• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1697-1705
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• 2020

Meju, a type of fermented soybean paste, is used as a starter in the preparation of various Korean traditional soybean-based foods. In this study, we performed Illumina-MiSeq paired-end sequencing for microbial communities and mass spectrometry analysis for metabolite profiling to investigate the differences between 11 traditional meju products from different regions across Korea. Even though the bacterial and fungal communities showed remarkable variety, major genera including Bacillus, Enterococcus, Variovorax, Pediococcus, Weissella, and Aspergillus were detected in every sample of meju. The metabolite profile patterns of the 11 samples were clustered into two main groups: group I (M1-5) and group II (M6-11). The metabolite analysis indicated a relatively higher amino acid content in group I, while group II exhibited higher isoflavone, soyasaponin, and lysophospholipid contents. The bioactivity analysis proved that the ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) radical-scavenging activity was higher in group II and the FRAP (ferric reducing antioxidant power) activity was higher in group I. The correlation analysis revealed that the ABTS activity was isoflavonoid, lipid, and soyasaponin related, whereas the FRAP activity was amino acid and flavonoid related. These results suggest that the antioxidant activities of meju are critically influenced by the microbiome and metabolite dynamics.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.1
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• pp.27-36
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• 2019

Soybean (Glycine max), as one of the foods with high plant proteins, contains a large amount of bioactive compounds and known to be effective in cardiovascular disease and obesity as well as in improving skin condition. The purpose of this study was to investigate the anti-photoaging effects of soybean fermented with Lactobacillus Rhamnosus ($Bio-Peptone^{(R)}$) by assessment of cytotoxicity against UVB, collagen synthesis after UVB-irradiation, tyrosinase activity, and melanin synthesis. Results showed that $Bio-Peptone^{(R)}$ protected skin fibroblasts against UVB-induced cytotoxicity and increased type I collagen synthesis. Furthermore, $Bio-Peptone^{(R)}$ significantly inhibited tyrosinase activity and reduced melanin contents. This study suggests that $Bio-Peptone^{(R)}$ has protective effects against UVB-induced skin damage. Thus, it is concluded that $Bio-Peptone^{(R)}$ is able to prevent skin damage against UVB and thus acts as anti-photoaging materials by protecting skin forming wrinkles and skin pigments.

• Journal of Environmental Health Sciences
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• v.36 no.1
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• pp.52-60
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• 2010

High performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC/MS) have been widely used to quantify aflatoxins in food, but these methods are expensive, time-consuming, unsuitable for analysis of the routine screening of large sample numbers and require derivatization and high level techniques to perform. The objective of this study is to detect aflatoxins in a large number of foods by a high efficient analytical system of combined enzyme linked immunosorbent assay (ELISA) for screening and LC/MS/MS for confirmation. The samples spiked individually with aflatoxin $B_1$ (0.5 and 1.0 ng/g) and total aflatoxins (10 ng/g) were analyzed by ELISA and LC/MS/ MS, and the recoveries for ELISA and LC/MS/MS were 71.8~119.2% and 70.8~135.3%, respectively. A total of 378 samples (grains, nuts, soybean and fermented soybean foods, pepper and fermented pepper foods) were purchased from the six major cities in Korea and analyzed by ELISA-LC/MS/MS system. Twenty two (5.8%; peanut: 11, pistachio: 2, walnut: 6, almond: 1, pepper powder: 1, pepper paste: 1) out of 378 samples were screened as aflatoxin B1 positive by ELISA, but, 4 (1.1%; peanut: 2, pistachio:1, pepper powder: 1) out of the 22 samples screened were confirmed as aflatoxins positive at levels of 1.02~52.79 ng/g by LC/MS/MS. ELISA-LC/MS/MS system provides a more rapid, accurate and cost-effective method for the detection of aflatoxins in large number of samples.

• Preventive Nutrition and Food Science
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• v.6 no.2
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• pp.101-106
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• 2001

Alpha-amylase and glucoamylase activities were higher in koji with 40% water than that with 30 and 50% water, and A. oryzae exhibited very high alpha-amylase and glucoamylase activities compared to A. sojae and A. niger. Acidic, neutral and alkaline protease activities also showed higher activities in koji prepared with flour, Korean wheat powder and soybean powder with 40% water based on the weight of the sample. Alpha-amylase, acidic, neutral and alkaline protease activities of all the koji samples according to incubation periods increased until 3~4 days of incubation and maintained nearly the same level or slightly decreased after 5 days of incubation. The protease activities of A. oryzae and A. sojae showed nearly the same trend regardless of differences in substrate conditions and koji materials, but those of A. niger showed a lower activity than those of A. oryzae and A. sojae. These results suggest that the preparation of koji is possible with Korean wheat powder and soybean powder and A. sojae can be utilized as a new strain for fermented foods using soybean as the main materials to increase functional properties and produce products having a new taste and flavor.

