• Applied Biological Chemistry
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• v.13 no.1
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• pp.1-27
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• 1970

The process of the forced aging of flue-cured tobacco leaves were studied extensively from various scientific points of view. The Flue-cured tobacco leaves were inoculated and fermented with nicotine resistant Hansenula yeast, or the leaves were subjected under simple forced aging. The above two processes of forced aging were studied from the summarized points of microbiology, physics, chemistry, and biochemistry, and the resulted products ware compared in their physical, chemical and biochemical quality determining factors with that of raw material tobacco leaves (dried-tobacco leaves) and 2 years aged high quality tobacco leaves. The summary results were as follows. 1) The Korean flue-cured tobacco leaves, were forcedly aged under the basic optimum aging condition, temperature $40^{\circ}C$, moisture contents 18%, relative humidity 74%. It was found that this aging condition was the best in bringing the quality of forcedly aged tobacco leaves to the utmost state. 2) Under this optimum temperature and moisture condition of forced aging in about 20 days the forcedly aged tobacco leaves both with yeast inoculation and without yeast inoculation showed the equivalent tobacco qualities comparable with that of more than 2 years aged tobacco leaves. 3) The forcedly aged tobacco leaves both with and without yeast inoculation under $40^{\circ}C$ temperature and $74^{\circ}C$ relative humidity achieved the necessary quality determining physical and chemical changes in about 20 days. 4) The microbial changes during the forced aging were as follows. The population of yeasts and bacteria increased until to 15 days of aging, then decreased thereafter. Whereas the molds grew continously until the end of fermentation. 5) The tobacco quality determing physico-chemico-properties of yeast inoculated aged and simple forcedly aged tobacco leaves, progressed as the follows in time. As the forced aging progresses, swelling and combustibility properties were improved. The pH, total reducing materials, total sugars, alkaloids contents decreased. The contents of organic and ether extractable materials increased. The total nitrogen, protein, crude fiber, ash contents showed no changes. The color properties, excitation purity, luminance, main wave length, showed equivalent changes comparable with that of 2 years aged tobacco leaves. 6) The changes in chemical components in yeast treated and simple forcedly aged tobacco leaves during $15{\sim}20{\;}days$ of forced aging were as follows. The following chemical components decreased as the aging. Sugars-sucrose. rhamnose, glucose. Pigments-chlorophyll, carotenes, xanthophyll and violax anthine. Polyphenols-rutin, chlorogenic and, coffeic acid. Organic acids-iso-butylic, crotonic, caprylic, galacturonic, tartaric, succinic, citric acid. Alkaloids-nicotine, nornicotine. The following components increased as the forced aging progressed. Sugars-frutose, maltose, raffinose. Amino acids-proline, cystine. Organic acids-formic, acetic, propionic, n-butyric, iso-valeric, n-valeric, malic, oxalic, malonic, ${\alpha}-ketoglutaric$, fumaric, glutaric acid. 7) During the forced aging of tobacco Leaves the oxygen-uptake decreased gradually. The enzyme activities of polyphenol oxidase, ${\beta}-amylase$ ${\alpha}-amylase$ decreased gradually. The activities of the enzymes, catalase, and invertase increased once then decreased at the later stage.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.1
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• pp.33-39
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• 1999

In order to understand the importance of tidal action and $NH_4{^+}$ -nitrification in the removal of dissolved oxygen (DO) and $NH_4{^+}$, concentrations of DO, $NH_4{^+}$, $NO_2{^-}$ and $NO_3{^-}$ were measured with time for water samples collected at different tidal state in the eutrophic macrotidal Han River estuary. Field measurements indicated that most environmental parameters, except for the water temperature and DO concentration, were tightly controlled by the eutrophic freshwater runoff and large-scale tidal action. Dark incubation of the water sample at $25^{\circ}C$ showed that the removal rates of DO and $NH_4{^+}$ in high tide sample were 2.76 ${\mu}M\;O_2\;d^{-1}$ and 1.76 ${\mu}M\;N\;d^{-1}$ respectively, and increased to 5.66 ${\mu}M\;O_2\;d^{-1}$ and 3.36 ${\mu}M\;N\;d^{-1}$ respectively, in low tide sample. These changes indicated that microbial degradation and uptake of organic matter and inorganic nutrients were more active during low tide. $NH_4{^+}$-nitrification responsible for total DO removal in low tide (23.81%) and $NH_4{^+}$ turnover rates due to $NH_4{^+}$-nitrification in low tide (0.18 $d^{-1}$) were approximately 3.7 times and 3 times, respectively, higher than those in high tide. These results indicated that $NH_4{^+}$ -nitrifying bacteria introduced into the Han River estuary during low tide played a significant role in the removal of DO and $NH_4{^+}$. The decreasing removal rates in DO and $NH_4{^+}$ with the increasing tidal level seemed to be associated with the salinity impact on the halophobic freshwater $NH_4{^+}$-nitrifying bacteria. The results implied that anthropogenic $NH_4{^+}$ sources should be treated prior to the freshwater runoff into the estuary for the effective control of $NH_4{^+}$ in the Han River estuary. These results also suggest that parallel ecological studies on the chemoautotrophic nitrifying bacteria are essential for the elucidation of nitrogen cycles in the eutrophic Han River estuary.

