Thermal processing of Nigerian freshwater molluscs 1: commercial sterilization of mussels in brine, sauce and egusi soup

The thermal resistances of Clostridium sporogenes ATCC 19404 spores in tropical freshwater mussels-based low acid products (pH = 5.8) comprising of mussels-in-brine (MIB), mussels-in-sauce (MIS) and mussels-in-egusi soup (MES) were investigated using the TDT - can method. The D-values. (min) within 104.4 to 121.1°C ranged from 43.5 to 0.94 (MIB), 46.8 to 1.3 (MIS) and 48.2 to 1.5 (MES). The z-values (°C) were 9.5, 10.13 and 10.6 for MIB, MIS and MES respectively. Commercial sterilization times of 4.7, 6.5 and 7.5 min at 121.1°C were established for MIB, MIS and MES respectively assuming instantaneous heating and cooling. Equivalent heating times at other temperatures for commercial sterilization of the products are provided.