• Journal of the Korean Society of Food Culture
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• v.34 no.2
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• pp.217-223
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• 2019

This study aimed to evaluate the characteristic differential between whole cabbage kimchi (pogi kimchi) and sliced cabbage kimchi (mat kimchi) during kimchi fermentation at $6^{\circ}C$. The difference of microbial and physicochemical properties was investigated until 6 weeks. For the changes in the microbial flora, both kimchi samples exhibited a continuous increase in total aerobic bacteria and lactic acid bacteria (LAB) population size up to 2 weeks followed by a stationary phase until 5 weeks. Interestingly, the number of LAB of mat kimchi was overall higher than that of pogi kimchi during kimchi fermentation. We speculate that mat kimchi has in a more advantageous growth condition than pogi kimchi for microbial growth because small kimchi cabbage size appropriately derives nutritional supply in order to increase the LAB growth. During lactic fermentation at $6^{\circ}C$, physicochemical changes in the pH, salinity, and titratable acidity was observed to be no significant differences between two types of kimchi. Furthermore the contents of organic acids such as oxalic acid, citric acid, malic acid, lactic acid, fumaric acid, and acetic acid was not significantly different (p>0.05) between both kimchi samples as well as the contents of total free amino acid.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.12
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• pp.1727-1734
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• 2005

The fermentation characteristics and mono- and di-saccharides compositions during the early stage of ensiling were studied with a temperate grass, Italian ryegrass (Lolium multiflorum Lam.) and a tropical grass, guineagrass (Panicum maximum Jacq.). The laboratory silos were kept in the room set at 25$^{\circ}C$, and then were opened on 0.5, 1, 2, 3, 5 and 7 days (14 days in Italian ryegrass) after ensiling, respectively. The Italian ryegrass silage showed a fast and large pH decrease caused by a fast and large production of lactic acid during the first 5 days of ensiling and succeeded to achieve lactic acid type fermentation; high lactic acid/acetic acid and lactic acid content at the end of ensiling (14 days), low values of pH (3.74), acetic acid, ethanol and ammonia-N/total nitrogen, none or only small amounts of Butyric acid, valeric acid and propionic acid. The guineagrass silage showed a slow decrease in pH and a slow increase in lactic acid content during the full ensiling period, causing a high final pH value, low contents of lactic acid, acetic acid, total volatile fatty acids and total organic acids. In Italian ryegrass silage, mono- and di-saccharides compositions decreased largely within the initial 0.5 day (12 h) of ensiling. Sucrose disappeared rapidly within the initial 0.5 day of ensiling, but fructose and glucose contents showed an initial rise by the activity of enzymes in plant tissues, and then decreased gradually. On the other hand, the contents of monoand di-saccharides in guineagrass showed the largest decreases due mainly to plant respiration within the initial 0.5 day of ensiling, and no initial rises in fructose and glucose contents during the early stage of ensiling because of the absence of fructans which are hydrolyzed into fructose and glucose in temperate grasses. In both silages, the rate of reduction in mono- and di-saccharides compositions within the initial 5 days of ensiling was ranked in the order of glucose>fructose>sucrose, suggesting that glucose and fructose might be more favorably utilized than sucrose by microorganisms and glucose is the first fermentation substrate. It was concluded that the silage made from Italian ryegrass with high moisture content had a good fermentation quality owing to the dominance of lactic acid bacteria and active lactic acid fermentation during the initial stage of ensiling. These results can be explained by rapid plant sap liberation and the high activity of plant enzyme hydrolyzed fructans into fructose and glucose within the initial 2 days of ensiling, which stimulate the homofermentative lactic acid bacteria growth. In ensiling a temperate grass, the physical characteristics may ensure the rapid onset of fermentation phase, which results from the smaller losses of water-soluble carbohydrates during the initial stage of ensiling and providing sufficient water-soluble carbohydrates for lactic acid bacteria. The silage made from guineagrass with intermediate dry matter and high initial mono- and di-saccharides content was stable silage. This could be explained by the higher incorporation of air during the very early stage of ensiling and the restriction of cell breakdown and juice release due to the properties of a tropical grass with coarse porosity and stemmy structures. These physical characteristics delayed the onset of lactic acid bacteria fermentation phase by extending the phases of respiration and aerobic microorganisms activity, causing the higher loss of water-soluble carbohydrates and the shortage of lactic acid bacteria fermentation substrates.

