• Journal of Dairy Science and Biotechnology
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• v.40 no.3
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• pp.103-109
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• 2022

Lactic acid bacteria with antibacterial activity can be effectively used as probiotics to inhibit the growth of harmful bacteria that cause food spoilage or food poisoning. In this study, Pediococcus pentosaceus M132-2, isolated from soybean paste, was analyzed for its effects on three major contaminating fungi. M132-2 was confirmed to exert antifungal activity by inhibiting the growth of all three fungi tested. In addition, M132-2 displayed excellent salt resistance and low temperature tolerance. Thus M132-2 can survive at the salinity level in cheese and at the low temperatures used in the aging process. Finally, when supernatant from an M132-2 culture was applied to Gouda cheese, the growth of contaminating fungi was significantly inhibited. Consequently, M132-2 may be useful for the prevention of spoilage of various foods, including cheese.

• Korean Journal of Agricultural Science
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• v.49 no.4
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• pp.893-904
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• 2022

It is well documented that the fruit of the vitamin tree, which is rich in vitamins A, C, E, and K, shows anti-diabetic, antibacterial, immune regulation, anti-inflammatory, and anti-aging effects. In some countries including Europe it has been used to develop various functional foods. This study was conducted to elucidate the fermentation properties of fermented milk supplemented with vitamin tree (Hippophae rhamnoides L.) fruit powder. The pH, titratable acidity, number of viable cells, and viscosity of the yogurt made with vitamin tree fruit powder were found to be higher than those of the control group, as the amount of supplemented powder added became higher and the fermentation progressed. Production of lactic, malic, and acetic acids increased relative to that of the control as the amounts of supplemented powder were higher. It was found that the increase in the decomposition of lactose to glucose and galactose was proportional to the amount of supplemented powder added and the elapsed fermentation time. During storage for 15 days the quality of yogurt supplemented with vitamin tree fruit powder was within the proper range of fermented milk quality in terms of pH, titratable acidity, and number of lactic acid bacteria. The yoghurt manufactured with vitamin tree fruit powder has a similar quality to that of the control, and therefore, a new functional yoghurt providing health benefits could be developed.

• Journal of Food Hygiene and Safety
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• v.22 no.4
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• pp.382-387
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• 2007

The approval of use of certain food-grade phosphates as food additives in a wide variety of meat products greatly stimulated research on the applications of phosphates in foods. Phytic acid is a natural plant inositol hexaphosphate constituting 1-5% of most cereals, nuts, legumes, oil seeds, pollen, and spores. In this study, we investigated antibacterial activity of sodium phytate (SPT) against Salmonella typhimurium in tryptic soy broth with different pHs and in chicken, pork and beef. In tryptic soy broth, SPT at the concentrations of 0.1, 0.5, and 1.0% effectively inhibited the growth of Salmonella typhymurium in a concentration-dependent manner. At pH 5.5-7.0 similar to meat pHs, 1% SPT almost completely inhibited the bacterial growth. The inhibitory effect of SPT was stronger at pH 7.0 than pH 5.5. In chicken, pork, and beef, SPT at the concentrations of 0.1, 0.5, and 1% significantly inhibited the growth of Salmonella typhimurium in a dose-dependant manner (p<0.01). The addition of 1% SPT in the meats significantly increased the meat pHs. These results indicate that SPT is very effective for inhibition of bacterial growth as a muscle food additive for increasing food safety and functions.

