• Title/Summary/Keyword: pH 영향

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Effects of Cultured Wild Ginseng Roots on the Alcoholic Fermentation (산삼배양근 첨가가 알콜 발효에 미치는 영향)

  • Jeong Heon-Sang;Kang Tae-Su;Woo Koan-Sik;Paek Kee-Yeoup;Yu Kee-Won;Yang Seung-Joon
    • Food Science and Preservation
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    • v.12 no.4
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    • pp.402-410
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    • 2005
  • In order to manufacture the alcoholic drinks using cultured wild ginseng roots(CWGR) of 5 and $10\%$ (w/v), sugar content of fermentation media was adjusted to 24-25 $^{\circ}$Brix with white sugar and glucose. And 3 kinds of yeast (S. cerevisiae(KCCM 50757), S. cerevisiae (KCCM 50583) and S. bayanus(ATCC 10601) were used and then the quality of alcoholic drinks was analyzed by physical, chemical and sensory evaluation. Alcohol content was highest value of $15.8\%$ in $10\%$ of CWGR, white sugar, and S. bayanus(ATCC 10601). Major alcohols were ethanol and 1-propanol. Number of yeast cells increased to 5 days fermentation and slightly decreased afterwards. The pH was decreased abruptly from 5.0 in initial fermentation to 3.1-4.1 in 5 days fermentation. Total sugar contents were decreased continuously with fermentation periods and showed 7.0-10.5 $^{\circ}$Brix in 20 days fermentation. Saponin patterns and contents were various and higher in wine treated with S. bayanus(ATCC 10601). From the sensory evaluation, the highest score of overall quality was observed in the alcoholic beverage of $10\%$(w/v) of CWGR, glucose, and S. cerevisiae(KCCM 50583).

Effect of sweeteners on the quality characteristics of ginger (Zingiber officinale Rosc) Jungkwa (감미료가 생강정과의 품질특성에 미치는 영향)

  • Lee, Yeong-Min;Lee, Hyeon-Jeong;Cho, Jeong-Seok;Choi, Ji-Young;Woo, Jin-Ho;Moon, Kwang-Deog
    • Food Science and Preservation
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    • v.24 no.3
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    • pp.406-412
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    • 2017
  • In this study the physicochemical properties and antioxidant capacities of ginger (Zingiber officinale Rosc) Jungkwa with different kinds of sweeteners were determined. Jungkwa made with different sugars (sugar, xylitol, honey or oligosaccharides) were compared in aspect of physiochemical properties, antioxidant activities, total phenolic contents and sensory evaluation. Moisture contents Jungkwa treated different kinds of oligosaccarides showed highest value, in the order of honey, xylitol and sugar. $L^*$ value of Jungkwa treated with xylitol was the highest, $a^*$ value of Jungkwa treated with honey, sugar JungKwa were higher then others. Free sugar contents of Jungkwa treated with sugar showed the highest value in sucrose, glucose and galactose. Jungkwa with xylitol showed lowest value in all free sugar contents. Hardness and chewiness of Jungkwa treated with xylitol showed the highest value. The antioxidant activity measured by DPPH and ABTS radical scavenging activity and total penolic content were the highest in Jungkwa treated with honey, followed by Jungkwa treated with xylitol, oligosaccharides and sugar. Appearance and color of oligosaccarides and honey treated Jungkwa were preferred. In ginger taste, sweetness, chewiness were highest in sugar treated Jungkwa (not significant difference in treatments). As a result, honey treated Jungkwa has higher antioxidant activity and quality than other sugar treatments.

Isolation and Characterization of Sulfur-oxidizing Denitrifying Bacteria Utilizing Thiosulfate as an Electron Donor (황(thiosulfate)을 이용하는 탈질 미생물의 분리 및 특성 파악)

  • Oh, Sang-Eun;Joo, Jin-Ho;Yang, Jae E
    • Korean Journal of Soil Science and Fertilizer
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    • v.39 no.6
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    • pp.409-414
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    • 2006
  • Sulfur-oxidizing bacteria were enumerated and isolated from a steady-state anaerobic master culture reactor (MCR) operated for over six months under a semi-continuous mode and nitrate-limiting conditions using thiosulfate as an electron donor. Most are Gram-negative bacteria, which have sizes up to 12 m. Strains AD1 and AD2 were isolated from the plate count agar (PCA), and strains BD1 and BD2 from the solid thiosulfate/nitrate medium. Based on the morphological, physiological, FAME and 16S rDNA sequence analyses, the two dominant strains, AD1 and AD2, were identified as Paracoccus denitrificans and Paracoccus versutus (formerly Thiobacillus versutus), respectively. From the physiological results, glucose was assimilated by both strains AD1 and AD2. Heterotrophic growth of strains AD1 and AD2 could be a more efficient way of obtaining a greater amount of biomass for use as an inoculum. Even though facultative autotrophic bacteria grow under heterotrophic conditions, autotrophic denitrification would not be reduced.