• Korean Journal of Environmental Agriculture
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• v.19 no.3
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• pp.194-200
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• 2000

The amount of swine wastewater reaches about $197,000m^3$ per day at live-stock houses in the whole country. A half of the swine wastewater resources are too small to be restricted legally. This untreated wastewater causes the eutrophication in the water bodies. In case of swine wastewater treatment, the solid-liquid separation must be performed because feces(solid phase) and urine(liquid phase) have large differences in nitrogen and phosphorus concentration. It is necessary to assess exactly the concentration of the pollutants in swine wastewater for planning the wastewater treatment facilities. A full-scale operation was carried out in K city and the plant is consists of conventional plant, the supplementary flocculation basin of chemical treatment process and $anaerobic{\cdot}aerobic$ basin for nitrogen removal. The improved full-scale swine wastewater treatment plant removed the $1,500{\sim}3,000mg/l$ of total-nitrogen(T-N) to 120mg/l of T-N and $131{\sim}156mg/l$ of total-phosphorus(T-P) to $0.15{\sim}1.00mg/l$ of T-N. Accordingly, as a results of operational improvement, the removal efficiencies of T-N and T-P were over $92{\sim}96%$, 99%, respectively. The continuous supply of organic carbon sources and the state of pH played important roles for the harmonious metabolism in anaerobic basin and the pH value of anaerobic basin maintained at about 9.0 for the period of the study.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.476-481
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• 1997

For the effect of water-soluble degraded chitosan on the shelf-life of tofu, sterilized distilled water, 0.5% degraded chitosan, 0.5% fumaric acid and 0.5% lactic acid used as an tofu-immersion solutions were investigated by microbial counts, pH, and turbidity during the periods of storage at $4^{\circ}C$. After 2 weeks storage, total aerobic microbial counts in tap water and sterilized distilled water used as an immersion solution were $3.8\;{\times}\;10^8$ and $1.8\;{\times}\;10^8\;CFU/mL$, respectively. In 0.5% fumaric acid and 0.5% lactic acid immersion solutions, the microbial counts were around $10^7\;CFU/mL$ after 2 weeks while the microbial population in 0.5% water-soluble degraded chitosan were, however, $1.6\;{\times}\;10^5\;CFU/mL$ after 2 weeks and $1.7{\times}10^7\;CFU/mL$ after 3 weeks. The lag phase of initial contaminated microbes in 0.5% degraded chitosan solution was longer than those of other treatments. The addition of 0.5% fumaric acid and 0.5% lactic acid decreased the initial pH to pH 5.0, while those of tap water, sterilized distilled water and 0.5% degraded chitosan stabilized the immersion solution at around pH 7.2. All initial pH values were decreased during storage and then slowly increased as storage time was increased. The turbidities in all treatments were increased during storage, but the addition of 0.5% degraded chitosan showed the lowest change, compared to other treatments, showing that the water-soluble degraded chitosan has a good antimicrobial effect and has a potential use to extend the shelf-life of tofu product.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1717-1726
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• 2013

Fermentation characteristics and health functionalities of kimchi by inoculating kimchi lactic acid bacteria (LAB) starters were studied. We manufactured single LAB starter kimchi (Lactobacillus plantarum pnuK, Lactobacillus plantarum 3099K, Leuconostoc mesenteroides pnuK), mixed LAB starter kimchi (Lb. plantarum pnu/Leu. mesenteroides pnuK, Lb. plantarum 3099/Leu. mesenteroides pnuK) with inoculum size of $10^6$ CFU/g, as well as naturally fermented kimchi (NK), and fermented them for 6 days at $15^{\circ}C$. The pH and acidity of the early phase of fermentation were not different, but kimchi with the starters showed rapid changes in the pH and acidity from 2 days of fermentation. As the fermentation progressed, the level of total aerobic bacteria and Lactobacillus sp. increased similarly with or without Lb. plantarum (LP) inoculation. However, the level of Leuconostoc sp. was high in kimchi inoculated with Leuconostoc sp. starter. In the sensory evaluation test, kimchi with starters received higher overall acceptability scores than those of NK; mixed starter added kimchi earned the highest score. In DPPH and hydroxyl radical scavenging activity, kimchi with the starters exhibited higher activity than that of NK. In the MTT assay of HCT-116 and HT-29 human colon cancer cells, NK showed inhibition rates of 63.4 and 51.9%, but LPpnuK achieved 77.1 and 68.8%, respectively. This study showed that inoculating starters in kimchi increased in vitro antioxidant and anticancer activities, and single starter (LP) added kimchi revealed higher functionality than the kimchi with mixed starter. Kimchis with the starters effectively up-regulated the gene expressions of the pro-apoptotic gene of Bax, but down-regulated Bcl-2. They promoted expressions of p53 and p21, and suppressed expressions of inflammation-related genes, iNOS and COX-2, compared with NK. Taken together, it is expected that using starters may help manufacture kimchi with improved sensory quality and health functionality.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.501-508
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• 2012

