ADVANCES IN
`
`FOOD RESEARCH
`
`Volume 12
`
`C. O. Chichester
`
`
`
`Petitioner Mylan Pharmaceuticals Inc. — Exhibit 1013 — Page 1
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`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1013 - Page 1
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`

`
`ADVANCES IN
`
`FOOD RESEARCH
`
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`Petitioner Mylan Pharmaceuticals Inc. — Exhibit 1013 — Page 2
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`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1013 - Page 2
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`

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`Petitioner Mylan Pharmaceuticals Inc. — Exhibit 1013 — Page 3
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`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1013 - Page 3
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`

`
`UTILIZATION OF SYNTHETIC
`GUMS IN THE FOOD INDUSTRY
`
`BY MARTIN GLICKSMAN
`Techaical Cenler. General Foods Corporation. Tarrytown. N . Y
`
`I . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`284
`A . Economic Background
`284
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`B . Cellulose Derivatives
`287
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`C . Completely Synthetic Gums . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`289
`11 . Microcrystalline Cellulose (Avicel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`290
`A . Background
`290
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`B . Food Applications
`291
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`I11 . Sodium Carboxymethylcellulose (CMC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`294
`A . Background . . . . . . . . . . .
`294
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`B . Properties
`295
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`C . Dairy Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`297
`D . Bakery Applications
`302
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`E . Salad Dressings, Sauces, and Gravies . . . . . . . . . . . . . . . . . . . . . . . . . . .
`305
`F . Confectionery
`307
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`G . Dietetic Foods .
`308
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`H . Processed Foods
`310
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`I . Dry Package Mixes . . . . .
`311
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`J . Food Preservation Applications
`312
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`I< . Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . .
`. . . . . . . . . . . . . . . . . . . 313
`IV . Methylcellulose and Hydroxypropylmethylcellulose . . . . . . . . . . . . . . 314
`A . Background
`314
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`B . Properties
`316
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`C . Bakery Products
`317
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`D . DieteticFoods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`320
`E . Dehydrated Foods
`322
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`F . FroeenFoods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`324
`G . Edible Protective Coatings
`327
`. . . . . . . . . . . . . . . . . . . . . . . . . . .
`H . Miscellaneous
`327
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`.
`V Other Cellulose Derivatives
`325
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`.
`A Hydroxyethylcellulose (HEC)
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`B . Ethylcellulose (EC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`330
`C . Ethylhydroxyethylcellulose (EHEC) . . . . . . . . . . . . . . . . . . . . . . . . .
`331
`D . Carboxymethylhydroxyethylcellulose (CMHEC)
`. . . . . . . . . . . . . . . . . . 331
`E . Klucel-Mixed Cellulose Ether . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`332
`VI . Polyvinylpyrrolidone (PVP)
`333
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`A . Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`333
`B . Properties
`334
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`C . Food Applications
`336
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`283
`
`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1013 - Page 4
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`

`
`284
`
`MARTIN GLICKSMAN
`
`VII. Carbopol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`340
`. . . . . . . . . . . . . . . . . . . . . .
`A. Background
`340
`. . . . . . . . . . . . . . . . . . . . . . . . . . . .
`. . . . . . . . . . . . . . . . . . . . . .
`342
`B. Properties
`. . . . . . . . .
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`C. Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`344
`VIII. Gantrez An . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`346
`A. Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`346
`B. Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`347
`C. Applications . . . . . . . . . . . . . . . . . . .
`348
`. . . . . . . . . . . . . . . . . . . . . . . .
`........................
`IX. Polyox . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`349
`A. Background
`349
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`, . , , . .
`350
`B. Preparation
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`C. Properties
`351
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`353
`D. Applications
`. . . . . . . . . . . . . . . . . . . . . .
`. . . . . . . . . . . . . . . . . . . . . . . . . .
`X. Research Needs
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`. . . . . 357
`359
`References
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`
`1.
