The viability of bifidobacteria introduced into kimchi

The viability of bifidobacteria in mul-kimchi, a type of kimchi with added water, was investigated under various conditions. When a mul-kimchi preparation was inoculated with five strains of Bifidobacterium at a concentration of 10(7) cfu ml-1, Bif. longum JK-2 showed the highest viability, maintaining a population of 10(6) cfu ml-1 after 1 week at 4 degrees C. The influence of NaCl concentration and initial pH on viability was further investigated in mul-kimchi inoculated with Bif. longum JK-2; NaCl concentrations greater than 3% (w/w) reduced viability considerably. In kimchi started with an initial pH of 6.5, the cells showed the highest survival. When mul-kimchi containing 2% NaCl (w/w) was inoculated with 10(8) cfu ml-1 Bif. longum JK-2, there was a 10-fold reduction in viability during 10 d of incubation at 4 degrees C. These results demonstrate acceptable levels of the organism in the product, suggesting the possible use of selected strains of bifidobacteria in commercial kimchi production.