• Korean Journal of Medicinal Crop Science
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• v.25 no.3
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• pp.146-151
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• 2017

Background: Rehmannia glutinosa is a perennial herb belonging to the family Scrophulariaceae. Its roots have been utilized as a traditional medicine. The aim of this study was to elucidate the basic information of the roots of the R. glutinosa cultivars and their utilization. Methods and Results: The roots of R. glutinosa cultivars were harvested in the end of March. The two iridoid glycosides, aucubin and catalpol, were analyzed by liquid chromatography/mass spectrometry (LC/MS), whereas ${\gamma}-aminobutyric$ acid (GABA) was analyzed by gas chromatography/mass spectrometry (GC/MS). The aucubin content was the highest in the Dakang cultivar, whereas no aucubin was detected in the five cultivars. All cultivars had more than 12 mg/g catalpol content, and the maximum catalpol content was found in Jihwang 1. The GABA content was the highest in Suwon 1, and it was 40 times more than that in the Yeongang cultivar. Conclusions: The highest aucubin, catapol and GABA contents were detected in the Dakang, Jihwang 1, and Suwon 1, cultivars respectively. This study provides the crucial information regarding the versatile utilization and pedigree selection of R. glutinosa cultivars.

• International Journal of Oral Biology
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• v.30 no.3
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• pp.91-98
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• 2005

Gamma-aminobutyric acid (GABA) is known as an inhibitory neurotransmitter in the neurons of the central nervous system. However, its detailed action mechanisms in the rostral gustatory zone of the nucleus tractus solitarius (rNTS) have not been established. The present study was aimed to investigate the distribution, role and action mechanisms of GABA in rNTS. Membrane potentials were recorded by whole cell recordings in isolated brain slices of the rat medulla. Superfusion of GABA resulted in a concentration-dependent reduction in input resistance in the neurons in rNTS. The change in input resistance ws accompanied by response to a depolarizing pulse were diminished by GABA. Superfusion of the slices with either $GABA_A$ agonist, muscimol, $GABA_B$ agonist, baclofen or $GABA_C$ agonist, TACA, decreased input resistance and reduced the nerve activity in association with membrane hyperpolarization. It is suggested that inhibitory signals playa role in sensory processing by the rNTS, in that GABA actions occur through activation of $GABA_A,\;GABA_B\;and\;GABA_C$ receptor. These results suggest that GABA has an inhibitory effect on the rNTS through an activation of $GABA_A,\;GABA_B\;and\;GABA_C$ receptors and that the GABAergic inhibition probably plays an important role in sensory processing by the rNTS.

• Preventive Nutrition and Food Science
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• v.15 no.3
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• pp.221-228
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• 2010

The objective of this research was to investigate the changes in the contents of physicochemical properties including $\gamma$-aminobutyric acid (GABA), total dietary fiber (TDF), amylose, protein, and fat content in brown rice through germination for 2 different years. Total phenolic contents and antioxidant activities of DPPH and ABTS radical scavenging capacities were also determined in different solvent extracts. For the physicochemical properties, GABA, TDF, protein, and fat content increased, whereas amylose levels decreased. Specially, GABA and TDF levels showed the greatest variations among cultivars and harvest years. Total phenolic content and antioxidant activity significantly increased. The average total phenolic content at a concentration of 0.5 mg/mL in different extract solvents occurred in this order: methanol>ethylacetate>chloroform>hexane extracts. Additionally, 'Keunnun' exhibited the highest GABA levels, highest total phenolic content, and highest antioxidant activity after germination, with increases of approximately 3.7, 2.0, and 1.9 times, respectively, compared to levels before germination. These results suggest that, because of its high physicochemical contents and strong radical scavenging activities, germinated brown rice can be used as beneficial supplement.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.4
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• pp.542-549
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• 2013