`
`INTRODUCTION
`
`A. ECONOMIC BACKGROUND
`Gums or hydrophilic colloids have been used in foods and in the food
`industry for hundreds of years to impart various functional properties to
`food products and thereby enhance over-all palatability and acceptability.
`The term “gum” has often been used incorrectly and ambiguously and has
`been applied to various rubbers, resins, etc., in the paint, rubber, and oil
`industries. I n the food industry, the term “gum” is more specifically de-
`fined as any material that can be dissolved or dispersed in a water medium
`to give viscous or mucilaginous solutions or dispersions.
`In the past, most gums were natural materials derived from seaweed
`extracts, tree and bush exudates, plant seed flours, and similar sources,
`and were almost all polysaccharides or mixtures of polysaccharides. To-
`day a new and growing category of gums, which is still in its infancy, is
`that of the synthetic gums. Although synthetic gums are currently only a
`small fraction of the total gum market, comprising about 100,000,000
`pounds of the total 3,000,000,000 pounds of water-soluble gums sold
`domestically (Anonymous, 1961a), they are steadily pressing a t the posi-
`tion of the natural gums and enlarging their foothold in the field as newer
`and better gums become available.
`Proponents of synthetic gums point to the giant advances of organic
`chemistry and feel that, as silk was replaced by nylon, rubber by neoprenc,
`waxes by plastics, so the natural gum polymers are targets for the synthetic
`organic chemist. Although exact duplications may not be possible, or even
`desirable, sufficient of the functional properties can be reproduced syn-
`thetically to create marketing opportunities for these new materials.
`As starting materials, the synthetic chemist has available two of
`
`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1013 - Page 5
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`

`
`UTILIZATION OF SYNTHETIC GUMS IN THE FOOD INDUSTRY
`
`285
`
`a t about
`nature’s cheapest and most abundant raw materials-starch,
`$0.06-0.09 per pound, and alpha-cellulose pulp, a t about $0.09-0.14 per
`pound. Both of these readily available polysaccharides are excellent start-
`ing materials for the production of gums. They both undergo chemical
`modification easiIy by heat, oxidation, or chemical treatment, and proper
`control of the modification makes possible a great variety of products. As
`Whistler (1959) pointed out, it is conceivable that as more is learned about
`the relationship of structure to the physical properties of polymers, gum
`properties will probably be custom-tailored into starch and cellulose
`molecules so that they will more closely match the properties desired in
`special gum applications. Caution is urged, however, and it must be re-
`membered that although synthetic chemical procedures may modify a
`polysaccharide to the desired end product, the materials and processing
`costs may be so high that the new gums will not be competitive in price
`with the natural gums. This is a stimulating challenge for industrial
`chemists and is a substantial protective barrier for the lower-cost natural
`gums. It is probable that in the foreseeable future, chemically modified
`starches and celluloses, as well as the purely synthetic gums, will con-
`tinually compete with the natural gums for the expanding markets for
`these materials.
`As mentioned before, the traditional market for water-soluble gums
`was estimated to have been 3 billion pounds in 1961 (Anonymous, 1961a).
`Of this total, the largest percentage by far was held by the natural gums,
`including the starches, whereas only about 100 million pounds was com-
`posed of the synthetic gums. A conservative projection of the expanding
`markets for this material suggests that by 1970 the total market will have
`expanded to 4 billion pounds, with the proportion held by synthetics
`doubling to 200 million pounds. The author feels that this estimate is much
`too conservative, and that the market for synthetic gums will increase
`a t a much faster rate. This seems to be evident from more recent data
`compiled by Berger (1962), in Table I, which estimate the total con-
`sumption of synthetic gums in 1962 a t 127,000,000 pounds, and this com-
`pilation is incomplete, not including data on such synthetics as Gantrez
`An, Polyox, Carbopol, and other newer and less known gums. I n addition,
`estimates of the potential market for water-soluble films alone range up
`to 20,000,000 lb per year (Anonymous, 1961a).
