• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.3
• /
• pp.381-387
• /
• 2003

This study was performed to establish the fermentation method of non-steamed brown rice vinegar using starch saccharifing enzyme. During vinegar fermentation, initial pH had increased in the higher concentration of alcohol and acetic acid. Final pH was gradually changed to pH 2.90~3.44 from 3.44~4.06. The higher total acidity of brown rice vinegar resulted from the higher alcohol concentration. The total acidity was slightly dropped after gradually increasing from the starting of fermentation. Initial pH was decreased from 3.67 to 3.16. The total acidity was gradually increased from the first day of fermentation with 1.02, it was 1.54 on the second day after fermentation and there was a tendency to decreased after the highest values with 6.53 fermentation for 12 days. In organic acid composition, oxalic, malic, acetic, citric, and succinic acid were detected. The total free amino acid was decreased to 1,121 mg%. The major amino acids were ${\gamma}$ -aminobutyric acid, $\alpha$-aminoadipic acid and alanine, and ${\gamma}$-aminobutyric acid was the highest (539 mg%). The mineral contents such as P and K was high in sample and followed by Mg, Na, Ca.

• Food Science and Preservation
• /
• v.18 no.5
• /
• pp.803-810
• /
• 2011

This study was performed to evaluate the quality of the commercial brown-rice vinegars of South Korean and Japanese origins, which were prepared via static acetic-acid fermentation. The major free amino acids of Korean brown-rice vinegars were proline, glutamic acid and phenylalanine, while those of the Japanese were proline, valine, phenylalanine, lysine, ${\gamma}$-aminobutyric acid, alanine and isoleucine. The ${\gamma}$-aminobutyric acid (GABA) and total amino acids (3686.37~4212.27 mg%) contents were found to be significantly higher in the Japanese than in the Korean brown-rice vinegars. The key volatile compounds of the Korean brown-rice vinegars, analyzed with GC-MS, were acetic acid, benzaldehyde, phenethyl alcohol and phenethyl acetate while those of the Japanese brown-rice vinegars were acetic acid, ethyl acetate, ethyl alcohol, isoamyl acetate, phenethyl acetate and benzaldehyde. The volatile patterns of the Korean and Japanese commercial brown-rice vinegars were effectively distinguished from each other using an electronic nose, through which it was also elucidated that the volatiles profiles were similar among the Japanese vinegars but were different among the Korean vinegars.

• Preventive Nutrition and Food Science
• /
• v.9 no.1
• /
• pp.58-64
• /
• 2004

This study investigated the effects of carnitine and/or ${\gamma}$ -aminobutyric acid (GABA) supplementation on lipid profiles and some immune related nutrient in mice. Balb/c male mice were orally treated with either an AIN-76 diet (Con), a control diet plus carnitine (CS, 0.5 g/kg bw), a control diet plus GABA (GS, 0.5 g/kg bw) or a control diet plus carnitine plus GABA (CGS, 0.25 g/kg bw, respectively) for 6 weeks. There were no significant differences in feed consumption, energy intake, body weight gain or feed efficiency ratio among the groups during the experimental period. However, abdominal fat deposits were smaller in CS, GS and CGS groups compared with the Con group. Serum and liver triglycerides also were lower in CS, GS and CGS and serum total cholesterol was significantly lower in the CGS group compared with the Con group. Serum LDL cholesterol was lower in the CGS group and liver HDL cholesterol was significantly higher in the CS group compared with Con group. In serum, stearic acid and selecholeic acid were lower, but arachidic acid was higher in the CS group. Liver stearic acid was higher but oleic acid lower in CGS group compared with Con group. In carnitine supplemented groups, serum and liver nonesterified carnitine (NEC), acidsoluble acylcarnitine (ASAC), total carnitine (TCNE) concentrations were higher in only the CS group, not CGS group. Serum vitamin A and E concentrations were not different among the groups. These results may suggest that carnitine and/or GABA supplementation improves lipid profiles in mice, but did not affect the immune-related nutrients that we measured under the experimental conditions of this study.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.11
• /
• pp.1745-1748
• /
• 2019

Gamma-aminobutyric acid (GABA) plays important roles in host physiology. However, the effects of GABA are greatly restricted due to its low bioavailability in the human body. Here, a high acid-tolerance GABA-producing strain, Lactobacillus brevis Bmb5, was isolated from kimchi. Bmb5 converted glutamate to GABA (7.23 ± 0.68 ㎍/μl) at a rate of 72.3%. The expression of gadB gene, encoding the enzyme involved in the decarboxylation of glutamate to GABA, was decreased upon incubation. Our findings indicate GABA production in Bmb5 is not directly correlated with gadB gene expression, providing new insight into the mechanisms underlying GABA production in Lactobacillus.

