• Journal of the East Asian Society of Dietary Life
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• v.6 no.1
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• pp.105-114
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• 1996

Certain Fungi Including Aspergillus flavus produce low molecular secondary metabolite that is toxic to human and animals, which have been termed mycotoxin. Given the proper humidity and temperature like summer in Korea, are capable of growing of those hazard fungi and elaborating mycotoxin on almost any organic substrate such as traditional foodstuffs and their raw materials including rice, barley, corn, meju, doenjang and gochujang etc. Until now, some people have examined to isolate various fungi such as Aspergillus sp., Penicillium sp. and Fusarium sp. from traditional foodstuffs and raw materials, and have screened various mycotoxin producing strains. Some mycotoxin contamination such as aflatoxin, ochratoxin, deoxynivalenol (DON) and zearalenone etc. also have been confirmed from similar above samples. But these data are different each other and inconsistent in experimental conditions and methods. Especially, almost experiments have been finished for one time. So more consistent experimental method and data are necessary to evaluate objectiely the safety of traditional foodstuffs subjected to the mycotoxin. For this purpose, we have to apply a new advanced technology to develop more simple and rapid methods for determination of mycotoxin and also have to concentrate our efforts on activation of research and accumulation of technology nth sustaining investment of financial support and enlargement of research installation. With those harmonious efforts, it should be possible to examine continuously nd systematically the mycotoxin contamination in our traditional foodstuffs and to assure the safety of them. Then we can maintain and develop the better traditional foodstuffs suited to internationalization.

• Korean Journal of Food Science and Technology
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• v.27 no.2
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• pp.230-234
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• 1995

Angiotensin converting enzyme(ACE) inhibitory peptides lowering blood pressure were fractionated from a commercial soybean paste(Doenjang). When the freeze-dried sample of soybean paste was extracted with cold water, the recovery yield of total nitrogen(TN) was shown to be 73.3% in 30 minutes. The cold water extract was filtered through PM-10 membrane(Amicon) for 3 hours in order to remove high molecular weight polypeptides. The TN and salt of ultrafiltrate were recovered to 80.8% and 99.2%, respectively, and its ACE $IC_{50}$ was $41.8{\mu}g/ml$. When the ultrafiltrate was divided into 7 fractions by reverse phase prep-HPLC, F5 fraction showed the highest ACE inhibitory activity ($IC_{50}=6.8{\mu}g/ml$) and salt could be collected into F1 fraction. Subsequently, the F5 fraction was divided into another five fractions by ion exchange prep-HPLC, all of which appeared to be high ACE inhibitory activity($IC_{50}=2.5{\sim}8.3{\mu}g/ml$). Among them, F53 fraction had the highest ACE inhibitory activity, and its main amino acid component was found to be histidine.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.522-525
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• 2014

The effects of temperature and inosine monophosphate (IMP) on the germination of artificially inoculated Bacillus cereus spores in ganjang, doenjang, and gochujang sauces were investigated. The pH and salt concentration of the sauces were as follows: ganjang (4.84, 7.45%), doenjang (4.26, 5.07%), and gochujang (3.54, 3.24%), respectively. Treatment at $40^{\circ}C$ or $80^{\circ}C$ resulted in a B. cereus growth of 0.8 log CFU/g in ganjang sauce; this concentration increased to 2.25 log CFU/g and 1.21 log CFU/g, respectively, when 10 mM IMP was added. Compared with that for ganjang sauce, the germination effect was comparatively lower for doenjang sauce by 10 mM IMP+$40^{\circ}C$ treatment (0.46 log CFU/g) and 10 mM IMP+$80^{\circ}C$ treatment (0.85 log CFU/g). However, no germination effect was noted for gochujang sauce by any treatment in this study. Therefore, the results suggested that pH is an important factor affecting spore germination in sauces.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.814-818
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• 2001

This study was carried out to investigate changes in salinity, pH, ascorbic acid, chlorophyll and its derivatives of the different gochu-jangachi (unripe hot pepper preserved in soybean paste and soy sauce). As the fermentation proceeded, the salinity of these samples stored at 15$^{\circ}C$ was higher than that stored at 5$^{\circ}C$. The pH of samples was slowly lowered and little different during the fermentation at 5$^{\circ}C$. In the during fermentation at 15$^{\circ}C$, the pH of gochu-jangachi with soybean paste was maintained over 5 until 60 days and that of gochu-jangachi with soy sauce was dropped under 5 after 32 days, after that the value was slowly decreased. As fermentation time passed, the content of ascorbic acid in gochu-jangachi was decreased rapidly at 15$^{\circ}C$ than at 5$^{\circ}C$ and that was disappeared after 16 days (soybean paste) and 20 days (soy sauce). In both samples, the degradation of chlorophyll a was faster than chlorophyll b, especially at 15$^{\circ}C$. The degradation of chlorophylls or production of pheophytin and pheophorbide were closely related to the ascorbic acid content during fermentation.