This study was carried out to compare species diversity of soil bacteria from Baekdudaegan mountain forests (Bonghwa-gun, Mungyeong-si and Sangju-si) in Gyeongsangbuk-do and to analyze the effects of soil environments on diversity and population of soil bacteria. Soil bacteria were isolated from soil samples by streak plate method, and identified by DNA extaction and 16S rDNA sequence analyses. The population of soil bacteria from the soil samples of Bonghwa-gun was the highest with $5.1{\times}10^5cfu/g$, and followed by those from Mungyeong-si and Sangju-si with $1.9{\times}10^5cfu/g$ and $1.1{\times}10^5cfu/g$, respectively. The population of soil bacteria from surface layer soil was the highest, and then gradually decreased according to soil depth. The increase in population of soil bacteria from soil samples of different sites was correlated with the increase of the altitude of soil sampling site, depth of A horizon, liquid phase among three phases of soil, water content and bulk density of soil. Two hundreds and sixty eight bacterial colonies from Bonghwa-gun were classified into 10 species, 8 genera. One hundred and thirty four bacterial colonies from Mungyeong-si were classified into 15 species, 9 genera. Forty four bacterial colonies from Sangju-si were classified into 5 species, 2 genera. The dominant species (occupancy rate) from Bonghwa-gun and Mungyeong-si were Bacillus weihenstephanensis (36% and 40%, respectively), and Sangju-si was Bacillus cereus (39%). The relationships between soil environment and community structure of soil bacteria were analyzed statistically by using ecological indices. The diversity, evenness and dominance indices of soil bacteria were 6.30, 2.04 and 0.59 in Bonghwa-gun, 9.09, 2.94 and 0.51 in Mungyeong-si, and 4.55, 2.34 and 0.71 in Sangju-si, respectively. The diversity and evenness indices were increased by the increase of water content, drainage condition and gravel content of soil, while the dominance index was decreased.

• The Korean Journal of Food And Nutrition
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• v.14 no.5
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• pp.457-466
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• 2001

In this study. HACCP system was applied to improve the quality of instant ablactation baby food with rising sanitary problem among SunSig(powder of roasted grains and vegetables) . It took about 9min 30 second to produce and the temperature status of raw materials were 30.9∼31.8$\^{C}$. Raw material and production phase goods had average 6.2 in pH and 0.23∼0.63 in water activity. The average number of total aerobic bacteria(TAB) and coliform were 1.4$\times$10$^4$ CFU/g, 5.5$\times$10 CFU/g in raw materials. And the number became 8.7$\times$10$^2$ CFU/g, 6.9$\times$10 CFU/g after 1st grinding step. The distributions of TAB and coliform in equipments were 3.8$\times$10$^4$ CFU/㎠, 8.0$\times$10 CFU/㎠ on the average. According to storage temperature, variations of number of TAB coliform were slight at 4$\^{C}$ but increased at 20$\^{C}$ and 30$\^{C}$ . Therefore following subjects can be issued on the basis of results. Minimize the storage time and keep at cool temperature. 1st and 2nd grinders should be managed hygienically. Establish the heating step during the production of instant action baby food. Instant ablactation baby food produced should be stored at cool and freeze condition.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.212-216
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• 1981

The growth of Lactobacillus bulgaricus treated with vanillin, ortho-vanillin and guaiaco1 was studied on synthetic medium in mechanically agitated chemostat culture, The exponential-phase growth rate exhibited a maximum at the cells treated with 50 ppm vanillin. That stimulation, however, appears to be an effect on growth rate rather than total cell growth. And the others were inhibited by the chemicals. Much greater inhibition in growth of the cells treated with 100 ppm of each chemical than oars treated with 50 ppm was observed after 25 hour fomentation. For aerobic microbes, the alcohol dehydrogenase reaction is enhanced for the reproduction of NAD, which consequently cause to stimulate fermentation. For micro-aerophilic microbes , however, the same effect was not observed at the present study at least in the case of cell concentration. However except f or one treated with 50 ppm vanillin the same effect was observed in the case of growth is to. From the result using the glucose as a substrate, it was found that the cell concentrations measured in terms of ultimate optical density (UOB/ml), were 0.96 and 0.92, when treated with 50 and 100 ppm vanillin; 0.40 and 0.45 when treated with ortho-vanillin 50 and 100 ppm: 0.49 and 0.47, when treated with guaiacol 50 and 100 ppm. The specific growth rates were 0.44, 0.15, 0.25, 0.29, 0.37, and 0.34; the specific production rates wire 0.33, 0.15, 0.16, 0.22, 0.28, and 0.26 and the glucose concentrations (g/1) after 25 hour fermentation were 23.5, 32.8, 31.5, 29.5, 28.0 and 28.8, these all in the same sequences as the first.