`In the food industry, the synthetic gums at present occupy a minor
`role. Of the total market of 100,000,000 pounds in 1961, only an esti-
`mated 12,000,000 pounds was consumed by the food industry (Anonymous,
`1961a), and this was chiefly by well-established gums such as carboxy-
`methylcellulose and methylcellulose. The newer synthetics will have a
`difficult, up-hill, and expensive battle to develop markets in the food
`
`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1013 - Page 6
`
`

`
`286
`
`MARTIN GLICKSMAN
`
`TABLE I
`ESTIMATED CONSUMPTION OF WATER-SOLUBLE GUMS"
`
`Millions of pounds
`
`1957
`
`1962
`
`32.7
`
`48.0
`
`27.0
`
`35.5
`
`1.8
`2.5
`
`20.0
`1 .o
`85.0
`
`2.5
`4.5
`
`25.0
`11.5
`127.0
`
`i
`
`Cellulose derivatives
`Carboxymethylcellulose
`Ethylcellulose (not water-soluble)
`Hy droxy ethylcellulose
`Carboxymethylhydroxyethylcellulose
`Ethylhydroxyethy lcell~ilose
`Methylcelluloc e
`Acrylates
`Polyacrylic acid salts
`Pol yacrylamide
`Miscellaneous
`Polyvinyl alcohol
`Polyvin ylpyrollidone
`Total
`
`a Berger, 1062.
`
`industry. The reason, of course, is the stringent FDA regulations requiring
`extensive animal feeding tests and experimental assurance of nontoxicity
`before allowing their use as food additives. As a result, most companies
`developing water-soluble gums tend to loolc for industrial applications and
`strive to develop profitable markets in these nonfood industries before
`attempting to penetrate the food industry. The ease of penetration or ac-
`ceptance is, of course, dictated by the novel and unique functional proper-
`ties offered by the new gum that cannot be matched by the current avail-
`able ones, or by the simple advantage of a cost reduction or product qual-
`ity improvement.
`In general, the synthetic gums tend to offer some of the following
`advantages over the natural gums:
`1) Uniformity of properties
`2) Constancy of price
`3) Unlimited availability-not
`ages, etc.
`4) LowB.0.D.
`I n a previous article, the author (Glicksman, 1962a) reviewed the
`properties and applications of the natural polysaccharide gums in the food
`industry and covered the common seaweed extracts, tree exudates, and
`plant seed gums. This chapter is a similar review of the use of the synthetic
`
`affected by crop failures, labor short-
`
`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1013 - Page 7
`
`

`
`UTILIZATION OF SYNTHETIC GUMS IN THE FOOD INDUSTRY
`
`287
`
`gums in foods. It not only includes the well-established cellulose deriva-
`tives and modifications but also investigates the potential utility of newly
`available nontoxic gums that the author feels will eventually find a place
`on the shelf of the food manufacturer.
`
`B. CELLULOSE DERIVATIVES
`The most abundant natural material in the world is cellulose, a linear
`polymer of P-D-glucopyranose. It constitutes approximately one-third of
`all vegetable matter, where it is the main constituent of the cell walls and
`provides the primary structural support for the plant. Cellulose has
`probably the largest molecular weight of all the natural polysaccharides
`and is one of the most resistant to attack by chemicals and microorgan-
`isms. Its molecules tend to remain extended but may normally undergo
`a degree of turning and twisting. Because of its size and strong associative
`forces, it can be brought into solution only under certain conditions.
`The purest natural cellulose is cotton fibers or linters, which on a dry
`basis consist of about 98% cellulose. Wood contains about 40-500/0 and,
`together with cotton linters, is the most important commercial source
`for raw-material cellulose. Agricultural residues, such as corn stalks, corn
`cobs, and wheat straw, contain about 30% cellulose and are available
`as a vast reservoir of potentially available raw material (Whistler and
`Smart, 1953).
`The cellulose derivatives commonly encountered in industry are ethers
`in which alkyl or hydroxyalkyl groups have been substituted upon one or
`more of the three available hydroxy groups in each anhydroglucose unit
`of the cellulose chain.