This study was conducted to investigate the chemical properties and functionality of probiotic potato juice fermented by Lactobacillus casei. Free sugar content (especially glucose) of potatoes decreased by fermentation, but organic acid contents increased by fermentation. Although the free amino acid content of Superior juice significantly decreased after fermentation, Haryeong significantly increased after fermentation. ${\gamma}$-Aminobutyric acid, a functional amino acid, was detected at high levels in all samples and slightly decreased with fermentation, but not significantly. The total polyphenol content of potato juice showed insignificant changes in all samples by fermentation. The hydroxyl radical scavenging activity of all samples was more than 90%, and most of the activity was maintained after fermentation. The nitrite scavenging ability of all samples greatly decreased with fermentation; however a SOD-like activity slightly increased with fermentation, except for Haryeong. There was a significant xanthine oxidase inhibitory effect in fresh potato juice (more than 45%) and a low loss by fermentation. From our results, most of the chemical properties and functionality of potato juice are maintained after fermentation, although free sugar content and nitrite scavenging activity decline. Thus probiotic potato juice fermented by lactic acid could be used as a functional beverage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.12
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• pp.1799-1805
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• 2015

Rice vinegar (RV) is primarily made from fermented rice or rice wine in Korea, China, and Japan. Ten commercially available naturally-fermented rice vinegars produced in Korea (KRV1~4), China (CRV1~2), and Japan (JRV1~4) were comparatively investigated for their physicochemical properties and antioxidant activities. KRV showed a significantly higher total acidity range (5.07~6.27) than both CRV (4.67~4.84) and JRV (4.64~4.84). These acidity ranges corresponded with respective standards of each country: Korea (Food Code), China (GB), and Japan (JAS). Six different organic acids were detected in RVs; acetic acid and succinic acid were the most prominent. Thirty different amino acids were detected in RVs, and main identified amino acids were alanine (KRV), phenylalanine and aspartic acid (CRV), and leucine and alanine (JRV). ${\gamma}-Aminobutyric$ acid was detected at high concentration in KRV1. KRV1 showed maximum total phenolic content, and DPPH and ABTS radical scavenging activities of samples were also determined with significantly increasing tendency. KRV1 (produced from brown rice with aging period of >1 year) exhibited the highest free amino acid content and antioxidant activity as compared to CRV and JRV.

• Animal Bioscience
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• v.34 no.4
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• pp.621-632
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• 2021

Objective: This study was conducted to investigate the effects of supplementation with rumen-protected γ-aminobutyric acid (GABA) on carcass characteristics and meat quality of Hanwoo steers. Methods: Eighteen Hanwoo steers with an average initial weight of 644.83±12.91 kg were randomly allocated into three different groups. Each group consisted of 6 animals that were treated with different diets formulated based on the animals' body weights. The control (C) group was fed a basal diet consisting of concentrate and rice straw with 74% total digestible nutrients (TDNs) and 12% crude protein (CP). The two other groups were treatment groups; one group was fed a basal diet (74% TDNs and 12% CP) supplemented with rumen-protected GABA at a dose of 150 mg/kg feed, and the other group was fed a basal diet (74% TDNs and 12% CP) supplemented with GABA at a dose of 300 mg/kg feed. Results: The GABA supplementation significantly contributed to better growth performance (p<0.05), especially the weight gain and average daily gain. It also contributed to the lower cooking loss (p<0.05), improvements in essential antioxidant enzymes and stable regulation of antioxidant activities in the longissimus lumborum of Hanwoo steers, as represented by the lower formation of malondialdehyde content within the meat, the inhibition of myoglobin oxidation indicated by the retention of the oxymyoglobin percentage, and the suppression of metmyoglobin percentage during cold storage (p<0.05). Conclusion: Higher doses of GABA may not significantly promote better animal performance and meat quality, suggesting that dietary supplementation with GABA at a dose of 100 ppm is sufficient to improve the meat quality of Hanwoo steers.

• Horticultural Science & Technology
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• v.29 no.2
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• pp.144-150
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• 2011

This study was conducted to investigate the nutrient components and physicochemical properties of general ('Superior') and colored potato. Proximate composition, reducing sugar, free sugars, free amino acids, organic acids, minerals were analyzed, and Hunter color values were measured in the study. 'Rose' and 'Blue' (colored potatoes) contained high levels of reducing sugar, and total free sugar content was greatly different according to varieties. Glutamic acid, arginine and ${\gamma}$-aminobutyric acid were detected to be the three major amino acids in colored potato, and the major organic acids of general potato were oxalic acid, tartaric acid, malic acid and citric acid. All potato contained high level of potassium, calcium and magnesium. The Hunter 'L' value was the highest in 'Jaseo'; Hunter 'a' value was high in 'Blue' and 'Jasim'; Hunter 'b' value was the highest in 'Haryoung'. Overall, colored potato had higher amount of nutrients and physicochemical properties than 'Superior'. Therefore, colored potatoes are expected to be highly valuable items for the development and applications of a functional food. In addition, these results will provide fundamental data for improving sitological value, breeding of new cultivar and promoting of roughage usage.