• Food Science of Animal Resources
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• v.31 no.2
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• pp.296-303
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• 2011

This study was conducted to determine the effects of stevia (Stevia rebaudiana Bertoni) and charcoal supplementation on meat quality traits in finishing pigs. A total of 420 pigs (LYD) were randomly allocated into seven treatments with three replications. The dietary treatments were T1 (control, basal diet), T2 (basal diet+0.3% stevia), T3 (basal diet+0.6% stevia), T4 (basal diet+0.3% charcoal), T5 (basal diet+0.6% charcoal), T6 (basal diet+0.3% stevia+0.3% charcoal), and T7 (basal diet+0.6% stevia+0.6% charcoal). Pigs were slaughtered conventionally on each marketing day and chilled overnigth. At 24 h postmortem, the Longissimus muscle from left side between the 6th and 14th rib was removed for the meat quality traits. The T6 group showed a higher pH, water holding capacity (p<0.05), and lower drip loss (p<0.05) than those in the T1 group. The T6 group showed lower (p<0.05) $L^*$ (lightness) and $b^*$ (yellowness) values and higher $a^*$ (redness) color value than those in the T1 group, resulting in a redder surface meat color. In the subjective evaluation, marbling and color scores improved in the T6 group compared to those in the other treatments. In the panel test, the T6 group tended to have higher tenderness and juiciness scores than those in the T1 group. In the storage characteristics, all treatments showed similar 2-thiobarbituric acid and volatile basic nitrogen values as well as total microbial counts during 7 d of cold storage. As a result, dietary supplementation with 0.3% stevia and 0.3% charcoal showed the highest meat quality traits and storage characteristics in finishing pigs.

• Food Science of Animal Resources
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• v.33 no.4
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• pp.531-541
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• 2013

This study was performed to investigate the antioxidant effect of Sansa (Crataegi fructus) extract in vitro, and to evaluate the functional effects of Sansa powder addition on the quality properties and storage characteristics of Tteokgalbi. Total polyphenol and flavonoid contents of Sansa extract were found to be 127.00 mg/g and 54.05 mg/g, respectively. The DPPH radical scavenging activity of Sansa extract was high and it was similar to the BHA and BHT. The Tteokgalbi was prepared by 0% (N), 0.1% (S1), 1% (S2), and 2% (S3) of the Sansa Powder. Addition of Sansa powder decreased the protein and lipid contents, but the ash content was significantly increased (p<0.05). Increasing the amount of Sansa powder in the pork Tteokgalbi tended to increase the water holding capacity (WHC) values and the cooking loss (p<0.05). The addition of Sansa powder increased the hardness and chewiness values, but did not affect the cohesiveness and springiness values. In the sensory evaluation, the S3 Tteokgalbi had the best score in color. Values of pH, total microbial counts, thiobarbituric acid (TBA) and volatile basic nitrogen (VBN) values decreased significantly added Sansa powder relative to the normal (p<0.05). The S3 Tteokgalbi was significantly (p<0.05) more effective for delaying lipid peroxidation than the other groups. Sansa powder addition increased the L (lightness) and a (redness) values. Therefore, the results demonstrate that adding the Sansa powder to the pork Tteokgalbi tended to improve antioxidative and antimicrobial effects during the chilled storage period.

