• Applied Biological Chemistry
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• v.25 no.4
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• pp.206-210
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• 1982

Effects of pH, organic acides and UV irradiation on the browning of ginseng were investigated. Browning of ginseng tended to increase slightly in the alkaline pH range, whereas no discernible pH effect was observed in the pH ranges of 3.0-5.0 and 10.0-12.5. The treatment of fresh ginseng with organic acid such as citric acid, succinic acid, and tartaric acid greatly enhanced the browning reaction of ginseng but all treatments of mixture of glucose, glutamic acid, and glucose+glutamic acid with fumaric acid decreased the browning reaction except the treatment of fumaric acid only. The addition of ascorbic acid in concentration of greater than 0.1 M markedly accelerated the browning reaction and concurrently increased the red color, a characteristic color of quality red ginseng. Irradiation of ultraviolet light while drying red ginseng increased the brown color intensity in the first 5 days and thereafter decreased the brown color intensity.

• Bulletin of the Korean Chemical Society
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• v.15 no.10
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• pp.881-888
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• 1994

The approximate rates and stoichiometry of the reaction of excess sodium tris(diethylamino)aluminum hydride (ST-DEA) with selected organic compounds containing representative functional groups under standardized conditions(tetrahydrofuran, $0{\circ}$) were studied in order to characterize the reducing characteristics of the reagent for selective reductions. The reducing ability of STDEA was also compared with those of the parent sodium aluminum hydride (SAH) and lithium tris(diethylamino)aluminum hydride (LTDEA). The reagent appears to be milder than LTDEA. Nevertheless, the reducing action of STDEA is very similar to that observed previously for LTDEA, as is the case of the corresponding parent sodium and lithium aluminum hydrides. STDEA shows a unique reducing characteristics. Thus, benzyl alcohol, phenol and 1-hexanol evolved hydrogen slowly, whereas 3-hexanol and 3-ethyl-3-pentanol, secondary and tertiary alcohols, were essentially inert to STDEA. Primary amine, such as n-hexylamine, evolved only 1 equivalent of hydrogen slowly. On the other hand, thiols examined were absolutely stable. STDEA reduced aidehydes and ketones rapidly to the corresponding alcohols. The stereoselectivity in the reduction of cyclic ketones by STDEA was similar to that by LTDEA. Quinones, such as p-benzoquinone and anthraquinone, were reduced to the corresponding 1,4-dihydroxycyclohexadienes without evolution of hydrogen. Carboxylic acids and anhydrides were reduced very slowly, whereas acid chlorides were reduced to the corresponding alcohols readily. Esters and epoxides were also reduced readily. Primary carboxamides consumed hydrides for reduction slowly with concurrent hydrogen evolution, but tertiary amides were readily reduced to the corresponding tertiary amines. The rate of reduction of aromatic nitriles was much faster than that of aliphatic nitriles. Nitrogen compounds examined were also reduced slowly. Finally, disulfide, sulfoxide, sulfone, and cyclohexyl tosylate were readily reduced without evolution of hydrogen. In addition to that, the reagent appears to be an excellent partial reducing agent: like LTDEA, STDEA converted ester and primary carboxamides to the corresponding aldehydes in good yields. Furthermore, the reagent reduced aromatic nitriles to the corresponding aldehydes chemoselectively in the presence of aliphatic nitriles. Consequently, STDEA can replace LTDEA effectively, with a higher selectivity, in most organic reductions.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.1-5
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• 1991

This study was conducted to examine the effect of the addition of calcium acetate and/or potassium sorbate on the characteristics of kakdugi(Korean seasoned pickles of cubed radish roots) fermented at $20^{\circ}C$ for 4 days or more. The sensory characteristics, pH, titratable acidity, non-volatile organic acids and texture by Instron were measured. The results of sensory evaluation on kakdugi stored at $20^{\circ}C$ for 4 days indicated that firmness, toughness, crispness, sour taste and overall desirability were increased by the addition of calcium acetate. Potassium sorbate was evaluated to decrease the sourness. Titratable acidity, pH and the amount of non-volatile organic acids were higher in samples containing calcium acetate than in other ones. Compression test with Instron gave the similiar result to sensory evaluation in the measurement of firmness. Calcium acetate and potassium sorbate showed synergistic effect greatly on the textural characteristics on kakdugis.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.12
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• pp.1601-1607
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• 2010