• Restorative Dentistry and Endodontics
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• v.25 no.4
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• pp.561-574
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• 2000

Poly-P has been used to prevent decomposition of foods and has been shown to have inhibitory effect on the growth of gram positive bacteria. The purpose of this study was to evaluate the effect of poly-P on the growth of Porphyromonas endodontalis, a gram negative obligate anaerobic rod, endodontopathic bacterium. P. endodontalis ATCC 35406 was in BHI broth containing hemin and vitamin K with or without poly-P. Inhibitory effect of each poly-P which was added at the beginning(lag phase) or during(exponential phase) the culture, MIC(minimum inhibitory concentration) was determined by measuring the optical density of the bacterial cell at 540nm. Viable cell counts were measured to determined whether poly-P has a bactericidal effect. Leakage of intracellular nucleotides from P. endodontalis was determined at 260nm and morphological change of P. endodontalis was observed under the TEM(transmission electron microscope). Binding of 32P-labeled poly-P to P. endodontalis was examined. SDS-polyacrylamide gel electrophoresis and zymography were performed to observe the changes in protein and enzyme profiles of P. endodontalis, respectively. The results from this study were as follows : 1. The minimal inhibitory concentration(MIC) of poly-P to P. endodontalis appeared to be 0.04~0.05%. 2. Poly-P added to the P. endodontalis culture during the exponential phase of P. endodontalis was as much effective as poly-P added at the begining of the culture, suggesting that the antibacterial effect of poly-P is not much dependent on the initial inoculum size of P. endodontalis. 3. Poly-P are bactericidal to P. endodontalis, demonstrating the decrease of the viable cell counts. 4. Intracellular nucleotide release from the P. endodontalis, was not increased in the presence of poly-P and was not reversed by the addition of divalent cations like $Ca^{2+}$ and $Mg^{2-}$. 5. Under the TEM, it was observed that fine electro-dense materials were prominent in the poly-P grown P. endodontalis, appearing locally in the cell, and the materials were more abundant and more dispersed in the cell as the incubation time with poly-P increased. In addition, highly electron dense granules accumulated in many poly-P grown cells, most of which were atypical in their shape. 6. Binding of 32P-labeled poly-P to P. endodontalis appeared to be 32.8 and 45.5 and 53.4% at 30 minutes, 1 hours and 2 hours, respectively. 7. In the presence of poly-P. the synthesis of proteins with apparent molecular masses of 25, 27, 35, 45 was lost or drastically decreased whereas expression of a protein with an apparent molecular mass of 75 was elevated. 8. Proteolytic activity of P. endodontalis was decreased by poly-P. The overall results suggest that use of poly-P may affect the growth of P. endodontalis, and the anti-bacterial activity of poly-P seems largely bactericidal. Changes in shape, protein expression, and proteolytic activity of P. endodontalis by poly-P may be directly and indirectly attributed to the antibacterial effect of poly-P. Further studies will be needed to confirm the effect of poly-P.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.249-254
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• 2002

To determine the abilities as both lactic starter and probiotics for fermented foods, we investigated the potency of acid production, proteolytic activity and lactose metabolism of Lactobacillus amylovorus IMC-1. And the strain was cultured with lactococci in 10% skim milk medium. It was also examined the bactericidal action of antibacterial substance, produced by the strain IMC-1, against pathogenic bacteria. L. amylovorus IMC-1 showed excellent production of acid in 10% skim milk supplemented with yeast extract, and produced 0.8 and 2.7% of acid at 12 and 72 h incubation, respectively. It was found that the activity of ${\beta}-galactosidase$, about $39\;{\mu}M/minute/dry$ cell weight (mg), was stronger than that of $phospho-{\beta}-galactosidase$ in the strain IMC-1. The strain showed weak proteolytic activity in 10% skim milk, thus it produced 6 and $69\;{\mu}g/mL$ of free tyrosine at 12 and 72 h cultivation, respectively. It was known that the strain utilized mainly ${\alpha}-casein$ than ${\beta}-casein$ from patterns of SDS-PAGE. Mixed culture produced more acid than single cultures of L. amylovorus IMC-1 and Streptococcus thermophilus NIAI 510. Single culture of Str. thermophilus and mixed culture showed increasing cheese flavor with incubation times. Optimal fermentation time of mixed culture for the acid production and flora of lactic starter was 16 and 12 h by adding 0.1 and 0.5% of yeast extract to 10% skim milk, respectively. Antibacterial substance produced by the strain IMC-1 reduced about 2 log of the viable cell counts of both Escherichia coli O157 and Shigella flexneri after 24 and 4 h incubation, and they were not detected after 48 and 6 h incubation, respectively.

