• Food Science and Biotechnology
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• v.15 no.1
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• pp.77-81
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• 2006

The dextransucrase activity of microorganisms which were identified as contributing to the fermentation of jeungpyeon made with yeast was measured. The dextran generated during fermentation was quantified and the viscosity changes were measured. The mechanism of network structure formation was clarified by observing the inside of the network structure over the fermentation periods ranging from 1 to 7 hr using scanning electron microscopy (SEM). The pH of jeungpyeon batter decreased significantly as the fermentation proceeded, whereas the viscosity increased. The identified lactic acid bacteria (LAB) were Leuconostoc mesenteroides subsp. mesenteroides, Pediococcus pentosaceus, Tetragenococcus halophilus, and Leuconostoc mesenteroides subsp. dextranicum. The yeast was identified as Saccharomyces cerevisiae A/Tor. Pretorien. The dextransucrase extracted from those microorganisms showed high activity. On the other hand, the amount of dextran generated from the batter increased significantly beyond 2 hr of fermentation, and the viscosity increment showed a similar trend. The SEM photos showed that the most homogeneous fine network structure was observed in the batter fermented for 2 hr. Therefore, we assumed that the dextran that was generated by microorganisms during fermentation interacted with the components of the batter to increase the stability of the network structure.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.365-370
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• 1999

To investigate the effect of natural plants on the prolongation of optimal fermentation time of kakdugi, various kakdugies, added with hot water extract from 105 kinds of natural plants(68 medicinal plants and 37 vegetables), were fermented at 20oC until optimal fermentation time. In case of control without addition, the time required to reach the optimum acidity(0.6% lactic acid) was 60 hr. Among 105 kinds tested, 48 plant(42 medicinal plants and 6vegetables) extracts decreased the acidity after 60 hr fermentation to less than 50% of control. In addition, these extracts extended the optimal fermen tation time(>120 hr) by more than 2 folds. Moreover, among the above 48 kinds, 12 sorts of extracts raised the hardness of kakdugi, by more than 30%, compared to control. And the number of lactic acid bacteria in kakdugi added with the above 12 kinds was not smaller than that of control. In sensory test, 8 kinds of medicinal plants(including Phyllostachys edulis) were found to be acceptable. Based on these results, it is suggested that kakdugi added with 8 kinds of medicinal plants was adequate in the prolongation of optimal fermentation time of kakdugi.

• Korean Journal of Medicinal Crop Science
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• v.20 no.6
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• pp.472-478
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• 2012

This study was carried out to investigate solid-state fermentation method using cellulolytic lactic acid bacteria Lactobacillus plantarum TO-2100 in order to increase piperidine alkaloid contents in mulberry leaves. Piperidine alkaloid, one type of which include 1-deoxynojirimycin (1-DNJ), is known to inhibit ${\alpha}$-glycosidase activities. Using this strain, the optimal solid-state fermentation conditions on mulberry leaves powder were found as the following: initial moisture content, temperature and relative humidity were 20%, $30{\sim}35^{\circ}C$ and 60 ~ 70%, respectively, and the fermentation time was 72 hrs. The piperidine alkaloid contents in the fermented mulberry leaves were 2.86% on dry powder, which is 7-fold increase from that of non-fermented mulberry leaves. The 1-deoxynojirimycin contents after applying preparative thin layer chromatography were 2.02% on dry powder, which is 8 times higher than that of non-fermented mulberry leaves. ${\alpha}$-Glycosidase activities was inhibited by 65.7 ~ 84.7% with 3 ~ 5% treatments of hot-water extracts of the fermented mulberry leaves, compared to 16.2 ~ 40.2% with 3 ~ 5% treatments of hot-water extracts of non-fermented mulberry leaves. Therefore, the results suggest that solid-state fermentation method does indeed increase of piperidine alkaloid contents on mulberry leaves.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.1
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• pp.96-101
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• 2013