• The Korean Journal of Food And Nutrition
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• v.29 no.5
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• pp.785-794
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• 2016

This research was conducted to evaluate quality changes in traditional Doenjang and manufactured Doenjang during a storage period of 8 weeks. Low-salt Doenjang and commercial Doenjang were purchased from different manufacturers and proximate analysis as well as changes in isoflavone, polyphenol, flavonoid contents of the samples were investigated using a mass spectrophotometer. The salinity of traditional Doenjang, low salt Doenjang, and commercial Doenjang were $13.2{\pm}1.15$, $7.17{\pm}2.74$, $10.67{\pm}0.35%$, respectively and the salt concentrations of the soybean pastes did not change during storage. After 8 weeks at $35^{\circ}C$, chromatic values of all the paste samples decreased somewhat, with traditional Doenjang exhibiting fewer changes as compared to manufactured Doenjang. Amino acid nitrogen, acidity, microbial population all tended to increase with time, although some samples showed fluctuations during the test period. Moreover, the total isoflavone contents of traditional Doenjang increased with storage time while that of manufactured Doenjang tended to decrease. The isoflavone aglycone was shown to be the highest in traditional Doenjang, while isoflavone glycoside was abundant in manufactured Doenjang. Total flavonoid contents showed similar trends regardless of samples; initial contents of total flavonoid was 0.6 mg/g which increased to more than twice to 1.4 mg/g at the end of storage period. Composition profile of Doenjang extracts was analyzed using UPLC-Q-ToF.

• Journal of Nutrition and Health
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• v.46 no.1
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• pp.86-97
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• 2013

This study investigated the eating habits of elementary school children and their perceptions related to traditional Korean foods, based on the health belief model. The subjects were fifth grade elementary school children (274 boys and 274 girls) in eight Korean cities. The results were as follows: The children ate almost three meals per day and were grateful for their meals. However, they irregularly consumed meals and snacks. They tended to eat heartily and did not eat foods that they had not yet eaten. Their meals were based on rice and they have eaten kimchi and vegetables at almost every meal. However, they had undesirable habits in eating other foods, such as fruits, fish, soybeans, and sweet foods. They did not sensitively or seriously perceive their eating habits in relation to their health. They perceived that it was very good for their nutrition, health, and tastes to eat traditional Korean foods, and they had pride in traditional Korean foods and eating style. Although they expressed some difficulty regarding availability and preparation of traditional Korean foods, they hardly felt difficulty in eating them. They had high dietary self-efficacy with regard to eating these foods, except for two items of self-regulation. Their eating habits showed positive correlation with dietary self-efficacy, perceived susceptibility, and perceived benefit. In conclusion, eating habits of elementary school children in relation to traditional Korean foods are not desirable, but not serious. They did not sensitively or seriously perceive their eating habits in relation to their health. However, they perceived that it was very good for their nutrition and health to eat traditional Korean foods, did not have a high level of difficulty in eating them, and had high dietary self-efficacy with regard to eating them. Therefore, we suggest that children should be exposed to various traditional Korean foods, along with education about them, in order to enhance their concern and motivation to eat them.

• Food Science and Preservation
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• v.24 no.1
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• pp.145-152
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• 2017

In this study, near infrared (NIR) spectroscopy known as a non-destructive analysis technique was applied to investigate peptide cleavage and consequent release of amino acids in soybean lumps as affected by its moisture content and incubation time during fermentation at 25 for 3 weeks. The NIR spectra of the soybean lump semi-dried and soaked in saline water showed that absorption intensity around 1,400 nm originating from hydrogen bonds of water decreased and absorption band shifted to 1,430 nm as moisture content decreased during incubation at 25 for 3 weeks. In addition, absorption around 2,050 nm which was assigned to amino groups increased as incubation time increased. NIR spectra data from 1,000 to 2,250 nm showed higher accuracy in the discriminant analysis between outside and inside parts of fermented soybean lumps than visible spectra result. NIR spectroscopy for the amino acid and moisture contents in traditional fermented soybean lumps showed relatively good accuracy with the multiple correlation coefficient ($R^2$) of 0.91 and 0.81, respectively, and root mean square error of cross validation (RMSECv) of 0.23 and 0.83%, respectively, in partial least square regression (PLSR). These results indicate that NIR spectral observations could be applicable to control the fermentation process for preparation of soybean products.

