 
Sample 0 M 6 M 0 M 6 M 0 M 6 M 0 M 6 M 
______________________________________ 
Control* 6 5 21.4 20.6 5 5 1 3D 
Experimental** 
5 5 34.2 22.8 4 4 1 1 
Pulmo- NT NT 16.3 17.6 NT 5 NT 3C 
care .RTM.++ 
______________________________________ 
NT = not tested 
*no stabilizer 
**75 ppm gellan gum 
+same test as bound sediment test except that container was not shaken 
prior to evaluation 
++Pulmocare .RTM. type product results are average of 3 production runs, 
stabilizer system was 40 ppm kappa carrageenan 
These data demonstrate that even though products may have similar 
viscosities, sedimentation is considerably less in the product formulated 
with gellan gum. The Experimental product also evidenced enhanced 6 month 
stability over the commercial Pulmocare.RTM. product for both the bound 
and unbound sediment. Other stabilizers, such as carrageenan and the like 
may decrease sedimentation and suspend powder additives somewhat, however 
they produce unacceptably high viscosities. High viscosities result in 
unacceptable mouthfeel characteristics and poor flow properties. Thus, it 
is surprising that gellan gum can produce a positive impact on physical 
stability with minimal increase in viscosity. 
EXAMPLE II 
Calcium and Phosphorous Deliveries 
As mentioned previously, medical nutritionals are often the sole source of 
nutrition for patients that are unconscious or unable to consume food 
orally. These patients typically receive the medical nutritional through a 
nasogastric tube or a gastrostomy tube. When patients are tube fed, it is 
also typical that an enteral pump be used to administer the nutritional 
over a long period of time. Typically, about 1 liter of medical 
nutritional is administered over a 24 hour period by the pump. If 
sedimentation occurs during storage and administration of the nutritional, 
inadequate levels of minerals, (e.g. calcium and phosphorous) will be 
administered and further clogging of the feeding tube may occur. 
In this Experiment, the Control and Experimental products were vigorously 
shaken using a mechanical shaker and placed in an enteral feeding 
container to which was connected a feeding tube pump set, an 8 French 
enteral feeding tube and an enteral feeding pump. The pump was set to 
deliver 30 cc/hr for a simulated 8 hour feeding. At the end of the 8 hour 
period, the entire delivered sample from each apparatus was collected and 
stirred vigorously to disperse any sedimented material. An aliquot of the 
sample was then analyzed for calcium and phosphorous. 
Table II sets forth the results of this Experiment. The fortification 
levels and the % of fortification recovery for each element is recited. 
"Fortification level" is the level at which each element is added to the 
medical nutritional at the time of manufacture. The recovery percentage of 
fortification represents the percentage of each element's fortification 
level that is delivered through the feeding tube. 
TABLE II 
______________________________________ 
Calcium and Phosphorous Pump Deliveries 
Sample 
Fortification 8 hr. Feed 
Recovery-% of 
0M 6M Mineral Fortification 
mg/L mg/L* 
______________________________________ 
Control Ca 1370 1037 77 48 
P 1328 1030 78 69 
Experimental 
Ca 1370 1302 95 94 
P 1328 1223 92 91 
______________________________________ 
*Average result of duplicate trials 
These data clearly demonstrate gellan gum's effectiveness in promoting the 
substantial delivery of calcium and phosphorous over an 8 hour feeding 
period. Further, this experiment reveals that the Control at 0 time and at 
6 months (0 m and 6 m) has substantially reduced delivery of calcium and 
phosphorous. From previous evaluations of the Pulmocare.RTM. product (40 
ppm carrageenan) using this same test, the Recovery percentage of 
Fortification at O M, values ranged from 60 to 69% for calcium (4 trials). 
At 4 M, the product values for calcium ranged from 28 to 58% and 71 to 89% 
for phosphorous. In contrast, the use of gellan gum provides good levels 
of delivery and stability at 0 time and after 6 months of storage. Since 
the minerals in the Control sample and the commercial product were not 
being fed, it must be assumed that they are being deposited within the 
tubes or remain in the container as bound or unbound sediment. 
