• Title, Summary, Keyword: Digestion

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A Study on Environmental and Economic Analysis for Each Treatment of Sewage Sludge(II) - Results of Economic Analysis - (하수슬러지 처리방법별 환경성 및 경제성 분석에 대한 연구(II) - 경제성 분석 중심으로 -)

  • Lee, Dongjin;Lee, Suyoung;Kwon, Younghyun;Cho, Yuna;Bae, Jisu
    • Journal of the Korea Organic Resources Recycling Association
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    • v.24 no.2
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    • pp.15-29
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    • 2016
  • This study investigated the environmental and economical assessment for sewage sludge treatment options including biogasification, incineration, carbonization, drying, and solidification. Considering B/C ratio for an anaerobic digestion treatment, for $270,000m^3/d$ (over $1,150m^3/day$), B/C was 1, as the moisture content increased to 95 %, B/C was 1 for $100000m^3/d$ (capacity of $400m^3/day$). Anaerobic digestion+solidification was the most economically feasible, then Anaerobic digestion+incineration and anaerobic digestion+drying were the next economically feasible and then anaerobic digestion+carbonization was the least economically feasible. If anaerobic digestion efficiency was improved to 45%, the treatment costs for anaerobic digestion+carbonization, anaerobic digestion+incineration and anaerobic digestion+drying were decreased to 3,000~5,000 won/t and the costs for anaerobic digestion+solidification was decreased to 2,000~3,000 won/t due to increasing of the beneficial cost of the biogas production.

Angiotensin I-converting Enzyme Inhibitory Activities of Porcine Skeletal Muscle Proteins Following Enzyme Digestion

  • Katayama, K.;Fuchu, H.;Sakata, A.;Kawahara, S.;Yamauchi, K.;Kawamura, Y.;Muguruma, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.3
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    • pp.417-424
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    • 2003
  • Inhibitory activities against angiotensin I-converting enzyme (ACE) of enzymatic hydrolysates of porcine skeletal muscle proteins were investigated. Myosin B, myosin, actin, tropomyosin, troponin and water-soluble proteins extracted from pork loin were digested by eight kinds of proteases, including pepsin, $\alpha$-chymotrypsin, and trypsin. After digestion, hydrolysates produced from all proteins showed ACE inhibitory activities, and the peptic hydrolysate showed the strongest activity. In the case of myosin B, the molar concentration of peptic hydrolysate required to inhibit 50% of the activity increased gradually as digestion proceeded. The hydrolysates produced by sequential digestion with pepsin and $\alpha$-chymotrypsin, pepsin and trypsin or pepsin and pancreatin showed weaker activities than those by pepsin alone, suggesting that ACE inhibitory peptides from peptic digestion might lose their active sequences after digestion by the second protease. However, the hydrolysates produced by sequential digestion showed stronger activities than those by $\alpha$-chymotrypsin, trypsin or pancreatin alone. These results suggested that the hydrolysates of porcine meat were able to show ACE inhibitory activity, even if they were digested in vivo, and that pork might be a useful source of physiologically functional factors.

Comparison of In Vitro Digestion Kinetics of Cup-Plant and Alfalfa

  • Han, K.J.;Albrecht, K.A.;Mertens, D.R.;Kim, D.A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.5
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    • pp.641-644
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    • 2000
  • In vitro true digestibility of cup-plant (Silphium perfoliatum L.) is higher than other alternative forages and comparative to alfalfa (Medicago sativa L.) even at the high neutral detergent fiber (NDF) concentration. This study was conducted to determine whether the digestion kinetic parameters of cup-plant could explain high in vitro true digestibility of cup-plant at the several NDF levels. Cup-plant and alfalfa were both collected in Arlington and Lancaster, Wisconsin to meet the NDF content within 40 to 50% range. The collected samples were incubated with rumen juice to investigate the digestion kinetics at 3, 6, 9, 14, 20, 28, 36, 48, and 72 h. Kinetics was estimated by the model $R=D_0\;e-k(t-L)+U$ where R is residue remaining at time t, and $D_0$ is digestible fraction, k is digestion rate constant, L is discrete lag time, and U is indigestible fraction. Parameters of the model were estimated by the direct nonlinear least squares (DNLS) method. Digestion rate and potential extent of digestion were not statistically different in either forage. However, alfalfa had shorter lag time (p<0.05). The indigestible fraction increased with maturation in alfalfa and in cup-plant (p<0.05). The ratio of indigestible fraction to acid detergent lignin (ADL) was higher in cup-plant than in alfalfa (p<0.05). From the results, alfalfa is probably digested more rapidly than cup-plant, however, cup-plant maintains higher digestibility with maturation due to a relatively slower increase of indigestible fraction in NDF.

