• Food Science and Biotechnology
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• 제15권3호
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• pp.474-477
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• 2006

Dynamic rheological properties of commercial 0.8, 1.0, and 1.2% gums [carboxylmethylcellulose (CMC), guar gum, hydroxypropylmethylcellulose (HPMC), tara gum, and xanthan gum], which can be dissolved in cold water, were investigated by small-deformation oscillatory measurements. Magnitudes of storage (G') and loss (G") moduli increased with increasing concentration of gum solutions except for xanthan gum. Guar gum exhibited greatest G' and G" values among all gums except for G' value at 0.8% concentration. Slopes of G' and G" decreased with increasing concentration of gum solutions except for xanthan gum. Tan ${\delta}$ (G"/G') values decreased with increasing concentration of gum solutions except for xanthan gum. Tan ${\delta}$ values of xanthan gum solutions were much lower than those of other gum solutions, indicating that xanthan gum solutions were predominantly more elastic than viscous.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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• pp.479-479
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• 2003

We investigated the tyrosinase inhibitory effect using whitening materials such as arbutin, ethyl ascorbyl ether, glabridin, kojic acid, magnesium ascorbyl phosphate and ascorbic acid. Tyrosinase inhibition rate were determined varying the enzyme concentration, reaction time, reaction temperature and pH. The optimal conditions to measure the inhibitory efficacy were as follows. : enzyme concentration 1,500 or 2,000IU/mL, reaction time 15min(for the enzyme concentration 1,500 IU/mL) and l0min(for the enzyme concentration 2,000IU/mL), reation temperature 42$^{\circ}C$, pH 6.5. Under these conditions $IC_{50}$/ of arbutin, ethyl ascorbyl ether, glabridin, kojic acid, magnesium ascorbyl phosphate and ascorbic acid were calculated. In the case of magnesium ascorbyl phosphate, the inhibitory effect of tyrosinase was very low and the $IC_{50}$/ of magnesium ascorbyl phosphate could not be calculated. Other five materials showed good inhibitory effect of tyrosinase and can be used for the whitening materials.

• 유기물자원화
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• 제4권1호
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• pp.23-31
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• 1996

가정에서 분리수거한 쓰레기와 혼합쓰레기 및 퇴비화 과정중에 있는 쓰레기의 중금속 농도를 측정하였다. 카드뮴의 농도는 봄철에 8 mg/kg 쓰레기, 겨울철에 13 mg/kg 쓰레기였다. 중금속의 농도는 월별로 큰 차이를 보였으며 1월과 2월, 4월, 5월에는 카드뮴의 함량이 부산물 퇴비의 기준인 5 mg/kg 쓰레기의 농도를 초과하였다. 가정쓰레기가 혼합되기 전 분리수거된 음식쓰레기의 퇴비화 과정중에 카드뮴의 함량을 측정한 바, 봄철과 겨울철에 부산물 퇴비화의 기준치를 초과하였다. 분리수거된 가정쓰레기에 수분조절제로 첨가된 석탄회는 퇴비중의 중금속 함량을 낮추는 효과가 있었다. 소형 퇴비화 용기에서 1개월 퇴비화한 음식쓰레기를 야외에서 야적하여 숙성시켰는데, 이 기간동안에 중금속의 축적은 일어나지 않았다.

• Journal of Nutrition and Health
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• 제39권2호
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• pp.115-120
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• 2006

The purpose of this study is to investigate the concentration of plasma choline of Korean and to clarify the relationship between plasma choline concentration and choline intake. Plasma choline concentration of 30 young adults (15 males, 15 females) aged 20-30 years living in Deajeon metropolitan city are analyzed and their dietary choline intake. Choline content of one day meal was directly analyzed with the use of enzymatic method. Plasma choline concentration from more than 12 hr fasting blood was analyzed by using HPLC-MS. Choline intakes of male subjects were in the range of 253.51-1724.14 mg and those of female subjects were in the range of 240.85-938.06 mg. Mean intakes of choline were $634.53{\pm}353.68mg$ in male subjects and $473.99{\pm}183.76mg$ in female subjects. Plasma choline concentration of total subjects was in the range of 5.08-14.01 ${\mu}mol/L$. Mean plasma choline concentration was $9.19{\pm}2.05{\mu}mol/L$ in male subjects and $8.11{\pm}1.70{\mu}mol/L$ in female subjects. Plasma choline concentration did not show significant correlation with choline intake in male and total subjects, but showed positive correlation with choline intake in female subjects (p<0.05). This result shows that more studies on large scaled samples are needed.

• 생태와환경
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• 제40권2호
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• pp.352-356
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• 2007

The effects of food concentration (Chlorella vulgaris) and predator (Pseudorasbora parva) density on the distributional pattern of Daphnia pulex was evaluated in observation chambers. It was found that in the chamber with higher food concentration, Daphnia began to aggregate and formed tighter swarms. The close distance between each individual and distance from the center of swarm were observed in higher food conditions however, this distributional pattern was not seen in the chamber without food. Thus it suggests that the food is necessary for the swarming behavior of Boptnia in natural habitat. The swarming developed regardless of predator existence and the predator density did not affect swarming pattern of Daphnia.

