Microcrystalline cellulose (MCC) is a term for refined
wood pulp
Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibers from wood, fiber crops, waste paper, or rags. Mixed with water and other chemical or plant-based additives, pulp is the major raw mate ...
and is used as a
texturizer, an
anti-caking agent
An anticaking agent is an additive placed in powdered or granulated materials, such as table salt or confectioneries, to prevent the formation of lumps ( caking) and for easing packaging, transport, flowability, and consumption. Caking mechanisms ...
, a
fat substitute A fat substitute is a food product with the same functions, stability, physical, and chemical characteristics as regular fat, with fewer Calories per gram than fat. They are utilized in the production of low fat and low calorie foods.
Background
...
, an
emulsifier, an extender, and a
bulking agent in
food production
The food industry is a complex, global network of diverse businesses that supplies most of the food consumed by the world's population. The food industry today has become highly diversified, with manufacturing ranging from small, traditiona ...
. The most common form is used in
vitamin supplements or tablets. It is also used in
plaque assays for counting viruses, as an alternative to
carboxymethylcellulose
Carboxymethyl cellulose (CMC) or cellulose gum is a cellulose derivative with carboxymethyl groups (-CH2-COOH) bound to some of the hydroxyl groups of the glucopyranose monomers that make up the cellulose backbone. It is often used as its sodiu ...
.
Structure
A naturally occurring
polymer
A polymer (; Greek '' poly-'', "many" + ''-mer'', "part")
is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...
, it is composed of
glucose
Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, u ...
units connected by a 1-4 beta glycosidic bond. These linear cellulose chains are bundled together as
microfibril A microfibril is a very fine fibril, or fiber-like strand, consisting of glycoproteins and cellulose. It is usually, but not always, used as a general term in describing the structure of protein fiber, e.g. hair and sperm tail. Its most frequently ...
spiralled together in
plant cell walls.
Each microfibril exhibits a high degree of three-dimensional internal bonding resulting in a crystalline structure that is insoluble in water and resistant to reagents. There are, however, relatively weak segments of the microfibril with weaker internal bonding. These are called amorphous regions; some argue that they are more accurately called dislocations, because of the single-phase structure of microfibrils. The crystalline region is isolated to produce microcrystalline cellulose.
Uses
Approved within the European Union as a thickener, stabilizer or emulsifier, microcrystalline cellulose was granted the
E number E460(i) with basic cellulose given the number E460.
MCC has use in
cosmetics
Cosmetics are constituted mixtures of chemical compounds derived from either natural sources, or synthetically created ones. Cosmetics have various purposes. Those designed for personal care and skin care can be used to cleanse or protect ...
as an
abrasive
An abrasive is a material, often a mineral, that is used to shape or finish a workpiece through rubbing which leads to part of the workpiece being worn away by friction. While finishing a material often means polishing it to gain a smooth, reflec ...
,
absorbent, anti-caking agent, aqueous
viscosity
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water.
Viscosity quantifies the inte ...
increasing agent, binder, bulking agent, emulsion stabilizer, slip modifier, and texturizer, which can be found in various hair and skin care products as well as
makeup
The asterisk ( ), from Late Latin , from Ancient Greek , ''asteriskos'', "little star", is a typographical symbol. It is so called because it resembles a conventional image of a heraldic star.
Computer scientists and mathematicians often voc ...
.
The MCC is a valuable additive in pharmaceutical, food, cosmetic and other industries. Different properties of MCC are measured to qualify its suitability to such utilization, namely particle size, density, compressibility index, angle of repose, powder porosity, hydration swelling capacity, moisture sorption capacity, moisture content, crystallinity index, crystallite size, and mechanical properties such as hardness and tensile strength.
Synthesis
MCC is pure partially depolymerized cellulose synthesized from α-cellulose precursor. The MCC can be synthesized by different processes such as reactive extrusion, enzyme mediated, mechanical grinding, ultrasonication, steam explosion and acid hydrolysis. The later process can be done using mineral acids such as H
2SO
4, HCl and HBr as well as ionic liquids. The role of these reagents is to destroy the amorphous regions leaving the crystalline domains.
The degree of polymerization is typically less than 400. The MCC particles with size lower than 5 μm must not be more than 10%.
Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) or differential scanning calorimetry (DSC) are also important to predict the thermal behavior of the MCC upon heat stresses.
Allergic reactions
At least one case of an allergic reaction to microcrystalline cellulose has been documented.
References
{{Reflist, 2
Cellulose