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

                                                  Ariahu*, C. C.; Igbabul, B.D. and Tiamiyu¹, L.O.
                                                                   Department of Food Science and Technology,
                                                                   University of Agriculture, Makurdi, Nigeria.
                                                                   ¹Department of Fisheries, University of Agriculture, Makurdi, Nigeria
                                                                   ccariahu@yahoo.com

Abstract

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 121.1⁰C ranged from 43.5 to 0.94 (MIB), 46.8 to 1.3 (MIS) and 48.2 to 1.5 (MES). The z-values (⁰C) 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 121.1⁰C 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.

 
Keywords: Clostridium sporogenes, “egusi soup”, mussels, heat resistance.