Two experiments were carried out to investigate i) the effects of four levels of lactic acid bacteria inoculants (LAB; 0, $2{\times}10^5$, $3{\times}10^5$ and $4{\times}10^5$ cfu/g fresh forage) and two physical forms of rice straw (whole and chopped rice straw) on silage fermentation quality and nutritive value of rice straw (RS) silage for lactating Holsteins and ii) the effects of the replacement of corn silage (CS) with different inclusion levels (0, 25 and 50%) of LAB treated RS on lactating performance of Holstein dairy cows. Rice straw packed with stretch film was ensiled for 45 d. The results showed that the higher level of LAB inoculants in the silage quadratically decreased pH, $NH_3$-N and acetic acid concentrations and increased the contents of lactic acid and total organic acids. The CP content and DM losses in the silage declined linearly as the level of LAB addition was increased. Compared with whole-plant rice straw silage (WRS), chopped rice straw silage (CRS) dramatically reduced pH by 0.83. The concentrations of $NH_3$-N were similar in WRS and CRS and both were less than 50 g/kg of total N. Chopping rice straw before ensiling significantly enhanced the lactic acid concentration and total organic acids content whereas the concentration of acetic acid declined. The CP, NDF and ADF content of CRS was 13.4, 5.9 and 10.2% lower than in WRS, respectively. Except for butyric acid concentration, significant interaction effects of inoculation level and physical form of RS were found on all fermentation end-products. Our findings indicated that milk yield and composition were not affected by different level of RS inclusion. However, because of the lower cost of WRS, cows consuming a ration in which WRS was partially substituted for CS had 3.48 Yuan (75% CS+25% WRS) and 4.56 Yuan (50% CS+50% WRS) more economic benefit over those fed a CS-based ration. It was concluded that the chopping process and LAB addition could improve the silage quality, and that substitution of corn silage with RS silage lowered the cost of the dairy cow ration without impairing lactation performance.

• Food Science and Preservation
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• v.22 no.3
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• pp.361-368
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• 2015

In this study, the fermentation characteristics of Yakju were investigated by addition of protein and lipid. These are classified according to raw material (rice, glucose) and inducing substance (rice protein, rice lipid). Alcoholic fermentation occurred at $25^{\circ}C$, after 14 days. The results of this study were as follows: Alcohol content of Yakju with rice protein was higher than those of other samples. The pH and glucose of rice Yakju were detemied to be 4.86~5.13 and 4.17~4.86, respectively. Titratable acid and the total amino acid content of the Yakju with rice protein were the highest among other samples. The optical density contents of the rice Yakju and glucose Yakju were 0.52~0.653 and 0.27~0.61, respectively. The concentration of organic acids in rice Yakju (433.98~519.31 mg%) was higher than that of glucose Yakju (303.76~387.50 mg%). The major organic acid components of the Yakju were succinic, citric, acetic and lactic acids. The nitrogen compound concentrations of rice Yakju (4377.38~10208.06 ppm) was higher than that of glucose Yakju (671.20~9368.93 ppm). The protein odor correlation coefficient was 0.98 (p<0.001) showing a very high correlation coefficient, while lipid odor coefficient showed a negative correlation with -0.038 (p<0.458).

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.3
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• pp.411-416
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• 2002

Yogurt base was prepared from whole milk and skim milk added with 0.2∼1.0% (w/v) of Saururus chinensis(Lour.) Bail water extract (SCe) and fermented with lactic acid bacterias (the mixed strain of Streptococcas themophilus and Lactobacillus bulgaricus) at 37$\^{C}$ for 24 hr. Quality characteristics of the yogurt were evaluated in terms of acid production, number of viable cells, viscosity and sensory property during lactic acid fermentation. The composition of organic acids was also measured by HPLC. Addition of SCe stimulated the growth of lactic acid bacteria and remarkably enhanced the acid production. The viscosity and lactic acid content of yogurt were also increased by addition of SCe. The sensory score of yogurt added with 0.4% of SCe was significantly higher than other groups in taste and overall acceptability The storage abilities of yogurts added with SCe were relatively good at 5$\^{C}$ for 15 days.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.4
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• pp.378-385
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• 1985

In order to investigate the application effects of soil amendment on wetland rice soil field and laboratory experiment were conducted on ill drained paddy field on which rice straw, Compost, Lime and Silicate materlials such as wallostonite and fused phosphate were applied. 1. As compared with check plot, rice yield was increased by application of soil amendments significantly in all plots but rice straw one. 2. The effects of soil amendment on rice production were in the order of fused phosphate and N.K, addition > silicate material and N.K, addition=Compost > rice straw and lime plot. 3. The significant correlation was showed among the rice yield and the numbers of panicle and grain. 4. The application of the rice straw restrained the rice growth because of nitrogen defficiency in early stage but increased rice yield due to the number of panicle due to supplying nitrogens late stage. 5. The application of rice straw in wetland soil promoted to occur organic acids such as $PCO_2$ and $HCO_3$, and decreased tillering due to these organic acids occuring in early growth stage.