`The effect of the substituent groups is to disorder and spread apart
`the cellulose chains so that water or other solvents may enter to solvate
`the chain. By controlling the type and amount (degree) of substitution, it
`is possible to produce products that have a wide range of functional
`properties (Battista, 1958).
`A typical substituted structure would be represented as follows :
`
`~ o ~ l p - o +
`
`i
`
`-O
`
`I
`I
`I
`I
`L
`where R = a substituent group.
`
`H
`
`H
`
`OR
`
`I
`I
`!
`
`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1013 - Page 8
`
`

`
`288
`
`MARTIN GLICKSMAN
`
`The more important water-soluble derivatives are the following, where
`R is:
`
`H y droxyethyl-
`Sodium carboxymethyl-
`Methyl-
`Ethyl hydroxyethyl-
`Hydroxypropyl-
`
`2-
`
`1
`
`HO-CHZ-CHZ-
`NaO 0 C-CH
`CHS-
`CH3-CH2-O-CHZ-CHz--
`HO-CH-CH2-CH2-
`or
`CHa-HOCH- CHt-
`When all three available hydroxyl positions on the ccllulosc iiioleculc
`are replaced by a substituent group, the derivative is said to have a
`degree of substitution (D.S.) of three. Actually, this is usually not the
`case, since partial substitutions are preferred, but it can readily be
`seen that varying the degree of substitution as well as the type of chemi-
`
`gum I
`
`TABLE I1
`IMPORTANT INDUSTRIAL CELLULOSE DERIVATIVES
`
`Trade name
`
`Chemical name
`
`Manufacturer
`
`DOME STIC
`a-Cellulose (microcr ystalline)
`Avicel
`Methocel, MC Methylcellulose
`Methocel, HG Hydroxypropylmethylcellulosc
`Sodium carboxymethylcellulose
`
`American Viscose Co.
`Dow Chemical Co.
`Dow Chemical Co.
`Hercules Powder Co.
`
`Cellulose
`
`Sodium carboxymethylcellulose
`
`Du Pont
`
`Natrosol 250 Hydroxyethylcellulose
`Cellosice
`Hydroxyethylcellulose
`Natrosol E 75 Ethylhydroxyethylcellulose
`CMKEC
`Carboxymethylhydroxyethylcellulose
`Klucel
`Mixed cellulose ether
`FOREIGN
`Methofas M Methylcellulose
`Methofm
`HPM
`Cellofas
`Celacol
`Celacol
`Modocoll
`
`Hydroxypropylmethylcellulose
`Ethylmethylcellulose
`Methylcellulose
`Hydroxyethylmethy lcellulose
`Ethylhydroxyethylcellulose
`
`Tylose
`
`Methylcellulose
`
`Edifas A
`Edifas B
`
`Methylethylcellulose
`
`Sodium carboxymethylcellulose i
`
`Hercules Powder Go.
`Union Carbide Corp.
`Hercules Powder Co.
`Hercules Powder Co.
`Hercules Powder Co.
`
`Imperial Chemical
`Industries, England
`
`British Celaneuc,
`England
`Mo Och Domsjo,
`Sweden
`Kalle and Company,
`Germany
`Imperial Chemical
`Industries, Eiigland
`
`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1013 - Page 9
`
`

`
`UTILIZATION OF SYNTHETIC GUMS IN THE FOOD INDUSTRY
`
`289
`
`cal substituent makes possible a tremendous range of permutations and
`combinations offering a wide range of functional properties. However,
`only a comparatively limited number of these derivatives have been
`found to have industrial applications, and the more important ones,
`which are usually sold under appealing trade names, are listed in Table
`11.
`I n addition to chemical derivatives of cellulose, another modification
`of cellulose has recently been developed that has functional gum proper-
`ties and has found novel uses in the food industry, primarily in low-
`calorie foods. This material is an acid-hydrolyzed cellulose product known
`as Avicel, or microcrystalline cellulose. Although not soluble in water, this
`material has a great absorptive capacity and functions as an effective
`thickening and bodying agent.