Influence of Starch Concentration and Mastication on the Lipid Digestion and Bioaccessibility of β-carotene loaded in Filled Hydrogels (베타-카로텐 탑재 하이드로 젤 농도와 저작에 따른 지방소화율과 생체접근율의 변화)

  • Mun, Saehun;Kim, Yong-Ro
    • Korean journal of food and cookery science
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    • v.33 no.2
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    • pp.181-189
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    • 2017
  • Purpose: This study was conducted to examine the effects of the starch concentration of filled hydrogel and the addition of ${\alpha}-amylase$ and simulated mastication processing in an oral phase on lipid digestion and ${\beta}-carotene$ bioaccessibility of filled hydrogels. Methods: Lipid digestion and ${\beta}-carotene$ bioaccessibility of the filled hydrogels were measured after the samples were passed through an in vitro gastrointestinal tract model consisting of oral, gastric, and small intestinal phases. Results: The initial rate and final extent of lipid digestion were higher in the filled hydrogels than in the emulsion when the filled hydrogels were treated in an oral phase without simulated mastication processing and addition of ${\alpha}-amylase$, regardless of starch concentration. However, when the filled hydrogels were minced using mortar and pestle for 2 min and were exposed to ${\alpha}-amylase$, the filled hydrogel fabricated with 5% starch showed the lowest lipid digestion rate and extent compared to the emulsion and other filled hydrogels. Bioaccessibility of ${\beta}-carotene$ was higher in the filled hydrogels than in the emulsion, regardless of the digestion method performed in an oral phase and starch concentration. However, there were appreciable differences in bioaccessibility of the filled hydrogels depending on whether or not simulated mastication and addition of ${\alpha}-amylase$ were employed. Conclusion: These results suggested that the rheological properties of initial filled hydrogels and simulated mastication processing in an oral phase plays an important role in determining the lipid digestion and ${\beta}-carotene$ bioacccessibility entrapped within filled hydrogels.

Evaluation of the Digestibility of Korean Hanwoo Beef Cuts Using the in vitro Physicochemical Upper Gastrointestinal System

  • Jeon, Ji-Hye;Yoo, Michelle;Jung, Tae-Hwan;Jeon, Woo-Min;Han, Kyoung-Sik
    • Food Science of Animal Resources
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    • v.37 no.5
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    • pp.682-689
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    • 2017
  • The aim of this study was to investigate the digestibility of different Korean Hanwoo beef cuts using an in vitro digestion model, in vitro physicochemical upper gastrointestinal system (IPUGS). The four most commonly consumed cuts - tenderloin, sirloin, brisket and flank, and bottom round - were chosen for this study. Beef samples (75 g) were cooked and ingested into IPUGS, which was composed of mouth, esophagus, and stomach, thereby simulating the digestion conditions of humans. Digested samples were collected every 15 min for 4 h of simulation and their pH monitored. Samples were visualized under a scanning electron microscope (SEM) to examine changes in the smoothness of the surface after digestion. Analysis of the amino acid composition and molecular weight (MW) of peptides was performed using reverse-phase high performance liquid chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis, respectively. Following proteolysis by the gastric pepsin, beef proteins were digested into peptides. The amount of peptides with higher MW decreased over the course of digestion. SEM results revealed that the surface of the digested samples became visibly smoother. Total indispensable and dispensable amino acids were the highest for the bottom round cut prior to digestion simulation. However, the total amount of indispensable amino acids were maximum for the tenderloin cut after digestion. These results may provide guidelines for the elderly population to choose easily digestible meat cuts and products to improve their nutritional and health status.

Effects of Mixing Ratio and Organic Loading Rate of Acid Fermented Food Wastes and Sewage Sludge on the Anaerobic Digestion Process (음식물찌꺼기 산발효산물과 하수슬러지의 혼합비 및 유기물부하가 병합처리에 미치는 영향)

  • Ahn, Chul-Woo;Park, Jin-Sik;Jang, Seong-Ho
    • Korean Journal of Environmental Agriculture
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    • v.25 no.3
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    • pp.247-256
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    • 2006
  • This study has been conducted for the process of food wastes disposal using surplus capacity of established sewage treatment plant by co-digestion of fermented food wastes and sewage sludge after thermophilic acid fermentation of food wastes. The co-digestion of thermophilic acid fermented food wastes and sewage sludge was performed by semi-continous method in mesophilic anaerobic digestion reactor. It showed great digestion efficiency as the average SCOD and VS removal efficiency in organic loading rate 3.30g VS/L.d. were 74.2% and 73.6%, and the gas production rate and average methane content were 0.440 L/g $VS_{add}.d$ and 66.5%, respectively. Based on the results of this study, the co-digestion of thermophilic acid fermented food wastes and sewage sludge in sewage treatment plant is able to improve treatment efficiency of anaerobic digestion reactor and to dispose food wastes simultaneously, and was proved excellent economical efficiency comparing with any other treatment methods.

