• Journal of Microbiology and Biotechnology
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• v.29 no.2
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• pp.191-199
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• 2019

We inoculated different combinations of three starter candidates, Bacillus licheniformis, Staphylococcus succinus, and Tetragenococcus halophilus, into sterilized soybeans to predict their contributions to volatile compound production through soybean fermentation. Simultaneously, we added NaCl to soybean cultures to evaluate its effect on the volatile compounds profile. Cells in soybean cultures (1.5% NaCl) nearly reached their maximum growth in a day of incubation, while cell growth was delayed by increasing NaCl concentrations in soybean cultures. The dominance of B. licheniformis and S. succinus in the mixed cultures of three starter candidates switched to T. halophilus as the NaCl concentration increased from 1.5% to 14% (w/w). Seventeen volatile compounds were detected from the control and starter candidate-inoculated soybean cultures with and without the addition of NaCl. Principal component analysis of these volatile compounds concluded that B. licheniformis and S. succinus made major contributions to producing a specific volatile compound profile from soybean cultures where both species exhibited good growth. 3-Hydroxybutan-2-one, butane-2,3-diol, and 2,3,5,6-tetramethylpyrazine are specific odor notes for B. licheniformis, and 3-methylbutyl acetate and 2-phenylethanol are specific for S. succinus. Octan-3-one and 3-methylbutan-1-ol were shown to be decisive volatile compounds for determining the involvement of S. succinus in the soybean culture containing 7% NaCl. 3-Methylbutyl acetate and 3-methylbutan-1-ol were also produced by T. halophilus during soybean fermentation at an appropriate level of NaCl. Although S. succinus and T. halophilus exhibited growth on the soybean cultures containing 14% NaCl, species-specific volatile compounds determining the directionality of the volatile compounds profile were not produced.

• Journal of the Korean Society of Food Culture
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• v.34 no.3
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• pp.268-276
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• 2019

This study separated different factors into the Korean Wave and Korean health food according to the interest in Korean culture among the Chinese living in China. We then conducted a two-step cluster analysis with gender, marriage status, academic background, interest in Korean culture, command of the Korean language and the status of having visited Korea as variables. The subjects were split into a Korean wave-preferring group, highly interested in Korean food as health food group and a low interested group according to clusters, and we then investigated for preference differences for 20 Korean food dishes. Between these two groups the statistics indicated a significant influence with a level p<0.001 for Bulgogi, Bibimbap, Kimchi, Galbi-tang, Galbi-gui, Chicken, Samgyepsal, Doenjang-Jjgae, Dak-galbi, Japchae and Gimbap p<0.01 for Samgye-tang and p<0.05 for Naengmyeon, Kimchi-Jjigae, Dak-galbi, Seolleongtang, Haemul-tang, Hanjeongsik and Tteok-bokki. Jeon and Juk did not show any statistically significant difference. Chinese consumers preferred Korean food for Samgyeopsal, Bulgogi and chicken and less preferred gruel, Hanjeongsik and Kimchi-Jjigae. The highly interested in Korean culture group preferred Samgyeopal, Bulgogi and Chicken, and less preferred Juk, Jeon and Hanjeonsik in that order. This study offers information on the Chinese's preference for different Korean food to any food service enterprises that manage Korean restaurants in China or that sell Korean cuisine and also basic data for differentiated marketing to those entering the Chinese market.