• Applied Biological Chemistry
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• v.29 no.3
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• pp.288-293
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• 1986

The washed fresh ginsengs packed with air, vaccum and nitrogen gas were irradiated at the levels of 1,2 and 3kGy gamma radiation and then stored at $4{\sim}5^{\circ}C$ for 90days to investigate the effects of gamma radiation on microbial inactivation, eelworm disinfestation and physicochemical changes. After a 90 day storage, $2{\sim}3kGy$ irradiated groups showed 20% of weight loss and 10% of rot while non-irradiated group 100% and 20% or more, respectively. Also the irradiated groups showed somewhat lower values of specific gravity, color density and hardness immediately after irradiation, thereafter higher value of them with storage time than those of non-irradiated group. The irradiation increased the yields of ginseng extract and crude saponins but no effects on the proximate composition and TLC and HPLC patterns of saponin. The food-borne microorganisms decreased in viable cell counts by $2{\sim}3$ log cycles with $2{\sim}3kGy$ radiation and the eelworms were completely disinfested with 1 kGy radiation.

• Korean Journal of Agricultural Science
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• v.23 no.2
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• pp.188-205
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• 1996

This study was conducted to examine the effects of dietary energy and protein sources on the rumen microbial population of sheep. The results obtained were summarized as the follows; 1. Ruminal pH was highest in sheep fed the diet rapidly degraded in the rumen(F-F) as a energy (barley plus beet pulp) and protein source (rapeseed meal), and lowest in the diet (F-S) of rapidly degradable energy source plus slowly degradable protein source (corn gluten meal + cotton seed meal) without affecting by postfeeding time. 2. Ruminal ammonia concentration was higher in corn (slowly degradable) for energy source and rapeseed meal (rapidly degradable) for protein source (S-F) than others, and abruptly increased at 1 hr after feeding regardless of treatments. 3. Concentration of ruminal total volatile fatty acid, acetate and propionate were highest in F-S and peaked at 1 hr after feeding firstly and formed second peak at 9hrs, respectively. 4. Digestibilities of the proximates and ADF were not affected by treatment but NDF was highest in F- F. 5. Nitrogen retention was highest in S-F and lowest in F-F and F-S. 6. Digestibility and metabolizability of energy, contents of OCP, TDN, DE and ME were not affected by treatment.

• Journal of Life Science
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• v.23 no.12
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• pp.1477-1485
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• 2013

The aim of this study was to evaluate changes in the meat quality and natural di-peptide (carnosine and anserine) content in the loin and ham cuts of female, Korean Native Black Pigs (KNBP) during cold storage for 10 days. The pH value of the loin and the ham cuts increased with an increase in the number of storage days. The lightness ($L^*$) of the loin cuts did not show any significant difference; however, the lightness of the ham cuts was decreased at storage day 10 (p<0.05). The redness ($a^*$) of the ham was higher than the redness of the loin (p<0.05) during the entire 10-days of storage. The water holding capacity of the loin was decreased from 78.5% to 67.9% during storage (p<0.05). The total number of microorganisms and coliforms was increased in both the loin and the ham during storage, and the initial total microbial contamination was higher in the ham cut (5.16 log CFU/g) than it was in the loin cut (4.87 log CFU/g). The carnosine content of the loin and the ham was in the range of 1.12-1.35 mg/ml and no significant difference was found between those two pork cuts. The anserine content of the ham cut was higher than it was in the loin cut until storage day 3. The ratio of carnosine and anserine increased with an increase in the number of storage days and it ranged from 27.6-59.7 for the loin cut and from 20.1-51.2 for the ham cut. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the loin and the ham cuts significantly decreased as the number of storage days increased. For both types of KNBP cuts, lipid oxidation and volatile basic nitrogen significantly increased after storage day 5. These results found that natural antioxidants carnosine and anserine decreased as the number of storage days increased, and anserine decreased more rapidly than carnosine (p<0.05).

