• Applied Biological Chemistry
• /
• v.44 no.4
• /
• pp.230-234
• /
• 2001

Traditional doenjang was fermented in different vessels, and its quality characteristics were investigated during ripening. Fermentation vessels used were dark brown glaze pot, dark brown glaze pot with glass lid and plastic box. Water content of doenjang decreased during fermentation, with doenjang pepared in dark brown glaze pot with glass lid showed the highest water content reduction. Water-soluble nitrogen content $(4.56{\sim}5.80%)$ was the highest at 8 months fermentation and amino type nitrogen content continuously increased until 12 months, with doenjang in dark brown glaze pot higher than those in plastic box. Sensory evaluation revealed the quality of doenjang fermented in plastic box was significantly lower than others after 4 months.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.31 no.2
• /
• pp.343-350
• /
• 2002

This study was conducted to standardize the manufacturing process of doenjang. The preparation methods, kinds and levels of the ingredients were determined by the statistical surveys of literatures obtained from cooking books, scientific papers and doenjang manufacturing factories. The standardized preparation of fermentation methods of doenjang were classified into two large groups, that were traditional and modified (commercialized) methods. Most soybeans used in doenjang preparation were the large size. To prepare traditional doenjang, soybeans were cleaned, scaled and cooked for 2 hrs at atmospheric pressure. These cooked soybeans were crushed in water and molded as brick shape. The molded soybean was dried for 2 days in the air, hung up by rice straw and fermented for 30~60 days under natural environmental condition (called meju). Recently soybean grain meju that inoculated with Asp. oryzae also frequently used to make traditional doenjang. The fermented meju was brined with a ratio of meju : salt : water = 18.4 : 14.6 : 67.0 and the meju-brine mixtures were ripened for 2 months. When the meju-brine mixture was fully fermented, it was separated into liquid and solid parts. The crushed solid part was further ripened in a separated pottery for 60 days and become doenjang. The liquid part was filtered, boiled and used as soy sauce. In modified commercial doenjang preparation, soybeans were cocked by autoclaving and then cooled about to 3$0^{\circ}C$. Separately, steamed barley grains or wheat flour were inoculated with 0.2% Asp. oryzae and incubated for 3 days at 3$0^{\circ}C$ and mixed with the crooked soybeans, salt, and water (soybean : salt : starch : water = 39.8 : 12.5 : 22.6 : 25.1). These mixtures were ripened for 30 days at 3$0^{\circ}C$. It seems that the manufacturing process of traditional doenjang needs to be more industrialized, whereas, the commercial doenjang preparation is going to adapt the traditional processing method of doenjang.

• Korean Journal of Food Science and Technology
• /
• v.26 no.5
• /
• pp.609-615
• /
• 1994

Fermented traditional soybean paste(doenjang), koji soybean paste by Aspergillus oryzae, natto soybean paste by Bacillus natto and koji & natto soybean paste by Aspergillus oryzae and Bacillus natto were analyzed for compositions of amino acids and contents of nitrogens. Amino type nitrogen was the highest in fermenting for 90 days as $271{\sim}868\;mg/100g$, and its contents were in the order of koji soybean paste>traditional soybean paste>koji & natto soybean paste>natto soybean paste in all samples tested. In compositions of total amino acids, glutamic and aspartic acids were rich in koji soybean paste but big differences were not observed in all samples. But some differences were observed in free amino acid compositions in all samples, that is, glutamic acid, tyrosine, lysine and aspartic acid were detected more abundantly. Sum of free amino acids for 90 days were in order of koji soybean paste>traditional soybean paste>koji & natto soybean paste>natto soybean paste. The ratios of free to total amino acids were $3.28{\sim}19.81%$ for 45 days, but increased to $10.88{\sim}25.10%$ for 90 days, and in order of traditional doenjang>koji doenjang>koji & natto doenjang>natto doenjang. Methionine and histidine showed higher ratios of free to total amino acid but lower in glutamic acid and aspartic acid. These results suggest that koji and traditional soybean paste of having high ratios of free amino acids to free and total amino acids may be more favorable in soybean paste fermentation.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.27 no.3
• /
• pp.448-454
• /
• 1998

