Gamma-aminobutyric acid (GABA) is a functional component with physiological activity that helps to protect the liver from blood pressure reduction and alcohol damage, and is known to be widely distributed in various vegetables and fruits. In this study, a fermented rice syrup with enhanced GABA content was developed. The improved syrup was prepared by adding monosodium glutamate (MSG) to saccharified rice and using a complex of three types of lactic acid bacteria (Lactobacillus brevis, Lactobacillus plantarum, Leuconostoc mesenteroides ) with excellent GABA production ability. The physicochemical changes of the fermented rice syrup were measured, and the final pH of the product was 4.7 with a total water-soluble solid content of 22.1 °Brix. Of the dissolved solids, glucose (39.6 mg/mL) and maltose (12.7 mg/mL) were the main components, and it was confirmed that all MSG was converted to GABA. From the experiment, it was established that the rice syrup obtained from secondary fermentation of saccharified rice is suitable as a beverage base. The fermented saccharified rice syrup was differentiated from conventional rice fermented products which typically use yeast and acetic acid bacteria in the production process. The enhanced fermented rice syrup produced in this study was made using lactic acid bacteria in the fermentation and saccharified rice.

Fermented foods of Korean temple are vegetable-based foods and their seasonings are limited to five pungent herbs. The aim of this study was to investigate cell-free supernatants (CFS) of lactic acid bacteria isolated from the fermented foods of Korean temples. Three selected CFS significantly inhibited the biofilm formation of Escherichia coli O157:H7 at 24 h, while one of the selected CFS markedly inhibited the biofilm formation at 72 h. However, only one CFS significantly attenuated the biofilm formation of Staphylococcus aureus at 24 h, but these CFS failed to inhibit the biofilm formation. Moreover, selected CFS effectively inhibited the growth of E. coli O157:H7, whereas the growth of S. aureus was not affected in the presence of CFS. These results suggest that CFS of lactic acid bacteria isolated from fermented foods of Korean temples shows antimicrobial activity agasint Gram-negative E. coli O157:H7, but not at Gramd-positive S. aureus .

When kimchi is frozen and thawed, the amount of lactic acid bacteria (LAB) and yeast is usually reduced by more than 2 logs, and its texture including its crispness and hardness are changed significantly. As a possible means to minimize these problems, various freezing (direct freezer with -25, -40, and -60oC and plate freezer with -40oC) and thawing methods (radio frequency (RF) thawing, plate thawing, and room temperature thawing) were investigated in terms of the amount of LAB and texture of kimchi. From the use of plate freezing and plate thawing, the amount of LAB of white cabbage kimchi could be maintained by more than 10% of its initial amount while that for red cabbage kimchi could be maintained by more than the initial amount. Pretreatment with trehalose (19 oBrix soluble solid content) to salted Chinese cabbage could maintain kimchi’s hardness and crispness. In order to maintain the texture and the amount of LAB in kimchi, the use of the plate freezer (-40oC) and the plate thawing (20oC) seemed to be effective with the assistance of trehalose.

Gastrodia elata Bl. (GE) is a traditional herbal medicine used for the treatment hypertension and cerebrovascular disease. The purpose of this study was to investigate the antioxidant effect and blood pressure control ability of the GABA containing fermented Gastrodia elata Blume. The fermentation strain provided by Dr. Gi in Seoul National University is L. brevis GABA100, excellent strain of GABA production, which is involved in the ability to degrade gastrodin glycosides and activation of brain function. The Gastrodia elata Blume fermented by Lactobacillus brevis GABA 100 showed antioxidant activity (total phenolic contents, DPPH radical and ABTS anion scavenging activities) than unfermented Gastrodia elata Blume. In the spontaneously hypertensive rats (SHR), the concentration of fermented Gastrodia elata Blume was administered at 500, 1,000, and 2,000 mg/kg for 8 weeks. Systolic blood pressure decreased statistically significantly (p<0.05), especially 2 weeks after feeding fermented Gastrodia elata Blume. Also, it showed a significant decrease in low, medium, and high concentrations of fermented Gastrodia elata Blume at 4 weeks and 8 weeks. These results indicated that Gastrodia elata Blume fermented by the excellent strain of GABA production L. brevis GABA100 shows the antioxidant function and the effect of suppressing the increase in blood pressure.