EXAMPLE III 
The procedure in Example I was followed except the Control sample had added 
to it 350 ppm of iota-carrageenan. The results of the initial stability 
study are set forth in Table III. 
TABLE III 
______________________________________ 
Initial Physical Stability Results 
Viscosity 
Sediment Pa .multidot. s .times. 
Bound 
Sample Liquid* 10.sup.3 Sediment 
______________________________________ 
Control 3 34.8 5 
350 ppm-iota 
Experimental 2 32.6 2 
75 ppm gellan gum 
______________________________________ 
*Same test as bound sediment test except that container was not shaken 
prior to evaluation 
This Example amply demonstrates that gellan gum is very effective in 
controlling sediment without increasing viscosity when compared to the 
commercially used iota-carrageenan. In addition, the level of the gellan 
gum added was about 20% of the iota level. Most importantly, the use of 
gellan gum significantly reduced the amount of bound sediment. 
Gellan gum significantly improved bound sediment scores and this is 
important because bound sediment is typically not dispersible, even when 
vigorous agitation is applied and therefore, the nutrients (Ca, P) which 
are trapped on the bottom of the container are not available to the 
consumer, thereby making the product nutritionally deficient in the 
absence of a stabilizer. 
Further, the gellan gum products did not experience any additional creaming 
over shelf-life. 
EXAMPLE IV 
Medical Nutritionals Containing Fiber 
The inclusion of dietary fiber in nutritional products has recently gained 
much favor as the physiological benefits of consuming fiber have become 
more apparent. The benefits of fiber consumption include reduced diarrhea, 
enhanced bowel function and improvement in the number of bifido bacteria 
in the intestines. 
One major problem with the inclusion of dietary fiber in a medical 
nutritional is that many sources of desirable dietary fibers, e.g., soy 
polysaccharides and others are often insoluble and their inclusion into a 
liquid nutritional that is already prone to sedimentation and phase 
separation, only aggravates the problem. Typical medical nutritionals 
contain dietary fiber, including soy polysaccharides, at levels from about 
0.5 to about 5.0% by weight. 
The medical nutritional industry is also moving towards disease specific 
products. An example of a disease specific product is the previously 
mentioned Pulmocare.RTM. Enteral Nutritional for patients with compromised 
respiratory systems. Another example of a disease specific product is 
Advera.RTM. enteral nutritional for patients infected with human 
immunodeficiency virus (AIDS). Advera is produced and marketed by the Ross 
Products Division of Abbott Laboratories, Columbus, Ohio. 
This medical nutritional contains a protein system comprising a mixture of 
hydrolyzed soy protein and intact protein. One problem with the use of 
hydrolyzed proteins in medical nutritionals relates to product physical 
stability. As proteins are broken down during hydrolysis, their ability to 
act as emulsifiers is diminished. Therefore, a product like Advera.RTM. 
has two problems to overcome when it comes to product stability: (1) 
insoluble dietary fiber; and (2) hydrolyzed proteins. 
Further investigation on enteral nutritional containing hydrolyzed protein 
and intact protein, can be found in U.S. Pat. No. 5,514,655 to DeWille et 
al. This patent also describes prior art attempts to solve the 
sedimentation problem. The teachings of U.S. Pat. No. 5,514,655 are 
incorporated herein by reference. 
The process to make Advera.RTM. is set forth in U.S. Pat. No. 5,403,826 to 
Cope et al. The teachings of U.S. Pat. No. 5,403,826 are herein 
incorporated by reference. 
In this experiment, the Control composition was the present Advera.RTM. 
product which contains 50 ppm kappa carrageenan and 300 ppm 
iota-carrageenan. The Experimental products contain 175, 225, 275 and 350 
ppm, KelcoGel F.RTM. gellan gum. The Control and Experimental formulas 
were evaluated for fiber sedimentation, flow rates and calcium and 
phosphorous deliveries. 