• Journal of the Korean Society of Food Culture
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• v.17 no.1
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• pp.78-89
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• 2002

Preferences of 814 elderly living in Incheon for dishes, food materials and cooking methods were investigated. The survey was conducted from Dec. 2000 to Jan. 2001 by questionnaires. Subjects preferred cooked rice with beans, kalkooksoo(hot noodle), gomtang(soup with beef), bibimbap(rice with assorted mixture) to other staple dishes. However, preference for hashed rice or curried rice was very low. More than 50% of the subjects liked soybean paste soup and stew, and the ratio of elderly who liked Chinese cabbage kimchi was 68.7%. There was no significant difference in preference for pan-fried foods according to food materials in them. Subjects liked injolmi(waxy rice cake), shikhye(fermented rice drink) and coffee the most. Most subjects preferred plant foods like vegetables, legumes and seaweeds to animal foods. Preference of elderly for milk and yoghurt was reatively high; however, that for ham, butter and cheese was low. Elderly in Incheon liked roasted beef, beef soup and roasted pork the most. Chicken was preferred when it was boiled in water with garlic, ginseng, and so on. Cooked and seasoned vegetables (Namul) were the most preferred type by elderly. Preferences for dishes and food materials were more affected by living places of the subjects than by sex, and the reverse was true in preference for cooking method of food materials.

• Journal of Food Hygiene and Safety
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• v.16 no.4
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• pp.274-279
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• 2001

Generally, non-aflatoxigenic fungi, such as Aspergillus oryzae, and Aspergillus are main microflora in Korean traditional fermented foods including Meju and soybean paste, but sometimes, Aspergillus flavus and Aspergillus parasiticus can be contaminated and accumulated aflatoxins during fermentation and storage. So the screening of aflatoxigenic strains in fermented traditional food is very important to improve the sanitary quality of those foods. In this work, we screened aflatoxin producing fungi from commercial Meju and soybean paste in Western Gyeongnam by immunoassay. Samples were randomly purchased from market of the commercial Meju(10 EA) and soybean paste(20 EA) in nine areas of Western Gyeongnam. Of the samples collected,24 strains and 22 strains of Aspergillus sp. were isolated from Meju and soybean paste, respectively. The isolated strains were cultured on SLS media at $25^{\circ}C$ for 15 days. The cultured broth were extracted with ethyl acetate and were analysed to determine aflatoxin B$_1$(AFB$_1$) by direct competitive ELISA(DC-ELISA). Six strains(25%) isolated from Meju, and 2 strains(9%) isolated from saybean paste, were confined as aflatoxin producing strains. The average range of aflatoxin productivity of isolates from Meju was 54.6 $\pm$ 38.7 ng/ml and that from soybean paste was 11.1 $\pm$ 8.6 ng/ml, respectively. Among them, isolated strain No. M-5-4 produced a high level of AFBl and showed 98.26 ng/ml of AFB$_1$. Every isolates were also re-confined their AFB$_1$productivity by thin layer chromatography(TLC). The TLC results also showed same trend as DC-ELISA results. As the above results, the screening of hazard mycotoxigenic fungi from traditional fermented foods should be necessary for the safety and the application of HACCP system in the food manufactory in Korea.

• YAKHAK HOEJI
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• v.4 no.1
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• pp.14-16
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• 1959

In order to confirm the biochemical process of the fermentation from soybean to maiju and of the fermentation from maiju to kanjang and dainjang, the introgen distributions of soybean, maiju, kanjang, and dainjang are studied on protein nitrogen, peptide nitrogen, amino nitrogen and volatile nitrogen. And the contents of amino nitrogen, peptide nitrogen, and true protein nitrogen to the total nitroge of soybean, maiju, kanjang, and dainjang are shown in table 1 and the ratios are shown in table 2 and the figure. According to the results indicated in the tables and figure, the following conclusions are summerized. 1. The main biochemical process at the fermentation from soybean to maiju would be the degradation from protein in soybean to peptide compounds in maiju. 2. The main biochemical process at the fermentation from maiju to kanjang and dainjand would be the degradation from peptide compounds in maiju to amino nitrogen compounds in kanjang and dainjang. 3. However bacause the protein nitrogen indicated as the ratio of protein nitrogen to total nitrogen is contained still higher content in dainjang. It is assumed that there might be two kinds of proteins in soybean one is the protein which could be converted to peptides at the maiju fermentation and to amino nitrogen compounds lastly at the kanjang fermentation. The other is the protein which would not be effected at these fermentation at all remaining as the protein nitrogen in dainjang. One of the finished products. 4. It can be indicated that the process from maiju to kanjang and dainjang would be due to the fermentation as indicated by HAW and CHOI.

