Método rápido para detecção de TNAse estafilocócica ém leite utilizando membrana de diálise

Abstract

Presence of thermonuclease in foods indicates that S. aureus developed at a critical number, enough to cause food intoxication. As the concentration of this enzyme in foods reaches only the level of ng, extraction and concentration processes are crucial for its detection. The use of dialysis membrane as an alternative method is proposed for TNAse extraction from milk inoculated with S. aureus 196-E. Milk samples, after heat treatment and without casein, were dialysed with different membranes against polyethylene glycol 6000 and sucrose. The nuclease activity in the extract was increased with heat treatment, improving the sensibility of the method. Both the use of commercial cellophane and sucrose for concentrating the sample is viable, indicating a rapid and cheap method for TNAse detection in milk contaminated with staphylococci.