This study was carried out to investigate the changes in antioxidant activity, and the isoflavone and free amino acid content in fermented tofu of the ingredients of kimchi (red pepper, garlic, ginger, and anchovies) and lactic acid bacteria (Pediococcus acidilactici KL-6) during 24 weeks of fermentation at $20^{\circ}C$. The total polyphenol content of various types of fermented tofu such as the control (tofu with kimchi ingredients mixture), tofu and kimchi ingredients with lactic acid bacteria (TL), and tofu in pre-fermented kimchi ingredients with lactic acid bacteria (TPL) ranged from 156.34 to 165.17 mg/g, showing that TPL was significantly higher in terms of fermentation time (6 weeks) compared to others. The DPPH free radical scavenging activity of TPL (84.11%) was higher than that of the control (76.68%) and TL (78.95%) after 12 weeks fermentation at $20^{\circ}C$. The changes of nitrite scavenging activity and SOD-like activity in the tested tofu showed the same tendency as the DPPH free radical scavenging activity during 14 weeks fermentation TPL showed statistically significant levels of increased antioxidant activity, so we compared the isoflavone and free amino acid content. The isoflavone and free amino acid content of TPL was 2.34 mg/g and 20.81 mg/g after 14 weeks fermentation, respectively.

• Applied Biological Chemistry
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• v.41 no.6
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• pp.405-409
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• 1998

This work was carried out to investigate the behavior of sugars contained in raw soybean during cooking and meju preparation processes, and the effects of sugar addition to the raw kanjang digestion liquor made from G8 and SB meju on the lactic acid and alcoholic fermentation of kanjang. Sharp reduction in sugars content in soybean during cooking and meju preparation process was observed. Rapid lactic acid and alcoholic fermentation in the G8 and SB kanjang with 5% added glucose was observed but not in the corresponding kanjang without sugar addition after inoculation of Pediococcus halophilus, Zygosaccharomyces rouxii and Candida versatilis starter culture to the low-salted raw kanjang digestion liquor made respectively from G8 and SB meju. 0.46% and 0.88% of lactic acid and 1% and 2% of alcohol content in the G8 and SB kanjang respectively was observed 160 hours after the inoculation of the lactic acid bacteria starter culture.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.678-684
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• 2013

This study measured the change of lactic acid bacteria during the ripening fermentation process of low salt fermented squid with no squid ink added. All study groups showed increase of Leuconostoc and rapid growth of total plate count at the beginning stage of ripening and the maximum microbial count showed at the optimum stage of ripening which gradually reduced after the optimum stage. It is believed that Lactobacillus occupied the major part of the total plate count after the optimum stage of the squid fermentation, and it was related to the quality after the optimized ripening stage. Streptococcus and Pediococcus were gradually increased until the optimum stage of the ripening, and then decreased rapidly. Yeasts were detected in the middle stage of the fermentation and rapid increase was shown after the last stage of the fermentation which suggests that yeasts participate in putrefaction of the low salt fermented squid. The change of lactic acid bacteria observed during the ripening fermentation of low salt fermented squid with squid ink added was that the total plate count increased until ripening middle stage but showed a tendency to slightly reduce after the middle stage. The length of time to reach the maximum value was longer than the no treatment groups. Among the lactic acid bacteria, Leuconostoc, Streptococcus and Pediococcus has increased until the middle stage of the ripening while Lactobacillus constantly increased to the end part of the ripening. Yeasts had no increasing in the early ripening stage, but after middle of the ripening, it started to increase. That kind of tendency was similar to the case of no treatment groups. However, the amount of lactic acid bacteria tended to be less than no treatment groups. The tendency of decreasing number of all bacteria in low salt fermented squid with squid ink added shows squid ink restricts the growth of all bacteria.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.303-310
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• 2002

