Antimutagenic effect of chungkookjangs prepared with the different kinds of soybeans
compared with doenjang were studied against aflatoxin B1(AFB1) using Ames test and
N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) using SOS chromotest. The
antimutagenic effects of methanol extracts from raw soybeans, non-fermented and
fermented chungkookjang were also evaluated in the same systems. Chungkookjang
samples exerted the different antimutagenicity according to the prepared variety of
soybeans in the Ames test using Salmonella typhimurium TA100. The chungkookjang
manufactured with var. Manrikong among the employed 1 year old soybeans showed
the highest antimutagenic effect against AFB1. The chungkookjangs prepared with
Manrikong, Jinpumkong and Hwangkeumkong among the freshly harvested soybeans
exhibited strong antimutagenic activity in the same system. The fermented
chungkookjang had the strongest inhibitory effects on the mutagenicity induced by AFB1,
however, the non-fermented chungkookjang showed lower inhibition rate than the raw
soybeans in the Ames test. In particular, the chungkookjang prepared with the freshly
harvested soybeans showed higher antimutagenic activity than that with the old
soybeans. In the SOS chromotest, the patterns of antimutagenic effects were almost
the same as shown in the Ames test system. The chungkookjang manufactured with
var. Manrikong in both the old and the fresh soybeans showed higher inhibitory effect
than doenjang on the SOS response induced by MNNG. These results indicate that the
variety, harvested time of the soybeans and the fermentation time of the chungkookjang
differ the degrees of the antimutagenicity of the manufactured final chungkookjangs.

Keywords: Kinds of soybeans, Chungkookjang, Antimutagenicity, AFB1, MNNG