Expandable low calorie compositions

There is disclosed compositions comprising primarily mixtures of edible cellulose fibers and/or colloidal cellulose microfibrils, incorporated with low-molecular animal and/or vegetable proteins, crosslinked with edible non-covalent and/or covalent crosslinking agents. The compositions possess a water-expandable property such as to grow in volume in an aqueous acidic medium and serve as a firm gelatinous binder for the edible components. The above mixture is compressed in dry powder forms into tablets and/or granular compositions capable of swelling at the acid pH of the stomach into a firm gelatinous physical mass or masses that effectively serve to provide a temporary reduction of the appetite by mechanical rather than systemic action.

BACKGROUND OF THE INVENTION 
This invention relates to new weight-control compositions comprising 
mixtures of edible cellulose fibers and/or colloidal cellulose 
microfibrils, incorporated with low-molecular animal and/or vegetable 
proteins, crosslinked with edible non-covalent and/or covalent 
crosslinking agents, to provide compositions possessing a water-expandable 
property such as to grow at least to several times their dry volume in an 
aqueous acidic medium. The above mixture is compressed in dry powder forms 
into tablets and/or granular compositions capable of swelling at the acid 
pH of the stomach into a firm gelatinous physical mass or masses that 
effectively serve to provide a temporary reduction of the appetite by 
mechanical rather than systemic action. 
The medical literature provides abundant evidence that the excessive intake 
of food and overweight constitutes a series health problem. Calorie intake 
above an individual's needs as a result of the excessive consumption of 
foods damage the heart and the circulatory system, particularly in the 
case of aged persons, pregnant women, and people suffering from diabetes. 
Recently, the use of appetite-reducing medicaments has become widespread. 
However, such drugs act as stimulants of the central nervous system and, 
therefore, the continuous administration thereof leads to series damages 
of the central nervous system and also to habituation. The side effects of 
such systemic drugs to control weight have become so series in recent time 
that they have come under FDA control. Amphetamines, for example, can no 
longer be used for weight control except by prescription under a 
physican's control; they have been removed for over-the-counter sales. 
Recently a number of attempts have been made to solve this problem by the 
administration of compositions containing indigestible substances. The use 
of these compositions leads to the feeling of fullness without causing 
weight increase. The following additives have been suggested: casein 
(British Pat. No. 990,523), mixtures of egg-albumin, casein, 
cellulose-ether, guar gum, agar pectin, carrageen, and sodium alginate 
(British Pat. No. 993,308), guar gum (British Pat. Nos. 1,041,600 and 
1,106,882), a mixture of soluble polyglucose citrate and insoluble 
polyglucose (British Pat. No. 1,182,961), microcrystalline cellulose (U.S. 
Pat. No. 3,023,104), a mixture of 50% of glutin flour, 1-10% of vegetable 
gums, and 50% of microcrystalline cellulose, peanut-shell, or wood-flour 
(U.S. Pat. No. 3,023,104), edible cheese (DAS No. 1,442,021), and 5-30% of 
finely dispersed pure cellulose (DAS No. 1,959,196). Special dry cakes for 
diabetic people have also been described, prepared from 100% of soya flour 
and 30-50% of protein (DAS No. 2,060,797). None of the above products 
meets in a satisfactory manner the requirements of pleasant and permanent 
consumption, good taste, and easy absorption from the intestinal tract. 
Many efforts have been made to use conventional fibrous cellulose as a 
bulking agent in low calorie food compositions and in pharmaceuticals. 
Fibrous cellulose has the advantage, in addition to providing desirable 
dietary fiber, of providing desired bulk without calories. However, a 
principal defect of this material has been its objectionable texture. This 
characteristic has greatly limited the use of fibrous cellulose both in 
the field of food technology and the field of pharmaceutical preparations. 
When fibrous cellulose has been mixed according to conventional methods 
with other food ingredients, the fibrous cellulose is usually very 
noticeable to the taste, is not smooth, has a fibrous or gritty feel to 
the tongue and mouth when chewed, and tends to accumulate as an insoluble 
or residual material in the mouth. As a result, the food compositions 
themselves have tended to be rendered unpalatable by the addition of 
fibrous cellulose. Reduction of the fibrous cellulose content of such 
compositions to the point where it is not detectable when chewed has 
effectively reduced the proportion of fibrous cellulose to the point where 
it has no longer been effective as a bulking agent or a source of 
significant dietary fiber. 
U.S. Pat. No. 4,042,719 disperses fibrous carbohydrates in a solution of 
cellulose ethers, subsequently drying the gelled mixture up to 
temperatures as high as 300.degree. C. to increase palatability by masking 
the fibrous taste of the fibrous carbohydrate. 
SUMMARY OF THE INVENTION 
According to the present invention there is provided a process for the 
preparation of a composition having a very low caloric value, which 
comprises dry mixing natural digestible carbohydrates and a highly foamed, 
low molecular weight protein such as gelatin prior to converting the dry 
mixture into tablets, capsules, or granular forms. In no instance, and 
unlike the prior art, are the ingredients dispersed in a gel solution 
prior to drying. 
According to an embodiment of the process of the present invention the 
carbohydrate components on the one hand and the protein components on the 
other are admixed in a finely divided dry state, optionally in the 
presence of further minor components such as flavorings and/or coloring. 
The main feature of the present invention is that no significant swelling 
of the compressed carbohydrate components and protein components occur 
until the components reach the stomach, and the component most responsible 
for the swelling of the tablet is the acidic gastric juices. 
One commercially available source of particulate fibrous celluloses 
satisfactory for use in compressed diet-aid invention is obtained from the 
Brown Company of Berlin, N.H. under the trade name SOLKA-FLOC. 
Satisfactory food grades of this particulate fibrous cellulose, also known 
as powdered cellulose, are grades SW-40 and BW-300. These are mechanically 
disintegrated and purified celluloses generally obtained from primarily 
alpha cellulose derived from wood pulp. Ninety-nine and five-tenths 
percent of this material will pass through a 33-micron screen and 99.0% 
will pass through a 23-micron screen. The average fiber length is 21 
microns and the average fiber width is 17 microns. Such relatively fine 
powdered celluloses, or an equivalent finely powdered cellulose, provide 
cellulose fibers which may be used as one bulking ingredient in producing 
our low calorie, edible carbohydrate/protein diet-aid tablets or capsules. 
The second key carbohydrate ingredient of this invention is 
microcrylstalline cellulose, commercially known as AVICEL and produced by 
the acid hydrolysis of alpha cellulose. These ultrapure forms of colloidal 
powdered celluloses are available from FMC Corporation of Philadelphia, 
Pa. as grades PH101 and PH105. 
The protein component of this invention comprises a product made from a 
highly aerated form of natural animal protein (such as gelatin) or natural 
vegetable protein (such as soybean protein) with or without edible 
crosslinking agents. The aqueous protein gels are dried down in their 
aerated form to less than 10% moisture, preferably to less than 7% 
moisture, and then are comminuted into ultrafine particulate form. Typical 
protein compositions suitable for use in this invention are described in 
U.S. Pat. No. 4,264,493 issued Apr. 28, 1981. 
Prior to blending and compressing into tablets, granules, or "plugs" for 
insertion into capsules, the combined proportions of edible cellulose 
including dry fibrous alpha cellulose and dry microcrystalline cellulose 
may range from 10-50% by weight and the amount of finely divided aerated 
natural protein may range from 50-10% by weight. The optimum compression 
varies with each formulation and generally ranges from 1000 psi to 7500 
psi.