• Korean Journal of Food Science and Technology
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• v.45 no.6
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• pp.796-800
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• 2013

Soybean-based fermented foods have been used as traditional condiments in Korea, Japan and China. Thirteen Korean types of soybean sauce that had been manufactured and sold in China were examined to evaluate their quality. The pH, salinity, and moisture content of the samples were pH 5.17-6.86, 8.0%-23.0%, and 46.446-70.40%, respectively. The amino-type nitrogen content was in the range of 199.18 to 736.46 mg%. The total aerobic bacterial counts were 4.83-7.89 Log CFU/g. The coliform count of gochujang (CNH-2) was 2.31 Log CFU/g, but none were detected in the other samples. Moreover, Bacillus cereus counts from samples of doenjang and gochujang were in the range 2.00-4.09 Log CFU/g. The protease and amylase activity of samples were 379.02-781.36 unit/g and 5.29-63.27 unit/g, respectively.

• Microbiology and Biotechnology Letters
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• v.45 no.4
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• pp.299-304
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• 2017

Biogenic amines such as histamine, tyramine, cadaverine, and putrescine may have detrimental effects on consumers' health; therefore, they must be considered hazardous substances in foods. In recent years, the application of microorganisms that can degrade biogenic amines has become an emerging method for reducing the amount of these amines in foods. Primarily, Bacillus sp. BCNU 9171 was isolated from Doenjang, a Korean traditional fermented soybean paste. The inhibitory effects of the cell-free supernatant (CFS) of Bacillus sp. BCNU 9171 on biogenic amine production by 4 amine-positive food pathogenic bacteria were investigated using high performance liquid chromatography (HPLC). Our results showed that 4 different CFS concentrations-10% [1 ml CFS + 9 ml histidine decarboxylase broth (HDB)], 25% (2.5 ml CFS + 7.5 ml HDB), 50% (5 ml CFS + 5 ml HDB), and 75% (7.5 ml CFS + 2.5 ml HDB)-reduced the biogenic amine production up to 87% compared with that of the control without CFS. These results suggested that it is advisable to use Bacillus sp. strain BCNU 9171 as a starter organism for the manufacture of fermented foods and to ensure food safety since it prevents the accumulation of high amounts of biogenic amines in fermented foods by amine-positive bacteria.

• Korean journal of food and cookery science
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• v.12 no.4
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• pp.527-534
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• 1996

enistein (G), and daidzein (D), the major isoflavones, were analyzed in 14 varieties of Korean soybean and various processed soybean products by using high performance liquid chromatography. Isoflavone contents (G+D) were greatly variable among varieties ranged from 308.2 $\mu\textrm{g}$/g to 1,134.2 $\mu\textrm{g}$/g and highest in Danyopkong and Jinpumkong. Among hypocotyl, cotyledon and hull of soybean the concentration of the isoflavone (G+D) in the hypocotyl was highest ranged from 2,971.7 $\mu\textrm{g}$/g to 5,704.9 $\mu\textrm{g}$/g. The distributions of genistein and daidzein were also different in hypocotyl, cotyledon and hull. Higher ratio of daidzein to genistein (D/G) was found in the hypocotyl (4-12) compared to cotyledon and hull (0.1-4). Isoflavone (G+D) contents of soymilks (Sinpaldal#2, Eunhakong) prepared at 16 hour hydration were decreased to 1.1-1.2 times compared with that at 8 hour hydration. Commercial soymilks contained much lower isoflavone (G+D) than laboratory soymilks. Soybean curd (Eunhakong) prepared with MgCl$_2$ showed higher isoflavone (G+D) contents than that with CaSO$_4$. But these values of two different soybean curds made at laboratory were similar to those of 3 commercial curds. The concentration of the isoflavones in soybean sprout separated with 3 parts revealed highest in the head and lowest in the stem. Compared with non-fermented soybean foods the fermented soybean produfts, Kochujang and soybean paste, Duen Jang, showed very low contents of isoflavone (G+D),2.8-3.0 $\mu\textrm{g}$/ｇ, 35.9-63.6 $\mu\textrm{g}$/ｇrespectively.