• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.201-208
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• 2004

This study, in which sheep were used as models for beef cattle, was conducted to determine the effect of replacing 100% of rice straw with deepstacked broiler Iitter(BL) as a roughage source on total tract apparent digestibility, digestible nutrient intake, ruminal and blood parameters, and N balance of sheep. Under the conventional formulated mix-rice straw(60: 40) feeding system(control), replacement of rice straw with BL resulted in similar(P> 0.05) total tract apparent digestibilities of fiber and organic matter, similar(P> 0.05) intake of digestible NDF, ADF and organic matter, and higher(P <0.05) intake of digestible crude protein. Feeding BL instead of rice straw resulted in 10wer(P <0.05) ruminal pH, higher(P <0.05) $NH^3-N$ concentration and similar(P> 0.05) rominal volatile fatty acid percentage and blood urea concentration. In a N balance study, increased(P<0.05) N intake for the BIAed group induced higher(P <0.05) quantities(g/d) of fecal and urinary N excretion, bodily N absorption, and N retention. It was concluded that deepstacked BL fiber was comparable to rice straw fiber as a roughage source and BL protein was also favorably utilized within the body of ruminant.

• Food Science and Industry
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• v.51 no.4
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• pp.302-312
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• 2018

Bioactive peptides generated from milk proteins play an important role in the prevention and alleviation of diabetes. Whey proteins possess direct insulinotropic effect by amino acids (especially branch chain amino acids) produced through its gastrointestinal digestion. Additionally, blood glucose level can be lowered by gut hormone which called incretin [glucose dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1)]. However, physiological effects of incretin readily disappeared by dipeptidyl peptidase-4 (DPP-4) causing degradation of GLP-1. Several DPP-4 inhibitors are currently used as therapeutic medicines for the treatment of type II diabetes. More than 60 natural peptide (2-14 amino acids) DPP-4 inhibitors were identified in milk proteins. Peptide DPP-4 inhibitors act as substrate inhibitor and delay breakdown of GLP-1 both in vitro and in vivo. This review summarizes nutritional quality of milk proteins, absorption and mode of action of bioactive peptides, and finally up-to-dated knowledge on DPP-4 inhibitory peptides derived from milk proteins.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.4
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• pp.593-598
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• 2011

This research was performed to determine the quality characteristics of steamed bread by the number of times through the fermentation process. The number of fermentations varied from 1 to 5 while the steamed bread was prepared by measuring the duration of fermentation, and samples were analyzed in terms of general ingredients, physical properties, in vitro starch hydrolysis, protein digestibility, and sensory characteristics. Five times of fermentation resulted in significantly higher water content (p<0.01), and single fermentation led to the highest protein content (p<0.01). Protein levels decreased as fermentation was repeated. Single fermentation gave the lowest specific bread volume (p<0.05) and it increased with the number of fermentation times. Physical properties also varied with the number of times of fermentation. With more fermentation, hardness, gumminess, and chewiness decreased (p<0.01), whereas resilience (p<0.01) and cohesiveness (p<0.05) increased. In vitro starch hydrolysis was higher with 5 times of fermentation than with single to 3 times of fermentation (p<0.05). Protein digestibility was also higher with 5 times of fermentation (p<0.05). In sensory evaluations, whiteness scores were higher with 4 to 5 times of fermentation (p<0.01) whereas scores for crumb uniformity were lower with 4 and 5 times of fermentation. Moistness (p<0.01), cohesiveness (p<0.01), and chewiness (p<0.05) showed their highest scores with 4 times of fermentation.

• Korean Journal of Poultry Science
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• v.12 no.1
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• pp.17-24
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• 1985

