ABSTRACT
Nisin is prepared and sold as a dry powder with a white to light-brown color. Its activity, or so-called potency, is measured in International Units (IU). Commercial nisin products contain approximately 1,000 IU per milligram of dry powder, which is 2.5% (w/w) pure nisin. The remainder is salt and other proteins derived from the fermentation broth. Conventionally, the fermentation medium contains milk protein or milk derivatives. However, for applications where milk proteins are prohibited, such as the use of nisin in liquid egg products, alternative fermentation media, such as those that are sugar based, must be used (EFSA, 2006b).