• 한국축산식품학회지
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• 제31권4호
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• pp.543-550
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• 2011

Various concentrations of whey protein isolate (WPI), such as 0.1, 0.5, 1.0, 2.5, and 5.0%(w/v), containing 1.0%(w/v) eugenol were prepared by high speed homogenization to formulate nanoemulsions (NEs) and to investigate their antimicrobial activity. The results showed that particle size decreased according to increases in WPI concentration. Similarly, the ${\zeta}$-potential value was reduced to a negative charge when using WPI concentrations >0.1%(w/v). In contrast, no significant differences in particle size were observed during 1 mon of storage, except for the 0.1%(w/v) WPI NE. The ${\zeta}$-potential value depended on the increase in WPI concentration and storage duration, except for NE1 and NE5, suggesting that a low or high concentration of emulsifier was not effective for maintaining the droplet form of the eugenol NE. The results of an antibacterial effect investigation indicated that the growth of Escherichia coli was inhibited based on an increase in eugenol concentration in all NE formulations. Moreover, a membrane permeability study showed that total leakage content increased according to incubation time.

• Food Science and Biotechnology
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• 제17권4호
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• pp.850-856
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• 2008

White, red, and extruded ginsengs were studied against 8 strains of food-borne pathogens and/or food spoilage microorganisms. The ginseng powders were extracted with different extractants and screened for antimicrobial activity using the disc diffusion and broth dilution techniques. The results showed that the yield of extraction was higher with increase of aqueous solution content and temperature. Preliminary screening revealed that the red ginseng extracts were most active, that has been found to be highly effective against all tested microbe except Listeria monocytogenes. Moreover, Bacillus subtilis has shown highly susceptible, which the diameters of inhibition zone values of 28 extracts were between 7 and 14 mm. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) recorded for the different crude ginseng extracts against microorganism using ranged from 6.25 to 100 mg/mL, indicated that the methanol extract of ginseng were more effective than ethanol and water extracts. The 60% methanol extract of red ginseng had the greatest effects against B. subtilis with MIC and MBC values at 6.25 mg/mL.

• 한국식품과학회지
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• 제47권4호
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• pp.431-437
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• 2015

In this study, high-acidity cider vinegar (HACV) was produced by alcoholic and acetic acid fermentation of apple concentrate without any nutrients and then the optimum alcohol concentration was determined through a qualitative study. HACV was fermented with different initial alcohol concentrations (6-9%) during the process of acetic acid fermentation. The highest content of reducing sugar, organic acids, and free amino acids was observed at 6% of initial alcohol concentration. Approximately 20 types of volatile compounds were identified by solid-phase microextraction (SPME) and GC-MS. The total volatile content was the highest at 6% of initial alcohol concentration, and the acid content was the lowest at 9% of the initial alcohol concentration. The HACV produced by a two-stage fermentation process was qualitatively better than commercial HACV presenting the highest value at 6% of initial alcohol concentration. Malic acid, aspartic acid, and hexyl acetate were selected as quality index components of HACV production by two-stage fermentation on the basis of correlation between their physicochemical properties and the sensory attributes of HACV.

• Food Science and Biotechnology
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• 제16권2호
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• pp.299-305
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• 2007

Response surface methodology was employed to optimize extraction conditions for finding the maximal functional properties of Pleurotus eryngii. Based on central composite design, the study plan was established with variations of microwave power (30-150 W), ethanol concentration (0-99.9%), and extraction time (1-9 min). Regression analysis was applied to obtain a mathematical model. A maximal yield of 47.86% was obtained when the microwave power, ethanol concentration, and extraction time were set at 122.7 W, 42.14%, and 8.3 min, respectively. A maximized electron donating ability of 93.32% was found under the following conditions: a microwave power of 144.19 W, an ethanol concentration of 49.52%, and an extraction time of 6.7 min. When the microwave power, ethanol concentration, and extraction time were set at 125.43 W, 40.54%, and 8.1 min, respectively, the maximum nitrite-scavenging ability was 80.47%. The optimum ranges of the extraction conditions, superimposed by the response surface methodology, could predicate a microwave power of 110-150 W, ethanol concentration of 0-45%, and extraction time of 7-9 min.

• 한국식품영양과학회지
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• 제24권1호
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• pp.60-66
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• 1995

The oxidation of purified pinenut oil containing various concentration of tocopherols and β-carotene were studied. α-tocopherol revealed an antioxidant activity at the concentration of lower than 0.05%, however, it showed a prooxidant activity when the concentration was higher than 0.05%. The antioxidant activity of γ-tocopherol was not affected by the concentraitons in the range of 0.01∼0.10% in pinenut oil. γ -Tocopherol resulted in higher antioxidant activity than that of α-tocopherol. β -carotene seemed to be a prooxidant when 0.01% of β-carotene was added. The fatty acids composition of purified pinenut oil have been changed during autoxidation. The concentration of linoleic acid decreased readly while oleic acid seemed to increase. And the concentration of saturated fatty acid has'nt been changed much during autoxidation.