• Journal of Life Science
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• v.22 no.2
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• pp.251-258
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• 2012

The purpose of this study was to investigate the probiotic properties of lactic acid bacterial strains isolated from animal feces. BCNU 9041 and BCNU 9042 isolates were assigned to Lactobacillus brevis on the basis of their physiological properties and 16S ribosomal DNA sequences analysis. They were confirmed as safe bioresources because of their non-hemolytic activities and non-production of harmful ${\beta}$-glucosidase, ${\beta}$-glucuronidase, tryptophanase, or urease. These isolates were also highly resistant to acid (at pH 2.5) and bile acids (at concentration of 0.3%, 0.6%, and 1% oxgall). In addition, they exhibited good antibacterial activity against food-borne bacteria, especially Bacillus cereus, Listeria monocytogenes, and Shigella sonnei. Furthermore, it was demonstrated that they have the highest levels of hydrophobicity and that they showed bile salt hydrolytic and cholesterol assimilation activity. These results suggest that BCNU 9041 and 9042 have good potential for application in functional foods and health-related products.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.spc1
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• pp.25-45
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• 1996

Soyfoods have potential roles in the prevention and treatment of chronic diseases, most notably cancer, osteoporosis, and heart disease. There is evidence that carcinogenesis are supressed by isolated soybean derived products in vivo such as a protease inhibitor, phytic acid, saponins and isoflavones. It is believed that supplementation of human diets with soybean products markedly reduces human cancer mortality rates. Especially, recent papers recognize the potential benefit of soybean isoflavone components for reducing the risk of various cancers. Isoflavones exhibit a multitude of medicinal effects that influence cell growth and regulation, which may have potential value in the prevention and treatment of cancer. In addition to potential biological effects, soybean isoflavones have the important physiological functions such as the induction of Bradyrizobium japonicum nod genes and the responses of soybean tissues to infection by Phytophthora megasperma as well as biochemical activities such as antifungal and antibacterial actions. Genistin, daidzin, glycitin and their aglycone (genistein, daidzein, glycitein) are the principal isoflavones found in soybean. Malonyl and acetyl forms have also been detected but they are thermally unstable and are usually transformed during the processing in glucoside form. Most soy products, with the exception of soy sauce, alcohol-extracted soy protein concentrate, and soy protein isolate, have total isoflavone concentrations similar to those in the whole soybean. Soybean-containing diets inhibit mammary tumorigenesis in animal models of breast cancer, therefore, it is possible that dietary isoflavones are an important factor accounting for the lower incidence and mortality from breast cancer. Of the total soybean seed isoflavones, $80\~90\%$ were located in cotyledons, with the remainder in the hypocotyls. The hypocotyls had a higher concentrations of isoflavones on a weight basis compared with cotyledons. Isoflavone contents were influenced by genetics, crop years, and growth locations. The effect of crop year had a greater impact on the isoflavone contents than that of location. The climate condition might be the attribution factor to variation in isoflavone contents. Also, while the isoflavone content of cotyledons exhibited large variations in response to high temperature during seed development, hypocotyls showed high concentration in isoflavone content. So, it is concluded that one of the factors affecting isoflavone content in soybean seeds is temperature during seed development. High temperature, especially in maturity stage, causes lower isoflavone content in soybean seed. It is also suggested that there may exist a different mechanism to maintain isoflavone contents between cotyledon and seed hypocotyls. In a conclusion, soy foods may be able to have a significant beneficial impact on public health.

