Introduction The most commonly used methods to determine and identify Norwalk virus are based on molecular biology. Methods A viral extraction protocol from food samples was studied in this work using artificial contamination test. It consists of a new protocol with a phase of viral elution from the food matrix performed using an eluting solution (glycine and beef extract at 3% pH 9) and a concentration phase with polyethylene glycol 8000. To detect Noroviruses, two techniques of molecular biology, polymerase chain reaction and real-time polymerase chain reaction, were compared. At the same time, tests of direct viral identification were conducted on soft fruits and salad obtained from the market. Results From the results obtained it was possible to evaluate how the phase of viral recovery represents an important critical point of the protocol. Conclusion It was possible to identify a greater sensitivity of the real-time polymerase chain reaction compared with the traditional polymerase chain reaction.