CMC (Carboxy methyl cellulose) is a food additive that is used as a thickening, emulsifying, anti-caking, and preservative agent. It is used for stabilizing ice creams and is largely used in breads and cakes to give it good volume, make it more tender and keep freshness longer.
CMC is used as an emulsifier in producing well shaped biscuits and in candy preparations for improving texture and quality. It is also used in chewing gums, margarines and peanut butter.
Generally all you have to do is mix the CMC Powder in water and then add it to the dough as per your recipe.
Note: CMC Powder has to be stored in air tight containers. Placing it in the refrigerator increases the shelf life.