Screening of gamma-aminobutyric acid-producing lactic acid bacteria and the characteristic of glutamate decarboxylase from Levilactobacillus brevis F109-MD3 isolated from kimchi

AIMS

This study aimed to screen the γ-aminobutyric acid (GABA)-producing lactic acid bacteria (LAB) from kimchi, and investigate the glutamate decarboxylase (GAD) activity of the highest GABA-producing strain.

METHODS AND RESULTS

Seven strains of LAB were screened from kimchi with GABA-producing activity. Strain Levilactobacillus brevis F109-MD3 showed the highest GABA-producing ability. It produced GABA at a concentration of 520 mmol l^-1 with a 97.4% GABA conversion rate in MRS broth containing 10% monosodium glutamate for 72 h. The addition of pyridoxal 5'-phosphate had no significant effect on the GAD activity of L. brevis F109-MD3. The optimal pH range of GAD was 3.0-5.0 and the optimal temperature was 65°C. The D value of GAD at 50, 60 and 70°C was 7143, 971 and 124 min respectively and Z value was 11.36°C.

CONCLUSIONS

Seven strains isolated from kimchi, especially F109-MD3, showed high GABA-production ability even in the high concentrations of MSG at 7.5% and 10%. The GAD activity showed an effective broad pH range and higher optimal temperature.

SIGNIFICANCE AND IMPACT OF THE STUDY

These seven strains could be potentially useful for food-grade GABA production and the development of healthy foods.

Relationship Between Plant Food (Fruits, Vegetables, and Kimchi) Consumption and the Prevalence of Rhinitis Among Korean Adults: Based on the 2011 and 2012 Korea National Health and Nutrition Examination Survey Data

The aim of the current study was to analyze the relationship between plant food (fruits, vegetables, and kimchi) and the prevalence of rhinitis among Korean adults using data from the 2011 and 2012 Korea National Health and Nutrition Examination Survey. A total of 7494 subjects aged from 19 to 64 years participated in a rhinitis morbidity survey, health behavior interview, and 24-h dietary recall test. Individuals with energy intakes less than 500 kcal or more than 5000 kcal were excluded. The results showed that kimchi intake was inversely associated with the prevalence of rhinitis. The prevalence of rhinitis decreased with increasing kimchi consumption. The quintile 4 (range of kimchi intake: 108.0-180.0 g) groups, compared with the reference of quintile 1 (0-23.7 g), showed a decrease of 18.9% (odds ratio [OR] = 0.811, 95% confidence interval [CI] = 0.672-0.979) in Model 4. In conclusion, consumption of kimchi lowers the risk of rhinitis, suggesting that its use should be encouraged among the Korean population.

Identification of Antifungal Substances of Lactobacillus sakei subsp. ALI033 and Antifungal Activity against Penicillium brevicompactum Strain FI02

This study was performed to investigate the antifungal substances and the antifungal activity against fungi of lactic acid bacteria (LAB) isolated from kimchi. LAB from kimchi in Imsil showed antifungal activity against Penicillium brevicompactum strain FI02. LAB LI031 was identified as Lactobacillus sakei subsp. Antifungal substances contained in L. sakei subsp. ALI033 culture media were unstable at high pH levels. Both, the control and proteinase K and protease treated samples showed clear zones, suggesting that the antifungal substances produced by ALI033 were non-protein substances unaffected by protesases. Both, the control and catalase showed clear zones, suggesting that the antifungal metabolite was not H2O2. The molecular weights of the antifungal substances were ≤3,000 Da. The organic acid content of crude antifungal substances produced by L. sakei subsp. ALI033 showed high concentrations of lactic acid (502.47 mg/100 g). Therefore, these results suggest that antifungal substance produced by L. sakei subsp. ALI033 is most likely due to its ability in producing organic acid.

Analysis of Kimchi, vegetable and fruit consumption trends among Korean adults: data from the Korea National Health and Nutrition Examination Survey (1998-2012)

BACKGROUND/OBJECTIVES

The purpose of this study is to analyze daily kimchi, vegetable and fruit consumption by general characteristics and vegetable and fruit consumption from 1998 to 2012 by the Korean population based on the data of the KNHANES (Korea National Health and Nutrition Examination Survey).

SUBJECTS/METHODS

This study is based on the 1998-2012 KNHNES. Analysis data on 54,700 subjects aged 19 years and older were obtained from health behavior interviews and the 24-hour dietary recall method.

RESULTS

Daily kimchi consumption and portion size of kimchi decreased significantly from 1998 to 2012 (adjusted P for trend < 0.0001). Meanwhile, daily consumption of both non-salted vegetable and fruit with and without kimchi did not significantly change between 1998 and 2012. Reduced consumption of kimchi, non-salted vegetable, and fruit was observed for both genders as well as daily meal episodes and cooking locations. Male and female subjects with insufficient non-salted vegetable and fruit intake were increased 1.4 times and 1.3 times, respectively, in 2012 than 1998. All subjects consumed at least 400 g/day of non-salted vegetable, fruit, and kimchi in each survey year, although they consumed insufficient amounts (< 400 g/day) of non-salted vegetable and fruit without kimchi.

CONCLUSIONS

Since Koreans generally consume high amounts of fermented vegetables, including kimchi, total vegetables and fruit. Consumption of these foods by the Korean adult population reached 400 g, which is the recommended intake of the WCRF/AICR. Based on this result, it is necessary to promote consumption of kimchi in the Korean population and research the development of low sodium kimchi in the future.