• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.3
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• pp.255-261
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• 1993

The effect of dried soymilk residue (DSR) on protein quality of tofu was studied. The amount of added DSR into soybean water extract was corresponding 10% (dry basis) of soybean used in tofu manufacturing. Proximate composition and in vitro protein qualities of soybeans at different stages of the conversion into tofu have also been investigated. Partially substituted tofu with DSR (TDSR) had higher moisture content (80.6%) than that of tofu prepared in traditional manner (TT). TDSR contained lower content of protein (38.9%) and total lipid (26.9%) compared to 45.8% of protein and 34.3% of total lipid for TT. A large amount of trypsin inhibitor (TI) in raw soybeans was diminished and extracted through tofu processing, and only 10~13% of TI in raw soybean remained in both tofu products (TDSR and TT). There was not a considerable difference in amino acid profiles between TT and TDSR, but TDSR had a higher content of lysine than that in TT. in vitro studies showed that TDSR and TT were comparable in terms of both in vitro digestibilities (90% over for four-enzyme digestibility and predicted digestibility) and discriminant computed protein efficiency ratio (2.07~2.14, DC-PER). Unlike those in vitro indices for protein quality, computed protein efficiency ratio (C-PER) of TDSR was much lower (1.4) than that of TT (1.95). It was revealed that C-PERs of tofu products were not in agreement with rat-PERs (1.7~1.9) in previous reports except for TT. However, DC-PER assay was more recommendable for protein quality of tofu products than C-PER assay.

• Food Science and Preservation
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• v.17 no.3
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• pp.410-417
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• 2010

Several extracellular protease-producing bacteria were isolated from Chungkookjang, a traditional Korean food of fermented soybeans, on skim milk agar plates. Among these bacteria, strain D14 exhibited the highest production (15.2 U/mL) and specific activity (40.0 U/mg protein) of extracellular protease activity as assessed on growth in a protease induction medium composed of 1% (w/v) soluble starch, 1.5% (w/v) skim milk, 0.5% (w/v) yeast extract, and 2% (w/v) NaCl. The bacterium was identified as Bacillus subtilis based on morphological and physiological characteristics and 16S rDNA sequence. A BLAST search of 16S rDNA sequences revealed that the isolate was most closely related to Bacillus subtilis subsp. subtilis strain NCIB 3610. The 16S rDNA sequence homology was 99.9%. Our isolate produced the highest level of protease when grown in a protease induction medium containing 1% (w/v) sorbitol and 0.5% (w/v) yeast extract. Fructose and glucose reduced enzyme production to 12.7% and 35.9%, respectively, of the level seen when the strain was grown in medium containing soluble starch. Soytone also reduced enzyme production to 61.4% of the level noted when the strain was grown in medium containing yeast extract.

• Journal of Life Science
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• v.31 no.10
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• pp.922-928
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• 2021

To profile the microbial compositions of Korean traditional fermented paste made from whole soybeans, Doenjang and Cheonggukjang, and compare their taxonomic differences, we analyzed the V3-V4 region of 16S rRNA of naturally fermented foods by using next generation sequencing. α-Diversity results showed that values indicating bacterial community abundances (OTUs) and richness (ACE, Chao1) were statistically significant (p=0.0001) in Doenjang and Cheonggukjang. Firmicutes was the most common phylum in both groups, representing 97.02% and 99.67% in the Doenjang and Cheonggukjang groups, respectively. Bacillus was the most dominant genus, accounting for 71.70% and 59.87% in both groups. Linear discriminant (LDA) effect size (LEfSe) analysis was performed to reveal the significant ranking of abundant taxa in different fermented foods. A size-effect threshold of 2.0 on the logarithmic LDA score was used for discriminative functional biomarkers. On the species level, Bacillus subtilis, Tetragenococcus halophilus, and Clostridium arbusti were significantly more abundant in Doenjang than in Cheonggukjang, whereas Bacillus thermoamylovorans, Enterococcus faecium, and Lactobacillus sakei were significantly more abundant in Cheonggukjang than in Doenjang. Permutational multivariate analysis of variance (PERMANOVA) showed that the statistical difference in microbial clusters between the two groups was significant at the confidence level of p=0.001. This research could be used as basic research to identify the correlation between the biochemical characteristics of Korean fermented foods and the distribution of microbial communities.

• Food Science and Preservation
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• v.24 no.6
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• pp.771-777
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• 2017

Although Doenjang is a representative traditional fermented food in Korea, made mainly from soybeans, it has been classified into a food group identified as having high sodium in the National Health and Nutrition Examination. It is necessary to develop a low sodium Doenjang to prevent the excessive sodium intake which may cause various diseases. However, the development of Doenjang with low sodium, without significant changes on quality, is an ongoing challenge. Therefore, the experiment was designed to reduce the salt content of the soaking water to 12.5-45%. The pH, saltiness. moisture, sodium, color, amino-type nitrogen, free amino acids and constituent amino acids composition of Doenjang were investigated to determine the effect of this salt reduction on the sensory quality of Doenjang. The reduction of sodium did not affect the pH, moisture and saltiness, and this changed maintained the same range as the control. The sodium content was reduced proportionally, and the amino acid nitrogen level was 500 mg%. Therefore, this study considered that a reduction of 25% of salt in the soaking water does not affect the quality of the Doenjang while reducing the sodium content of the final Doenjang.