• Journal of the Korean Society of Food Culture
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• v.35 no.6
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• pp.503-523
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• 2020

The purpose of this study was to select 30 representative Korean dishes by a systematic review of preferences and recognition of Korean foods. The papers for the review were located using the keywords 'hansik', 'hanguk eumsik' from DBpia, KISS, NDSL and RISS, and 18 relevant papers were finally short-listed. To analyze the preferences of Koreans and foreigners for Korean dishes, respondents were chosen from various regions such as Asia, Europe, South Pacific, Africa, and North/South America. A total of 4,053 respondents participated in the selected papers and Korean dishes were classified according to the content analysis based on books published by the Rural Development Administration (RDA). Among the main dishes, two kinds of cooked rice were selected, bibimbap and kimbap. Also, noodles, dumplings, and sliced rice cake soup varieties mul-naengmyeon, guksujangguk, mandu, and tteokguk were selected as main dishes. The side dishes selected included 6 kinds of soup, miyeokguk, yukgaejang, samgyetang, gomtang, seolleongtang, and galbi-tang. Other side dishes selected were six types of stews namely doenjang-jjigae, kimchi-jjigae, sundubu-jjigae, haemultang, maeuntang, and dakbokkeum-tang. Three kinds of grilled side dishes selected were bulgogi, galbi-gui, and samgyeopsal-gui. Galbi-jjim was selected in the category of braised or steamed foods. Tteokbokki and japchae were the stir-fried food selected. Pan-fried foods and fried foods selected included a kind of haemul-pajeon and dak-gangjeong respectively. Seasoned vegetables selected were samsaek-namul including gosari-namul, sigeumchi-namul and doraji-namul. Two kinds of baechukimchi and kkakdugi were selected as kimchies, and sikhye was selected in the category of beverages and teas. These results could be used as selection criteria in developing recipes for representative Korean menus.

• Nutrition Research and Practice
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• v.15 no.3
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• pp.382-395
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• 2021

BACKGROUND/OBJECTIVES: Excess intake of dietary sodium, either directly or indirectly, increases the risk of several diseases, including cardio-cerebral vascular diseases such as stroke and hypertension. Excessive sodium intake and increased prevalence of hypertension have emerged as major issues worldwide. Therefore, the present study evaluated the recent trends in dietary sodium intake and the food sources of sodium intake in the Korean population using the Korea National Health and Nutrition Examination Survey (KNHANES, 2013-2017) data. SUBJECTS/METHODS: This study used the one-day 24-h recall dietary intake survey data from the 2013-2017 KNHANES to determine the average daily sodium intake by sex and age and the main dishes and food groups contributing to the dietary sodium intake. RESULTS: The mean sodium intake range was 3,477.2-3,889.6 mg/day during 2013-2017. The major food groups contributing to sodium intake were seasonings (1,597.5-1,870.5 mg/day), vegetables (680.4-756.7 mg/day), and cereal and grains (573.2-609.4 mg/day). Noodles and dumplings (536.7-573.2 mg/day), kimchi (487.3-539.6 mg/day), and soups (367.6-428.9 mg/day) were the top three dish groups that contributed to the sodium intake. In these dishes, the major sources of sodium intake were ramyeon (age groups 10-18 and 19-29 yrs), baechukimchi (age groups 40-49 and 50-59 yrs) and doenjang-kuk (age groups 60-69 and ≥ 70 yrs), respectively. CONCLUSIONS: In summary, reducing the consumption of soups and kimchi is an effective way to reduce sodium intake. Personalized nutrition education on dietary sodium intake management is required because of the different food sources contributing to the sodium intake according to the subjects' age.

• Food Science of Animal Resources
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• v.42 no.6
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• pp.928-941
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• 2022

