• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.7
• /
• pp.1104-1110
• /
• 1999

We condicted two experiments to evaluate the interaction among fumaric acid (FA), protected acids (PA), or no additional acid (NO) and two different levels of acid buffering capacity (BC) in diets for 14-d-old weaned pigs. BC was varied substituting mono-calcium phosphate and calcium sulfate for dicalcium phosphate and calcium carbonate. In the high BC diet plus PA, FA was also added. In Exp. 1, 48 gilts were raised for 31 days on the six diets, evaluating growth performance and fecal digestibility. In Exp. 2, 42 gilts were raised. With each diet three subjects were sacrificed after 19 days and four after 38 days. In addition, six subjects were sacrificed at weaning. Growth and carcass performance, ileal digestibility, bacterial populations and pH in the gut were assessed. The piglet performance and stomach, ileal and cecal pH, and empty body composition were not affected by the diets. Empty body composition other than ash content was affected by piglet age (p<0.01). The BC did not influence digestibility. The dietary inclusion of PA improved fecal digestibility of protein (p<0.05) compared to the addition of FA and NO. Ileal digestibility slightly increased with both acid additions (p<0.10), the groups receiving PA showing the higher values. Piglets fed diets with low BC had lower Lactobacillus and E. coli counts in the ileum (p=0.07) and higher Lactobacillus in the colon (p=0.08). Acidified diets tended to reduce E. coli counts in the ileum (p=0.10) and increased Lactobacillus in the colon (p=0.09). The addition in the diet of PA increased Lactobacillus in the ileum compared to the sole addition of free fumaric acid (p=0.07). The addition of protected acids, combined with free fumaric acid in the case of high BC diets, increased protein digestibility and Lactobacillus counts and reduced E.coli counts. Only some changes in the concentration of bacterial population can be expected with a diet of low BC.

• Journal of the Korean Chemical Society
• /
• v.20 no.1
• /
• pp.59-72
• /
• 1976

The addition of one mole of zinc chloride to 2.33 moles of sodium borohydride in tetrahydrofuran at room temperature gave a clear chloride-free supernatant solution of zinc borohydride after stirring three days and standing at room temperature.The approximate rates and stoichiometry of the reaction of zinc borohydride with 54 selected organic compounds were determined in order to test the utility of the reagent as a selective reducing agent. Aldehydes and ketones were reduced rapidly, aromatic ketones being somewhat slowly, and the double bond of cinnamaldehyde was not attacked. Acyl halides were reduced rapidly within one hour, but acid anhydrides were reduced at a moderate rate. Carboxylic acids, both aliphatic and aromatic, were slowly reduced to alcoholic stage. Esters were inert to this reagent but a cyclic ester, γ-butyrolactone, was slowly attacked. Primary amides were reduced slowly with partial evolution of hydrogen, whereas tertiary amides underwent neither reduction nor hydrogen evolution. Epoxides and nitriles were all inert, as well as nitro, azo, and azoxy compounds. Cyclohexanone oxime and phenyl isocyanate were reduced slowly but pyridine was inert. Disulfide, sulfoxide, sulfone and sulfonic acids were stable to this reagent.

• Korean Journal of Food Science and Technology
• /
• v.31 no.5
• /
• pp.1211-1215
• /
• 1999

The solid yields and color changes of garlic aqueous extracts were determined to study the effects of enzymatic hydrolysis, pH treatment, and addition of organic acids and some organic or inorganic salts. Hydrolysis with commercial polysaccharases resulted in an $15{\sim}20%$ increase in the solid yields, with a greenish color change in the garlic extracts. pH treatment gave it similar effect at the pH range of $4.4{\sim}5.0$. Among the salts and acidulants used, $CaCl_2$, sodium oxalate, tartaric and phosphoric acids were effective for increase in the yield and $K_{4}P_{2}O_{7}$ was effective for both yield increase and control of greening.

