• Korean Journal of Food Science and Technology
• /
• v.43 no.6
• /
• pp.735-741
• /
• 2011

Bealmijang is a short-term fermented regional product that is prepared with soybean and extra ingredients. In this study, starter strain candidates were screened from Bealmijang for fermented soybean paste products. Twenty one bacterial strains producing extracellular enzymes (amylase, cellulase, protease, xylanase and lipase) were isolated from Bealmijang, buckwheat sokseongjang. The isolates were assessed for fibrinolytic and antibacterial activities, and salt tolerance. Strain HJ18-4, identified as Bacillus subtilis (AB601598) by biochemical properties (89.6%) and 16S rDNA sequencing (100%), showed the highest enzymatic, fibrinolytic, and antibacterial activities among the isolates. Although the growth of HJ18-4 was inhibited by the increase of NaCl concentration, the growth still exceeded that of B. subtilis KACC 10114 at 5% and 10% NaCl. These results suggest that B. subtilis HJ18-4 is suitable as a starter for soybean paste manufacture.

• Food Science and Preservation
• /
• v.22 no.4
• /
• pp.545-552
• /
• 2015

This study investigated the quality characteristics of popped rice Doenjang prepared with different Bacillus strains (Bacillus subtilis KACC 15935, and Bacillus subtilis HJ18-9). The changes in the enzyme activity (protease, cellulase, and ${\alpha}$-amylase), amino-type nitrogen and ammonia-type nitrogen contents, and the reducing sugar were investigated during the fermentation period. Enzymes such as protease, cellulase, and a-amylase plays an important role in the changes in composition of nutrients, and in flavor and taste of popped rice Doenjang. Protease activities of the popped rice deonjang fermented with different Bacillus strains (control, B. subtilis KACC 15935, and B. subtilis HJ18-9) was in the range of 171.77-185.97 unit/g at the beginning of fermentation, and there were no significant differences among the samples. On the other hand, the protease activity in popped rice Doenjang fermented with B. subtilis HJ18-9 increased significantly up to $248.77{\pm}4.53unit/g$ at the end of fermentation (p<0.05). Cellulase activity and a-amylase activity of popped rice Doenjang in HJ18-9 was higher than these of other samples. After 56 days of fermentation, amino-type nitrogen in popped rice deonjang fermented with control, B. subtilis KACC 15935, and B. subtilis HJ18-9 increased significantly up to $174.99{\pm}3.70$, $166.59{\pm}1.40$, $225.39{\pm}3.70mg%$, respectively (p<0.05). These results suggested that B. subtilis HJ18-9 was a suitable starter for the preparation of soybean paste.

• Journal of the East Asian Society of Dietary Life
• /
• v.26 no.2
• /
• pp.163-170
• /
• 2016

This study investigated the quality characteristics of doenjang prepared with different Bacillus strains (Bacillus subtilis KACC 15935 and Bacillus subtilis HJ18-9). Changes in enzyme activities (protease, cellulase, and ${\alpha}-amylase$), amino-type nitrogen and ammonia-type nitrogen contents, and reducing sugar were investigated during the fermentation period. Enzymes such as protease, cellulase, and ${\alpha}-amylase$ play important roles in the composition of nutrients, as well as in the flavor and taste of doenjang. After 60 days of fermentation, protease activities in control doenjang, and doenjang fermented with B. subtilis KACC 15935, and B. subtilis HJ18-9 increased significantly up to $382.58{\pm}4.02$, $342.58{\pm}7.94$, and $392.58{\pm}1.91unit/g$, respectively (p<0.05). At the beginning of fermentation, protease activities were in the range of 156.88~182.71 unit/g. Cellulase and ${\alpha}-amylase$ activities of doenjang in HJ18-9 were higher than those in other samples. After fermentation, amino-type nitrogen in doenjang fermented with control, B. subtilis KACC 15935, and B. subtilis HJ18-9 increased significantly up to $143.25{\pm}1.62$, $141.86{\pm}2.14$, and $150.23{\pm}1.62mg%$, respectively (p<0.05). These results suggest that B. subtilis HJ18-9 is a suitable starter for the preparation of doenjang.

• Food Science and Preservation
• /
• v.21 no.1
• /
• pp.121-128
• /
• 2014

This study was conducted in order to investigate the change of isoflavone composition (glycoside and bio-active aglycone), and to evaluate the quality characteristics of Cheonggukjang, which was prepared by different bacillus strains. After the 48-hour fermentation, the contents of daidzein, genistein, and glycitein in the Bacillus subtilis HJ18-3 have significantly increased up to approximately $89.06{\pm}3.59$, $10.36{\pm}0.28$, and $101.37{\pm}3.67ug/g$, respectively. The contents of daidzein, genistein, and glycitein in the Bacillus subtilis KACC 15935 were $38.88{\pm}5.39$, $12.58{\pm}2.14$, and $80.13{\pm}0.71ug/g$, respectively. The original content of daidzein was 3.96 ug/g, while genistein and glycitein were not measured. However, the contents of daidzen and genistein in HJ18-3 and in KACC 15935 were decreased. The ${\alpha}$-Amylase and cellulase activities of Chungkookjang in HJ18-3 were higher than in the KACC 15935. The contents of Chungkookjang in HJ18-3 were $29.70{\pm}11.66$ and $4861.3{\pm}388.07unit/g$, respectively. The amino type nitrogen contents and ammonia type nitrogen contents of Chungkookjang in KACC 15935 were higher than in the HJ18-3. These results suggested that it could be used to increase the bioactivity via fermentation with the Bacillus subtilis possessing a ${\beta}$-glucosidase activity with a view towards the development of functional foods.