The purpose of this study was to evaluate the physicochemical components and antioxidant activities of wheat sprout powder prepared by the enzymatic hydrolysis and lactic acid bacteria treatment. The four kinds of pre-treatment were: no treatment (WP), treated with enzyme (WPE), treated with lactic acid bacteria (WPL), and treated with enzyme and lactic acid bacteria (WPEL) were applied to the wheat sprout powder. The WPEL had higher total free amino acid and essential amino acid content than the other samples. As for the volatile aroma of the wheat sprout powder, 29 types of compounds were identified in the WP and WPL, 28 types in the WPE, and 27 types in the WPEL, respectively. The total polyphenols and flavonoids contents, in the wheat sprout powder was enhanced with the enzyme and the lactic acid bacteria pre-treatment. The WPEL had highest DPPH radical scavenging activities. The overall acceptability was the highest at 6.24 points in the WPEL. Based on these observations, it was confirmed that the enzyme and lactic acid bacteria pre-treatment could improve the antioxidant activities and active component of the wheat sprout powder.

The creation of probiotic-containing fermented milk products for use by human is an important research topic and has high potential for development. Also, studies have shown that heat-killed probiotics are more stable and easier to use than live probiotics. However, as of this time, research has not been reported in Korea that has evaluated the product or functionality of fermented milk after the addition of heat-killed probiotics. This study was conducted to verify the physiological activity of heat-killed Enterococcus faecalis EF-2001 after its addition to Lactobacillus-fermented milk. Briefly, NFM normal fermented milk (NFM) was used as the control sample, whereas fermented milk with 100 μg/mL EF-2001 (EFM1) and fermented milk with 500 μg/mL EF-2001 (EFM2) were used as the treated samples. Among the samples, EFM2 had the highest acidity of 1.15, but no other factors significantly differed (p<0.05). Furthermore, EFM2 had the highest Lactobacillus count of 9.22 (p<0.05). ABTS, DPPH and FRAP were measured to determine the antioxidant activity of the samples. With respect to those parameters, EFM2 had the highest antioxidant measurements. Therefore, the study confirmed that the addition of E. faecalis EF-2001 to NFM is suitable with the standard and does not affect the quality of characteristics. In conclusion, the treatment sample had higher antioxidant activity than did NFM; this result may be used as a basic for further research and as a guideline for the manufacturing of heat-killed probiotic-containing NFM.

Whey is a major by-product of cheese manufacture and contains many valuable constituents, such as β-lactoglobulin, lactoferrin and immunoglobulin. The current study determined the anti-biofilm activity of bioconversion of whey by Lactobacillus plantarum (LP-W), L. rhamnosus GG (LR-W), L. brevis (LB-W) and Enterococcus faecium (EF-W) against foodborne pathogenic bacteria, Escherichia coli O157:H7 and Listeria monocytogenes. When the foodborne pathogenic bacteria were co-incubated with LP-W, LR-W, LB-W or EF-W, biofilms by E. coli O157:H7 and L. monocytogenes were significantly reduced by all bioconversion of whey. Moreover, LP-W, LR-W, LB-W and EF-W also dramatically reduced pre-formed biofilm by E. coli O157:H7 and L. monocytogenes, suggesting that the bioconversion of whey effectively suppress the development and disruption of biofilm by foodborne pathogenic bacteria. Furthermore, in order to determine the growth kinetics of E. coli O157 and L. monocytogenes planktonic cells in the presence the bioconversion of whey, LP-W, LR-W, LB-W and EF-W did not significantly inhibited the growth of foodborne pathogenic bacteria, implying that the bioconversion of whey reduces the biofilm without the decrease of bacterial growth. Taken together, these results suggest that bioconversion of whey by lactic acid bacteria could be a promising agent for the reduction of microbial biofilm.

