Effect of Urushiol-Free Extracts from Fermented-Rhus verniciflua Stem Bark with Fomitella fraxinea on the Fermentation Characteristics of Doenjang (Soybean Paste)

• Published in: Hangug gynnhaghoi ji Vol. 40; no. 4
• Main Authors: Choi, H.S., National Academy of Agricultural Science, RDA, Suwon, Republic of Korea, Jeong, S.T., National Academy of Agricultural Science, RDA, Suwon, Republic of Korea, Choi, J.H., National Academy of Agricultural Science, RDA, Suwon, Republic of Korea, Kang, J.E., National Academy of Agricultural Science, RDA, Suwon, Republic of Korea, Kim, E.G., National Academy of Agricultural Science, RDA, Suwon, Republic of Korea, Noh, J.M., National Academy of Agricultural Science, RDA, Suwon, Republic of Korea, Kim, M.K., Chonbuk National University, Iksan, Republic of Korea
• Format: Journal Article
• Language: Korean
• Published: 01-12-2012
• Subjects: Doenjang; FERMENTACION; FERMENTATION; Fomitella fraxinea; FRVSB; Rhus verniciflua; Soybean paste
• ISSN: 0253-651X; 2383-5249

The effect of fermented Rhus verniciflua stem bark (FRVSB) extract on the microbial count, enzyme activity, concentrations of free amino acids and organic acids, and physiochemical properties of doenjang (soybean paste) was evaluated during brine fermentation. The FRVSB extract increased the total free amino acid concentration by 1.3-3.1-fold on the 42∨nd day of brine fermentation. After the filtration of brine, the following microbial counts were obtained in the doenjang: bacteria, 0.3×10∨8-12.0×10∨8 cfu/g; mold, 3.0×10⁴-21.0×10⁴ cfu/g; yeast, 1.0×10⁴-2.0×10⁴ cfu/g; Escherichia coli, not detected; and Bacillus cereus, 3.0×10²-25.0×10² cfu/g. The FRVSB extract addition enhanced the protein and starch degrading activity by 13.8-26.0% and 16.1-35.1%, respectively. The extract increased the total free amino acid content by 1.4-3.0-fold. Lactic acid, acetic acid, and pyroglutamic acid were the predominant organic acids in doenjang. Moreover, the proximate composition, pH, moisture, ash, salt, and amino nitrogen content were increased.