Microcrystalline cellulose is a term for refined wood pulp and is used as a texturizer, an anti-caking agent, a fat substitute, an emulsifier, an extender, and a bulking agent in food production.The most common form is used in vitamin supplements or tablets.pproved within the European Union as a thickener, stabilizer or emulsifiers microcrystalline cellulose was granted the E number E460(i) with basic cellulose given the number E460.