Probiotics improve the immune system. However, the effects of its lactic acid bacteria on atopic dermatitis relief and inflammation improvement is not fully understood. Recently, one of the probiotics, Lactobacillus helveticus HY7801 (HY7801), was found to have an anti-inflammatory effect. In this study, we investigated the effects of HY7801 on atopic dermatitis-induced animal models. After four weeks of oral administration, the group treated with HY7801 showed amelioration of the atopic dermatitis compared to the group receiving placebo. In the HY7801 treated group, the epidermal hyper-proliferation and collagen deposition were inhibited compared to the placebo group, and the secretion amount of the inflammatory factors, such as TNF-α, IL-4 were reduced. In conclusion, these results suggest that HY7801 acts as a functional probiotic via amelioration of the atopic dermatitis such as a decrease of epidermal hyper-proliferation, and collagen deposition and anti-inflammatory effects.

According to the previous study, Lactobacillus pentosus A67 and L. plantarum subsp. plantarum C2 were isolated and screened. In this study, culture broths of strains A67 and C2 were performed various physiological activity assays including antimicrobial, antioxidant, cytotoxicity, cell proliferation activity. The remarkable anti-microbial activities using the culture broths of the two strains were showed by disc diffusion method, MIC tests. In the 2,2-diphenyl-1-picryl hydrazyl (DPPH) and superoxide dismutase (SOD) assays to verify antioxidant activity, culture broths of strains A67 and C2 significantly scavenged free radical maximum by 91.33% and 81.95% respectively compared with arbutin. Also, they showed equivalent activity same as 297.22 units and 255.56 units of SOD respectively. In RAW264.7 cells, culture broths of strain A67 and C2 showed no cytotoxicity. Moreover, they showed significant cell proliferative effects by 173.5% and 143.5% compared to control group respectively. Overall, this study showed that the culture broths of strain A67 and C2 had antimicrobial and antioxidant activities, which could synergically increase the physiological activities. And they had no cytotoxicity and cell proliferative effects. Therefore, it is expected that L. pentosus A67 and L. plantarum C2 could be applied to a wide variety of functional materials including food and medicine as new probiotics.

Soymilk has been substituted for milk for people who are suffering from lactoseintolerance. In this study γ-aminobutyric acid (GABA) producing lactic acid bacterium, Lactobacillus plantarum LP2, was applied to ferment soymilk for improving its functionality. GABA production was proved in MRS broth supplemented 3% monosodium glutamate (MSG) and soymilk including 10% (w/v) soymilk powder and 5%(w/v) fructooligosaccharide where L. plantarum LP2 was applied. In addition to the soymilk, isolated soy protein (ISP), which was enzyme-treated, was added to it for improving the content of free amino acids including glutamic acid. L. plantarum LP2 was well grown and produced GABA in the soymilk medium.

The purpose of this study was to analyze the effects of the pre-treatment method on the measurement of probiotic cell counts. The probiotic cell count was not significantly different in the pre-treatment method such as experimenters, diluted solution, medium, and homogenization duration. The mean value of probiotic cell count with capsule was 2.2×1010±9.5×109 CFU/g. This probiotic cell count was converted into 2.8×1010±1.2×1010 CFU/g based on the net weight. The mean value of probiotic cell count without capsules was 4.3×1010±1.8×1010 CFU/g. As a result of this comparison, probiotic cell count showed significant difference with and without capsules. Thus, it is suggested that the probiotic cell count is measured by removing the capsule in capsule probiotics.

The purpose of this study was to investigate the quality and antioxidant properties of three fermented sweet potato cultivars (Shinyulmi, Hogammi, and Shinjami) using lactic acid bacteria. During the fermentation, the pH was lowered and the titratable acidity increased. The viable cell counts of lactic acid bacteria increased 8.44-9.62 log CFU/g. Organic acid content (especially lactic acid) of sweet potatoes increased by fermentation. Also, γ-Aminobutyric acid increased more than 8.6 times by fermentation in all samples. The total polyphenol and flavonoid contents of sweet potato, showed insignificant changes in all samples by fermentation. ABTS radical scavenging activity of all samples slightly decreased by fermentation, but not significantly. DPPH radical scavenging activity decreased slightly by fermentation except Shinyulmi. However, when compared with the varieties, Shinjami showed the highest activity. The reducing power of Shinjami decreased slightly by fermentation, but activity was the highest among all samples. Based on these results, most of the chemical properties and functionality of fermented sweet potato are retained after fermentation, although some antioxidant activity decreases. We suggest that three fermented sweet potato cultivars (Shinyulmi, Hogammi, and Shinjami) using lactic acid bacteria can be used in various applications because of their effective functional properties.