Effect of Non-paralyzed side and Paralyzed side of Elastic Band Combined with Proprioceptive Neuromuscular Facilitation Lower Extremity Patterns on Balance in Chronic Stroke Patients (비 마비 측과 마비 측에 적용한 탄력밴드를 결합한 고유수용성 신경근 촉진법 하지패턴이 만성 뇌졸중 환자의 균형에 미치는 영향)

  • Lee, Young-Min;Ham, Min-Sik;Kim, Taek-Soo
    • PNF and Movement
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    • v.13 no.4
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    • pp.181-188
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    • 2015
  • Purpose: This study aimed to examine the effects of proprioceptive neuromuscular facilitation (PNF) lower extremity patterns combined with elastic bands applied to stroke patients diagnosed with hemiplegia through self-training using the non-paralyzed side approach and the paralyzed side approach, and to investigate the differences in the effects. Methods: Nine chronic stroke patients who were being treated not more than twice a week at H, K, R, and C hospitals located in Gangwon-do, performed self-training for 16 minutes, two times per day for four weeks between August and October 2015. The subjects' balance ability was measured using the Tetrax stability index, the weight distribution index, the Berg Balance Scale (BBS), and the Timed Up and Go (TUG) test before the experiment and four weeks later. Among the statistical methods, paired t-tests were conducted for intra-group comparison of the measurements taken before and after the experiment, and independent t-tests were conducted for inter-group comparison of the ex post facto values. The statistical significance level was set to 0.05. Results: When the lower extremity patterns were applied to the non-paralyzed side group and the paralyzed side group, significant intra-group differences were observed for the Tetrax stability index, the weight distribution index, the Berg Balance Scale (BBS), and Timed Up and Go (TUG) tests (p<0.05); however, the inter-group comparisons showed no significant differences. Conclusion: The non-paralyzed side approach was found to be easy for patients to participate in and it also affected the patients' paralyzed side. Although the paralyzed side approach produced good exercise effects in a short period of time, it could result in adverse effects, such as a decrease in motivation and self-confidence. Therefore, these approaches are considered to be more effective when they are selectively applied depending on the purpose of the intervention and the degree of a patients' participation.

Physicochemical and sensory properties of non-alcoholic red wine produced using vacuum distillation (진공 증류 공정에 의해 제조된 무알코올 레드 와인의 이화학적 및 관능적 특성 분석)

  • Kim, Ye-Na;Kim, Sung-Soo;Yu, Hwan Hee;Kim, Tae-Wan
    • Korean Journal of Food Science and Technology
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    • v.53 no.5
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    • pp.593-600
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    • 2021
  • In this study, the vacuum distillation process for producing non-alcoholic red wine was optimized via response surface methodology. As a result of optimizing the responses (alcohol content, yield) for independent variables (operating time, boiling point, and temperature difference), 1% alcohol content and 81.15% yield were obtained at an operating time of 24.5 min, boiling point of 65℃, and temperature difference of 8℃. To investigate the physicochemical and sensory properties, non-alcoholic wines with different boiling points (bp 25℃, bp 45℃, and bp 65℃) and a blended wine (4.2% of control wine added) were prepared. As the boiling point increased, the alcohol content decreased, and CI (color intensity) and Hue increased. Blended wine exhibited the highest value and bp 65℃ showed the lowest value in terms of sensory properties. In conclusion, distillation at a low boiling point and blending control wine could be used to prepare non-alcoholic wine with a high preference.