• Journal of Mushroom
• /
• v.13 no.4
• /
• pp.334-337
• /
• 2015

${\gamma}$-Aminobutyric acid (GABA) is basically neurotrasmitter produced by the decarboxylation of L-glutamic acid catalyzed by glutamic acid decarboxylase (GAD), which was known to convert monosodium glutamate (MSG) to GABA. To investigate enhancement of reversion rate of GABA, the yogurt fermentation with addition of nanoparticle winter mushroom and hydroponic ginseng was used. The conversion rate was revealed to nanoparticle winter mushroom and hydroponic ginseng fermenter (88%) > winter mushroom fermenter (52%) > nanoparticle winter mushroom fermenter (44%). The results showed that nanoparticle winter mushroom and hydroponic ginseng supplemented substrates for enhancement of GABA may be used more effectively as one of potential sources of functional foods.

• Bulletin of Food Technology
• /
• v.13 no.4
• /
• pp.131-133
• /
• 2000

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.51 no.5
• /
• pp.477-490
• /
• 2018

This study investigated the changes in the quality of doenjang (a fermented bean paste) with the addition of Sea tangle Saccharina japonica powder fermented by lactic acid bacteria (FSP). Doenjang was prepared without or with FSP and with various amounts of doenjang (0, 0.25, 0.5, 1 and 3% by volume), and fermented at $25^{\circ}C$ for 12 weeks. After 12 weeks, the antioxidant activity, microbiological characteristics, and physicochemical parameters were examined. We detected no significant differences in the color profiles. However, following the addition of FSP to doenjang, the amino nitrogen content and antioxidant properties were enhanced. Furthermore, the FSP-doenjang contained higher levels of ${\gamma}$-aminobutyric acid (297.55-300.03 mg/100 g), a biofunctional ingredient. These results suggest the potential for developing a traditional Korean fermented food with enhanced antioxidant activity and ${\gamma}$-aminobutyric acid content using FSP.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.51 no.3
• /
• pp.213-220
• /
• 2018

This study was conducted to investigate changes in the quality of Gochujang following the addition of sea tangle Saccharina japonica powder fermented by lactic acid bacteria (FSP). Gochujang was prepared with or without FSP and fermented at $16^{\circ}C$ for 24 weeks, as detailed in a previous study. No significant physicochemical changes in moisture, crude protein content, pH, salinity and amino nitrogen content were observed among the varieties of Gochujangs evaluated (Commercial Gochujang, Gallic-Gochujang and FSP-Gochujang). In addition, we detected no significant differences in microbiological profiles. However, following addition of FSP to Gochujang, the color was affected and antioxidant properties were enhanced. The DPPH radical scavenging activity of FSP-Gochujang increased by 58.8% and 24.8% compared with Commercial Gochujang and Gallic-Gochujang, respectively. Furthermore, analysis of the free amino acid content revealed higher levels of ${\gamma}$-Aminobutyric acid (100.9 mg/100 g), a biofunctional ingredient, in FSP-Gochujang. Thus, these results suggest the potential for development of a traditional Korean fermented food with enhanced antioxidant activity and ${\gamma}$-Aminobutyric acid content using FSP.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.2
• /
• pp.209-221
• /
• 2019

Gamma-aminobutyric acid (GABA) is a neurotransmitter that exerts several physiological functions and positive effects on human health. The aim of this study was to isolate and characterize the strains that had GABA-producing abilities from various fermented fish products. A total of 91 acid-producing strains were isolated from 41 samples of fermented fish products, and 27 strains showing GABA-producing abilities were identified by the 16S rDNA sequences. Among the strains, 31% strains tolerated at high-salt environment of 10-20% throughout the fermentation of fish sauces. The 27 isolates that produced GABA at various concentrations did so in the range of 5 to 454 mM. These GABA-producing isolates were identified as lactic acid bacteria of 14 strains, which included twelve Lactococcus lactis, one Enterococcus faecium, and one Lactococcus pentosus; eight Bacillus cereus group, which included seven B. thuringiensis and one B. cereus; and five Staphylococcus spp. Interestingly, with Vietnamese fish sauces, we mostly identified species of B. thuringiensis and Staphylococcus spp., while with Korean fermented fish products, the majority of the strains identified belonged to L. lactis. Among the strains, B. thuringiensis LH2134 produced the highest levels of GABA at 366 mM among the strains identified from Vietnamese fish sauces, whereas L. lactis LA43, a new strain isolated from Korean jeotgal (salted shrimp paste), produced the highest amount of GABA at 454 mM and the glutamate concentration in the medium was essential for GABA accumulation. Therefore, such the isolates might serve as good starters for development of more GABA-reinforced foods among fermented fish products.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.1
• /
• pp.104-109
• /
• 2007

Lactic acid bacteria that accumulated ${\gamma}-aminobutyric$ acid (GABA) in culture medium were screened to identify strains with high GAB A-producing ability. One strain, MS, which was isolated from kimchi, showed the highest GABA-producing ability among the screened strains. MS was identified as Lactobacillus buchneri based on Gram-staining, metabolic characteristics, and 16S rDNA sequence determination, Optimum culture conditions for GABA production were determined: MRS broth containing 5% MSG, 1% NaCl, and 1% glucose, at an initial pH of 5.0, the incubation temperature at $30^{\circ}C$ for 36 h. Under these conditions, MS produced GABA at a concentration of 251 mM with a 94% GABA conversion rate. Moreover, culture extracts of Lb. buchneri MS partially or completely protected neuronal cells against neurotoxicantinduced cell death.