Alterazione nei wurstel durante la conservazione.

It has been studied the spoilage of some italian wurstel, sold in local supermarket. The study included the identification of the causative microorganisms and the variation of physical-chemical parameters (pH, Aw, lactic acid, ammonia). The spoilage consisted of a white surface coating or slime, which appeared later than the thirtieth day of storage. The case was due to an uncontrolled development, during the storage, of thermoduric heterofermentative LAB, survived the pasteurization, such as Leuconostoc spp. and B. thermosphacta. There was no evidence of off-odor or off-flavor and no pH changing, due to deacidifying action of B. thermosphacta and the production of ammonia. It was not also observed in frankfurters altered any loss of vacuum.