Using the procedure set forth in Example II, it was determined that all the 
Experimental samples delivered at least 125% of the label claim levels for 
both calcium and phosphorous. The Experimental with 275 ppm gellan gum, 
performed the best with yields of greater than 150%. The gravity flow 
rates of the Experimental samples decreased from 562 ml/hr for the 175 ppm 
to 318 ml/hr for the 350 ppm gellan gum. The gravity flow rate for the 
Control was 789 ml/hr. As observed for the Pulmocare.RTM. product, the 
weak gel structure of gellan gum functions to stabilize the product and 
suspend insoluble minerals such as calcium, however it also sometimes 
slightly increases viscosity and thereby reduces gravity flow rates if 
used at high levels. Gravity feeding, in general, is not recommended for 
Advera.RTM.; however enteral pump deliveries were very good due to the 
shear thinning properties of the product containing gellan gum. It was 
found that the minimal shear applied during pumping was enough to reduce 
the viscosity and allow proper flow of the product. 
It was also determined that calcium and phosphorous recoveries from all of 
the Experimental samples remained above label claim for a 24 hour pumping 
trial. Visual inspection of the samples placed in a transparent container 
revealed that the Control product underwent a distinct phase separation 
within 1 week. The distinct phase separation becomes quite visible when 
the insoluble fiber begins to settle. This defect was much more apparent 
in the Control formula than the Experimentals which contained gellan gum. 
Acceptable levels of gellan gum in Advera.RTM. type products can range 
from 225 to 275 ppm. Of those tested, the best product was that containing 
about 275 ppm gellan gum. From this experiment, it was determined that an 
Advera.RTM. type product can be significantly improved through the 
incorporation of gellan gum. The gellan gum appears to favorably interact 
with the dietary fiber, such as soy polysaccharide, to greatly increase 
its suspension in the liquid nutritional. In addition, gellan gum forms a 
shear-thinning, soft gel that requires only minimal shear to attain 
acceptable flow properties. 
EXAMPLE V 
The procedure of Example I was used except that 1% cocoa powder was added 
to produce a chocolate flavored Pulmocare.RTM. type product. Flavoring 
powders, such as cocoa powder, place an additional burden on the physical 
stability of medical nutritionals, since these powders are very prone to 
sedimentation and once fallen from solution, these powders have a tendency 
to form hard sediments that are not easily redispersed. Typical medical 
nutritionals contain flavoring powders, including cocoa powder, at levels 
ranging from about 0.5 to about 5.0% by weight. 
The Control product in this experiment contained 40 ppm of kappa 
carrageenan while the Experimental product contained 75 ppm of gellan gum. 
Table IV sets forth the results of the initial physical stability. 
TABLE IV 
______________________________________ 
Chocolate Pulmocare .RTM. 
Liquid Viscosity Bound 
Sample Sediment Pa .multidot. s .times. 10.sup.3 
Sediment 
______________________________________ 
Choc-40 ppm 
6 27.1 5 
Kappa 
Choc-75 ppm 
5 41.1 3 
Gellan gum 
______________________________________ 
The calcium and phosphorous deliveries for the Control and the Experimental 
were about equal with both delivering about 100% of fortification. 
This Example indicates that bound and unbound sediment ratings were 
significantly reduced when gellan gum was used as a stabilizing agent. 
Gellan gum also provides very acceptable calcium and phosphorous 
deliveries. The Experimental (75 ppm gellan gum) product also had slightly 
higher gel scores which are to be expected as the formation of a soft gel 
structure is essential to the gellan gum's stabilizing effect. No creaming 
defects were observed over the shelf-life (12 months) of the gellan gum 
containing product. Based on this study, it can be concluded that 
chocolate flavored medical nutritionals can be produced which have 
excellent physical stability and low viscosity (less than 0.05 
Pa.multidot.s) provided up to about 75 ppm, of gellan gum is used in the 
formula. 
Additional testing was conducted on these samples to determine the yield 
stress values and the viscosity of each sample with increasing rates of 
shear. The Experimental product possessed a yield stress of 0.5677 
dyne/cm.sup.2 while the Control product was 0.3981 dyne/cm.sup.2. The 
viscosity of the Experimental product was 0.04393 Pa.multidot.s at a shear 
rate of 1.292/sec. Table V sets forth the viscosity of each product at 
increasing levels of shear. 