• Journal of Plant Biotechnology
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• v.50
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• pp.142-154
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• 2023

Plant abscission is a natural process in which plant organs or tissues undergo detachment, a strategy selected by nature for the disposal of nonessential organs and widespread dissemination of seeds and fruits. However, from an agricultural perspective, the abscission of seeds or fruits represents a major factor that reduces crop productivity and product quality. Therefore, during the crop domestication process in traditional agriculture, mutants exhibiting suppressed abscission were selected and crossbred, thereby enabling the production of modern crop varieties such as rice, tomatoes, canola, and soybeans. These crops possess a unique trait of retaining ripe fruits or seeds in contrast to disposal via abscission. During the previous century, research on quantitative trait loci along with genetic and molecular biological studies on Arabidopsis thaliana have elucidated various cell biological mechanisms, signaling pathways, and transcription regulators involved in abscission. Additionally, it has been revealed that various hormone signals, which are involved in plant growth, play crucial roles in modulating abscission activity. Researchers have developed several chemical treatments that target these hormones and signal transduction pathways to enhance crop yields. This review aimed to introduce the previously identified signal transduction pathways and pivotal regulators implicated in abscission activity. Moreover, this review will discuss the future direction of research required to investigate crop abscission mechanisms for their potential application in smart farming and other areas of agriculture, as well as areas within model systems that require extensive research.

• Journal of Life Science
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• v.28 no.4
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• pp.454-464
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• 2018

Black soybeans are used as food sources as well as for traditional medicines because they contain an abundance of natural phenolic compounds. In this study, total phenolic contents (TPCs) of Korean black seed coat soybean varieties Socheongja (SCJ), Socheong 2 (SC2) and Cheongja 2 (CJ2) as well as their antioxidant capacities were investigated. Among them, TPCs were abundantly present in the order of CJ2$H_2O_2$-stimulated HaCaT human keratinocytes. Our results revealed that treatment with SCJ and SC2 prior to $H_2O_2$ exposure significantly increases the viability of HaCaT cells, indicating that the exposure of HaCaT cells to SCJ and SC2 conferred a protective effect against oxidative stress. SCJ and SC2 also effectively inhibited $H_2O_2$-induced apoptotic cell death through the blocking of mitochondrial dysfunction. SCJ and SC2 also attenuated the phosphorylation of Histone H2AX. Furthermore, they effectively induced the levels of thioredoxin reductase (TrxR) 1, a potent antioxidant enzyme, which is associated with the induction of nuclear transcription factor erythroid-2-like factor 2 (Nrf2); however, the protective effects of SCJ and SC2 were significantly reversed by Auranofin, a TrxR inhibitor. These results indicate that they have protective activity through the blocking of cellular damage related to oxidative stress via the Nrf2 signaling pathway. In conclusion, our study indicated that SCJ and SC2 might potentially serve as novel agents for the treatment and prevention of skin disorders caused by oxidative stress.

• Journal of Life Science
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• v.34 no.4
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• pp.254-263
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• 2024

Korean jang is a food made using fermented soybeans, and the typical products include gochujang (GO), doenjang (DO), cheonggukjang (CH), and ganjang (GA). In this study, 16S rRNA metagenome analysis was performed on a total of 200 types of GO, DO, CH, and GA using next-generation sequencing to analyze the microbial community of fermented soybean foods and compare taxonomic (biomarker) differences. Alpha diversity analysis showed that in the CHAO index, the species richness index tended to be significantly higher compared to the DO and GA groups (p<0.001). The results of the microbial distribution analysis of the GO, DO, CH, and GA products showed that at the order level, Bacillales was the most abundant in the GO, DO, and CH groups, but Lactobacillales was most abundant in the GA group. Linear discriminant analysis effect (LEfSe) analysis was used to identify biomarkers at the family and species levels. Leuconostocaceae, Thermoactinomycetaceae, Bacillaceae, and Enterococcaceae appeared as biomarkers at the family level, and Bacillus subtilis, Kroppenstedtia sanguinis, Bacillus licheniformis, and Tetragenococcus halophilus appeared at the species level. Permutational multivariate analysis of variance (PERMANOVA) analysis showed that there was a significant difference in the microbial community structure of the GO, DO, CH, and GA groups (p=0.001), and the microbial community structure of the GA group showed the greatest difference. This study clarified the correlation between the characteristics of Korean fermented foods and microbial community distribution, enhancing knowledge of microorganisms participating in the fermentation process. These results could be leveraged to improve the quality of fermented soybean foods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.5
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• pp.736-745
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• 2016

