To reduce the pungency of Capsicum without losing its biological activity, Capsicum was fermented with bacteria isolated from traditional Korean foods. By comparing the capsaicin-degrading capacities of the isolated strains, the capsaicin and dihydrocapsaicin contents of the P3-3 strain were found to be much less than the other strains, and the P3-3 strain was identified as Bacillus subtilis. After 48 h-fermentation with B. subtilis P3-3, the ferments showed sharp decreases in capsaicin and dihydrocapsaicin from initial contents of 103.0 and 16.7 mg/100 g to 12.2 mg/100 g and 7.6 mg/100 g, respectively. The biological activities of commercial capsaicin (CAP), non-fermented Capsicum (NFC) and fermented Capsicum (FC) were also investigated by examining their effects on the swimming capacity of mice. The relative plasma free fatty acid (FFA) levels were as follows in decreasing order until 120 min of test duration: CAP > FC > NFC > control. The plasma adrenaline level of the CAP group showed a more rapid increase compared to the NFC and FC groups until 30 min after oral administration. In conclusion, this study found no differences in the enhancement of swimming endurance between FC and NFC in mice. (c) 2010 Elsevier Inc. All rights reserved.