1Hokkaido Kushiro Fisheries Experimental Station, Kushiro, Hokkaido 085-0027, 2Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-8611, 3Hokkaido Industrial Technology Center, Hakodate, Hokkaido 041-0801, Japan
Two microbial strains of yeast Saccharomyces cerevisiae IZS-Sc1 and lactic acid bacterium Leuconostoc mesenteroides subsp. cremoris IZS-Lmc1 were inoculated into salmon Izushi as starter cultures for ripening. The strains had previously been isolated from ripened Izushi at 5°C. After Izushi had been ripened for a cumulative temperature of 280°C•d at 5, 10, 15 and 20°C, investigation of chemical and microbiological characteristics and organoleptic observations were carried out for the ripened Izushi. Inoculation of starter cultures accelerated ripening of Izushi. In the 5°C-ripened Izushi, the inoculated species were dominant, occupying 93-100%, and an organoleptically higher evaluation was obtained. For the Izushi ripened at 10, 15 and 20°C, yeast was not detected as well as in those without inocula and a tendency toward excessive ripening was observed. The Effect of ripening temperature on the characteristics of Izushi samples inoculated with starter cultures was closely similar to the effect on those without inocula.