`
`C. COMPLETELY SYNTHETIC GUMS
`In addition to the modified natural products, or semisynthetics, a
`completely synthetic approach has led to the preparation of many inter-
`esting and useful hydrophilic polymers. The main advantage of the com-
`pletely synthetic products is elimination of a dependence upon an un-
`certain natural source of raw materials. In addition, synthetic products
`permit more accurate tailoring of chemical structure to desired product
`properties for specific applications.
`Although many synthetic polymers have been created over the past
`few decades, only a comparatively few are of interest to the food industry,
`primarily because of their lack of toxicity. These are reviewed in this
`article, and, although they have not yet penetrated the food field signifi-
`cantly, the author feels that this will come with time and is essentially
`dependent upon meeting FDA regulations concerning proof of nontoxicity.
`The more important gums in this category are the vinyl polymers:
`1) Polyvinylpyrollidone (PVP)
`2) Carboxyvinyl polymer (Carbopol)
`3) Poly (methyl vinyl ether/maleic anhydride) (Gantrez An)
`I n addition to these, other vinyl polymers of widespread industrial
`applications have only limited potential for food use, because of toxicity
`or other detrimental features. The more important of these are polyvinyl
`alcohol (Vinol, Elvanol) , which has found a broad application as a water-
`soluble packaging film ; polyvinylmethyl ether, a heat-sensitive thicken-
`ing agent; polyacrylic acid (vinyl formic acid) and its salts, which have a
`wide range of hydrophilic properties, including a suggested use of the
`alkali metal acrylates as an ice cream stabilizer (Kamlet, 1954) ; and
`polyacrylamides, which are effective cationic thickening agents and coagu-
`lants.
`
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`MARTIN GLICKSMAN
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`Another group of synthetic gums that have great potential for food
`applications are the recently developed Polyox resins, which are ex-
`tremely high-molecular-weight polymers of ethylene oxide having very
`desirable nonionic thickening properties, and are nontoxic.
`The properties and potential uses of these synthetic gums in the food
`industry are discussed in the following sections. The discussion is restricted
`to those that have or may have important applications in foods-PVP,
`Polyox, Carbopol, and Gantrez An.
`
`II. MICROCRYSTALLINE CELLULOSE (AVICEL)
`
`A. BACKGROUND
`Although cellulose is not a gum material and is insoluble in water, a
`new type of cellulose has recently been developed that has many of the
`functional characteristics and applications of typical hydrophilic ma-
`terials. For this reason, microcrystalline cellulose-or Avicel, as i t is
`named-is
`included in this review.
`Cellulose, the most abundant organic material known, has been used
`as a food product as part of plant foods for many years. The normal
`alpha-cellulose found in nature is a fibrous material that does not absorb
`water and is comparatively inert under most conditions. Avicel is a new
`microcrystalline cellulose that is nonfibrous. It is prepared by the acid
`treatment of alpha-cellulose under special processing conditions, as dis-
`closed by the recent patent of Battista and Smith (1961). Under con-
`trolled hydrolysis with hydrochloric acid, alpha-cellulose is reacted to
`give two components-an
`acid-soluble fraction and an acid-insoluble
`fraction. The acid-insoluble material is composed of a crystalline residue
`that is washed and separated and is referred to as a cellulose crystallite
`material. Essentially, what has happened is that the amorphous regions
`of the polymer are hydrolyzed completely, leaving the crystallite regions
`as isolated microcrystallites, which are defined as the level-off degree of
`polymerization cellulose, or DP cellulose. In other words, if the hydrolysis
`reaction were continued, the degree of polymerization would not change,
`and essentially, the level-off period, or maximum reactivity, has been
`achieved. The average level-off DP consists of 15 to 375 anhydroglucose
`units, the constituent chains of each aggregate being separate from those
`of neighboring aggregates. These aggregates are characterized by sharp
`X-ray diffraction patterns indicative of a substantially crystalline struc-
`ture (Battista and Smith, 1962).
