Determination of Aerobic Plate Count and Coliforms in Raw Swordfish Fillet by Conductimetric Method

JIN-HWA DAI AND TSUNG-CHAIN CHANG

Food Industry Research and Development Institute, Hsinchu, Taiwan, R.O.C.

ABSTRACT

   The feasibility of using a conductimetric method for determination of aerobic plate count and coliforms of swordfish fillet was investigated. Based on the change of conductance in the incubation cells, the relationship between the detection times and total plate count or coliforms was established by the Malthus 2000 (Malthus Instruments Limited, Crawley, England) system. The linear correlation coefficient between the log value of aerobic plate count of swordfish fillet and the detection time was -0.87, while the linear correlation coefficient between the log value of most probable number (MPN) of coliforms in the fish and the detection time was -0.92. Conductance measurement has the advantages of rapidity, automation and high capacity for analysis. Therefore, the technique can be used as an alternative method to conventional plate counting and the most probable number method for determination of aerobic plate count and coliforms, respectively, in swordfish fillet.

Key words : Conductimetric method, Swordfish fillet, Aerobic plate count, Coliforms.