In order to investigate an effect of non-protein nitrogen on the biological utilization of protein, hatched single comb White Leghorn male chicks were fed for the first 8 days with a commercial chicks mash, next 6 days with protein-free diet and subsequent 6 days with protein-free diets and protein diets containing 10.59% of crude protein supplemented with 0, 0.5, 1.0 and 1.5%, respectively. During experimental feeding period, chicks fed protein-free diets had intaked gradually lower feed and had shown a similar body weight loss though urea contents were increased. When birds fed protein diets, body weight gain and feed intake were not different among birds fed the graded levels of urea although feed conversions were shown a highering tendency along with increasing urea contents. According as supplemented urea were increased, protein efficiency ratio f (PER) and net protein ratio (NPR) were increased in chicks fed protein-free diets, which were shown a lowering trend in chicks fed protein diets. Effect of supplemented urea on the urinary excretion of uric acid were not found in birds fed protein-free diets, while which were increased in birds fed protein diets with the increase of urea contents. Urea addition did not affect the excretion of total creatine in birds fed protein-free or protein diets. Excretion of ammonia was jogjered in order to increasing level of urea in birds fed protein-free diets, but which were not found any particular effect in birds fed protein diets. Also urea excretion were gradually increased with the increasing contents of urea in protein-free and protein diets. Nitrogen balance of birds fed protein-free diets were minus values, which were increased with increasing urea contents in diets. When birds fed protein diets, nitrogen balance and urinary nitrogen excretion was highered and fecal nitrogen excretion were not altered as urea levels of diets increased. Digestibility of urea nitrogen supplemented in protein-free diets were lowered along with increasing contents of urea, but biological value(BV) and net protein utilization(NPU) was found a highering tendency in birds fed protein-free diet containing 1.5% of urea. When birds fed with protein diets, digestibility, BV and NPU of protein were found a highering trend in birds fed protein diets added with 0.5% of urea.

• Microbiology and Biotechnology Letters
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• v.16 no.2
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• pp.105-110
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• 1988

The production of single cell protein using the amylolytic fusant obtained from cell fusion between Hansenula anomala and Saccharomyces cerevisiae was studied. The fusant12 strain was selected for single cell protein production from starchy materials among five fusants. Optimum nitrogen source and its concentration for the growth of fusant12 were ammonium sulfate and 0.1%, respectively. Optimum concentration of soluble starch and optimum pH of the basal medium were lord and pH 5.6, respectively. Autolysis of fusant12 was effectively carried out by addition of 5% (v/v) ethyl acetate to the cell suspension and liquidization for 30 min before incubation for 24 hr at 3$0^{\circ}C$. Coculture of fusant12 and non-amylolytic yeast, Torulopsis candida YA-l5, resulted in the increase of the mass as compared to the monoculture of fusant12. The cell mass on tapioca medium was increased about 2.5 times as on soluble starch medium. The content of crude protein and nucleic acid of the dry cell were 39% and 5.8%, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.2
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• pp.117-124
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• 1984

Sarine scrap usually comprises about $40\%$ of the raw fish in processing. The purpose of this study is to establish the desirable methods for proteinaceous materials from the sardine scrap through autolysis or enzymatic digestion and to convert them into useful by-products such as sardine sauce. Sardine scrap was chopped and mixed with equal weight of water, and be hydrolyzed them by autolysis and/or by addition of commercial proteolytic enzyme and various concentrations of sodium chloride. The optimal conditions for hydrolysis of sardine scrap were revealed in temperature at $55^{\circ}C$ and 4 hours digestion with bromelain($0.4\%$) and commercial complex enzyme ($6.0\%$), and those conditions were also applicated in autolysis. The maximum hydrolyzing rate of protein and released amino nitrogen were $82.5\%,\;5.2\%$ through autolysis, $84.3\%,\;5.8\%$ by bromelain digestion and $92.5\%,\;5.9\%$ by complex enzyme, respectively. In the products prepared from sardine scrap through autolysis or bromelain digestion, hypoxanthine was dominant, as $17.4 {\mu}mole/g$, dry matter for autolysis and $16.0 {\mu}mole/g$, dry matter, for bromelain digestion among the nucleotidcs and their related compounds, respectively. The abundant free amino acids were leucine, glutamic acid, lysnie, valine and alanine. The contents of those amino acids were $51.3\%,\;48.3\%$ of the total free amino acids, respectively. And the contents of 5'-IMP and TMAO were negligible but total creatinine was developed in value from $9.2\%\;to\;10\%$ of total extracted nitrogen. The flavor of sardine sauce prepared from sardine scrap by autolysis or enzyme digestion were not inferior to that of traditional Korean soy sauce by sensory evaluation.