• Journal of Food Hygiene and Safety
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• v.29 no.1
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• pp.40-46
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• 2014

We have screened Bacillus strains suitable for the fermentation of soybean products with respect to the control of Bacillus cereus and the reduction of biogenic amines. Of 26 isolates, a strain named as the SCK A08 carried antimicrobial activity against B. cereus and Staphylococcus aureus, major food poisoning species in soybean products. PCR analysis revealed that the SCK A08 strain did not contain genes for Bacillus cereus toxins including nonhemolytic enterotoxin, hemolytic enterotoxin, cytotoxin K, cereulide and certrax. The SCK A08 strain could degrade histamine, tyramine, putrescine, and cadaverine by 67.41%, 76.59%, 57.32%, and 50.69%, respectively, during fermentation in cooked soybeans containing 0.5% (w/w) of each biogenic amine. The morphological and biochemical properties and phylogenetic relationships based on 16S rRNA gene sequences indicated that the isolate was most closely related to Bacillus licheniformis. Use of the strain SCK A08 would be a potential measure to overcome two hygienic problems that were frequently faced during manufacture of traditionally fermented soybean products.

• Journal of the Korean Society of Food Culture
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• v.35 no.5
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• pp.467-477
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• 2020

Doenjang is a major fermented soy-based food in Korea. Recent investigations have shown that fermented soybean foods have immunity-enhancing, anti-cancer, anti-obesity and anti-diabetic effects. Several studies also have reported that genistein and daidzein, which are easily absorbed in the body are produced in larger quantities in aged doenjang. The purpose of this study was to evaluate the variations in the anti-cancer effects of commercialized doenjang as it ages. Four groups were formed for this study according to aging periods of doenjang, namely short (under 5 years, S group), mid (under 10 years, M group), long (under 15 years, L group) and very long (over 15 years, E group). The anti-cancer effects of doenjang were determined by cell cytotoxicity assays in A549, YAC-1, and HepG2 cancer cell lines. Also, NK cell activity and splenocyte proliferation were assayed for cancer immunotherapy. The quantities of phenolic compounds in doenjang at different ages were also measured. The results showed that the anti-cancer effects increased in the S and M groups for all three cancer cell lines. Interestingly, similar to this result, splenocyte proliferation and NK activity were also the highest in the S and M groups. In contrast, the E group showed significantly reduced splenocyte proliferation. The quantity of phenolic compounds was similar to that of the anti-cancer results. Collectively, these results suggest that the fermentation period of doenjang plays a very important role in determining its anti-cancer effects.

• The Korean Journal of Food And Nutrition
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• v.22 no.3
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• pp.449-455
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• 2009

The principal objective of this study was to determine the quality and potential of DHEA formation after the addition of diosgenin of yam(Dioscorea spp.) during the fermentation of soybean paste. All samples were divided into three groups based on the variety of yam. In sample A, the soy source was not separated from soybean paste and in sample B, the soybean source was separated from soybean paste. The range in salt concentration in the samples was as follows : sample A: 10.5~11.8%, samples B: 7.9~8.8%. However, no substantial differences between the two samples, in terms of salt content, were observed. The crude protein and crude lipid content were found to decrease with the fermentation time of soybean paste(passage of 30 days: 26.4~32.3% and 4.45~5.90%, passage of 60 days: 24.5~28.5% and 3.95~4.90%, respectively). As the fermentation time of soybean paste increased, the nitrogen from amino compounds increased(passage of 30 days: 531.9~687.7 mg%, passage of 60 days: 551.3~706.8 mg%). In regards to color and preference, sample B, where the soy source was separated from soybean paste, was better than sample A, where the two components were not separated. After a soybean paste fermentation time of 60 days, the diosgenin of yam, which was added to the soybean paste, was not detected in tested samples, and the contents of DHEA formation in soybean paste were as follows: sample A: $488.0\pm42.5{\sim}719.3\pm44.8{\mu}g/g$, sample B: $287.3\pm20.6{\sim}482.7{\pm}36.5{\mu}g/g$.