• Preventive Nutrition and Food Science
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• v.15 no.2
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• pp.113-119
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• 2010

The aim of this study was to investigate changes in 7 nutritional components (fatty acid, protein, fat, ash, total dietary fiber (TDF), $\gamma$-aminobutyric acid (GABA), and $\gamma$-oryzanol) of paddy rice (PR) and brown rice (BR) throughout the germination process, as measured at different shoot lengths (10 mm, 20 mm, and 30 mm). With the increase of shoot length, the nutritional components' concentrations increased, as compared to the concentrations measured before germination. Moreover, BR exhibited higher GABA, $\gamma$-oryzanol, and protein than PR. Among the components, TDF, GABA, and $\gamma$-oryzanol showed significant concentration differences throughout germination, while the others exhibited only slight variations. In particular, GABA and $\gamma$-oryzanol were predominantly increased in grains of 10 mm shoot length. These compounds might prove to be important factors from germinated rice. Additionally, the germinated cultivar 'Keunnun' might also prove to be a very important food source, owing to its high GABA and $\gamma$-oryzanol contents. These results suggest that variations in nutritional components related to the increase of shoot length may prove to be important when considering the beneficial aspects of rice on human health.

• Korean Journal of Poultry Science
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• v.49 no.4
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• pp.247-253
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• 2022

This study was conducted to investigate the effects of γ-aminobutyric acid (GABA) and a probiotic mixture on egg quality, blood parameters, and corticosterone content in broiler breeder stock in summer in Korea. A total of 72 broiler breeders (Arbor Acres) at 49 weeks old were randomly divided into the following three groups of 24 heads each: control, GABA, and probiotics (1 × 10⁸/g Bacillus licheniformis, 1 × 10⁷/g Lactiplantibacillus plantaru, and 1 × 10⁷/g Clostridium butyricum). The hens were fed a diet containing 50 mg of GABA/kg of feed and 0.1% probiotics for 6 weeks. Egg quality, blood parameters, and stress levels (corticosterone concentration) of the broiler breeders were evaluated. No significant differences were observed in the egg weight, albumen height, Haugh units, yolk color, shell thickness, or shell strength between the groups. There were no significant between-group differences in the blood biochemical profile, including total cholesterol, triglyceride, glucose, total protein, aspartate aminotransferase, alanine aminotransferase, albumin, and inorganic phosphorus concentrations. The corticosterone concentration was significantly lower in the GABA and probiotics groups than the control group (P < 0.05) at 6 weeks of age. In conclusion, these results suggest that dietary probiotics and GABA significantly improve the stress levels of broiler breeders in summer in Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.1
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• pp.35-40
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• 2018

${\gamma}$-Aminobutyric acid (GABA) has antihypertensive and anti-stress effects on humans. The present study aimed to investigate the effect of glutamate concentration, bran content, and barley cultivars on GABA production and determine the optimal reaction condition. Barley bran resulted in higher GABA productivity compared with that of rice bran. The higher the bran content, the higher was the GABA productivity. Furthermore, high glutamate concentration resulted in high GABA production. However, there was a decrease in the glutamate conversion rate. The production of GABA varied with temperature and barley cultivar. The optimal condition for GABA production using barley bran was 0.15 g/mL barley content, 10 mM glutamate concentration, and $20^{\circ}C$ reaction temperature. Under optimal condition, the GABA concentration was 10.34 mM, and glutamate conversion rate was 75.1%. Furthermore, the GABA productivity of the GABA production reaction using barley bran differed depending on the cultivar. Dasong and Yeongbaekchal showed higher GABA productivity than that by other cultivars.