`The commercially available microcrystalline cellulose comes as a
`white, fine flour and is low in ash, metals, and soluble organic materials.
`It is insoluble in water, dilute acid, common organic solvents, and oils.
`
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`UTILIZATION OF SYNTHETIC GUMS IN THE FOOD INDUSTRY
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`291
`
`TABLE I11
`PROPERTIES OF MICROCRYSTALLINE CELLULOSE~
`
`Composition
`Molecular weight
`Equilibrium moisture, %
`(58% R.H., 72°F.)
`Organic extractables, %
`Ash, %
`Calcium, ppm
`Iron, ppm
`Copper, PPm
`Manganese, ppm
`Absolute density
`Bulk density
`Average particle size, .LI
`
`Water
`Dilute alkali
`Ililute acid
`Organic solvents
`Oils
`
`* Herald, 1962.
`
`Microcrystalline cellulose
`30,000-50,000
`
`5
`<0.04
`<0.06
`< 60
`< 20
`<4
`0-2
`1.55
`0.304.80
`10-50
`
`Solubility
`
`Insoluble, dispersiblc
`Partially soluble, swells
`Insoluble, resistant
`Insoluble, inert
`Insoluble, inert
`
`It is partially soluble, with some swelling, in dilute alkali. Table 111
`summarizes the chemical and physical properties of this material (Herald,
`1962).
`
`R. FOOD APPLICATIONS
`The main food applications for this material were described by Trau-
`bcrman (1961) :
`1) Avicel in dry form or as a gel can be incorporated as a bulking
`agent in many food products to effect significant calorie reduction without
`impairing the palatability or appearance of the food.
`2) Avicel dispersed in water produces stable gels containing up to
`20% or more of solids. These gels are spreadable, and a t lower concentra-
`tions, creamy colloidal suspensions can be obtained.
`3) In dry form, Avicel is an effective absorbent and can convert
`oil-base foods, such as cheese, peanut butter, and also syrups, such as
`molasses and honey, to free-flowing, granular powders for use in dry
`package mixes and similar convenience foods.
`The primary application proposed for Avicel is as a new ingredient
`for the control of calories in a wide range of food products. The promo-
`tional literature by the manufacturer, American Viscose Corp. (1962),
`proclaims Avicel to be the noncaloric ingredient and states that i t con-
`
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`292
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`MARTIN GLICKSMAN
`
`tributes functional properties, such as stability, body bulk, opacity, tex-
`ture, and palatability. These applications are disclosed and illustrated by
`Battista (1962) in a broad spectrum of diversified food uses.
`However, these are all basically reduced-calorie food compositions,
`and the examples covered are methods and formulations for making a wide
`variety of low-calorie products, such as honey-flavored doughnuts, peanut
`butter cookie dry mix, bran muffins, layer cake, fibrous breakfast food,
`chocolate pudding, chocolate dessert topping or sauce, soft pudding,
`peanut butter streusel-type crumb topping, low-calorie cream salad
`dressing, imitation butter or margarine, mayonnaise-type salad dressing,
`Cheddar cheese spreads, dry-mix ice cream, malted milk shake, catsup,
`caramel candy, and milk chocolate.
`
`I. Dry Powder Uses
`In dry form, Avicel powder, which resembles flour, can be easily in-
`corporated into foods to be blended or homogenized. In baked goods, this
`has been used for the production of low-calorie cookies marketed by Wes-
`ton Biscuit Company. The cookies, sold as “Sweet 16” cookies, contain
`only 16 calories per piece and are fortified with vitamins (Anonymous,
`1962a).
`Microcrystalline cellulose, which has a vast surf ace area because of
`the many fissures and holes in the submicroscopic surface area, is cx-
`tremely absorbent, particularly for fatty materials. This function or
`property makes it possible to convert oily or syrupy products into dry,
`free-flowing powders, It has been suggested that butter-fl avored mixes
`can be formulated that, upon the addition of water and stirring, produce
`smooth, butter-flavored, bread spreads. By use of other flavors, such as
`cheese and spices, other flavored spreads may also be prepared (Anony-
`mous, 1962d).