TABLE V 
______________________________________ 
Viscosity of Viscosity of 
Shear Rate-1/sec. 
Experimental Pa .multidot. s 
Control Pa .multidot. s 
______________________________________ 
1.292 0.04393 -- 
2.129 -- 0.0187 
23.31 0.03182 -- 
38.95 -- 0.01829 
47.73 0.02779 -- 
73.65 -- 0.01777 
77.98 0.02579 -- 
497.1 -- 0.01738 
501.1 0.02121 -- 
1090 -- 0.01700 
1115 0.01958 -- 
1486 -- 0.01689 
1490 0.01955 -- 
______________________________________ 
This data demonstrates the shear-thinning properties of a nutritional 
formula using the invention as described herein. It is interesting to note 
that the product according to this invention has a high initial viscosity 
that rapidly drops upon the application of shear. It is, in part, this 
unique property of gellan gum that allows the present invention to fulfill 
a long felt need in the medical nutritional industry and thus advance the 
state of the art in the field of medical nutritionals. In addition, the 
shear-thinning aspect of the present invention enhances mouthfeel of the 
nutritional product and facilitates tube feeding. 
The data also demonstrate that evaluation of a product based on Brookfield 
viscosity at a shear rate of 13 reciprocal seconds can be misleading, 
because under actual conditions of use, such as tube feeding or pouring, 
the viscosity of a shear thinning product may be appreciably lower. The 
viscosity during pouring (100 reciprocal seconds) or during tube feeding, 
is actually a more important physical feature of product performance. 
EXAMPLE VI 
Ensure.RTM. is produced and marketed by the Ross Products Division of 
Abbott Laboratories, Columbus, Ohio. As mentioned previously, the use of 
cocoa powder in nutritionally complete liquid formulas only aggravates the 
problems of physical stability. Also, as noted previously, the presence of 
fiber in these compositions further aggravates the formation of bound and 
unbound sediment in these formulations. 
In this experiment, two batches of chocolate Ensure.RTM. were prepared. The 
Control contained 350 ppm Viscarin.RTM. SA-359 (iota-carrageenan) from FMC 
of Philadelphia, Pa. The Experimental product contained 75 ppm of gellan 
gum (KelcoGel F.RTM.). The samples were packaged into 802 (ml) glass 
bottles and then terminally sterilized. Shelf life testing was conducted 
at 3, 6, 9 and 12 months. 
Both samples contained about 21% solids by weight, about 3.5% to 3.6% fat 
by weight and 3.7% to 3.8% protein by weight. 
The testing for bound and unbound sediment was conducted as described in 
Example I. The data from the physical stability testing is set forth in 
Table VI. 
TABLE VI 
______________________________________ 
Physical Stability of Chocolate Ensure .RTM. Through 12 Months 
Bound Sediment Unbound Sediment 
Sample 3 M 6 M 9 M 12 M 3 M 6 M 9 M 12 M 
______________________________________ 
Iota-carrageen- 
4 2 5 5 6E 1* 6D 6D 
an 350 ppm 
Control 
Experimental 
4 2 5 5 1 1 1 3B 
75 ppm Gellan 
Gum 
______________________________________ 
*Unusual rating may be due to bottle to bottle variability and/or 
evaluator inexperience 
This data clearly indicates that gellan gum at almost one fifth the 
concentration of the commercially accepted carrageenan provides 
outstanding reduction in the formation of unbound sediment. The 3B rating 
of the Experimental at 12 months of storage may be due to bottle to bottle 
variability and/or evaluator variability. In any event, the 3B rating for 
the gellan gum sample was twice as good as the Control. The 3 vs. 6 rating 
means that the gellan gum sample had one half the number of flakes or 
particles of the Control, while the B vs. D ratings means that the gellan 
gum particles were one half the size of the Control particles. Further, 
from the 3 month data, the Experimental product with gellan gum exhibited 
no particles or flakes (unbound sediment score of 1) after two minutes of 
quiescent standing, while the carrageenan Control received a rating of 6E 
(10.1 to 20.0 mm sediment particle or flake size) 
EXAMPLE VII 
In this experiment, the use of gellan gum alone was compared to gellan gum 
in combination with other commercially available stabilizers and to the 
use of a commercially available stabilizer alone. The base formulation was 
vanilla Ensure.RTM. with fiber which contains 3.8 g of a dietary fiber 
blend per 237 ml of product. The fiber blend was 24.2% oat fiber and 75.8% 
by weight soy polysaccharide. The Control sample contained no stabilizer 
system, while Experimental VIIA to VIIE contained various stabilizers as 
shown in Table VII. 
