• Food Science of Animal Resources
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• v.33 no.3
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• pp.377-389
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• 2013

Gamma-amino butyric acid (GABA) is a kind of pharmacological and biological component and its application is wide and useful in Korea specially, becoming aging society in the near feature. GABA is request special dose for the purposed biological effect but the production of concentrated GABA is very difficult due to low concentration of glutamic acid existed in the fermentation broth. To increase GABA concentrate using fermentation technology, high content of glutamic acid is required. For this reason, various strains which have the glutamic acid decarboxylase (GAD) and can convert glutamic acid to GABA, were isolated from various fermented foods. Most of GABA producing strains are lactic acid bacteria isolated from kimchi, especially added monosodium glutamate (MSG) as a taste enhancer. Optimizing the formulation of culture media and the culture condition, GABA conversion yield and amounts were increased. Finally GABA concentration of fermentation broth in batch or fed batch fermentation reached 660 mM or 1000 mM, respectively. Furthermore formulation of culture media for GABA production developed commercially. Many studies about GABA-rich product have been continued, so GABA-rich kimchi, cheese, yogurt, black raspberry juice and tomato juices has been also developed. In Korea many biological effects of GABA are evaluated recently and GABA will be expected to be used in multipurpose.

• Journal of Animal Science and Technology
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• v.58 no.3
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• pp.10.1-10.10
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• 2016

Background: Airag, alcoholic sour-tasting beverage, has been traditionally prepared by Mongolian nomads who naturally ferment fresh mares' milk. Biochemical and microbiological compositions of airag samples collected in Ulaanbaatar, Mongolia and physiological characteristics of isolated lactic acid bacteria were investigated. Methods: Protein composition and biochemical composition were determined using sodium dodecyl sulfate-gel electrophoresis and high performance liquid chromatography, respectively. Lactic acid bacteria were identified based on nucleotide sequence of 16S rRNA gene. Carbohydrate fermentation, acid survival, bile resistance and acid production in skim milk culture were determined. Results: Equine whey proteins were present in airag samples more than caseins. The airag samples contained 0.10-3.36 % lactose, 1.44-2.33 % ethyl alcohol, 1.08-1.62 % lactic acid and 0.12-0.22 % acetic acid. Lactobacillus (L.) helveticus were major lactic acid bacteria consisting of 9 isolates among total 18 isolates of lactic acid bacteria. L. helveticus survived strongly in PBS, pH 3.0 but did not grow in MRS broth containing 0.1 % oxgall. A couple of L. helveticus isolates lowered pH of skim milk culture to less than 4.0 and produced acid up to more than 1.0 %. Conclusion: Highly variable biochemical compositions of the airag samples indicated inconsistent quality due to natural fermentation. Airag with low lactose content should be favorable for nutrition, considering that mares' milk with high lactose content has strong laxative effect. The isolates of L. helveticus which produced acid actively in skim milk culture might have a major role in production of airag.

• Journal of Microbiology and Biotechnology
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• v.25 no.1
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• pp.26-32
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• 2015

Four types of straw, namely, soybean, wheat, corn, and rice, were investigated for use in lactic acid production. These straws were mainly composed of cellulose, hemicellulose, and lignin. After pretreatment with ammonia, the cellulose content increased, whereas the hemicellulose and lignin contents decreased. Analytical results also showed that the liquid enzymatic hydrolysates were primarily composed of glucose, xylose, and cellobiose. Preliminary experiments showed that a higher lactic acid concentration could be obtained from the wheat and soybean straw. However, soybean straw was chosen as the substrate for lactic acid production owing to its high protein content. The maximum lactic acid yield (0.8 g/g) and lactic acid productivity (0.61 g/(l/h)) were obtained with an initial reducing sugar concentration of 35 g/l at 30℃ when using Lactobacillus casei (10% inoculum) for a 42 h fermentation period. Thus, the experimental results demonstrated the feasibility of using a soybean straw enzymatic hydrolysate as a substrate for lactic acid production.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.460-465
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• 2001

To prepare vinegar using concentration apple juice, response surface methodology (RSM) was applied to optimize and monitor the vinegar fermentation properties by two stage fermentation. In the first stage, the optimum conditions for maximum alcohol contents were 18.56。Brix of initial sugar concentration, 61.96 rpm of agitation rate and 67.32 hr of fermentation time. The optimum condition for maximum acidity in the second stage (vinegar fermentation) were 201.53 rpm of agitation rate and 179.42 hr of fermentation time. Malic acid content was the highest and its content little changed during acetic acid fermentation. Lactic acid content increased a little during alcohol fermentation. Acetic acid content apparently increased during acetic acid fermentation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1065-1070
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• 1998