Sample Pretreatment for the Determination of Metal Impurities in Silicon Wafer (실리콘 웨이퍼 중의 금속 불순물 분석을 위한 시료 전처리)

  • Chung, H.Y.;Kim, Y. H.;Yoo, H.D.;Lee, S.H.
    • Journal of the Korean Chemical Society
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    • v.43 no.4
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    • pp.412-417
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    • 1999
  • The analytical results obtained by microwave digestion and acid digestion methods for sample pretreatment to determine metal impurities in silicon wafer by inductively coupled plasma-mass spectrometry (ICP-MS) were compared. In order to decompose the silicon wafer, a mixed solution of $HNO_3$ and HF was added to the sample and the metal elements were determined after removing the silicon matrix by evaporating silicon in the form of Si-F. The recovery percentages of Ni,Cr and Fe were found to be 95∼106% for both microwave digestion and acid digestion methods. The recovery percentage of Cu obtained by the acid digestion method was higher than that obtained by the microwave digestion method. For Zn, however, the microwave digestion method gave better result than the acid digestion method. Fe was added to a silicon wafer using a spin coater. The concentration of Fe in this sample was determined by lCP-MS, and the same results were obtained in the two pretreatment methods.

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Understanding Starch Utilization in the Small Intestine of Cattle

  • Harmon, David L.
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.7
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    • pp.915-922
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    • 2009
  • Ruminants possess the capacity to digest very large amounts of starch. However, in many cases diets approach 60% starch and even small inefficiencies present opportunities for energetic losses. Ruminal starch digestion is typically 75-80% of starch intake. On average, 35-60% of starch entering the small intestine is degraded. Of the fraction that escapes small-intestinal digestion, 35-50% is degraded in the large intestine. The low digestibility in the large intestine and the inability to reclaim microbial cells imposes a large toll on post-ruminal digestive efficiency. Therefore, digestibility in the small intestine must be optimized. The process of starch assimilation in the ruminant is complex and remains an avenue by which increases in production efficiency can be gained. A more thorough description of these processes is needed before we can accurately predict digestion occurring in the small intestine and formulate diets to optimize site of starch digestion.

A Study on Kinetics in One-Phase Anaerobic Digestion (단상 혐기성 소화공정에서의 동력학적 연구)

  • 조관형;조영태
    • Journal of Environmental Science International
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    • v.9 no.1
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    • pp.75-80
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    • 2000
  • Kinetic data for the acid phase anaerobic digestion were presented in this study and the constants were determined with acid production rate and gas production rate. Process models based on continuous culture theory were used to describe the characteristics of the acid forming microorganisms and to enable further development toward utilization of the process in a more rational manner. Acid phase digestion can be separated with appropriate manipulation of hydraulic retention time in anaerobic digestion. Kinetic analysis of data from the various hydraulic retention times using a phase specific model obtained form the acid phase indicated maximum specific growth rate of 0.40/h, saturation constant of 2,000mgCOD.$\ell$, yield coefficient of 0.35 mgVSS/msCOD utilized and decay constant of 0.04/h for the acid production rate. Similar analysis of data for the gas production rate indicated maximum specific growth rate of 0.003/h, saturation constant of 2,200mgCOD/$\ell$, yield coefficient of 0.035 mgVSS/mgCOD utilized and decay constant of 0.06/h.

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A Study on Usage of Results from Batch Reactor for Design of Aerobic Digestion (호기성 소화조 설계시 회분식 반응조에서 획득된 결과의 이용방안에 관한 연구)

  • Choung, Youn-Kyoo;Ko, Kwang-Baik;Park, Joon-hong
    • Journal of Korean Society of Water and Wastewater
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    • v.8 no.3
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    • pp.1-8
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    • 1994
  • In the general process of design for aerobic digestion, the design for field plant of which inflow pattern is continuous inflow is performed using the results from lab scale batch reactor. However, the recent researchers reported that the general designs were performed as over-estimated, Therefore, in this study, laboratory batch experiments were carried out at $20^{\circ}C$ and pH 7.5 on the aerobic digestion of waste activated sludge at different solid levels. This treatise could consider the negligence about effective digestion periods the usage of VSS as solid concentration, and the effect of initial solid concentration of solid degration rate coefficient($k_d$) as reasons of the overestimated design, and showed the scheme of how to design for aerobic digestion from batch experiment.

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