The Control and Experimentals were prepared and aseptically packaged into 
237 ml plastic containers. Information concerning aseptic processing and 
packaging can be found in U.S. Pat. No. 5,303,325 to Pasternak et al. The 
teachings of U.S. Pat. No. 5,303,325 are incorporated herein by reference. 
The samples were stored for six months and then evaluated for physical 
stability as set forth in Example I. The results of the 6 month stability 
study are set forth in Table VII. 
TABLE VII 
______________________________________ 
6 Month Stability Data of Ensure .RTM. with Fiber, Aseptic Process 
Bound Unbound 
Sample Sediment Sediment 
______________________________________ 
Control 6/4.0* 1 
0 ppm stabilizer 
Experimental VII A 5/1.0* 1 
50 ppm gellan gum 
Experimental VII B 5 1 
100 ppm gellan gum 
Experimental VII C 5 1 
50 ppm gellan gum 
1000 ppm Avicel .RTM. 
Experimental VII D 5 1 
50 ppm gellan gum 
1000 ppm Avicel .RTM. 
200 ppm iota-carrageenan 
Experimental VII E 5 1 
50 ppm gellan gum 
1500 ppm Avicel 
Experimental VII F 6/2.0* 4D 
500 ppm 
Recodan .RTM. 
______________________________________ 
*depth of sediment in mm 
+Avicel .RTM. Cellulose Gel is a microcrystalline cellulose sold by FMC, 
Inc. 
++Recodan .RTM.CM is an emulsifier/stabilizer sold by Grinsted Products o 
Kansas. 
Recodan .RTM. is a mixture of monoand diglycerides, carrageenan and guar 
gum which is promoted as being useful in cocoa containing products where 
the separation of the fat and cocoa content of the product is avoided. 
From this experiment, it is evident that gellan gum alone or in combination 
with other conventional stabilizers provides acceptable stability to 
nutritionally complete, aseptically filled liquid formulas. In fact, 
gellan gum alone at about 100 ppm provides better stability to the 
nutritional than 500 ppm of a conventional stabilizer that is recommended 
for this type of product (Recodan.RTM.). This surprising result means that 
cost savings in raw materials and processing can be realized through the 
use of gellan gum alone. Further, gellan gum avoids the medical and 
regulatory problems reported with carrageenans and microcrystalline 
cellulose. 
EXAMPLE VIII 
Addition of Gellan Gum 
In this experiment, the point of addition of the gellan gum during the 
manufacture of the nutritionally complete liquid formula was investigated. 
Numerous experiments, as set forth below, were conducted on a laboratory 
scale using KelcoGel F.RTM. as the gellan gum. 
Initially, the gellan gum was added to hot (180.degree. F.) water 
containing citric acid, pH of 2.20. The gum powder dispersed into the 
solution but did not go into solution. KOH was added to the dispersion to 
arrive at a pH of about 12.0. At a pH of about 12.0, the gellan gum was 
fully dissolved. 
In the next experiment, 2 gms of the powdered gum was added to about 400 
gms of hot (190.degree. F.) corn oil. Under mild agitation, the gum 
dispersed, but did not go into solution (hydrate). 
The next test consisted of adding gellan gum to hot (about 185.degree. F.) 
water at a pH of 7.0. About 2 gms of the gum was added under mild 
agitation, it failed to disperse and formed "fish eyes". Fish eyes are the 
gellan gum particles that bind together (form clumps) to form a ball of 
gel that appears in the dispersion to resemble the eye of a fish. 
