• Journal of Microbiology and Biotechnology
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• v.19 no.12
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• pp.1644-1649
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• 2009

This study investigates the buffering effects of calcium salts in kimchi on the total acidity, microbial population, and dextransucrase activity. Calcium chloride or calcium carbonate was added to dongchimi-kimchi, a watery radish kimchi, and the effects on various biochemical attributes were analyzed. The addition of 0.1% calcium chloride produced a milder decrease in the pH after 24 days of incubation, which allowed the lactic acid bacteria to survive longer than in the control. In particular, the heterofermentative Leuconostoc genus population was 10-fold higher than that in the control. When sucrose and maltose were also added along with the calcium salts, the dextransucrase activity in the kimchi was elevated and a higher concentration of isomaltooligosaccharides was synthesized when compared with the control. Calcium chloride was determined as a better activator compound of dextransucrase than calcium carbonate, probably because of its higher solubility. Therefore, the results of this study confirm the ability of the proposed approach to modulate the kimchi fermentation process and possibly enhance the quality of kimchi based on the addition of dietary calcium salts.

• Korean journal of food and cookery science
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• v.4 no.2
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• pp.39-50
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• 1988

Main lactic acid bacteria fermenting “Baechu Kimchi” and” “Dongchim”, which are indigenous fermented food in Korea, were isolated at optimum fermentation period and identified. The three groups of food preservatives-sorbic acid, p-hydroxybutyl benzoate (POBB), p-hydroxypropyl benzoate (POPB), and sorbic acid-POBB were prepared, and the effect of the food preservatives and various salt concentrations on those lactic acid bacteria was examined. The results obatined are as follows; 1. Lactic acid bacteria were isolated from “Baechu Kimchi” and “Dongchimi”and identifed as Leuconostoc mesonteriodse, Lactobacillus plantatum, Lactobacillus brevis, Streptococcus faecalis, and Pedicoccus pentosaceus. 2. Lactic acid bacteria were grown much better at 0.5-2% NaCl level than 0% NaCl level. 3. Among the isolated lactic acid bactera, Lactobacillus plantarum showed the highest acid producibility. The lower the concentration of NaCl, the higher the acid producibility by Leuconostoc mesentroides, and the other bacteria produced a large amount of acid at 0.5-2.5% NaCl level. 4. Both the sorbic acid (0.05-0.1%) and sorbic (0.05%)-POBB (0.004%) groups showed the highest preservatives effect. In contrast, however, POPB (0.01% ) Group showed the lowest effect, and the preservatives effect was enhanced by the addition of NaCl. Lactobacillus plantarum was least affected by all preservatives, whereas Leuconostoc mesentroides was most affected by them.

• Food Science and Preservation
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• v.6 no.4
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• pp.448-455
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• 1999

The starters, 0.3% of Leuconostoc mesenteroides, Lactobacillus brevis and Lactobacillus fermentum, were added in radish juice to process the radish juice by single and mixed cultures. The radish Juice was fermented for 7 days at 25$^{\circ}C$, 20 days at 15$^{\circ}C$, and 36 days at 5$^{\circ}C$. When fermented at 25$^{\circ}C$, the number of lactic acid bacteria in the juice made with mixed culture was higher than that of the single culture. But, juice fermented at low temperatures (15∼5$^{\circ}C$), the addition of starters was not effective, although there were some differences by inoculation strains. Although there was a little differences by inoculation strains, the content of nonvolatile organic acid and L-ascorbic acid were found more in the juice inoculated with lactic acid bacteria than the juice not inoculated. When the single and mixed cultures at the optimal maturity were tested, the significant difference was found at 5% level except the yeasty and moldy smell and the unripe taste. According to the preference test, the mixed-cultured radish juice incubated at 25$^{\circ}C$with Lactobacillus brevis and Leuconostoc mesenteroides were evaluated superior to commercial Dongchimi. As a result, taste and quality of radish juice was improved by addition of starters.

• Journal of Food Hygiene and Safety
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• v.23 no.2
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• pp.113-120
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• 2008

The influence of incubation temperature, pH and media components on bacteriocin production by Lactobacillus plantarum K11 were investigated. The highest activity was observed in MRS broth, but no bacteriocin activity was obtained in TSB. The bacteriocin was produced from the exponential growth phase and its activity also reached a maximum in MRS broth, but then dropped after 16 hr because of degradation by extracellular proteolytic enzymes or exhaustion of medium nutrients. The optimal temperature and pH for production of bacteriocin were $37^{\circ}C$ and pH 7.0 in MRS broth, respectively. The addition of 0.5 or 1.0% glucose and $0.5{\sim}1.5%$ lactose to MRS resulted in the increase of the bacteriocin production. With 0.5% NaCl and $K_2HPO_4$, the activities were significantly higher than that of control, respectively. However, increasing nitrogen sources such as beef extract, casein, and tryptone and salts such as $NH_4PO_4$, $MgSO_47H_2O$, and $MnSO_4H_2O$, had detected a negative influence upon the bacteriocin production. Consequently, because the bacteriocin produced by L. plantarum K11 was affected by various incubation conditions, the bacteriocin activity of L. plantarum K11 applied in food as a novel starter will be dependent on environmental factors such as fermentation conditions and food ingredients.