Lactobacillus pentosus A67 and L. planarum subsp. plantarum C2 was tested the probiotics characterization such as acid, bile acid and antibiotics resistance. Isolates were isolated from the traditional Korean food, collected from traditional markets and homes in Seoul and Gyeonggi Province, and were selected the isolates A67 and C2, which were the most antibacterial to E. coli. According to the analysis of 16S rRNA base sequences, the results showed that L. pentosus ATCC 8041 (similarity 100%), and L. plantarum subsp. plantarum ATCC 14917 (similarity 100%). L. pentosus A67 showed a survival rate of about 98.35% and the L. plantarum C2 showed a survival rate of about 95.62% at pH 2.5, respectively. L. pentosus A67 showed a survival rate of about 94.56% and the L. plantarum C2 showed a survival rate of about 88.81% on the 0.3% bile salt, respectively. L. pentosus A67 and L. plantarum C2 were survived by antibiotics such as the quinolone, aminoglycoside, macrolide, glycopeptide, tetracycline, cephalosporin and phenicillin families. On basis of these results, L. pentosus A67 and L. plantarum C2 are the candidates for useful probiotics.

Nowadays micro-dust is a serious problem in Korea. In particular micro-dust contains heavy metals such as Pb (lead) and Cd (cadmium) which negatively effect on human health. In this study, we intended to isolate lactic acid bacteria which can scavenge the heavy metals. Firstly we isolated two lactic acid bacteria which were resistant to Ag, Cu, and Zn (30-100 mM AgNO3, CuSO4, ZnSO4 in MRS broth). The two lactic acid bacteria CJNU 1877 and JG 15 were identified Lactobacillus paracasei and Enterococcus faecium, respectively. Subsequently the strains were inoculated in MRS broth and agar plate where 100 ppm of Pb(NO3)2 and CdSO4 were added, respectively. They did grow in the conditions and we found aggregations from 24 h cultures, indicating the strains can absorb the heavy metals, which was further proved by scanning electron microscopy (SEM) and Inductively Coupled Plasma-Optical Emission Spectrometer. Therefore the isolated lactic acid bacteria can be used as a probiotics harboring heavy metal scavenging activity.

Ginseng, the root of the Panax ginseng, has been widely used as a traditional herbal medicine in Korea, China, and Japan for thousands of years. Now ginseng has become popular as functional health food and natural medicine and it is one of the bestselling natural products in the world. Gut microbiota has been found to play an important role in the metabolism and pharmacological action of orally administered ginseng. Recent animal and clinical studies have shown that compound K (20-O -beta-D-glucopyranosyl-20(S)-protopanaxadiol, CK) is the major ginsenoside metabolite deriving from gut microbiota-induced biotransformation and is more efficiently absorbed into the systemic circulation than its parent ginsenosides. Since ginsenoside metabolism varies between individuals depending on the population of gut microbiota, much attention paid to the transformation of major ginsenosides into more pharmacologically active ginsenosides using diverse methods including heating, acid hydrolysis, microbial conversion, and enzymatic treatment. Recently, in food and drug industry and academia, the development of fermented ginseng products using probiotic bacteria is being intensively studied due to the potential health benefits of ginsenoside metabolites and probiotics. This review summarizes recent studies on the metabolism of ginsenoside by gut microbiota and biotransformation of ginsenoside using lactic acid bacteria and their enzymes.

본 연구는 2017년 국내에서 유통되는 유산균을 함유한 건강기능식품과 가공식품 120건에 대하여 프로바이오틱스 함량, pH와 산도를 분석하였다. 또한, 건강기능식품 중 프로바이오틱스 5개 제품에 대한 보존방법에 따른 변화를 조사하였다. 프로바이오틱스 제품 85건 중 2건이 표시량 이하였고, 가공식품 35건은 모두 적합이었다. 프로바이오틱스 제품의 프로바이오틱스수, pH, 산도 평균은 각각 1.2 × 1010 CFU/g (표시량: 3.4 × 109 CFU/g), 5.35, 1.29%이었으며, 가공식품 중 유산균 함유량 표시 식품 17건의 유산균수 평균은 5.8 × 108 CFU/g이었다. 프로바이오틱스 5제품의 보존온도(−20℃, 4℃, 20℃, 40℃)와 보존기간(1, 3, 6개월) 경과에 따른 프로바이오틱스 함량 변화를 관찰한 결과, 보존기간 1개월에서 6개월 후 프로바이오틱스수 감소율은 평균 59%이었고, 4℃에서 가장 낮은 감소율과 40℃에서 가장 높은 감소율을 나타내었다. 또한, 5개 제품 중 3제품에서 보존기간 1개월에서 3개월 경과 후 40℃에서 70%이상 급격한 균수 감소를 관찰할 수 있었다. 따라서 프로바이오틱스 제품의 보존온도와 보관기간에 따른 변화를 고려할 때 프로바이오틱스 제품은 냉장보관을 권장하며 구입 후 되도록 단기간에 섭취하는 것이 바람직한 것으로 판단된다.

