A Novel Combined Sterilization Method of Minced Fish Products

In order to prolong the shelf-life of the minced fish products at room temperature, a novel combined sterilization method was proposed. Bacillus subtilis was chosen as the indicator bacteria, because it is one of the most heat-resistant bacteria probably exists in fish products. A self-made ohmic heating system was used to inactivate the indicator bacteria in the surimi firstly. After sterilized by ohmic heating system, the samples were vacuum-packed and put into an incubator at 35 °C for several hours to give the favorable growth condition to the remained spores of Bacillus subtilis. Then the second sterilization can proceed – heating them by boiling water for several minutes. Response Surface Design was used to determine the optimal sterilization parameters including: electric field intensity 40 V/cm, sterilization time of ohmic heating 5 min, culture time in an incubator 12 h, and heating time by boiling water 25 min. The results demonstrated that the minced fish products with high sensory quality and having 15 days the shelf-life at the room temperature can be obtained by using the proposed sterilization method.