Effect of input variable characteristics on the performance of an ensemble machine learning model for algal bloom prediction (앙상블 머신러닝 모형을 이용한 하천 녹조발생 예측모형의 입력변수 특성에 따른 성능 영향)

  • Kang, Byeong-Koo;Park, Jungsu
    • Journal of Korean Society of Water and Wastewater
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    • v.35 no.6
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    • pp.417-424
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    • 2021
  • Algal bloom is an ongoing issue in the management of freshwater systems for drinking water supply, and the chlorophyll-a concentration is commonly used to represent the status of algal bloom. Thus, the prediction of chlorophyll-a concentration is essential for the proper management of water quality. However, the chlorophyll-a concentration is affected by various water quality and environmental factors, so the prediction of its concentration is not an easy task. In recent years, many advanced machine learning algorithms have increasingly been used for the development of surrogate models to prediction the chlorophyll-a concentration in freshwater systems such as rivers or reservoirs. This study used a light gradient boosting machine(LightGBM), a gradient boosting decision tree algorithm, to develop an ensemble machine learning model to predict chlorophyll-a concentration. The field water quality data observed at Daecheong Lake, obtained from the real-time water information system in Korea, were used for the development of the model. The data include temperature, pH, electric conductivity, dissolved oxygen, total organic carbon, total nitrogen, total phosphorus, and chlorophyll-a. First, a LightGBM model was developed to predict the chlorophyll-a concentration by using the other seven items as independent input variables. Second, the time-lagged values of all the input variables were added as input variables to understand the effect of time lag of input variables on model performance. The time lag (i) ranges from 1 to 50 days. The model performance was evaluated using three indices, root mean squared error-observation standard deviation ration (RSR), Nash-Sutcliffe coefficient of efficiency (NSE) and mean absolute error (MAE). The model showed the best performance by adding a dataset with a one-day time lag (i=1) where RSR, NSE, and MAE were 0.359, 0.871 and 1.510, respectively. The improvement of model performance was observed when a dataset with a time lag up of about 15 days (i=15) was added.

Synthesis of Ethylamines for the Reductive Amination of Ethanol over Ni Catalysts: Effect of Supports (니켈 촉매상에서 에탄올의 환원성 아민화반응에 의한 에틸아민 제조 : 담체의 영향)

  • Jeong, Ye-Seul;Shin, Chae-Ho
    • Korean Chemical Engineering Research
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    • v.57 no.5
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    • pp.714-722
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    • 2019
  • Catalysts were prepared by using incipient wetness impregnation method with 17 wt% Ni on a support ($SiO_2-Y_2O_3$, $Al_2O_3$, $SiO_2-ZrO_2$, $SiO_2$, $TiO_2$, MgO) and the catalytic activity in the reductive amination of ethanol with ammonia in the presence of hydrogen was compared and evaluated. The catalysts used before and after the reaction were characterized using X-ray diffraction, nitrogen adsorption, ethanol-temperature programmed desorption (EtOH-TPD), isopropanol-temperature programmed desorption (IPA-TPD), and hydrogen chemisorption etc. In the case of preparing $ZrO_2$ and $Y_2O_3$ supports, the small amount of Si dissolution from the Pyrex reactor surface provoked the formation of mixed oxides $SiO_2-ZrO_2$ and $SiO_2-Y_2O_3$. Among the catalysts used, $Ni/SiO_2-Y_2O_3$ catalyst showed the best activity, and this good activity was closely related to the highest nickel dispersion, and low desorption temperature in EtOH-TPD and IPA-TPD. The low catalytic activity on Ni/MgO catalysts showed low activity due to the formation of NiO-MgO solid-solutions. In the case of $Ni/TiO_2$, the reactivity was low due to the low nickel metal phase due to strong metal-support interaction. In the case of using a support as $SiO_2-Y_2O_3$, $Al_2O_3$, $SiO_2-ZrO_2$, and $SiO_2$, the selectivities of ethylamines and acetonitrile were not significantly different at similar ethanol conversion.

Rheological properties of flour dough containing roasted rice bran (볶은 쌀겨를 첨가한 밀가루 반죽의 rheology 특성)

  • Shin, Hyun-Kwang;Lee, Jeong-Hoon;Chung, Koo-Chun;Lee, Si-Kyung
    • Korean Journal of Food Science and Technology
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    • v.50 no.6
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    • pp.587-593
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    • 2018
  • This study was carried out to investigate the effect of roasted rice bran (RRB) on the rheological properties of bread dough. According to farinograph analysis, the consistency of the control sample was greatest. There were no significant differences in water absorption (p<0.05). Lower values of development time, stability, and time to breakdown, which were affected, by the addition of RRB, were observed for RRB-containing dough samples, compared to the control dough sample. Addition of RRB significantly increased the mixing tolerance index (MTI). According to rheofermentometer analysis, the values of H'm, $T^{\prime}_1$, and retention volume decreased with increase in the amount of RRB added. According to the rapid visco analyzer (RVA) analysis, peak viscosity, holding strength, and setback values were greater in the control than in the RRB-containing samples. The addition of RRB to the flour influenced rheological properties like fermentation volume and acidity. The total acidity increased with the increase in the amount of RRB added. The present study has indicated that there was no significant difference between the rheological properties of the control and 5% RRB-containing dough samples. Therefore, the addition of 5% RRB could be an effective way to produce functional flour bread without affecting its desirable physical properties.