Cheonggukjang, a traditional Korean fermented soy food, was prepared by inoculation of Bacillus subtilis EMD4 or Bacillus amyloliquefaciens EMD17 with anti-bacterial or anti-fungal activities into soybeans. Cheonggukjang was also prepared by co-inoculation of EMD4 and EMD17 (1:1, v/v). Control cheonggukjang was prepared by using B. subtilis KACC16450 (Natto strain). Growth of B. cereus cells spiked with starter organisms was completely inhibited by B. amyloliquefaciens EMD17 after 12 h of fermentation at $37^{\circ}C$. Growth of B. cereus was also inhibited by B. subtilis EMD4, but the degree of inhibition was weaker. After 48 h of fermentation, cheonggukjang samples were stored for 10 days at $4^{\circ}C$. B. cereus cells were not detected from cheonggukjang inoculated with EMD4, whereas significant numbers still present in control. The pH values of cheonggukjang samples were not significantly different. During fermentation, cheonggukjang fermented with EMD17 showed the highest fibrinolytic activity and during storage, cheonggukjang fermented with a Natto strain was the highest. Cheonggukjang fermented with a Natto strain also showed the highest amount of total phenolic compounds. The results show that control of B. cereus in cheonggukjang is possible by using starters such as B. amyloliquefaciens EMD17.

• Korean Journal of Remote Sensing
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• v.39 no.5_1
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• pp.521-535
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• 2023

When converting rice fields into fields,sorghum (sorghum bicolor L. Moench) has excellent moisture resistance, enabling stable production along with soybeans. Therefore, it is a crop that is expected to improve the self-sufficiency rate of domestic food crops and solve the rice supply-demand imbalance problem. However, there is a lack of fundamental statistics,such as cultivation fields required for estimating yields, due to the traditional survey method, which takes a long time even with a large manpower. In this study, U-Net was applied to RGB images based on unmanned aerial vehicle to confirm the possibility of non-destructive segmentation of sorghum cultivation fields. RGB images were acquired on July 28, August 13, and August 25, 2022. On each image acquisition date, datasets were divided into 6,000 training datasets and 1,000 validation datasets with a size of 512 × 512 images. Classification models were developed based on three classes consisting of Sorghum fields(sorghum), rice and soybean fields(others), and non-agricultural fields(background), and two classes consisting of sorghum and non-sorghum (others+background). The classification accuracy of sorghum cultivation fields was higher than 0.91 in the three class-based models at all acquisition dates, but learning confusion occurred in the other classes in the August dataset. In contrast, the two-class-based model showed an accuracy of 0.95 or better in all classes, with stable learning on the August dataset. As a result, two class-based models in August will be advantageous for calculating the cultivation fields of sorghum.

• Journal of Nutrition and Health
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• v.41 no.5
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• pp.439-447
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• 2008

There is a limitation to estimate vitamin $B_{12}$ intake due to lack of data on vitamin $B_{12}$ content in many Korean foods. In this study, vitamin $B_{12}$ content was determined in some soybean or vegetable-fermented foods, edible seaweeds and other frequently consumed foods in Korea by microbioassay using Lactobacillus delbruecki ATCC 7830. The traditional type of Doenjang and Chungkookjang contained 1.85 ${\mu}g/100$ g and 0.69 ${\mu}g/100$ g of vitamin $B_{12}$, respectively, while the factory-type of Doenjang and Chungkookjang contained 0.04-0.86 ${\mu}g/100$ g and 0.06-0.15 ${\mu}g/100$ g. Vitamin $B_{12}$ was not detected in steamed soybeans and Tofu which is a not-fermented soybean product, indicating that vitamin $B_{12}$ in Doenjang and Chungkookjang might be produced during the fermentation process. The Korean-style soy sauce contained 0.04 ${\mu}g$ vitamin $B_{12}$/100 mL, but vitamin $B_{12}$ was not detected in Japanese-style soy sauce and white miso. Commercial Kimchi, a representative Korean vegetable- fermented food, made of Korean cabbage, Yeolmu, or Mustard leaves contained 0.013-0.03 ${\mu}g$ vitamin $B_{12}$/100 g, while Kimchi without red pepper and fermented fish sauce (White Kimchi) did not. Vitamin $B_{12}$ content was very high in some edible seaweeds such as laver (66.76 ${\mu}g/100$ g dry weight) and sea lettuce (84.74 ${\mu}g/100$ g dry weight), and it was 17.12 ${\mu}g/100$ g of dried small anchovy, 1.07 ${\mu}g/100$ g of whole egg, and 0.02 ${\mu}g/100$ g of coffee mix. From these results, it is assumed that Koreans take substantial amount of vitamin $B_{12}$ from plant-origin foods. And, with these data, we will be able to calculate dietary vitamin $B_{12}$ content more correctly than before. In conclusion, soybean-fermented foods, Kimchi, laver and sea lettuce are recommendable as good sources of vitamin $B_{12}$ for vegetarians or Korean elderly on grain and vegetable based diet.