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

• Korean Journal of Food Science and Technology
• /
• v.44 no.6
• /
• pp.743-749
• /
• 2012

Black soybean paste (BSP) is a bealmijang manufactured with barley flour and black soybeans. This study investigated the quality characteristics of BSP prepared with Bacillus subtilis HJ18-4 (HJ18-4). ${\alpha}$-Amylase and protease activities of BSP rapidly increased on day 6 and day 9, respectively, ($41.45{\pm}0.3-42.72{\pm}0.16$, $21.84{\pm}0.24-23.11{\pm}0.35unit/g$) after which the activities were constant or decreased slightly. Amino type nitrogen contents increased until day 23 ($173.78{\pm}3.51-195.63{\pm}1.51mg\;%$), whereas ammonia type nitrogen sharply decreased on day 9. On day 30, lactic acid bacteria counts were higher compared with the initial count ($7.91{\pm}0.05-8.17{\pm}0.02log\;CFU/g$). Meanwhile, B. cereus and total aerobic counts in HJ18-4 added BSP were lower than that in the control. These results implied that BSP could be edible after 30 days of fermentation, and the addition of HJ18-4 in meju could contribute to the safety of the black soybean paste by the inhibition of B. cereus growth.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.12
• /
• pp.1694-1699
• /
• 2011

The quality characteristics and physiological effects of chunggukjang fermented naturally (NF-c), with Bacillus subtilis-SKm (BS-c), with Bacillus subtilis HJ18-4 (BH-c), and with Bacillus subtilis KCCM 42923 (BK-c) were investigated. The characteristics of fermentation were determined by protease, ${\alpha}$-amylase and ${\gamma}$-GTP activities, and additionally the amounts of amino-type and ammonia-type nitrogens. BS-c showed the highest protease, ${\alpha}$-amylase, and ${\gamma}$-GTP activities, and also amino-type nitrogen content among the four types of chunggukjang. The ammonia-type nitrogen content in BS-c was similar to that of BK-c and NF-c. BH-c showed the lowest enzyme activities and amino-type and ammonia-type nitrogen content. BS-c, BH-c, BK-c, and NF-c showed a similar overall acceptability during sensory evaluation. BS-c also showed the strongest DPPH free radical scavenging and anti-proliferative activities in HT-29 human colon carcinoma cells. These results suggested that B. subtilis-SKm was suitable to be used as a starter to enhance the quality and effects of chunggukjang.

• The Korean Journal of Food And Nutrition
• /
• v.26 no.4
• /
• pp.753-758
• /
• 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
• /
• v.22 no.4
• /
• pp.535-544
• /
• 2015

This study was conducted to investigate the changes of isoflavone composition (glycoside and bio-active aglycone) in Cheonggukjang and to evaluate its quality characteristics depending on different soybean cultivars (Daewon, Daepoong, Wooram, Hwangkeumol and Saedanback). The bioactivity of Cheonggukjang was enhanced during fermentation at $37^{\circ}C$ for 48 h. Activities of ${\alpha}$-amylase, protease, and cellulase increased significantly after 48 h fermentation (p<0.05). In addition, amino-type nitrogen and reducing sugar contents in Cheonggukjang fermented with B. subtilis increased significantly after 48 h fermentation (p<0.05). Among the isoflavones, the content of $\beta$-glucosides and acetyl-glucosides decreased, while aglycone content increased during fermentation. Especially, Cheonggukjang fermented with Daepoong cultivars showed the greatest increase in daidzein, genistein and glycitein contents. After 48 h fermentation, the contents of daidzein, genistein and glycitein in the Cheonggukjang fermented with Daepoong cultivars increased significantly up to $503.65{\pm}2.76$, $111.40{\pm}0.42$, and $633.95{\pm}6.01{\mu}g/g$ (p<0.05), respectively. Total aerobic and anaerobic cell counts increased with increase in fermentation time. Therefore, it would be beneficial for the food industry if components of Cheonggukjang could be separated and used to develop functional products.

• The Korean Journal of Food And Nutrition
• /
• v.25 no.3
• /
• pp.505-512
• /
• 2012

This study evaluated the quality characteristics of rice-doenjang prepared with Aspergillus oryzae MD05 and Bacillus subtilis HJ18-4. The physicochemical characteristics of rice-doenjang prepared with three types of meju, such as grain type(Rice 1), disc shape(Rice 2), and brick shape(Rice 3), were compared. We determined amino and ammonia nitrogen contents, protease and amylase activities, reducing sugar content, and total aerobic counts and lactic acid bacteria counts. The amino nitrogen and reducing sugar contents in all meju types gradually increased during fermentation. The amino nitrogen contents reached 151.5~200.0 mg%. Rice 3 were had the highest levels among the 4 types of rice-doenjang. After 42 days of fermentation, amylase and protease activity of Rice 3 were 366.57 and 94.26 unit/g, respectively, which were the highest levels among the 4 types of rice-doenjang. The total aerobic bacteria counts were not changed during 42-day fermentation. This results suggest that high quality characteristics of brick-shaped meju(Rice 3) were better than those of the other meju preparations.