Effects of Soil Improvement and Growth of Watermelon on Plastic Film House by Soil Treatment of Miscanthus sinensis (억새 처리에 따른 시설수박 생육과 토양 특성에 미치는 영향)

  • Ahn, Byung-Koo;Ko, Do-Young;Kim, Hyo-Jin;Kim, Tae-Bok;Chon, Hyong-Gwon;Kang, Yong-Gu
    • Korean Journal of Environmental Agriculture
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    • v.38 no.3
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    • pp.124-132
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    • 2019
  • BACKGROUND: Silver grass (Miscanthus sinensis) No. 1 was developed for production of bio-ethanol, and for the purpose the silver grass growing sector was established in Geumgang basin, Iksan, Jeonbuk, in 2011. However, the other application potentials except for using as the bio-energy resources should be considered because of the drop in international oil prices. Therefore, there is the necessity of a scientific basis to use the silver grass instead of rice straw as the organic matter source that is used for improvement of soil quality in the plastic film house. METHODS AND RESULTS: The silver grass was applied at 5, 10, 15 and 20 Mg/ha and tilled before the watermelon was planted in the plastic film-house. The control plot was treated with 10 Mg/ha with rice straw, and watermelons have been cultivated for 3 years(2017~2019). Soil aggregation, soil chemistry, and the growth characteristics were investigated, when the watermelon was harvested every year. Soil aggregation levels at the 2nd and 3rd year of watermelon harvest were similar from the plot applied with the silver grass at 5 Mg/ha and the control plot, and increased in the silver grass treated plots with more than 10 Mg/ha. However, there was no statistically significant difference between the plots. The nitrogen mineralization of silver grass in the control plot tended to be similar to the 5 Mg/ha plot, but the silver grass treated plots with over 10 Mg/ha showed low nitrogen mineralization. Soil EC on harvest stage was proportional to the applied mass of the silver grass, but pH was in inverse with the applied mass. Soil organic matter content, available phosphate, and exchangeable cations increased with the continued use of silver grass. Watermelon weight found to be the best on more than 15 Mg/ha of silver grass, and the sugar content was highest when 10 Mg/ha was treated. CONCLUSION: The use of the silver grass at 10 Mg/ha annually as the organic source was effective in replacing rice straw while growing fruits and vegetables on the plastic film house.

Effects of Environmental Substrate Composition on the Growth and Yield of Hydroponically Grown Tomato (토마토 양액재배시 배지 환경조성이 생육 및 생산성에 미치는 영향)

  • Lee, Jaesu;Lee, Hyundong;Lee, Sanggyu;Kwak, Kangsu;Kim, Balgeum;Kim, Taehyun;Baek, Jeonghyun;Rho, Siyoung;Hong, Youngsin
    • Journal of Environmental Science International
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    • v.28 no.9
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    • pp.729-735
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    • 2019
  • The aim of this study was to determine the effects of different compositions of environmental substrates on hydroponic tomato cultivation. Three different substrates were used in coir chip:dust (v/v=50:50; CP1), coir chip:dust (v/v=80:20; CP2), and rock wool cube with CP2 (CPR). The amount of irrigation during the cultivation period was 190 mL/(plant time) in all substrates. The pH and EC were 5.8-6.2 and 2.6-2.9 dS/m, respectively. The drainage rate in CP1 was 31%, in CP2 was 36%, and in CPR was 29%. The growth of tomato plants in terms of height was higher in CP1 and CPR. The leaf area was greater in CP2. The fresh and dry weights were greater in CP2 and CPR treatments. The net photosynthesis in CP2 ($19.31{\mu}mol\;CO_2/m^2s$) and root activity in CP2 were higher among all three treatments. The soluble solid content of fruit was not significantly different among treatments. The yield per plant in CP2 and CPR treatments was 17% greater than the yield per plant in CP1. Therefore, the most suitable substrate for hydroponic tomato cultivation is the substrate mixed with coir chip:dust (v:v=80:20; CP2), i.e., CPR.