`In a similar manner, natural dyes can be adsorbed by the micro-
`crystalline celluIose aggregates. These may then be used to carry edible
`dyes into fat-based products, such as butter or margarine, without caus-
`ing speckling or blooming in the product. Trauberman (1961) suggests
`that since many of the oil-soluble dyes have been banned for food use,
`this application may be helpful for coloring fatty foods with water-
`soluble nontoxic natural vegetable dyes.
`Avicel in dry form can also be compressed to form various shapes and
`sizes that can disintegrate rapidly in water. Thus, it can be used in the
`preparation of individual pre-measured or pre-weighed items, such as
`cubes or tablets, for dispensing accurately messurcd sinounts of ingredi-
`ents.
`A paste of Avicel with water can be extruded into ribbons and other
`
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`UTILIZATION OF SYNTHETIC GUMS IN THE FOOD INDUSTRY
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`293
`
`shapes, and in this way, spaghetti noodles and macaroni products can be
`formed.
`In one novel applicat,ion, the Nestle Company is using Avicel as an
`additive to its Keen soft drink powder in order to impart greater opacity
`to the reconstituted beverage (Anonymous, 1962b).
`The oil-absorbent characteristics of Avicel offer advantages for use
`in various meat products. When used on the surface of bacon, i t is claimed
`to curb curling and prevent sticking of the slice strip during storage. When
`used as a coating on each side of hamburger patties, it is claimed to pre-
`vent loss of some of the juices and to reduce shrinkage. A suggested use
`for the material is in meat products, to be added by housewives or insti-
`tutional operators to ground meat in preparing meat-loaf dishes, sauces,
`etc.
`It can also be used as a vehicle for absorbing oily seasonings or flavor
`components and for incorporating these materials into processed meats
`(Trauberman, 1961).
`
`8. Gel-Based Products
`The use of Avicel with water at solids levcls of 30 to 36% will give gel-
`like materials ranging in degrees of thixotropy, viscosity, and opacity.
`With these gels, it is possible to prcpare colloidal spreads containing up to
`20% solids or more. These colloidal gels are particularly useful in the
`formulation of smooth food products such as dressings, spreads, dips,
`sauces, and aerosol-type toppings.
`At higher solids contents, the gels have the physical characteristics of
`animal fats or hydrogenated vegetable oils. Vegetable oils and fats nor-
`mally used in products similar to mayonnaise or salad dressing can be
`partially replaced with Avicel, thus reducing the caloric values by more
`than 50%. By combining the gels with edible oils or fats and using the
`proper dispersing agent, calorie-control foods that taste like sour cream,
`hollandaise sauce, and cheese dips can be made readily (Anonymous,
`1960a).
`One such product, a low-calorie salad topping containing 82% fewer
`calories, was recently put on the market by Otto Seidner, Inc., of Westerly,
`Rhode Island. This product, made with Avicel, contains only 33 calories
`per teaspoon instead of the normal 20 per teaspoon (Anonymous, 1 9 6 2 ~ ) .
`Palatable dietary custards and puddings can also be made by con-
`trolling the Avicel content of the product, and aerosol (foamable) prepara-
`tions, such as toppings, containing excellent body, spreadability, and
`stability are also easily prepared.
`The value of Avicel in aerosol or foamed food toppings was illus-
`trated in a patent by Herald et al. (1962). In addition to reduced calorie
`
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`

`
`294
`
`MARTIN GLICKSMAN
`
`content, the toppings made with Avicel also have the desirable properties
`of foam retention (no sagging), smoothness in appearance and eating
`quality, and a rich mouthfeel despite the lower content of fatty materials.
`In addition, it is claimed that the products after extrusion and foaming
`do not leak water, collapse, or develop a coarse texture on standing.
`I n frozen dessert preparations, such as simulated ice cream, a sub-
`stantial amount of Avicel can be incorporated to reduce