• 한국식품과학회지
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• 제54권2호
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• pp.228-234
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• 2022

Various types of tea have been cultivated to obtain different flavors and enhance their functional properties. The objective of this study was to investigate the physicochemical properties of γ-aminobutyric acid (GABA) teas produced from commercial Korean green, white, and black teas. The concentration of total minerals was reduced in GABA green tea and GABA white tea but was improved in GABA black tea. The essential, non-essential, and total free amino acid contents were remarkably increased in the GABA teas. The amino acid GABA content was increased by 561.00 and 294.20 times in GABA white tea and GABA black tea, respectively. The antioxidant potential was not reduced, although the total polyphenol and total flavonoid contents decreased in GABA green tea and GABA black tea. The results indicated that the overall nutritional value of commercial green, white, and black teas could be improved by processing them into GABA teas.

• The Korean Journal of Physiology and Pharmacology
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• 제3권5호
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• pp.461-469
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• 1999

Glutamate and ${\gamma}-aminobutyric$ acid (GABA) are major excitatory and inhibitory neurotransmitters in the vertebrate retina, respectively. Using the whole-cell patch clamp technique and a rapid solution changer, glutamate and GABA receptors have been extensively investigated in carp retina. Glutamate receptors on both horizontal and amacrine cells may be an AMPA preferring subtype, which predominantly consists of flop splice variants. $GABA_A$ and $GABA_C$ receptors coexist in bipolar cells and they both show significant desensitization. Kinetics analysis demonstrated that activation, deactivation and desensitization of the $GABA_C$ receptor-mediated response of these cells are overall slower than those of the $GABA_A$ response. Endogenous modulator $Zn^{2+}$ in the retina was found to differentially modulate the kinetic characteristics of the $GABA_C$ and $GABA_A$ responses.

• BMB Reports
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• 제36권3호
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• pp.319-325
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• 2003

Changes in the concentrations of $\gamma$-aminobutyric acid (GABA), soluble calcium ions, glutamic acid, and the activity of glutamate decarboxylase (GAD) were investigated in non-germinated vs. germinated brown rice. Brown rice was germinated for 72 h by applying each of the following solutions: (1) distilled water, (2) 5 mM lactic acid, (3) 50 ppm chitosan in 5 mM lactic acid, (4) 5 mM glutamic acid, and (5) 50 ppm chitosan in 5 mM glutamic acid. GABA concentrations were enhanced in all of the germinated brown rice when compared to the non-germinated brown rice. The GABA concentration was highest in the chitosan/glutamic acid that germinated brown rice at 2,011 nmol/g fresh weight, which was 13 times higher than the GABA concentration in the non-germinated brown rice at 154 nmol/g fresh weight. The concentrations of glutamic acid were significantly decreased in all of the germinated rice, regardless of the germination solution. Soluble calcium and GAD were higher in the germinated brown rice with the chitosan/glutamic acid solution when compared to the rice that was germinated in the other solutions. GAD that was partially purified from germinated brown rice was stimulated about 3.6-fold by the addition of calmodulin in the presence of calcium. These data show that the germination of brown rice in a chitosan/glutamic acid solution can significantly increase GABA synthesis activity and the concentration of GABA.

• Food Science and Biotechnology
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• 제17권5호
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• pp.940-946
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• 2008

In the development of a nutrient enhanced functional food, kimchi was produced by using high $\gamma$-aminobutyric acid (GABA) producing lactic acid bacterium as a starter strain. The strain isolated from kimchi was identified by using an API kit and named Lactobacillus sp. OPK 2-59. Kimchi was produced by 3 methods 1) monosodium glutamate (MSG) added (M group); 2) starter added (S group); 3) MSG+starter added (M&S group). The produced kimchi was fermented for 24 hr in an incubator at a temperature of $15^{\circ}C$ and stored at $0-1^{\circ}C$ to examine its characteristics. The M&S group exhibited a sharper increase in acidity and a steeper fall in pH as well as a higher number of lactobacilli. The M&S group kimchi had 18 mg/100 g (fresh weight, f.w.) of GABA, whereas the M and S group each had 6 mg/100 g (f.w.) GABA. According to functional evaluation, the M&S group kimchi, which has higher GABA, was not significantly different in taste, color, texture, or smell, but the M&S group was generally superior. In summary, using Lactobacillus sp. OPK 2-59 and MSG, a high quality kimchi with increased GABA content can be produced as a functional food.

• 한국미생물·생명공학회지
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• 제49권4호
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• pp.559-565
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• 2021

유산균 L. plantarum SGL058과 L. lactis SGL027로부터 OFAT 방법을 이용하여 탄소원 및 질소원의 종류와 농도에 대해 실험을 진행하였다. 또한 TLC 분석방법을 통해 GABA 생성능력이 우수한 균주 L. plantarum SGL058과 L. lactis SGL027를 선정하였다. 두 균주를 이용하여 각각 5-L 발효기에서 546.7 ㎍/ml (L. plantarum SGL058)과 404.6 ㎍/ml (L. lactis SGL027)의 GABA를 생산하였다. 이러한 연구결과는 유산균을 이용한 GABA 생산과정에 있어서 유용한 정보를 제공할 것으로 판단된다.