This study aimed to analyze the microbiological composition and sensory characterization of fermented sausage using strains isolated from Kimchi (GK1, Pediococcus pentosaceus SMFM2016-GK1; NK3, P. pentosaceus SMFM2016-NK3), Doenjang (D1, Debaryomyces hansenii SMFM2021-D1), and spontaneously fermented sausage (S8, D. hansenii SMFM2021-S8; S6, Penicillium nalgiovense SMFM2021-S6). The control was commercial starter culture. Nine treatments were applied [GD (GK1+D1), GS (GK1+S8), GDS (GK1+D1+S8), ND (NK3+D1), NS (NK3+S8), NDS (NK3+D1+S8), GND (GK1+NK3+D1), GNS (GK1+NK3+S8), and GNDS (GK1+NK3+D1+S8)] by mixing lactic acid bacteria and yeast, and S6 was sprayed. The microbial composition of fermented sausage was analyzed [aerobic bacteria (AC), Lactobacillus spp. (LABC), Staphylococcus spp. (STPC), and yeast and mold (YMC)], and pH and electronic nose and tongue measurements were taken. The AC, LABC, STPC, and YMC values of the control and treatment groups tended to increase during fermentation (p>0.05). The STPC values of the GD, GS, ND, and GDS groups were similar to that of the control on day 3. The pH of the control on day 3 was significantly lower than that of the GD, ND, and GND groups (p<0.05). Higher levels of 4-methylpentanol, 2-furanmethanol, and propyl nonanoate, which provide a "fermented" flavor, were detected in the GD group compared to in the control and other treatment groups. GD and ND groups showed higher umami values than the control and other treatment groups. Therefore, it is expected that GD can be valuable as a starter culture unique to Korea when manufacturing fermented sausage.

• Journal of Microbiology and Biotechnology
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• v.32 no.11
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• pp.1462-1470
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• 2022

Natural antimicrobial substances are needed as alternatives to synthetic antimicrobials to protect against foodborne pathogens. In this study, a bacteriocin-producing bacterium, Bacillus subtilis HD15, was isolated from doenjang, a traditional Korean fermented soybean paste. We sequenced the complete genome of B. subtilis HD15. This genome size was 4,173,431 bp with a G + C content of of 43.58%, 4,305 genes, and 4,222 protein-coding genes with predicted functions, including a subtilosin A gene cluster. The bacteriocin was purified by ammonium sulfate precipitation, Diethylaminoethanol-Sepharose chromatography, and Sephacryl gel filtration, with 12.4-fold purification and 26.2% yield, respectively. The purified protein had a molecular weight of 3.6 kDa. The N-terminal amino acid sequence showed the highest similarity to Bacillus subtilis 168 subtilosin A (78%) but only 68% similarity to B. tequilensis subtilosin proteins, indicating that the antimicrobial substance isolated from B. subtilis HD15 is a novel bacteriocin related to subtilosin A. The purified protein from B. subtilis HD15 exhibited high antimicrobial activity against Listeria monocytogenes and Bacillus cereus. It showed stable activity in the range 0-70℃ and pH 2-10 and was completely inhibited by protease, proteinase K, and pronase E treatment, suggesting that it is a proteinaceous substance. These findings support the potential industrial applications of the novel bacteriocin purified from B. subtilis HD15.

• Food Science of Animal Resources
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• v.43 no.3
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• pp.454-470
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• 2023

This study analyzed the microbiological (Lactobacillus spp., Staphylococcus spp., mold, yeast, aerobic bacteria) and physicochemical properties [pH, salinity, water activity, volatile basic nitrogen (VBN), and thiobarbituric acid reactive substances]. The starters were used by mixing Debaryomyces hansenii separated from Korean Doenjang (D) and fermented sausage (S). The starter was inoculated with dry-cured ham and aged for 6 weeks at 20℃ and 25℃, respectively. The aerobic bacteria, Lactobacillus spp., and Staphylococcus spp. of D, S, and DS treatment showed significantly higher values at 25℃ than at 20℃. Among them, S25 treatment showed a high tendency. At week 6, the mold of the S25 treatment was significantly higher than the S20 treatment, and the yeast was higher in 25℃ than 20℃ (p<0.05). The pH of all treatment groups increased with the aging period. Compared with that at 25℃, the pH was significantly higher at 20℃ (p<0.05). The water activity showed a significant decrease as the aging period increased, and the treatment of D25, S20, and DS20 showed a significantly higher value at week 6 (p<0.05). Compared with that at 20℃, the VBN content was higher at 25℃. At week 6, the VBN contents of the C20, S25, and DS25 groups were higher than those of the other treatment groups. Therefore, inoculation of D. hansenii separated from fermented sausage produced in Korean starter at 25℃ is expected to improve the safety of harmful microorganisms and physiochemical properties in dry-cured ham.

