• KSBB Journal
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• v.18 no.4
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• pp.312-317
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• 2003

The addition of glycine up to 0.5％ (w/v) to Luria broth (LB) media on the secretion of levansucrase in a recombinant strain Escherichia coli JM109/pUPLK1 was observed to enhance the release of periplasmic proteins from the cell to the broth, without significantly affecting the cell growth rate and protein productivity. However, the glycine concentration at 1 ％ (w/v), the cell density attainable at the stationary phase fell to about 50％ and the extracellular activity of levansucrase corresponded to about 80％ of the total (extracellular plus intracellular) activity and increased by 2.6-fold, comparing to the cells grown in the absence of glycine. The increased pH at stationary phase accelerated the degradation of levansucrase. Maximal extracellular activity was attained when 1 ％ glycine was supplemented at the onset of strain growth.

• The Korean Journal of Food And Nutrition
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• v.34 no.2
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• pp.187-195
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• 2021

This study was performed to investigate the antioxidant and antidiabetic activities of soybean fermented with Monascus. Also, the changes in the content of isoflavones and Monacolin K were analyzed. It was observed that the glycoside forms of daidzin and genistin were converted to aglycones of daidzein and genistein within 6 days of fermentation. The product can be used as a health functional material that can increase bioavailability. Monacolin K production was found to increase significantly with the progression of fermentation with an increase to 0.04 mg/g and 0.44 mg/g on 6 and 12 days of fermentation, respectively. The DPPH radical scavenging activity of soybean fermented with Monascus was significantly increased compared to that of soybean. The protein expression of inflammation-related genes (TNF-α, IL-6, and COX-2) in the MIN cell was significantly increased in the presence of alloxan compared to the normal group, but a decrease was observed in the presence of soybean fermented with Monascus. In conclusion, soybean fermented with Monascus showed the highest antidiabetic and antioxidant effects. These results suggest that soybean fermented with Monascus has the potential to be used as a beneficial ingredient with antidiabetic and antioxidant effects.

• The Korean Journal of Food And Nutrition
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• v.35 no.2
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• pp.127-136
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• 2022

Comparing the quality characteristics of kimchi were measured and anticancer effects using AGS human gastric cancer cells were observed. Five kinds of kimchi samples were made of Kanghwa Baek kimchi (KB), Kangwha Turnip kimchi (KT), Turnip: Chinese cabbage = 1:1 Baek kimchi (T1B1), Turnip:Chinese cabbage = 4:1 Baek kimchi (T4B1), Turnip mul kimchi (T). As a result T kimchi showed the best fermentation characteristics among the five samples. T kimchi had a lower percentage of the total number of aerobic bacteria, while the number of lactobacillus was higher than that of other samples. The mRNA and protein expression levels of apoptosis-related factors found that T kimchi significantly increases the mRNA expression levels of caspases-3 and caspases-9 in AGS human gastric cancer cells as compared to the other kimchi samples. It showed high anticancer effects in the order of T, T1B1, and KB kimchi. As the anticancer effect of Turnip mul kimchi made only of turnip was higher, the higher the turnip content, the higher the anticancer effect. These results show that there were changes in fermentation characteristics such as pH, acidity, number of lactic acid bacteria, and anticancer effects according to the ratio of turnip and cabbage.

• The Korean Journal of Food And Nutrition
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• v.35 no.5
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• pp.359-368
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• 2022

In this study, the quality characteristics of kimchi, such as its salinity, pH, and acidity, were measured and compared, and the HT-29 human colon cancer cells were used to show the anticancer effects of kimchi. The kimchi samples used herein included standard kimchi (SK), turnip kimchi (TK), and turnip-powder-added kimchi (TPK). The measured pH and acidity of TK and TPK showed no significant differences with those of SK. Compared to SK and TK, TPK had higher DPPH scavenging activity and higher total flavonoid content, confirming its antioxidant activity. The cancer cell growth inhibition rates of TK and TPK were significantly higher than that of SK. In HT-29 cells treated with TPK, the mRNA expression of Bcl-xL, an anti-apoptosis-related gene, was lower, and the mRNA expressions of the apoptosis-related genes Bax, Bad, and caspase-9 were higher. TPK showed significantly higher levels of mRNA expressions for the cell-cycle-related genes p53 and p21 than the other samples, in addition to suppression effects on cancer cell proliferation. Compared to SK, TK and TPK suppressed the growth of colon cancer cells and showed higher anticancer effects. Therefore, it is shown that kimchi with added turnip powder had high anticancer effects.