• Food Science of Animal Resources
• /
• v.33 no.3
• /
• pp.325-330
• /
• 2013

Kefir is traditional fermented milk produced by various lactic acid bacteria (LAB) and yeast, which produce lactic acid, ethanol, carbon dioxide, and other flavor compounds. The purpose of this study was to evaluate the effects of different commercial oligosaccharides, such as maltotriose, fructooligosaccharide (FOS), galactooligosaccharide (GOS), and isomaltooligosaccharide (IMO), on the fermentation properties of kefir. First, we determined the acidification kinetic parameters, such as $V_{max}$, $t_{max}$(h), $t_{pH5.0}$(h), and $t_f$(h) of fermented milk supplemented with 4% (w/w) of different oligosaccharides. The probiotic survival and chemical composition (pH, organic acids profile, and ethanol content) of kefir during fermentation were also measured. Compared to control fermentation, all oligosaccharides increased acidification rate and reduced the time to complete fermentation (pH 4.7). The addition of FOS, in particular, resulted in the lowest $t_f$(h) and the highest populations of LAB and yeast during fermentation. All oligosaccharides increased ethanol production during fermentation. Further, significant differences were observed in the formation rates of six organic acids during fermentation. This study provided comparative data on the properties of commercial oligosaccharides for kefir manufacturing. Consequently, FOS especially had the potential for adequate and effective oligosaccharides in commercial kefir for the improvement of cost- and time-effectiveness.

• Journal of Applied Biological Chemistry
• /
• v.63 no.4
• /
• pp.429-437
• /
• 2020

This study aimed to investigate the change in physicochemical properties and lactic acid bacterial communities during kimchi fermentation at different temperatures (8, 15, and 25 ℃) using two molecular genetics approaches, multiplex polymerase chain reaction and 16S rRNA gene sequencing. The pH during fermentation at 8, 15, and 25 ℃ decreased from 6.17 on the initial fermentation day to 3.92, 3.79, and 3.48 after 54, 30, and 24 days of fermentation, respectively, while the acidity increased from 0.24% to 1.12, 1.35, and 1.54%, respectively. In particular, the levels of lactic acid increased from 3.74 g/L on the initial day (day 0) to 14.43, 20.60, and 27.69 g/L during the fermentation after 24, 18, and 12 days at 8, 15, and 25 ℃, respectively, after that the lactic acid concentrations decreased slowly. The predominance of lactic acid bacteria (LAB) in the fermented kimchi was dependent on fermentation stage and temperature: Lactobacillus sakei appeared during the initial stage and Leuconsotoc mesenteroides was observed during the optimum-ripening stage at 8, 15, and 25 ℃. Lac. sakei and Lactobacillus plantarum grew rapidly in kimchi produced at 8, 15, and 25 ℃. In addition, Weissella koreensis first appeared at days 12, 9, and 6 at 8, 15, and 25 ℃ of fermentation, respectively. This result suggests that LAB population dynamics are rather sensitive to environmental conditions, such as pH, acidity, salinity, temperature, and chemical factors including free sugar and organic acids.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.4
• /
• pp.711-715
• /
• 2004

The stability of 80% ethanol-soluble pigments from Monasus purpureus CBS 281.34 was investigated according to storage temperature, pH and addition of organic acid. Also, the stability of ethanol-soluble pigment in aqueous system was examined after the addition of distilled water in the range of 0∼80% during the storage at 1$0^{\circ}C$ and 2$0^{\circ}C$ for 4 weeks with water soluble pigment. The heat stability was the highest (9.74%) when the 80% ethanol-soluble pigments were stored at 1$0^{\circ}C$ for 4 weeks. However, the 80% ethanol-soluble pigments stored at 6$0^{\circ}C$ and 8$0^{\circ}C$ for 24 h and 12 h greatly decreased by 23.06% and 30.36%, respectively. Although the 80% ethanol-soluble pigments were stable in the range of pH 4∼8, the degradation rate of pigment increased at pH 2 and PH 10.80% ethanol extract was adjusted to PH 4 by adding organic acids. The rate of pigment degradation was not different from control for 4 weeks. Red pigment was stable in the treatment of organic acids. And the stability of ethanol-soluble pigment in aqueous system was gradually decreased as the pigment content and storage time increased. Additionally, the stability of ethanol-soluble pigment was higher at 1$0^{\circ}C$ than at 2$0^{\circ}C$.

• Korean Journal of Microbiology
• /
• v.43 no.4
• /
• pp.304-310
• /
• 2007

Bacillus cereus 1-1 strain produced 2 mM of ALA in the aerobic dark condition without any inhibitor like levulinic acid. The optimum culture conditions for the ALA production were that preculture and main culture were continued for 18 hr in TCY medium, and 16 mM of organic acids like acetic acid were added at the late log phase when the pH was 6.8. And the addition of 0.3% glucose was effective at the beginning of the main culture. ALA production was continued for more than 8 hr by the addition of glutamic acid instead of acetic acid, and was inhibited by addition of $40\;{\mu}M$ gabaculine seriously. These results confirmed that B. cereus 1-1 strain produced ALA through C-5 pathway.