• Microbiology and Biotechnology Letters
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• v.9 no.4
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• pp.253-261
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• 1981

Fermented foods available in Korea may be classified into four groups, namely, fermented soybean products, fermented cereal products, fermented vegetable products, and fermented fishery products based on raw materials used. The representative fermented foods based on soybean are Kanjang(soysauce), Doenjang(fermented soybean pastes), and Kochujang(red pepper added-fermented soybean paste). Such fermented products are made using Meju(functioning as a starter and prepared by fermentation of steamed soybean mash) as an essential ingredient, and used widely as a soup base and/or in seasoning side-dishes for everyday meals year around. Excepting Sikhae, all fermented products based on rice and other cereal grains are of alcoholic nature. Takju (Makgeolli) used to be made using rice as the major raw material, however, mainly due to the shortage of rice in recent years, other cereals, such as, barely, corn, and wheat flours are also used to replace rice today. Owing to such changes in the raw materials. the popularity of Takju has been somewhat reduced, yet it is still widely consumed in rural areas. Although Chungju is a popular rice wine with superior qualify over Takju, the amount consumed is considerably limited. The highest qualify rice wine, Bupju, in particular, is made by a low temperature fermentation using glutinous rice. Kimchi is an unique fermented vegetable product of long tradition in Korea. Although it was for consumption mainly in winter season serving as a source of vitamins, today it is widely used throughout the year. Except Kkakdugi and Dongchimi, all of the fermented vegetable products contain salted Korean cabbage as an essential item, while they abound in varieties depending on material composition and methods of processing, and also on seasons and localities Next to Kimchi in this category is Kkakdugi made of raddish in popularity and quantity consumed. The four groups of fermented food products described above are reviewed in some detail and evaluated in terms of their nutritional significances, processes and microorganisms involved. and their commercial potentials. Jeotkal (or Jeot) is a name given to all fermented products of fishery origin. A number of Jeot can be prepared by adding salt and allowing fermentation to the raw materials such as shrimp, anchovy octopus, clam, oyster, etc.

• Food Science and Preservation
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• v.30 no.1
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• pp.28-41
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• 2023

Non-aflatoxigenic Aspergillus oryzae and aflatoxigenic A. flavus cannot be clearly identified by partial sequencing of the internal transcribed spacer (ITS) and 18S ribosomal ribonucleic acid (18S rRNA) regions. This study aimed to compare the accuracy among three aflatoxin detection methods using ultra-performance liquid chromatography (UPLC), high-performance liquid chromatography (HPLC), and an enzyme-linked immunosorbent assay (ELISA) kit and to select the non-aflatoxigenic Aspergillus sp. isolated from soybean paste. All analytical methods were suitable according to the international standards of Codex Alimentarius FAO-WHO (CODEX) or the Ministry of Food and Drug Safety (MFDS). UPLC exhibited the best of limit of detection (LOD) and limit of quantification (LOQ). Based on UPLC, HPLC, and the ELISA kit assay, the P5 and P7 strains isolated from soybean paste had 1,663.49, 1,468.12, and >20 ㎍/kg and 1,470.08, 1,056.73, and >20 ㎍/kg, respectively, detected and re-identified as A. flavus. In contrast, the P3 and P4 strains (A. oryzae), which were detected below the MFDS standards in all assays, were confirmed as non-aflatoxigenic fungi. Among the methods evaluated for quantitative analysis of aflatoxin, UPLC and HPLC are superior in terms of accuracy, and the ELISA kit rapidly detects low concentrations of aflatoxin. Furthermore, this study demonstrates that any Aspergillus sp. isolated for use as a fermentation starter should be analyzed for potential aflatoxin production using UPLC and HPLC for accurate quantitative analysis or ELISA for the rapid detection of low-level concentrations of aflatoxin.