An optimization for fermentation processes to make lactic acid juice with extracts from apples, carrots, celery, watercress, jujube and lycii (3 : 3 : 1 : 1/2 : 1 : 1/2) using co-cultures of Leuconostoc mesenteroides, Lactococcus lactis and Lactobacillus cellobiosus isolated from Dongchimi had been investigated on the emphasis of composition of sugars and sodium chloride at various temperatures. The concentration of sugars less than 25% and salt less than 0.8% did not affect remarkably the cell growth of lactic acid bacteria and acid formation during fermentation. The fermenting juice showed increases in the population of lactic acid bacteria and acidity, and decreases in population of coliform bacteria and sugar concentration with high cultural temperature. At $25^{\circ}C$ viscous substance was not formed as it had at $15^{\circ}C$. The optimum composition, based on the sensory evaluation, was determined to be oligosaccharide and 0.2% for sodium chloride. It took 3 days to produce the most preferable juice of pH 3.62 at $25^{\circ}C$. At the optimal state the fermented juice showed viable cell counts (cfu/mL) of exponential numbers 8 for lactic acid bacteria and 4 for yeast. Coliform bacteria which had been $5.6{\times}10^2\;cfu/mL$ at the beginning of fermentation were not detected.

• Korean Chemical Engineering Research
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• v.48 no.3
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• pp.342-349
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• 2010

Lactic acid is widely used in the food, chemical and pharmaceutical industries, and there is an increasing demand for lactic acid as the raw material of poly lactic acid(PLA), which is a biodegradable polymer. Lactic acid production has been changing over from production by synthesis to production by fermentation, since the fermentation process is more nature friendly and economic. However, the fermentation method generates excess water and impurities with high boilers. The presence of high boilers and non volatility of lactic acid makes the separation of lactic acid very difficult job. Also, the purification-separation process requires the many investment costs and energy costs. Reactive distillation concept was also introduced for the process, giving higher selectivity and yield compared to the convention method. We introduce a new highly integrated process, reactive diving wall column, to reduce the capital and energy cost for producing a pure lactic acid. The reactive dividing wall column combines reactive distillation and dividing wall column. We compared capital and energy consumption required for the purification of lactic acid the between the proposed design structures. And we examined the effect of major process variables on the process performance and determined optimal process.

• Membrane Journal
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• v.23 no.4
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• pp.304-311
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• 2013

In fermentation-separation processes, nanofiltration membrane processes can be used to separate organic acid and other byproducts such as sugars and proteins. In this study, new nanofiltration membranes were prepared to improve organic acid permeability during the separation processes of fermentation broth. Positively charged nanofiltration membrane was introduced to reduce lactic acid rejection by electrostatic attraction between lactic acid and nanofiltration membrane. Newly fabricated nanofiltration membranes were prepared by grafting cationic polyelectrolyte, PEI, on membrane surface. Thenanofiltration membranes showed positively charged surface potential. As a result, lactic acid rejection was remarkably reduced while the rejection of glucose was not changed significantly.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.10
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• pp.1481-1487
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• 2016

Lactic acid bacteria showing alginate-degrading and cellulolytic activity were isolated and identified as a starter for seaweed fermentation. A total of 331 strains of lactic acid bacteria isolated from various Korean traditional foods, such as Kimchi, Jeotgal, and Makgeolli, were examined alginate-degrading and cellulolytic activity by the plate assay method. Six strains showed strong alginate-degrading and cellulolytic activity among the isolated 331 strains. Among these six strains, four strains (strain No. 162, 164, 192, and 196) showed probiotic properties (antimicrobial activity, tolerance to simulated gastric juice, artificial bile acid, and NaCl). No. 192 strain (Gram-positive cocci, catalase negative, and homofermentative) showed the best probiotic properties among selected strains and was identified as Enterococcus faecium by 16S rRNA sequencing. Strain No. 192 (E. faecium) showed the best growth and antioxidative activity during seaweed (sea mustard and sea tangle) fermentation for 72 h at $37^{\circ}C$ among the four selected strains.