• The Korean Journal of Food And Nutrition
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• v.36 no.4
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• pp.296-308
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• 2023

This study investigated the anti-obesity effects of Coriandrum sativum L. ethanol extracts in a high fat diet-induced obesity model (DIO). We confirmed the anti-obesity effects by analysing the expression of the related proteins, weight gain, dietary intake, dietary efficiency, blood biochemistry, histological analysis and western blot analysis. After oral administration of Coriandrum sativumL. ethanol extracts at concentrations of 250 and 500 mg/kg, a significant improvement in dietary efficiency, reduction in weight gain, triglycerides, total cholesterol and LDL-cholesterol in blood lipid was observed for 8 weeks. In addition, improvement in blood glucose and metabolism confirmed through glucose tolerance test was observed. Further, the concentration of alanine transaminase (ALT) in blood was significantly decreased, which improved the fatty liver caused by high-fat diet intake as confirmed by liver tissue analysis. This phenomenon was confirmed to decrease the expression of fat accumulation-related PPARγ and FAS protein in the liver tissue. Especially, it is believed that FAS, a liposynthetic enzyme, has a stronger inhibitory effect than PPARγ. Therefore, Coriandrum sativum L. ethanol extract is thought to improve obesity by reducing blood lipids levels, improving glucose metabolism and inhibiting synthesis of the fat that accumulates in the liver in high-fat diet-induced obesity animal models.

• The Korean Journal of Food And Nutrition
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• v.36 no.3
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• pp.172-184
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• 2023

The objective of this study was to determine the efficacy of a natural product of cherry tree (Prunus serrulata var. spontanea: PS) as a test substance for improving cytokine and ovalbumin-specific IgE using an ovalbumin-induced asthma disease model of 5-week-old male BALB/c mice. Lung tissue pathology was analyzed to confirm anti-inflammatory and asthmatic effects. As a result of examining the effect on changes in inflammatory cells in bronchoalveolar lavage fluid in an ovalbumin-induced asthma disease model by administering the PS sample, total cells, eosinophil, neutrophil, lymphocyte, and monocytes were significantly decreased. Concentrations of cytokine-based TNF-alpha and IL-4 and immunoglobulin E in serum were significantly increased in the asthma-inducing negative control group than in the normal group. However, high concentrations of PS decreased them. In histopathological examination of the lung tissue, it was confirmed that inflammatory cells infiltrated around the alveoli and bronchioles were increased in ovalbumin-induced asthma disease model. After administration of cherry tree extract, bronchiolar morphological changes such as mucosal thickening were slightly improved. From the above results, it was confirmed that extract of cherry tree significantly reduced inflammation expression and tissue damage in alveolar tissues. It was also confirmed that the cherry tree extract had an excellent efficacy in improving asthma inflammation.

• The Korean Journal of Food And Nutrition
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• v.36 no.5
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• pp.403-414
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• 2023

This study aimed to determine the anti-obesity effect of adding Wolfiporia extensa Ginns (W) to fermented pollack skin products in an obesity-induced animal model. The experimental groups were the normal diet group (C), high-fat diet group (HF), dried pollack skin (H1), fermented pollack skin (H2), and W of 0.1 (F2-WL), 0.3 (F2-WM), and 0.5 (F2), respectively. It was confirmed that adding W to fermented pollack skin reduced blood triglycerides, total cholesterol, and LDL levels, while increasing HDL levels. Wolfiporia extensa Ginns was effective in controlling weight and improving blood lipids in a dose-dependent manner. In histological analysis, findings of fatty liver induced by a high-fat diet were improved by the addition of H2 and W. Size and density of fat globules in the epididymis were decreased. In addition, the concentration of TNF-α was increased in the high-fat diet group, but decreased by the addition of fermented pollack skin and W. In conclusion, adding fermented dried pollack skin and Wolfiporia extensa Ginns was effective for weight control and blood lipid improvement. Thus, the use of by-products in functional foods is expected to have a high value in the future.