Decreasing the pH of the dispersion to 3.0 and increasing the pH to about 
12 did not result in the gum going into solution. 
The next experiment added gellan gum to cold water and the dispersion was 
then heated to 175.degree. to 185.degree. F. The gum dispersed readily and 
no clumping or fisheye formation was observed. 2.02 gms of sodium citrate 
was then added and the solution became clear, indicating that the gellan 
gum had gone into solution (become hydrated). 
This experiment revealed that the gellan gum can be added to cold water 
without the formation of clumps and that a sequesterant such as sodium 
citrate allows for the gum to become soluble or hydrated. 
This experiment formed a solution of tri-calcium phosphate in hot water. 
The gellan gum was then added under mild agitation. The gum did not 
disperse as it formed fish eyes. This method of incorporation would not be 
acceptable for commercial production. 
In this experiment, gellan gum was dry blended with sucrose at 1:100 and 
1:10 ratios (4 g gellan gum:40 g sucrose and 0.4 g gellan gum:4 g sucrose) 
and added to hot water. The dispersions formed readily and upon the 
addition of 2.02 g of sodium citrate, the gellan gum went into solution. A 
1:20 ratio was found to be the most preferred. 
From the results of these observations, it was concluded that in commercial 
product, the process for the incorporation of gellan gum into a 
nutritionally complete liquid formula would comprise: (a) the formation of 
a dispersion of (i) gellan gum in water; or (ii) gellan gum and a sugar, 
such as sucrose, in water; (b) admixing a sequesterant to the dispersion 
formed in step (a) to form a solution; and (c) admixing additional 
components to form a nutritionally complete liquid formula. In a preferred 
embodiment, the gellan gum is dry blended at a weight ratio of 1:20 to 
1:10 with sucrose prior to addition to hot water to form a dispersion. The 
gellan gum/sucrose dispersion then has a sequesterant, such as sodium 
citrate, added to it prior to proceeding with the addition of additional 
components. Essentially complete hydration of the gellan gum is required 
to realize the full benefit of this stabilizer in a nutritionally complete 
formula. 
INDUSTRIAL APPLICABILITY 
The data demonstrate that the liquid nutritional prepared in accordance 
with this invention possesses improved physical stability with respect to 
creaming and sedimentation. The problems encountered by the medical and 
infant nutritional industry in preparing products that exhibit good 
shelf-life (product stability) are unique. Due to the high loadings of 
solids (e.g., minerals, vitamins, flavors and fiber) found in these 
products and the high viscosities, the nutritional industry, until now, 
has failed to provide a low viscosity solution to this long felt need. 
Through the discovery disclosed in this invention, the nutritional 
industry can prepare and supply liquid nutritional products that do not 
suffer from the problem of sedimentation. More specifically, it has been 
determined that gellan gum promotes the delivery of sufficient insoluble 
nutrients (e.g. minerals) as measured by delivery of calcium and 
phosphorous with acceptable viscosity, good flow characteristics and 
reduced sedimentation. It has also been demonstrated that gellan gum 
prevents flavoring powders, such as cocoa, from compacting and improves 
the suspension properties of insoluble fibers. This is especially 
important in that distinct phase separation can create a perception of a 
spoiled product while creaming can impact on the correct delivery of 
nutrients such as protein and lipid. In addition, the weak gel structure 
of gellan gums breaks down easily under low shear conditions allowing for 
convenient consumption. Further, gellan gums are readily available and 
have no adverse physiological effect. 
An important advantage of the use of gellan gums in nutritionally complete 
formulas is a reduction in the over fortification of the formula with 
calcium and phosphorous to allow for the delivery of these minerals to 
meet required daily intakes and/or label claims. As the nutritionally 
complete formulas can have reduced levels of over fortification, an 
economic benefit can be realized. 
While the liquid nutritional herein described and the method of making same 
constitute preferred embodiments of the invention, it is to be understood 
that the invention is not limited to this precise formulation and that 
changes may be made therein without departing from the scope of the 
invention which is defined in the appended claims.