Effects of soybean cultivar and starter strain on biogenic amines formation during Cheonggukjang fermentation.

Cheonggukjang, a traditional Korean fermented seasoning, contains biogenic amines (BAs). This research aimed to explore the effects of soybean cultivar, strain, and temperature on BAs formation during Cheonggukjang fermentation. Moisture, pH, total aerobic plate count, and protease activity were measured. Free amino acids (FAAs) and BAs were determined by high-performance liquid chromatography. Total FAA and BA contents tended to increase with fermentation time. Total BAs in the samples initially ranged from 112.65 to 153.05 mg/kg and ultimately increased to 155.72-614.28 mg/kg at 25 °C and 201.95-738.39 mg/kg at 37 °C, respectively. Bacillus licheniformis-inoculated samples had the highest total BA content (over 400 mg/kg) after 96 h of fermentation. Final histamine content in cv. 'Somoktae'-made samples generally exceeded that in samples produced by the other two cultivars. These findings indicate that soybean cultivar, strain, and fermentation temperature all play pivotal roles in controlling the contents of BAs in Cheonggukjang.

Monitoring and risk assessment of biogenic amines in Korean commercial fermented seasonings.

Fermented seasonings are widely used in Korean cuisine; however, some contain high levels of biogenic amines (BAs). In this study, in order to estimate the potential BA risk from fermented seasoning, the BA contents in 50 commercial brands (n = 292) of five seasonings (soy sauce, Gochujang, Doenjang, Ssamjang, and Cheonggukjang) and their changes due to different cooking methods were evaluated by high-performance liquid chromatography. The risk assessment for consumer exposure was evaluated by computing the estimated daily intake (EDI), histamine (HIS) intake, and tyramine (TYR) intake. Maximum contents of HIS detected in Cheonggukjang, soy sauce, Doenjang, and Ssamjang were 318.46, 148.15, 123.65, and 114.07 mg/kg, respectively. However, even in the worst-case scenario, the EDI value and HIS intake results demonstrated that the seasonings had a limited impact on the risk of HIS poisoning due to their low consumption. Cheonggukjang exhibited the highest TYR content (312.89 mg/kg), and the TYR exposure results implied that those taking classical antidepressant monoamine oxidase inhibitors should pay attention to Cheonggukjang. After stir-frying, the total BA retentions in soy sauce and Gochujang were only 51.45% and 57.08%, respectively, which may be caused by high temperature. Based on the results of this study, the five seasonings contained various BAs, which can be influenced by the cooking process, and all five seasonings are safe for the general population in terms of the risk of BAs.

Evaluation of the biogenic amines in low-salt shrimp paste cooked under various conditions.

Shrimp paste, a type of traditional Chinese food prepared from shrimp fermented with salt, contains biogenic amines (BAs). In this study, the BA content, salinity, and pH of eight commercial low-salt shrimp pastes were analyzed. In addition, the influences of various cooking conditions on the BA content of it were evaluated by HPLC. The total BA amount per product ranged between 32.39 and 1051.16 mg/kg. The salinity and pH were found significantly inversely correlated with the total BA amount. Of the cooking methods tested, after microwave heating and stir-frying, the total BA amount of shrimp paste, which showed the highest BA amount among 8 samples, declined from 1051.16 to 598.48 and 650.49 mg/kg, respectively; however, boiling or steaming showed no significant effects on the total BA amount. These results indicated possible health risk of low-salt shrimp paste whereas the risk could be reduced by choosing appropriate cooking method.