Sorbitol is a white, sweetish, hygroscopic, crystalline sugar alcohol of
six-carbon. It is found naturally in various berries and fruits. Or it is
prepared synthetically by high-pressure catalytic hydrogenation of glucose sugar
derived from cornstarch. It melts at 93 to 98 C depending on the form. It is
used as a a sweetening agent, food additive, toothpaste, tobacco, toiletries and
in cosmetics. It is used for vitamin-C fermentation. It is used as a excipient
and intravenous osmotic diuretic in pharmaceutical fields. It is also used in
the manufacture of polyethers for polyurethanes and surfactants. The term
sorbitan describes the anhydride form of sorbitol, whose fatty acids are
lipophilic whereas sorbitol body is hydrophilic. This bifunctionality in one
molecule provides the basic properties useful in cleaners, detergents, polymer
additives, and textile industry as emulsifiers, wetting agents, and viscosity
modifiers. Sorbitan esters are rather lipophilic (or hydrophobic) surfactants
exhibiting low HLB (Hydrophilic-Lipophilic Balance) values; having an affinity
for, tending to combine with, or capable of dissolving in lipids (or
water-insoluble). While, the ethoxylated sorbitan esters are hydrophilics
exhibiting high HLB values; having an affinity for water; readily absorbing or
dissolving in water. The type of fatty acid and the mole number of ethylene
oxide provides diverse HLB values for proper applications.
Fatty
Acids are aliphatic carboxylic acid with varying length
hydrocarbon chains at one end of the chain joined to
terminal carboxyl (-COOH) group at the other end. The
general formula is CnH2n+1COOH
or R-(CH2)n-COOH.
Fatty acids are predominantly unbranched and those with
even numbers of carbon atoms between 12 and 22 carbons
long react with glycerol to form lipids (fat-soluble
components of living cells) in plants, animals, and
microorganisms. Fatty acids all have common names respectively
lilk lauric (C12), MyrIstic (C14), palmitic (C16), stearic
(C18), oleic (C18, unsaturated), and linoleic (C18,
polyunsaturated) acids. The saturated fatty acids have
no double bonds, while oleic acid is an unsaturated
fatty acid has one double bond (also described as olefinic)
and polyunsaturated fatty acids like linolenic acid
contain two or more double bonds. Lauric acid (also
called Dodecanoic acid) is the main acid in coconut
oil (45 - 50 percent) and palm kernel oil (45 - 55 percent).
Nutmeg butter is rich in myristic acid (also called
Tetradecanoic acid ) which constitutes 60-75 percent
of the fatty-acid content. Palmitic acid(also called
Hexadecylic acid ) constitutes between 20 and 30 percent
of most animal fats and is also an important constituent
of most vegetable fats (35 - 45 percent of palm oil).
Stearic acid ( also called Octadecanoic Acid)
is nature's most common long-chain fatty acids, derived
from animal and vegetable fats. It is widely used as
a lubricant and as an additive in industrial preparations.
It is used in the manufacture of metallic stearates,
pharmaceuticals, soaps, cosmetics, and food packaging.
It is also used as a softener, accelerator activator
and dispersing agent in rubbers. Oleic acid (also called
octadecenoic acid) is the most abundant of the unsaturated
fatty acids in nature.