PHYSICAL FUNCTIONS OF HYDROCOLLOIDS

Physical Functions of Hydrocolloids L E O N A R D STOLOFF

Downloaded by UNIV OF BRITISH COLUMBIA on July 14, 2016 | http://pubs.acs.org Publication Date: January 1, 1960 | doi: 10.1021/ba-1960-0025.ch001

Marine Colloids, Inc., Rockland, Maine

I Ν ALL times, ancient or present, men have jealously guarded trading a d vantages. These advantages might be in the physical possession of a com modity or position, or in some unique knowledge. A commodity or position can be acquired by chance or by force and maintained only by force. K n o w l edge acquired by chance or by diligent, intelligent search is a more peacefully maintained possession. Whether known as skill, trade secret, know-how, or working formula, its possessor cannot be deprived of that knowledge by force. He can, however, lose his trading position by a surfeit of his particular com modity or to a superior knowledge. Thus, traders in commodities based on skill or secret information tend to repress training and study i n their fields. This is particularly true when the general advance of academic knowledge has not approached the area involved and where exercise of the skill or knowledge cannot be learned from observation or study of the product produced. The use of hydrophylic colloids, vegetable gums, stabilizers—call them what you will—falls in this category. The achievement of a texture, a feel, an appearance, a unique physical system, are trade advantages worth holding. These papers are presented, partly, because some of the outs would like to be in on the know-how, and some of the ins would like to be " i n - e r . " That desire in itself could not produce a worthwhile report, unless those with the secret information realize that the gradual advance of systematic knowledge to their area can make these papers productive. T h e amount of information revealed will be governed by the extent of their awareness that the tide of general knowledge has reached a point where they benefit more from their con tribution than they lose from their revelation. Through the agency of the food and drug laws requiring ingredient declarations on labels, the foodproducing industry has perhaps been forced closest to this point. The heavy participation of food industry members is not without meaning. The subject matter has been divided into 6 broad physical functions: Production of viscosity or body Gelation Stabilization of emulsions Stabilization of suspensions Stabilization of foams Control of crystal growth

Although there seem to be definite categories, there is an amazing degree of interrelation between these functions. Viscosity alters a gel structure. A ι

PHYSICAL FUNCTIONS OF HYDROCOLLOIDS Advances in Chemistry; American Chemical Society: Washington, DC, 1960.

ADVANCES IN CHEMISTRY SERIES

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gel structure, i n turn, affects viscosity. The difference between an emulsion, a suspension, and a foam is that of a solid compared to a liquid as compared to a gas, but whichever way one looks or stands, the ramifications of flow and gelation are involved. In a l l these papers certain names of hydrocolloids—gums, starches, muci lages—constantly recur. A list of some of the more common, commercially available hydrocolloids, their names, and their structural formulas, as far as they are known, has been prepared for ready reference and is given below. Several of these formulas have been reproduced from the book, "Industrial Gums," through the courtesy of Academic Press.

Guaran or Locust Bean Gum

CH OH 2

Alginic Acid

c

V

γ »

MV

c Η4\Η A

COOH

\

,c -Ν.

Ο*

?

0

Pectic Acid

X

X _ ®

G

©

Κ* ® 1©

X-

Gum Arabic

A

L

P

©

-GALP 1®

1©

GA 1®

1©

X

X - L- RHAM NOPYRANOSE GALP - GALACTOPYRANOSC GA - GLUCURONIC ACID

®

G A L

\Γ-°

Μ / Μ

Ο

P°

1®

1® GA I®

1©

X

OR L-ARABOFURANOSE


MO

Τ

A


STOLOFF—PHYSICAL FUNCTIONS


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PHYSICAL FUNCTIONS OF HYDROCOLLOIDS

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