• The Korean Journal of Food And Nutrition
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• v.36 no.6
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• pp.535-542
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• 2023

We investigated the anti-inflammatory effects of shiitake mushroom and kelp (SMK) mixture extracts in lipopolysaccharide (LPS)-stimulated murine RAW 264.7 cells. Treatment of RAW 264.7 cells with LPS significantly increased NO (nitric oxide) production, pro-inflammatory cytokines (tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-6, and IL-1β), and inflammation-related genes (COX-2 and inducible nitric oxide synthase (iNOS)). In cytotoxicity testing using RAW 264.7 cells, SMK mixture extracts in the range of 1-16 ㎍/mL did not inhibit cell proliferation. However, SMK mixture extracts significantly inhibited NO production in a dose-dependent manner (p<0.05). SMK treatment significantly decreased TNF-α, IL-6, IFN-γ, and IL-1β levels compared to the LPS group, and similarly, pro-inflammatory cytokine mRNA levels also decreased. SMK mixture extracts reduced the mRNA expression of COX-2 and iNOS in RAW 264.7 cells compared to LPS (p<0.05). The above results show that SMK mixture extracts suppressed the inflammatory response induced by LPS. In particular, the extracts were shown to regulate the inflammatory response by suppressing the expression of inflammatory cytokines and inflammation-related enzymes.

• Food Science and Preservation
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• v.16 no.6
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• pp.804-809
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• 2009

Recently, many Koreans have started to consume aged kimchi fermented long-term at low temperatures. In the present study, the effect of low temperature ($5^{\circ}C$) on pH, titratable acidity (TA), organic acid level, viable microbial cell count, amino acid concentration, and polygalacturonase activity (PG) during long-term fermentation (46 weeks) of kimchi, were evaluated. After 10 weeks of fermentation, kimchi had a pH of 4.1 and a TA of 1.0%, respectively after 46 weeks fermentation, these values were 3.9 and 1.3%, respectively. Lactic acid, the ratio of lactic acid to acetic acid, and the ratio of Lactobacillus species/Leuconostoc species in kimchi increased as fermentation progressed from 10 weeks to 46 weeks. However, total viable cell counts of aerobic bacteria, yeasts, Lactobacillus species, and Leuconostoc species, free amino acid levels, and PG decreased as the fermentation period was extended from 10 weeks to 46 weeks.

• Journal of Nutrition and Health
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• v.36 no.1
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• pp.32-39
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• 2003

Phytoestrogens, especially soy-derived isoflavones, are receiving great scrutiny as a food supplement for preventing hormone dependent disease such as postmenopausal osteoporosis. Their beneficial effects are derived from aglycone form of isoflavones, such as daidzein, genistein or glycitein. In contrast to the common usage of soybean, black bean (Rhynchosia Molubilis : Yak-kong) has been used as a supplement for preventing postmenopausal osteoporosis in oriental medicine. To investigate the effects of the saliva, artificial stomach fluid, and digestive enzymes on the conversion of glycosidic isoflavone to aglycone form, soybean and black bean were extracted with 70% methanol and freeze-dried. The recovery yield of methanol extracts of black bean was 14.1% which was higher than that of soybean, 13.5%. In terms of total isoflavones, we routinely obtained larger amount of isoflavones from black bean than those from soybean. By incubating methanol extracts of soybean and black bean with IN HCI for 180 min, the proportions of aglycones relative to the total isoflavone were significantly increased (32.4% and 52.4%, respectively). In vitro conversion, digestive enzymes ($\beta$-glucosidase and $\alpha$-glucosidase) may hydrolyze glycosidic bond of isoflavone more effectively than saliva or artificial stomach fluid did. It seems to say that the activity of $\beta$-glucosidase was higher than those of $\alpha$-glucosidase. The rate of conversion of glucoside form to aglycone form in black bean and soybean was low in physiological condition (pH) tested, although the enzymatic hydrolysis of glucoside was active. These results demonstrated that the composition of aglycone in food may be the important factors in terms of the bioavailability of isoflavones. (Korean J Nutrition 36(1): 32-39, 2003)