Coffee is a commonly consumed beverage that contains anti-inflammatory compounds such as caffeine, chlorogenic acid, cafestol, trigonelline, and kahweol. Lactobacillus plantarum is a lactic acid bacterium most frequently used in the fermentation of food products of plant origin. L. plantarum is able to degrade some food phenolic compounds and provide high value-added compounds such as powerful antioxidants or food additives approved as flavouring agents. In this study, we investigated the anti-inflammatory effects of coffee extract fermented by L. plantarum on RAW264.7 macrophages. In lipopolysaccharide-stimulated RAW264.7 cells, these coffee extracts exhibited antiinflammatory activities through the reduction of nitric oxide (NO) production and inducible NO synthase expression. Fermented coffee extracts significantly decreased the expression of inflammatory cytokines such as tumor necrosis factor α, interleukin 1β, interleukin 6, and interferon γ. Cyclooxygenase-2, which is one of the key biomarkers for inflammation, was significantly suppressed. These results might be helpful for understanding the anti-inflammatory mechanism of fermented coffee extract on immune cells and, moreover, suggest that fermented coffee extract may be a beneficial anti-inflammatory agent.

최근 두부 제조시장은 소용량 소포장, 건강한 원료를 첨가한 웰빙두부, 어린이용 캐릭터 두부 등으로 다양한 두부제품이 출시되었고, 소매시장 규모는 ’14년 4,169억원에서 ’16년 4,418억원으로 6%정도 성장하였으며, 국내산 두부로 판매가 가장 증가한 품목은 연두부로 현대인들이 식사대용으로 선호하고 있다. 또한 두부응고제로는 chloride-type, sulfate-type, glucono-δ-lactone 및 lactic acid와 같은 산성응고제 등이 있으나 대부분 화학 응고제로 최근에는 천연 응고제에 대한 소비자 요구도가 높아지고 있는 추세이다. 천연 응고제로 김치에서 분리한 유산균을 이용하여 연두부와 같은 식감을 가진 전두부를 만들고자 본 연구를 실시하였다. 전두부 재료로는 ’16년에 재배된 대원콩을 air mill로 분쇄하여 콩가루 입도를 50㎛수준으로 사용하였고, 전두부제조기(HTM-100A)를 이용하여 5배의 물을 넣고 제조하였으며, 대조구로는 압착두부를 만들어 사용하였다. 두부응고를 위한 균주로는 전북농업기술원에서 분리한 Lactobacillus sakei C-11 등 단백질분해능이 우수한 3종을 사용하였고, 시판균주로 KACC에서 분양받은 Lactobacillus sakei를 활용하였다. 제조방법은 콩분말과 물을 혼합하여 두유를 끓인 후 식혀서 균주를 넣고 30～32℃로 24시간을 배양하면서 응고되는 정도를 관찰하였다. 균주종류별 시간에 따른 응고정도는 Lactobacillus paracasei 3YC-3와 Lactobacillus sakei C-11 처리구에서 9시간 이후로 양호하였으며, 대조균주는 18시간 이후 동일한 응고가 관찰되었다. 시간별 생균수 증가를 보면 Lactobacillus paracasei 3YC-3이 2시간부터 생균수 증가가 활발하여 24시간에 가장 많은 생균수가 관찰되었으며, 균주별 이소플라본 함량을 보면 Lactobacillus paracasei 3YC-3이 압착두부 대비 41%, 시판균주 Lactobacillus sakei 대비 37%가 높게 나타났다.