• Korean Journal of Food Science and Technology
• /
• v.34 no.1
• /
• pp.57-64
• /
• 2002

This study was carried out to investigate the effect of yucca extract on the flavor development in Chungkookjang fermented by Bacrillus sp. b01. The changes in the contents of amino-type N, ammonia type N, volatile compounds and organic acids, and those in the activities of ${\alpha}-amylase$ and protease were also determined with aging period. The amount of amino-type N increased gradually with time and was slightly higher in Chungkookjang containing yucca extract than in control. The content of ammonia-type N in Chungkookjang decreased by the addition of yucca extract. During aging, a little higher amylase activity was detected in Chungkookjang containing yucca extract. However, the amylase activity was the lowest in Chungkookjang containing 1 mg/g of yucca extract. The protease activity was slightly higher in Chungkookjang containing yucca extract. The organic acids, such as citrate, acetate, malate, fumarate, and succinate, were detected. The yucca extract reduced the production of tetramethylpyrazine which was responsible for the unpleasant odor, but enhanced the production of 2,5-dimethylpyrazine and 2,6-dimethylpyrazine which contributed to the taste. Sensory evaluation showed that the addition of yucca extract of 0.5 mg/g significantly improved the flavor and taste of products.

• Journal of Korean Society for Atmospheric Environment
• /
• v.31 no.4
• /
• pp.345-355
• /
• 2015

Carbonaceous compounds in the atmospheric particulate matter with an aerodynamic diameter of less than or equal to a nominal $10{\mu}m$ ($PM_{10}$) were analyzed for the samples collected during the period of August 2006 to August 2007 at Jongro in Seoul. A total 18 dicarboxylic acids (DCAs) and levoglucosan, as well as organic carbon (OC), elemental carbon (EC), and water soluble organic carbon (WSOC), were analyzed. Distinctive seasonal patterns of the concentrations of OC, EC, and WSOC including levoglucosan were observed with the highest concentrations in winter and the lowest concentrations in summer. In addition, OC, WSOC, and most of DCAs showed also higher concentration in summer than in winter. Using the seasonal patterns and relevant indicative ratios (WSOC/EC and $OC_{sec}/OC_{tot}$) of the carbonaceous compounds, it was verified that (1) primary emission sources were elevated in winter, and (2) the formation of secondary OC increased due to the prompted photochemical reaction in summer. Results from this study also suggest that some organic compounds were likely attributed to longrange transport.

• Journal of Environmental Health Sciences
• /
• v.19 no.3
• /
• pp.1-16
• /
• 1993

This paper describes an investigation to determine whether the activated sludge (AS) process could be used for the treatment of wastewater at the Union Carbide Coporation (UCC) plant in Seadrift, Texas. This plant presently utilizes a waste stabilization pond (WSP) system for treatment of the wastewater. The treatment system consists of an in-plant primary WSP and two off-plant WSPs (secondary and tertiary WSPs), run in series. The total hydraulic detention time of the WSP system is approximately 150 days. Several laboratory-based treatability studies have been conducted to evaluate the performace of the WSP system and the degradability of specific chemical compounds. From an additional study, it was determined that the WSP system was stressed and occasionally operating near the limit of its treatment capacity. The existing primary WSP plays an important role in the overall treatmemt system, because it not only functions as a pH and organic-strength equalization basin, but also serves as a "preconditioning" basin by fermenting high strength organic wastes to volatile organic acids for subsequent degradation in the escondary WSP. However, in view of pending RCRA legislatin conerning the "proposed organic toxicity characteristics limits" (40 CFR Part261: Federal Register, July, 1988), it is possible that the primary WSP will have to be abandoned in favor of alternative treatment options. Therefore the main purpose of this study was to perform activated sludge treatability evaluations for the development of an alternative to the existing primary WSP treatment ststem. In addition, another purpose was to determine the degradability of bis(2-chloroethyl)ether (Chlorex or CX) and benzene(BZ) in the activated sludge process. The presence of these two chemicals in the wastewater of the plant prompted the question of whatedether they could be degraded in an activated sludge system.