• Journal of Applied Biological Chemistry
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• v.54 no.2
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• pp.126-134
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• 2011

In this study, the characteristics of alcohol fermentation using ripe Daebong persimmon juice were studied in static fermentation condition by Saccharomycess cerevisiae CS02 in an effort to develop new types of functional wine. Attempts were made to modify the ripe Daebong persimmon juice in order to find suitable conditions for alcohol fermentation. The modified ripe Daebong persimmon juice that was most suitable for alcohol fermentation contained $24^{\circ}brix$ of sugar supplemented with sucrose as a carbon source and 0.5 g/L of $(NH_4)_2HPO_4$ as a nitrogen source. After 9 days of fermentation at $25^{\circ}C$, $12.2{\pm}0.02%$ of alcohol was produced from the modified juice and its pH markedly decreased to $3.97{\pm}0.02$. The wine contained free sugar such as fructose ($0.12{\pm}0.02$ g/L), some organic acids such as malic acid ($35.92{\pm}0.24$ g/L), succinic acid ($8.12{\pm}0.03$ g/L), oxalic acid ($22.14{\pm}0.11$ g/L), and citric acid ($13.63{\pm}0.08$ g/L), as well as some flavanols and phenolic acids such as catechin gallate ($38.99{\pm}0.32$ mg/L), epicatechin gallate ($110.21{\pm}0.16$ mg/L), gallic acid ($163.88{\pm}1.11$ mg/L), epigallocatechin ($15.97{\pm}0.18$ mg/L), and tannic acid ($13.36{\pm}0.02$ mg/L). In addition, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (84.25%) and $ABTS^{\cdot+}$ radical (99.65%) scavenging activities were increased significantly with a corresponding increased in the organic acid and phenolic acid contents, but decreased in the flavonoids.

• Korean Journal of Ecology and Environment
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• v.36 no.3 s.104
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• pp.235-241
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• 2003

The effect of ultraviolet (UV) radiation on the characteristics of algae-derived dissolved organic matter (DOM) was examined by comparing the biodegradability and DOM fraction distribution of algal DOM before and after UV exposure. Algal DOM from two axenic cultures of Microcystis aeruginosa and Oscillatoria agardhii were irradiated for 24 h at a UV intensity of 42 W/$m^2$. A complete degradation of algal DOM during the UV exposure did not occur, remaining at constant concentrations of dissolved organic carbon(DOC). After UV exposure, however, microbial degradations were reduced by 17% in M. aeruginosa and 53% in O. agardhii, respectively, and decomposition rates also were two times lower in UV exposed algal DOM. In addition, the chemical compositions of algal DOM altered substantially after UV radiation exposure. The proportions of hydrophilic bases (HiB; protein-like DOM) decreased considerably in both algal DOM sources after UV exposure (16.8% and 20.0% of DOM, respectively), whereas those of hydrophilic acids (HiA; carboxylic acids-like DOM) increased as much as the decrease of the HiB fraction. Capillary ion electrophoresis (CE) analysis showed that several carboxylic acids increased significantly after UV exposure, further confirming an increase in HiA fractions. The results of this study clearly indicate that algal DOM can be changed in its chemical composition as well as biodegradability without complete degradation by UV radiation.

• Korean Journal of Food Science and Technology
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• v.22 no.6
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• pp.700-706
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• 1990

The curd yogurt was prepared from milk or milk added with skim milk powder or soy proteins. Acid production by lactic acid bacteria in milk containing additive of 2% was investigated and quality of curd yogurt(sensory property and keeping quality) was examined. Some organic acids in curd yogurt were analyzed by HPLC. The soy proteins, particularly defatted soy flour or soy flour, stimulated acid production by lactic acid bacteria more than skim milk powder. Among the four organisms tested, Leuconostoc mesenteroides and Lactobacillus bulgaricus produced more acid than L. casei and L. delbrueckii. HPLC analysis of organic acids in curd yogurt showed that the amount of lactic acid and acetic acid markedly increased during the fermentation by L. bulgaricus for 24 hours while the amount of citric acid markedly decreased. The major organic acid produced during the fermentation was lactic acid. Addition of soy proteins to milk reduced sensory property of curd yogurt. Among the soy proteins tested, soy protein concentrate or soy protein isolate added sample showed better sensory acceptability than other samples. When curd yogurt was kept at $5^{\circ}C$ for two weeks, titratable acidity, pH and number of viable cells of curd yogurt were not changed.