• Journal of Life Science
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• v.28 no.6
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• pp.688-696
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• 2018

Hemp seed (Cannabis sativa L.; HS), an annual herbaceous plant in the Cannabis genus, has been reported to play various biological functions in immunity increase, atherosclerosis, constipation, hyperlipidemia prevention, anti-inflammatory, and anti-cancer. In recently years, as superfood, the growing interest in the health care benefits of hemp seed has led to increased consumption. In this study, we investigated the effect of an ethanol extract of HS fermented with lactic acid bacteria (Lactobacillus plantarum KCTC 3107, L. plantarum KCTC 3108, L. brevis BHN-LAB128, L. paracasei BHN-LAB129). An antibacterial activity against Staphylococcus aureus and Bacillus cereus were 13.99 mm and 15.17 mm, respectively. The ethanol extracts of fermented hemp seed by lactic acid bacteria that the contents of total polyphenol, total flavonoid content, DPPH radical scavenging activity, SOD-like activity, and ${\alpha}$-glucosidase inhibitory activity were increased compared to non-fermented hemp seed. Also, tyrosinase inhibitory activity of the fermented hemp seed (FHS), known to melanin increasing substance was increased. In these results, we suggested that FHS have effects of anti-oxidant, ${\alpha}$-glucosidase inhibitory activity, and tyrosinase inhibitory activity. Hence, we proposed that FHS has possible to development as functional foods and cosmetics.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.1
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• pp.10-17
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• 2017

The natural preservative "complex Scutellaria baicalensis extract (BHC)" contains Scutellaria baicalensis, Glycyrrhiza uralensis (liquorice), Zizyphus jujube (jujube), and Astragalus propinquus (milk vetch root). BHC has been used as a natural preservative for more than 10 years to increase storage duration and quality of food with strong antibacterial activity. BHC has been added into functional foods as a subsidiary ingredient. However, no studies have been performed to test whether or not BHC affects the activity of main functional ingredients. In this study, we tested whether or not BHC has any effect on the hepatoprotective activity of lactic acid-fermented garlic extract (LAFGE) when formulated in a clinical test supplement. $H_2O_2-induced$ oxidative damage in HepG2 cells was not attenuated by BHC, indicating that BHC had no influence on the protective effect of LAFGE against oxidative damage. Furthermore, BHC had no effect on the hepatoprotective effect of LAFGE against acetaminophen-induced acute liver injury in rats, as indicated by no changes in alanine transaminase and aspartate transaminase levels. In conclusion, BHC, formulated in the clinical test supplement with LAFGE, had no effect on hepatoprotective activity, indicating BHC could be considered as a suitable natural preservative for liquefied functional food materials.

• Journal of Life Science
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• v.30 no.6
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• pp.491-500
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• 2020

Lactic acid bacteria are widely known to prevent and treat intestinal health conditions, heart disease, depression, and obesity. In Korea, such bacteria are commonly consumed through various fermented foods, although most are isolated from kimchi, and research on the lactic acid bacteria in fermented seafood is insufficient. This study was therefore conducted to observe changes in bacterial flora according to the culture date of lactic acid bacteria in the fermentation of traditional Korean Gajami Sikhae produced in Pohang and to isolate the bacteria of probiotic value. The bacteria were periodically isolated and identified from date of preparation to 50 days after preparation to investigate which Lactobacillus are involved in Gajami Sikhae. As fermentation progressed, it was confirmed that Pediococcus sp. and Lactobacillus sp. participate predominantly in the early and later periods of fermentation, respectively. During the entire fermentation period, 170 isolates were screened, and the following five species were found to be involved: Pediococcus pentosaceus, Pediococcus inopinatus, Leuconostoc mesenteroides, Lactobacillus brevis, and Lactobacillus plantarum. Five strains of these species were selected through acid and bile tolerance tests, and their coaggregation, autoaggregation, hydrophobicity, antibacterial, and antioxidant activities were then evaluated. As a result, it is thought that L. brevis GS1022, which has excellent digestive fluid resistance, and P. inopinatus GS316, which has excellent cohesiveness, may be useful as probiotic strains.