Use of Nisin in Preparing Beverage-Quality Sterile Chocolate-Flavored Milk

Summary Nisin was used to aid heat sterilization of chocolate-flavored milk at levels ranging from 0 to 800 Reading Units per ml. Heat treatments given the chocolate-flavored milk ranged from an F value of 0.2 to 9.0. The relationship between the per cent thermophilic spoilage during incubation at 131F for 3 wk and the level of nisin added before heat treatment of F=3.0 was shown to exist. An F value required to prevent thermophilic spoilage for several concentrations of nisin was also demonstrated. Use of an F value of 3 and the addition of 80 Reading Units of nisin per ml as a heat sterilization aid resulted in a beverage-quality, commercially sterile chocolate-flavored milk.