Lactic acid bacteria KL 1, KD 6, KL 4 strains isolated from kimchi, or obtained Lactobacillus acidophilus, Lactobacillus plantarum, Leuconostoc mesenteroides with and without yeast(Saccharomyces cerevisiae) were inoculated in fruit vegetable juice for mixed culture fermentation 3 days at 3$0^{\circ}C$, and then their chemical changes were studied during fermentation. The amount of organic acid produced by the mixed culture fermentation of KL 1 and yeast was 0.82%(3 days) or 0.58%(1 day) and with the final pH of 3.3(3 days) or 4.2(1 day). These mixed culture systems of isolated strains or other bacterial strains had almost similar results of growth rate and acid production. The contents of vitamin C and carotene were retained and stabilized as 70~80% level of their initial values after 24 hrs fermentation. And also ethanol was produced as of the range in 9.6mg%(W/V) by the mixed culture fermentation of KL 1 and yeast, however, the content of ethanol in single culture fermentation by KL 1 strain was much lower than that of mixed culture. The major components of organic acids in fermented juice by mixed culture were considered as malic(26.0%), lactic(49.9%), succinic and citric acid, whereas these of unfermented juice were malic(53.2%), citric and other acids. On other hand, reducing sugar was decreased from 18.3mg/ml in fresh juice to about 12mg/ml in juice by mixed culture fermentation. Concentrations of fructose, glucose and sucrose were also greatly reduced in fermented juice.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.779-786
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• 2012

Rhodiola sachalinensis fermentates by lactic acid bacteria were prepared using the adsorption process, and were investigated for changes of the main compounds and anti-oxidative activities during the adsorption and fermentation process. While the R. sachalinensis extract (RSE), which did not go through the adsorption process, showed little change in pH during fermentation and a significant reduction in the number of lactic acid bacteria, the pre-preparatory adsorption process was found to be helpful for promoting fermentation and for maintenance of bacterial numbers. The contents of total phenolic compounds mostly decreased during the adsorption process, but showed an increasing tendency to rebound during the fermentation process. The contents of salidroside and p-tyrosol in the RSE were 1153.3 mg% and 185.0 mg% respectively, and they did not significantly change after treatment with acid clay or bentonite as adsorbents, which were 1093.0 and 190.5 mg% by acid clay, and 882.2 and 157.3 mg% by bentonite. When the extract was fermented after treatment with acid clay or bentonite, the salidroside contents were decreased by 282.7 and 505.0 mg% respectively, but the p-tyrosol contents were increased by 714.0 and 522.4 mg% respectively. Compared to the DPPH radical scavenging activity of the RSE (66.8%) at the conc. of 0.1%, that of the fermented RSE, which went through adsorption process with acid clay or bentonite, was significantly increased to 79.4 and 72.7% respectively at the same concentration (p<0.05). Though fermentation by lactic acid bacteria was suppressed in the RSE, the results suggested that the adsorption process may promote fermentation without any change in the content of major active compounds. It is expected that fermentation by lactic acid bacteria could improve the antioxidant activity and various associated functionalities of R. sachalinensis.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.6
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• pp.807-811
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• 2005

This experiment examined the characteristics of fermented juice of epiphytic lactic acid bacteria (FJLB) prepared by the addition of glucose, sucrose and molasses as a fermentation substrate. The effect of FJLB on the fermentative quality and changes in chemical composition during fermentation of guineagrass silage were also investigated. The pH value of the silages treated with FJLB rapidly decreased, and reached to the lowest value within 7 days of start of fermentation, as compared to the control. The number of lactic acid bacteria (LAB) in the treated silages increased for the first 3 days, thereafter the number of LAB declined gradually up to the end of the experiment. Silages treated with FJLB had larger populations of LAB than the control. Ammonia-nitrogen production increased throughout the ensiling period, which in the control and no-sugar added FJLB silages were higher than the other treated silages. Lactic acid levels varied with the time of ensiling and among the silage treatments. For any sugar FJLB treated silages, the lactic acid increased initially, and then slightly reduced to less than 50 g/kg of dry matter until 49 days after ensiling, except the silage treated with glucose added FJLB. Nevertheless, lactic acid content of the control decreased constantly from the beginning of ensiling and was not found after 35 days. Moreover, acetic acid content increased throughout the ensiling period. All the FJLB treated silages had significantly (p<0.05) lower pH and ammonia-nitrogen content, while significantly (p<0.05) higher lactic acid content and V-score value compared with the control. This study confirmed that the applying of FJLB with any sugar substrate improved fermentative quality of silage.

