Bacteriology of butter VII. Effect of reworking butter on growth of bacteria

Abstract

<p>1. With unsalted butter made from pasteurized cream inoculated with various organisms and held at approximately 10°0., reworking after several days had the following effects:</p> <p>a. The growth rates of bacteria frequently were increased.</p> <p>b. The time required for development of defects commonly was decreased.</p> <p>c. When butter culture was added to the cream, the pH values of the butter serum decreased more rapidly.</p> <p>d. When lipolytic organisms were added to the cream, the acidities of the fat increased more rapidly.</p> <p>2. The printing of butter in a type of equipment which subjected it to reworking tended to aggregate the moisture.</p> <p>3. The reworking of butter may accelerate various microbiological changes in the product. Distributing organisms to previously uninfected moisture droplets and providing a greater food supply for certain of the organisms in the butter by aggregating the moisture are apparently of importance in this connection.</p>