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.3
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• pp.270-277
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• 1995

The phosphate fractions and their relationships with other soil characteristics in greenhouse soils located on the southwest region in Korea were studied to demonstrate the possibility of the application of phosphate solubilizing microorganisms. The average contents of organic matter of 4.0% and exchangeable K, Ca, Mg of 1.16, 3.4, and $1.2cmol\;kg^{-1}$ respectively were higher than the aiming level for improvement of low fertile soil. Especially, available $P_2O_5$ of $1,193mg\;kg^{-1}$ was far more than the aiming level. The distribution of greenhouse soils classified by their total P contents was 46.1% for the range of $1,000{\sim}2,000mg\;kg^{-1}$, 29.6% for $2,000{\sim}3,000mg\;kg^{-1}$, and 12.9% for $3,000{\sim}4,000mg\;kg^{-1}$. And the soils containing more than $1,000mg\;kg^{-1}$, available $P_2O_5$ occupied 63.0% of the examined soils. The main forms of inorganic phosphates in greenhouse soils were Ca-P and Fe-P. The P fractions compared to total P were significantly correlated to soil pH, while available P was not so. Available phosphate was significantly correlated with the contents of organic matter and nitrogen, which are closely related to soil microbial activity, at the probability level of less than 1%.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.277-285
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• 2010

The objective of this study was to manufacture spent layer chicken meat products by natural freeze-drying. The spent layers of chickens that were slaughtered at 80 wk were obtained from a local slaughter house and separated into two halves of carcasses. The samples were divided into the following groups: 1) control (non-curing), 2) curing, and 3) curing with 2% trehalose before drying. The cured meats were placed at $2^{\circ}C$ for 7 d and then transferred to a natural drying spot located in Injae City, Gangwondo, Korea. The experiment was conducted from January to March in 2008. The average temperature, RH, and wind speed were $-1.5^{\circ}C$, 63%, and 1.8 m/sec, respectively. The cured treatments showed higher pH, lower Aw and lower shear force value compared with the control. Based on the results of TBARS (2-thiobarbituric acid reactive substances) level and volatile basic nitrogen value, lipid oxidation and protein deterioration were inhibited in curing treatments during drying. Trehalose acted as a humectant because it maintained a lower water activity despite the relatively higher moisture content during drying. The polyunsaturated fatty acids content and sensory attributes were higher in cured treatments than in the control during drying. Most of the bacterial counts in the treated groups were lower by 2 Log CFU/g after 1 mon of drying, and Salmonella spp. and Listeria spp. were not found in any treatment. There was also no microbial safety problem associated with dried meat products. Based on the results of this experiment, dried meat products could be manufactured from precured spent layer chickens by natural freeze-drying during winter.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.6
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• pp.447-453
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• 2007

With a broad objective for the development of microbial based fertilizers, a total of 373 strains were isolated from rhizoplane and rhizosphere of pepper, tomato, lettuce, pasture, and grass. The efficacy of the isolates to augument overall plant growth was evaluated. After screening for their plant growth promotion and antagonistic properties in vitro efficient strains were further selected. The most efficient strains was characterized by 16S rRNA gene sequences and biochemical techniques and was designated as Bacillus subtilis S37-2. The strains facilitated plant growth and inhibited the plant phathogenic fungi such as Fusarium oxysporum (KACC 40037, Rhizoctonia solani (KACC 40140), and Sclerotinia sclerotiorum (KACC 40457). Pot based bioassay using lettuce as test plant was conducted by inoculating suspension ($10^5$ to $10^8cells\;mL^{-1}$) of B. subtilis S37-2 to the rhizosphere of lettuce cultivated in soil pots. Compared with non-inoculated pots, marked increase in leaf (42.3%) and root mass (48.7%) was observed in the inoculation group where the 50ml of cell mixture ($8.7{\times}10^8cells\;ml^{-1}$) was applied to the rhizosphere of letuce either once or twice. Antagonistic effects of B. subtilis S37-2 strain on S. sclerotiorum (KACC 40457) were tested. All the tested lettuce plants perished after 9 days in treatment containing only S. sclerotiorum, but only 17% of lettuce was perished in the inoculation plot. B. subtilis grew well in the TSB culture medium. The isolates grew better in yeast extracts than peptone and tryptone as nitrogen source. The growth rate was 2~4 times greater at $37^{\circ}C$ as compared with $30^{\circ}C$ incubation temperature. B. subitlis S37-2 produced $0.1{\mu}g\;ml^{-1}$ of IAA (indole 3-acetic acid) in the TSB medium containing L-tryptophan($20mg\;L^{-1}$) in 24 hours.