• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.8
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• pp.1236-1241
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• 2013

This study was conduct in order to provide information on formula optimization, salinity, and water content for commercialization of traditional buckwheat Soksungjang. To do this, we determined quality characteristics such as total microbial flora counts, amino-type nitrogen content, total polyphenol content, antioxidant activity, and performed a sensory evaluation. The moisture contents showed a gradual decrease during the fermentation period. There was no significant difference in all samples. During 70 days of fermentation, the pH showed a similar trend starting at a pH of 6, and dropping sharply to 5.5, except Experiment C (15% buckwheat powder in the meju, 10% NaCl, and 130% water in the total Soksungjang). On the other hand, total acidity increased regularly, however, its ranges were various points in all samples. The microbial population was reduced by 1~3 log cycle in all samples during the fermentation period. The content of amino-type nitrogen showed a gradual increase during fermentation, ranging from 160 to 213 mg% after 70 days. No remarkable difference in total polyphenol content and antioxidant activity was observed in all samples. In sensory evaluation, Soksungjang with 30% (control) and 15% (Experiment C) buckwheat showed a significantly higher overall score.

• Korean Journal of Food Science and Technology
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• v.43 no.1
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• pp.77-82
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• 2011

This study was conducted to provide information for improving the quality characteristics of Buckwheat Soksungjang (BWS). We determined aminotype nitrogen content, total microbial flora counts, the population of Bacillus cereus, presence of volatile compounds, fibrinolytic activity, antioxidant activity, ACE inhibition rate, and a sensory evaluation. The aminotype nitrogen increased gradually during fermentation. We found a decreasing population of B. cereus during fermentation, thus, the edible period for BWS was more than 30 days after fermentation. Acetaldehyde, butanol, and pyrazine were detected as volatile compounds after fermentation. The fibrinolytic activities of a 10% BWS water extract were high at 120.8 units compared to the control (71.6 units). In a sensory evaluation, Soksungjang with 60% added BW showed a significantly higher score (p < 0.001) for color, taste, smell, texture, and overall. The results suggest that a new type of shortened fermented soybean paste had good safety, bioactivities, and sensory characteristics within 4 weeks.

• Food Science and Preservation
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• v.20 no.5
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• pp.699-704
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• 2013

Buckwheat Soksungjang (BS) is a bealmijang manufactured with buckwheat and soybeans. We manufactured BS using Bacillus subtilis HJ18-4 (HJ18-4), which has high enzyme activities and antibacterial effects. HJ18-4 was inoculated in a different process during the BS manufacturing, which was the meju-making time (Treat 1), and the salt water time was added (Treat 2). The physiochemical and microbial characteristics of the BS were analyzed. As a result, the total aerobic counts (7~8 log CFU/mL) in the BS increased after 15 days of fermentation. Especially, Treat 1 showed higher total aerobic counts and amino-type nitrogen (65.38~202.52 mg%) than Treat 2. During the BS fermentation, the reduction of the sugar contents and the enzyme (protease and amylase) activities decreased. In the relative quantitative expression level of PlcR, Treat 1 did not show toxin gene expressions at the end of the fermentation on Day 23. Treat 1 showed suitable B. cereus physiochemical quality characteristics and inhibition effects. When the modified-form type of fermented soybean paste was manufactured with a single starter, it could not reproduce the natural fermentation quality. These results suggest that the addition of a starter (HJ18-4) in the Meju manufacturing process could enhance the quality characteristics of the manufactured BS via natural fermentation and by suppressing B. cereus.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.753-758
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• 2013

This study evaluated the quality characteristics for optimization of premix-type Buckwheat (Fagopyrum esculentum) Soksungjang (BS). First, according to the amount of salt (8, 10, 12%), coliform counts were not detected in BS with 10 or, 12% salt at 21 days and Bacillus subtilis HJ 18-4 as a starter at 7 days. Therefore, 10% salt with starter culture might be considered as suitable conditions for safety. Second, according to the ratio of water (1:1, 1:1.5, 1:1.8), BS prepared with the same weights of meju powder and water showed the highest aminotype nitrogen content (688.76mg%) at 35 days; thus, an adequate fermentation state was established at this condition compared to others. Third, according to the type of container (pot, plastic, glass), the aminotype nitrogen contents were higher in the plastic container and pot than in the glass bottle. Lastly, according to the batch size (1.25, 2.5 kg), the coliform of the 2.5 kg sample decreased faster than that of 1.25 kg samples at 14 days. These results suggest that BS prepared with the same ratio of water and meju powder fermented with HJ 18-4 as a starter and 10% salt in a pot, plastic container (3 weeks) and glass container (4 weeks) showed desirable fermentation qualities.

• Food Science and Preservation
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• v.21 no.2
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• pp.239-245
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• 2014

This study was performed to provide fundamental information regarding the quality change of buckwheat soksungjang (BWS) during its storage. BWS was divided into three different containers (pot, plastic, and glass) and was stored at three different temperatures (5, 15, and $25^{\circ}C$), and the changes in pH, acidity, amino-type nitrogen, total bacterial count, and chromaticity were examined during the storage period. The pH (0 day, pH 4.37) and acidity (0 day, 2.93% acidity) of the samples, except at the 15 and $25^{\circ}C$ pots, did not show any significant change during storage, but 98 days after storage, the pH values of the 15 and $25^{\circ}C$ pots were pH 5.6 and 7.4, and their acidity values were 1.85 and 0.71%, respectively. At 98 days, the amino-type nitrogen of the $25^{\circ}C$ plastic sample had slightly increased to $0.75{\pm}0.01%$, and that of the $25^{\circ}C$ pot had drastically risen to $0.92{\pm}0.01%$. It was also shown that little change in the total bacterial count was found during the experiment period in every sample. The chromaticity results confirmed that the L (lightness), a (redness), and b (yellowness) values of the $25^{\circ}C$ pot sample showed relatively large changes during storage compared to the other samples. These results suggest that the desirable storage temperature of BWS is in the range of $5-15^{\circ}C$, and that a glass container is the most suitable container for BWS as it can reduce the quality alteration during storage.

• Journal of Microbiology and Biotechnology
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• v.26 no.1
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• pp.44-55
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• 2016

Bacillus cereus is a gram-positive, rod-shaped, spore-forming bacterium that has been isolated from contaminated fermented soybean food products and from the environment. B. cereus produces diarrheal and emetic toxins and has caused many outbreaks of foodborne diseases. In this study, we investigated whether B. amyloliquefaciens RD7-7, isolated from rice doenjang (Korean fermented soybean paste), a traditional Korean fermented soybean food, shows antimicrobial activity against B. cereus and regulates its toxin gene expression. B. amyloliquefaciens RD7-7 exhibited strong antibacterial activity against B. cereus and inhibited the expression of B. cereus toxin-related genes (groEL, nheA, nheC, and entFM). We also found that addition of water extracts of soybean and buckwheat soksungjang (Korean fermented soybean paste made in a short time) fermented with B. amyloliquefaciens RD7-7 significantly reduced the growth and toxin expression of B. cereus. These results indicate that B. amyloliquefaciens RD7-7 could be used to control B. cereus growth and toxin production in the fermented soybean food industry. Our findings also provide a basis for the development of candidate biological control agents against B. cereus to improve the safety of fermented soybean food products.