Meju for doenjang and kochujang was prepared as a model at Sunchang areaand monitored with major changes. Kochujang meju was prepared on September 12 and doenjang meju on November 12, 1995. Kochjang meju was found to be naturally fermented at 80~90% RH, 15~2$0^{\circ}C$ and doenjang meju was at 80~90% RH and 0~5$^{\circ}C$. The shapes of kochujang meju and doenjang meju were doughnut-type and rectangular, respectively. Weight losses during fermentation were 48% and 28%, respectively. The pH drop and acip production of kochujang meju were negligible. However, pH of doenjang meju decreased from 6.29 to 5.88 and acidity increased from 0.08 to 0.23% as lactic acid. Protein in meju was found to be rapidly solubilized during the early stage of fermentation. Soluble protein cotents of kochujang meju after 7 days and 60 days were 8.23%, respectively. The doenjang mejus were 2.15% after 20 days and 5.72% after 60 days. Soluble suger content increased with the fermentation time. The soluble sugar content was higher in kochjang meju. Acidic protease was highly produced during meju fermentation. $\alpha$-Amylase and $\beta$-amylase were detected in the kochujang meju, of which glutinous rice consisted, but negligible in doenjang meju. Lipase was detected in kochujang meju, but was, negligible in doenjang meju. Microbial population increased drastically after 7 days of fermentation in kochujang meju and 20 days of fermentation in doenjang meju.

• Korean journal of food and cookery science
• /
• v.26 no.3
• /
• pp.314-322
• /
• 2010

The effects of five colored soybean (blue, red, yellow, white, and black) varieties on the quality characteristics of soybean paste (Doenjang) were investigated for proximate composition, salt content, pH, color, organic acid content, amino acid content, and mineral content after 80 days of aging. Soybean paste (Doenjang) samples were divided into TDS (traditional Doenjang prepared with soybean) and TDM (traditional Doenjang prepared with mixed soybeans, kidney bean, black soybean, kind of small bean, sword bean, green bean, red bean, at a radio of 1:1:1:1:1(w/w)). Moisture content was 49.66% for TDM and 49.52% for TDM. Protein and salt contents of the TDS sample were higher than those of TDM. The "L" values of the TDB sample increased the aging period was decreased. In contrast, the "L" and "$\alpha$" values of TDM did not show any significant differences. The main organic acids detected were malic acid > lactic acid > tartaric acid in the TDS and TDM samples. Glutamic acid contents were 2.83 g/100 g for the TDS sample and 2.15 g/100 g for the TDM. The levels of K, Mg, and Ca of the TDS sample were higher than those of TDM. No significant difference occurred between TDS and TDM regarding their quality characteristics after 80 days of aging. Further studies needed include sensory evaluation and functionality of soybean paste made from mixed soybean materials.

• The Korean Journal of Food And Nutrition
• /
• v.32 no.6
• /
• pp.598-610
• /
• 2019

The purpose of this study was to investigate the quality characteristics and antioxidant activity by collecting four times on six samples of Jeonbuk regional soybean pastes (Doenjang) traditionally prepared for this study. The water content of samples decreased according to progress of the aging period and the water content of the fourth sample collected was 42.40~59.64% (p<0.05). The salinity of the fourth Doenjang samples was 11.80~18.60%. The amino-type nitrogen content was 122.67~540.33 mg% immediately after the preparation of Doenjang in the Jeonbuk region and the content of the fourth collection samples increased from 251.49 to 982.36 mg% (p<0.05). The isoflavone glycosides decreased but daidzein, genistein and glycitein, which are aglycones, increased during aging periods. The total polyphenol content of the fourth collected samples was 11.99~19.27 mg GAE/g (p<0.05). The DPPH radical scavenging activity, ABTS radical scavenging activity and FARP of the fourth Doenjang samples were 51.88~81.21%, 84.14~90.32%, and 1.08~3.11 mg Trolox/g, respectively. As a result of quality analysis on Doenjang, the superiority of traditional Doenjang has been proven by the increase of amino nitrogen content and antioxidant activity according to the aging period. However, factor analysis on quality differences of regional Doenjang should be conducted to ensure standardization and quality improvement.