EXAMPLE 1 
To a 20% solution of a natural edible gelatin (bloom 300, pH 4.4) at 
40.degree. C., about 1.66% by weight of ammonium alum is added with 
stirring. This mixture is then aerated in a high speed mixer such as a 
Waring Blendor while it is cooled. The resulting solid gel is cut into 
approximately one-eighth inch cubes and dried to at least 10% moisture, 
preferably below 7% moisture. The dried cubes of foamed gelatin are ground 
to approximately 50-70 micron particles. 
Fifty grams of the above finely divided gelatin, 35 grams of SOLKA-FLOC 
SW-40, and 15 grams of AVICEL Microcrystalline Cellulose (PH 101) are dry 
blended to produce a uniformly mixed tableting powder. This mixture is fed 
to a standard tableting machine and compressed at 2000 psi into 0.5 gram 
tablets. 
When these tablets are added to simulated gastric juice at a pH of about 2, 
they grow progressively to a swollen mass ranging from 6 to 15 times their 
original volume. 
EXAMPLE 2 
To a 30% solution of natural edible gelatin (bloom 225 at a pH 4.5) at 
40.degree. C. about 1.66% by weight of ammonium alum with stirring is 
added, this addition being made using a 10% aqueous solution of ammonium 
alum. 
This mixture is then aerated in a high speed mixer such as a Waring Blendor 
or Osterizer and cooled in trays as a sheet while its temperature cools to 
room temperature (25.degree. C.). The resulting solid gel is cut into 
approximately one-eighth inch cubes and subsequently dried to at least 10% 
moisture, preferably below 7%. The dried cubes of foamed gelatin are gound 
to approximately 50-70 micron particles. 
Fifty grams of the above finely divided gelatin, 35 grams of SOLKA-FLOC 
SW-40, and 15 grams of AVICEL Microcrystalline Cellulose (PH 101 Grade) 
are dry-blended to produce a uniformly mixed tableting powder. This 
mixture is fed to a standard tableting machine and compressed at 2,500 psi 
into 0.5 gram tablets. 
When tablets prepared in this way are added to simulated gastric juice at a 
pH of about 2, they grow progressively to a swollen mass from 10 to 20 
times their original volume. 
EXAMPLE 3 
To a 40% dispersion of natural edible soybean protein at 60.degree. C. and 
pH 8.0, about 2.0% of potassium alum is added, this addition being made 
using a 5% aqueous solution of potassium alum. 
This protein mixtureis now treated with the procedure of Example 2, 
paragraphs 2 and 3. 
Fifty grams of the above prepared finely divided foamed soybean protein, 30 
grams of SOLKA-FLOC SW-40, and 20 grams of AVICEL Microcrystalline 
Cellulose (PH 105 Grade) are dry-blended to produce a uniformly mixed 
tableting powder. This mixture is fed to a standard tableting machine and 
compressed at 3,000 psi into 0.45 gram tablets. 
Tablets prepared in this way, when added to simulated gastric juice at a pH 
of about 2, grow progressively into a very highly swollen mass from 5 to 
15 times their original volume. 
Various changes and modifications may be made in practicing this invention 
without departing from the spirit and scope thereof and, therefore, the 
invention is not to be limited except as defined at the appended claims.