• Journal of Microbiology and Biotechnology
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• 제27권11호
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• pp.1952-1960
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• 2017

Recently, soybean isoflavone aglycones (i.e., daidzein and genistein) and ${\gamma}-aminobutyric$ acid (GABA) have begun to receive considerable consumer attention owing to their potential as nutraceuticals. To produce these ingredients, multiple microorganisms and their enzymes are commonly used for catalysis in the nutraceutical industry. In this work, we introduce a novel fermentation process that uses whole-cell biocatalysis to accelerate GABA and isoflavone aglycone production in doenjang (a traditional Korean soybean paste). Microbial enzymes transform soybean isoflavone glycosides (i.e., daidzin and genistin) and monosodium glutamate into soybean isoflavone aglycones and GABA. Lactobacillus brevis GABA 100 and Aspergillus oryzae KACC 40250 significantly reduced the production time with the aid of a protease. The resulting levels of GABA and daidzein were higher, and genistein production resembled the levels in traditional doenjang fermented for over a year. Concentrations of GABA, daidzein, and genistein were measured as 7,162, 60, and $59{\mu}g/g$, respectively on the seventh day of fermentation. Our results demonstrate that the administration of whole-cell L. brevis GABA 100 and A. oryzae KACC 40250 paired with a protease treatment is an effective method to accelerate GABA, daidzein, and genistein production in doenjang.

• Biomolecules & Therapeutics
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• 제23권3호
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• pp.268-274
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• 2015

${\gamma}$-Aminobutyric acid (GABA), a major inhibitory neurotransmitter in the mammalian central nervous system, is involved in sleep physiology. Caffeine is widely used psychoactive substance known to induce wakefulness and insomnia to its consumers. This study was performed to examine whether GABA extracts from fermented rice germ ameliorates caffeine-induced sleep disturbance in mice, without affecting spontaneous locomotor activity and motor coordination. Indeed, caffeine (10 mg/kg, i.p.) delayed sleep onset and reduced sleep duration of mice. Conversely, rice germ ferment extracts-GABA treatment (10, 30, or 100 mg/kg, p.o.), especially at 100 mg/kg, normalized the sleep disturbance induced by caffeine. In locomotor tests, rice germ ferment extracts-GABA slightly but not significantly reduced the caffeine-induced increase in locomotor activity without affecting motor coordination. Additionally, rice germ ferment extracts-GABA per se did not affect the spontaneous locomotor activity and motor coordination of mice. In conclusion, rice germ ferment extracts-GABA supplementation can counter the sleep disturbance induced by caffeine, without affecting the general locomotor activities of mice.

• 한국식품과학회지
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• 제42권6호
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• pp.688-692
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• 2010

The aim of this study was to investigate the effects of molecular weight and concentrations of chitosan on the germination of brown rice. Brown rice was germinated at $30^{\circ}C$ for three days in various chitosan solutions. The germination rate of the brown rice increased with increasing concentrations of chitosan solution, and was higher in the chitosan solution than in water. GABA content increased with increasing germination time and chitosan solution concentration. As the molecular weight of the chitosan decreased, germination rate and GABA content increased in the brown rice. The GABA content of germinated brown rice using low molecular weight chitosan A in a 100 ppm solution was 5145.5 nmole/g. This is approximately a five times higher value than that of the water-germinated brown rice. Texture properties were enhanced in all the germinated brown rice samples in chitosan solution compared to the brown rice germinated in water. These results indicate that chitosan solution treatment can increase germination rate and GABA synthesis activity in brown rice during germination, and can also improve the texture properties of brown rice.

• 한국버섯학회지
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• 제15권1호
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• pp.38-44
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• 2017

최근 식용과 약용버섯으로 각광을 받고 있는 꽃송이버섯(Sparassis latifolia 혹은 S. crispa)은 베타-글루칸이 풍부하여 다양한 생리활성을 나타낸다고 알려져 있다. 꽃송이버섯에 다량 포함된 베타-글루칸과 더불어 뇌기능을 증진시킬 수 있는 영양성분이 보강된다면 약용버섯의 기능성이 더욱 증대되어 농가소득 증대와 국민 건강증진에 큰 기여를 할 것으로 판단된다. 본 연구에서는 꽃송이버섯 균사체 배양 시 아미노산을 첨가하였을 시 균사 생장이 촉진됨과 함께 GABA 함량이 증대되었고, ${\beta}-glucan$ 함량에는 유의적인 효과가 없는 것을 확인하였다. 균사의 생장에는 glutamic acid와 ornithine 모두 효과가 있었으나, GABA 함량에 대해서는 glutamic acid의 첨가가 훨씬 효과적임을 확인하였다. 이는 꽃송이버섯 균사체의 GABA-shunt에 glutamic acid가 영향을 미친 것으로 사료된다. 생성된 GABA의 소멸과 다른 화합물의 신규 생성에 대해서는 아직 결과를 도출하지 못하였으므로, 이 부분에 대한 추가 연구가 필요하리라 사료된다.

• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.579-584
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• 2013

In this study, we synthesized functional dendrimer derivatives as nonviral gene delivery vectors. Poly(amidoamine) dendrimer (PAMAM, generation 4) was modified to possess functional amino acids to enhance gene transfection efficiency. PAMAM G4 derivatives conjugated with L-arginine (Arg) and ${\gamma}$-aminobutyric acid (GABA) showed higher transfection efficiency and lower cytotoxicity compared to the native PAMAM G4 dendrimer. The polyplex of the PAMAM G4 derivative/pDNA was evaluated using an agarose gel retardation assay and Picogreen reagent assay. Additionally, the MTT assay was performed to examine the cytotoxicity of synthesized polymers. All PAMAM G4 derivatives showed lower cytotoxicity than PEI25kD. Particularly, PAMAM G4-GABA-Arg displayed enhanced transfection efficiency compared to the native PAMAM G4 dendrimer.