• Korean Journal of Microbiology
• /
• v.47 no.3
• /
• pp.275-280
• /
• 2011

In order to evaluate the diversity and change of bacterial population during the manufacturing process of traditional soybean paste (doenjang), bacterial communities were analyzed using 16S rRNA gene-based pyrosequencing. In rice straw, the most important inoculum source for fermentation, the bacterial sequences with a relative abundance greater than 1% were assigned to four phyla, Proteobacteria (71%), Actinobacteria (20.6%), Bacteroidetes (4.2%), and Firmicutes (1.3%). Unlike bacterial community composition of rice straw, a different pattern of bacterial population in meju was observed with predominantly high abundance (99.1%) of Firmicutes. Phylum composition in young doenjang was almost same as that of meju. Major genera in young doenjang were Bacillus (81.3%), Clostridium (6.9%) and Enterococcus (6.3%) and the predominant species among bacterial population was B. amyloliquefaciens (63.6%). Abundance of the phylum Firmicutes in mature doenjang was 99.98%, which was even higher value than those in meju and young doenjang. Predominant species in mature doenjang were B. amyloliquefaciens (67.3%), B. atrophaeus (12.7%), B. methylotrophicus (6.5%), B. mojavensis (3.2%), and B. subtilis. (2.5%), which were also identified as major species of the microbial flora in meju. These results suggested that rice straw was a primary source for supplement of Bacillus species in manufacturing the traditional doenjang and that some species of Bacillus strains were mainly involved in the fermentation process of traditional doenjang.

• Korean journal of food and cookery science
• /
• v.25 no.1
• /
• pp.90-97
• /
• 2009

Changes in the quality characteristics of doenjang prepared with a meju containing components of Acanthopanax senticosus, Angelica gigas and Corni fructus during storage were evaluated. Three types of doenjang produced using each of these components showed lower Hunter's L and a values than the values of the control during the initial stage of storage: however, these values were similar to those of the control after 60 days of storage. Doenjang containing A. gigas showed a similar degree of browning to that of the control during the early stage of storage, while the degree of browning observed in the other samples was much higher than that og the control during this period. Despite these initial differences, the browning in all samples became similar after extended storage. The level of acidity increased gradually for up to 60 days, after which it decreased slightly. The pH of all treatments decreased with storage time. The amino-N contents of all types of doenjang increased gradually, reaching peak values after 60 days. Doenjang with A. senticosus and A. gigas had a strong characteristic flavor that reduced the native flavor of doenjang. Doenjang with C. fructus showed a similar overall palatability to that of the control.

• Microbiology and Biotechnology Letters
• /
• v.47 no.2
• /
• pp.234-241
• /
• 2019

In Korea, traditional doenjang is manufactured using the conventional method at home and by small-scale enterprises. Because this age-old process depends on natural inoculation of various microorganisms, it is difficult to reproduce or maintain consistency in the final product quality across batches. Moreover, doenjang occasionally prepared by this method raises safety concerns related to aflatoxin, biogenic amine, and Bacillus cereus contamination. To develop starters that can be conveniently used at home or in small industry settings for the manufacturing of safe and flavor-improved doenjang, autochthonous microbe starters were developed in dried forms as ready-to-use starters. Each starter powder prepared by heat- or freeze-drying methods remained stable even after 24-week storage. These ready- to-use starter powders were successfully applied to lab-scale fermentation for the production of safe and flavor-improved doenjang. We believe that these ready-to-use starter powders will benefit small-scale enterprises in the manufacturing of doenjang of good reproducible quality.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.19 no.2
• /
• pp.156-162
• /
• 1990

Antimutagenic effect of doenjag (Korean fermented soy paste) on mutagenesis induced by aflatoxin B1 (AFB1) in Salmonella typhimurium strains TA98 and TA100 was studied. AFB1 revealed maximum mutagenicity at dose level of 1 $\mu$g/plate with metabolic activation system in both strains. Strong antiutagenic activity toward AFB1 was completely inhibited at the level of 50% of the doenjang extract. At the same concentration 64-66% and 39-53% of the AFB1 induced mutageneses were blocked when the methanol extracts of raw and cooked soybeans were added in the system respectively Raw soybeans showed higher ihhibition rate to the mutagenicity than cooked soybeans but the fermented soybeans(doenjang) was the most effective (p<0.05) Other soybean fermented foods such as commercial doenjang natto and miso were also exhibited some antimutagenic activities however the traditional doenjang was the most effective and then commercial doenjang. Natto and miso were less effective.