• Journal of Practical Agriculture & Fisheries Research
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• v.3 no.1
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• pp.116-131
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• 2001

Experiments were conducted to determine effects of whole and processed corns on in situ disappearance rates of nutrients in the rumen and in vitro degradability of dry matter by rumen microorganisms. Whole corn(WC) was processed into four different types; ground corn(GC), cracked corn(CC), flaked corn(FC), and soaked corn(SC). In the in situ experiment, the rate of ruminal DM disappearance after 48 hour incubation was highest in GC(76.1%) and lowest in WC and SC(12% ; P<0.01). The rate of ruminal CP disappearance after 48 hour incubation was highest in GC and CC(48 and 38%, respectively; P<0.01). The rate of ruminal OM disappearance after 48 hour incubation was highest in GC(76.14%) and lowest in WC and SC(11.82 and 12.26%, respectively; P<0.01). In the in vitro experiment, the two-stage incubation technique was used to measure digestibilities of whole and processed corns. The digestibility of DM was higher in GC, CC and FC(86.95, 85.84 and 82.29%, respectively) than in WC(15.36%; P<0.01).

• Journal of Nutrition and Health
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• v.26 no.8
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• pp.998-1005
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• 1993

This study was attempted to investigate the effects of enzymatic modification of milk protein with Meju protease on its acid clotting and digestibility. The proteases used in this study were isolated from Meju(fermented soybeans) and had specific acticity of 250 units/mg protein at pH 7.0. These proteases were found to be at least 3 different isoenzymes of different pH optima(pH 4.0, 6.0, 10.0). The optimum temperature was 5$0^{\circ}C$. Hydrolyzed skim milk showed 30.5% degree of hydrolysis for 1 hr. and 36.4% degree of hydrolysis for 3.5 hrs. of protease treatment at pH 7.0. Upon acidification to pH 4.0, skim milk produced large and dense coagulum, but the coagulum was getting smaller by protease treatment. Generally, digestability of skim milk at pH 4.0 was lower than pH 2.0. At pH 4.0, native skim milk and control group had problem with hydrolysis of skim milk protein. Among protease treated groups, 1 hour treated skim milk was most effectively hyrolyzed at pH 4.0.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1979.10a
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• pp.243.1-243
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• 1979

단세포 단백(SCP)은 토지나 천후조건에 의존하지 않고 대량생산할 수 있는 식량자원이라는 점에서 앞으로 예상되는 지구상의 식량난을 타개할 수 있는 방법으로 주목되고 있다. 단세포 단백을 사료로 이용하는 이외에 식품에 직접 사용하려는 노력이 꾸준히 진행되고 있으며 서구에서는 식용단세포단백의 생산가공이 시작되고 있다. 단세포 단백를 식용으포 직접 이용하기 위하여서는 위생성은 물론 소화성과 기능성은 향상시켜아 하는데 이 목적을 위한 세포벽 파괴의 단백질 추출기술에 관한 연주가 앞서야 한다. 최근 MIT에시는 Yeast의 세포벽 파괴와 단백질 추출 mechanisln을 SEM (Scanning Electron Microscape) 등을 이용한 형태학적 연구로 규명하였다. 식품재료로서의 단세포 단백의 물성과 기능에 대하여 앞으로 연구 할 점이 많으며 이 분야의 연구결과를 검토하여 본다.

• Journal of the Korean GEO-environmental Society
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• v.13 no.11
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• pp.37-42
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• 2012

This study investigated the use of Geobacter lovleyi with TBOS(Tetrabutoxysilane) for TCE(Trichloroethylene) dechlorination. The TCE dechlorination by Geobacter lovleiy was mathematically described as the independent variables such as initial concentration of TCE, protein mass of Geobacter lovleyi and initial concentration of TOBS, and these were modeled by the use of response surface methodology(RSM). These experiments were carried out as a Box-Behnken Design(BBD) consisting of 15 experiments. The application of RSM yielded the following equation, which is empirical relationship for the dechlorination efficiency($Y_1$, %) of TCE and first order kinetic constant of TCE($Y_2,\;d^{-1}$) by independent variables in coded unit : $Y_1=-11.50X_1$(initial concentration of TCE) + $4.25X_2$(protein mass as Geobacter lovleyi injected mass) - $4.75X_3$(initial concentration of TBOS) - ${6.58X_1}^2$ - ${8.58X_2}^2$ + 93.67, $Y_2=-10.92X_1+5.06X_2-4.89X_3-{4.93X_3}^2-2.19X_1X_2+2.54X_1X_3-2.19X_2X_3+16.71$. In this case, the value of the adjusted determination coefficient(adjusted $R^2$= 0.975 and 0.934) were closed to 1, showing a high significance of the model. Statistical results showed the order of TCE dechlorination at experimental factors to be initial TCE concentration > initial TBOS concentration > protein mass, but the interaction effects were non-significant.