• Journal of Ginseng Research
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• v.42 no.1
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• pp.57-67
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• 2018

Background: Ginseng contains many small metabolites such as amino acids, fatty acids, carbohydrates, and ginsenosides. However, little is known about the relationships between microorganisms and metabolites during the entire ginseng fermentation process. We investigated metabolic changes during ginseng fermentation according to the inoculation of food-compatible microorganisms. Methods: Gas chromatography mass spectrometry (GC-MS) datasets coupled with the multivariate statistical method for the purpose of latent-information extraction and sample classification were used for the evaluation of ginseng fermentation. Four different starter cultures (Saccharomyces bayanus, Bacillus subtilis, Lactobacillus plantarum, and Leuconostoc mesenteroide) were used for the ginseng extract fermentation. Results: The principal component analysis score plot and heat map showed a clear separation between ginseng extracts fermented with S. bayanus and other strains. The highest levels of fructose, maltose, and galactose in the ginseng extracts were found in ginseng extracts fermented with B. subtilis. The levels of succinic acid and malic acid in the ginseng extract fermented with S. bayanus as well as the levels of lactic acid, malonic acid, and hydroxypruvic acid in the ginseng extract fermented with lactic acid bacteria (L. plantarum and L. mesenteroide) were the highest. In the results of taste features analysis using an electronic tongue, the ginseng extracts fermented with lactic acid bacteria were significantly distinguished from other groups by a high index of sour taste probably due to high lactic acid contents. Conclusion: These results suggest that a metabolomics approach based on GC-MS can be a useful tool to understand ginseng fermentation and evaluate the fermentative characteristics of starter cultures.

• Journal of the East Asian Society of Dietary Life
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• v.11 no.5
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• pp.379-385
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• 2001

The effects of lactic acid bacteria from kimchi fermentation, specifically Lactobacillus plantarum(LP) and Leuconostoc mesenteroides (LM) on the quality of the bread product was investigated. The two types of bacteria were cultivated in the sterilized radish juice used for kimchi fermentation. The concentration of bacteria was measured at 3.0$\times$10$^{9}$ ~3.3$\times$10$^{9}$ /mL. The bacteria were added at the ratios of 5% and 10% to a mixture with wheat flour before subsequent dough fermentation. An LM+LP treatment to the mixture was also made at 5% of LP and 5% of LM. The measured pH in the dough with LM+LP was the lowest among all of treatments. The products of 5% LM treatment showed the shortest fermentation time. Loaf production by volume was the highest from the 10% LM treatment. The % of moisture loss of the bread during the shelf-storage was less when treated with lactic acid bacteria than when left untreated. The least moisture loss was observed when the bread was treated with the LM+LP mixture. Hardness of the bread also decreased with the presence of lactic acid bacteria. The order of hardness was: control > 5% LP > LM+LP > 5% LM > 17% LM > 10% LP. Staling degree of the bread when treated with lactic acid bacteria was lower than that of the control. The least staling occurred when treated with LM 10% and LP 10%.

• Journal of Environmental Health Sciences
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• v.31 no.1
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• pp.79-85
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• 2005

This study was undertaken to investigate the changes of index microorganisms and lactic acid bacteria of traditional Korean fermented vegetables (kimchi) during the ripening and fermentation period. A type of kimchi, baechoo-kimchi, was prepared and stored at $10^{\circ}C$ for 8 days. The numbers of the total aerobic bacteria, psychrotrophilic bacteria, coliform bacteria, and Escherichia coli in the kimchi and also in raw materials of the kimchi (Chinese cabbage, green onion, ginger, garlic, and red pepper) were counted using appropriate media. The highest number of aerobic bacteria was detected from ginger, then red pepper, then garlic, then Chinese cabbage, and lowest number from green onion. The highest number of psychrotrophilic bacteria was detected from red pepper, then Chinese cabbage, then garlic, then ginger, and the lowest number from green onion. Coliforms and E. coli were not detected from all of the raw materials of kimchi. Total aerobic bacteria and lactic acid bacteria of the kimchi showed gradually increasing during ripening and fermentation. The number of psychrotrophilic bacteria showed a similar level in the kimchi. Coliform bacteria were detected at the 3rd, 4th, and 5th day of the kimchi fermentation period, although they were not detected from the raw materials of the kimchi. However, the bacteria were not detected in the kimchi after 6 days. E. coli was not detected in all kimchi samples. The pH value of the kimchi gradually decreased, and acidity increased over fermentation period. This study indicates that there was contamination of coliform bacteria during the process of kimchi preparation, and lactic acid bacteria proliferated in the kimchi during fermentation inhibited the growth of coliforms. More research is needed to evaluate the inhibitory effects of each raw materials of kimchi.