• Bulletin of the Korean Chemical Society
• /
• 제32권5호
• /
• pp.1640-1644
• /
• 2011

Water-soluble mutant of intrinsically insoluble protein, crambin, was produced by mutagenesis based on the sequence analysis with homologous proteins. Thr1, Phe13, and Lys33 of crambin were substituted for Lys, Tyr, and Lys, respectively. The resultant mutant was soluble in aqueous buffer as well as in dodecylphosphocholine (DPC) micelle solution. The $^1H-^{15}N$ spectrum of the mutant crambin showed spectral similarity to that of the wild-type protein except for local regions proximal to the sites of mutation. Solution structure of water-soluble mutant crambin was determined in aqueous buffer by NMR spectroscopy. The structure was almost identical to the wild-type structure determined in non-aqueous solvent. Subtle difference in structure was very local and related to the change of the intra- and inter-protein hydrophobic interaction of crambin. The structural details for the enhanced solubility of crambin in aqueous solvent by the mutation were provided and discussed.

• 농업과학연구
• /
• 제16권2호
• /
• pp.201-211
• /
• 1989

Mucor rennet의 이용(利用) 가능성(可能性)을 타진(打診)하기 위하여 Blue cheese를 제조(製造)하고 그 각종(各種) 질소화합물(窒素化合物)의 특성(特性)을 조사(調査)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. Blue cheese의 수율(收率)은 calf rennet과 Mucor rennet간(間)에는 큰 차이(差異)가 없었다. 2. 숙성과정중(熟成過程中) cheese의 고형분(固形分) 함량(含量)은 증가(增加)하였고 첨가비율(添加比率)에 따른 차이(差異)는 인정(認定)되지 않았다. 3. water soluble nitrogen은 숙성(熟成)이 진행(進行)됨에 따라 증가(增加)하였으며 숙성초일(熟成初日)부터 calf rennet에 비(比)하여 Mucor rennet 편이 높았고 숙성(熟成) 40일(日)부터는 혼합(混合)rennet이 calf rennet보다 낮았다. 4. non protein nitrogen, peptone amino nitrogen, water soluble protein nitrogen, proteose nitrogen, peptone nitrogen 및 숙성율등(熟成率等)도 water soluble nitrogen과 동등(同等)한 변화(變化)를 보였다. 5. Mucor rennet으로 제조(製造)한 Blue cheese casein을 전기영동(電氣泳動)한 결과(結果) as-casein과 ${\beta}$-casein의 분해도(分解度)가 높았으나 calf rennet로 제조(製造)한 Blue cheese의 as-casein과 ${\beta}$-casein의 분해도(分解度)는 비교적 낮았고 숙성(熟成) 60일(日)에는 Mucor rennet 처리구(處理區)의 casein은 다소 잔존(殘存)함을 알 수 있었다. 6. Blue cheese를 60일간(日間) 숙성(熟成)시켰을때 유리(遊離)아미노산(酸) 함량(含量)은 Mucor rennet으로 제조(製造)한 cheese보다 전(全) 숙성기간(熟成期間)동안 많았다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제23권10호
• /
• pp.1386-1398
• /
• 2010

Soybean contains a high concentration of carbohydrates that consist mainly of non-starch polysaccharides (NSP) and oligosaccharides. The NSP can be divided into insoluble NSP (mainly cellulose) and soluble NSP (composed mainly of pectic polymers, which are partially soluble in water). Monogastric animals do not have the enzymes to hydrolyze these carbohydrates, and thus their digestion occurs by means of bacterial fermentation. The fermentation of soybean carbohydrates produces short chain fatty acids that can be used as an energy source by animals. The utilization efficiency of the carbohydrates is related to the chemical structure, the level of inclusion in the diet, species and age of the animal. In poultry, soluble NSP can increase digesta viscosity, reduce the digestibility of nutrients and depress growth performance. In growing pigs, these effects, in particular the effect on gut viscosity, are often not so obvious. However, in weaning piglets, it is reported that soy oligosaccharides and soluble NSP can cause detrimental effects on intestinal health. In monogastrics, consideration must be given to the anti-nutritive effect of the NSP on nutrient digestion and absorption on one hand, as well as the potential benefits or detriments of intestinal fermentation products to the host. This mirrors the needs for i) increasing efficiency of utilization of fibrous materials in monogastrics, and ii) the maintenance and improvement of animal health in antibiotic-free production systems, on the other hand. For example, ethanol/water extraction removes the low molecular weight carbohydrate fractions, such as the oligosaccharides and part of the soluble pectins, leaving behind the insoluble fraction of the NSP, which is devoid of anti-nutritive activities. The resultant product is a high quality soy protein concentrate. This paper presents the composition and chemical structures of carbohydrates present in soybeans and discusses their nutritive and anti-nutritive effects on digestion and absorption of nutrients in pigs and poultry.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2010년도 춘계학술발표대회
• /
• pp.43.2-43.2
• /
• 2010

Most of previous methods for the dispersions of carbon nanotube were achieved by various chemical functionalizations. In this study, however, we generated highly water dispersed carbon nanofibers by altering intrinsic materials property only, such as crystallinity of outer layers of carbons, without chemical treatment. Although most of chemical functionalization requires acidic treatment and may degrade their chemical functions by interacting with other molecules, suggested strategy demonstrated a simple but chemically non-degradable carbon nanotube for the application of various medical applications, such as drug delivery system and implant coatings.Furthermore, protein adsorption was increased by the reducing surface crystalinity since outer activated surface induced more adsorption of oxygen and eventually greater protein adsorption than pristine carbon nanofibers.

• 한국수산과학회지
• /
• 제29권6호
• /
• pp.754-760
• /
• 1996

Effects of washing and additives on the texture of squid surimi gel which has been known to hard to gelation due to high protease activities and many water solubles were studied by SDS-PAGE, compression test, jelly strength and transmission electron microscopy analysis (TEM). Myosin (205 kDa) heavy chain was the major protein in water soluble fractions. It was impossible to make a gel after washing of the minced squid meat. These results suggested that squid (Todarodes pacificus) minced meat does not need a washing for good jelly products. $3.0\%$ of bovine plasma protein (BPP) produced the hardest gel ($16\%$ harder than the control) among the additives including egg white (EW), potato extracts (PE) and transglutaminase-K (TG-K) by compression test (P>0.05). Microstructure of control, $2\%$ EW and $4\%$ TG-K treated gels showed a sponge-like structure with more vacant space. Gels containing $3\%$ BPP formed the most rigid and arranged networks. Those results indicates that poor gel-network formation Was due to the degradation of myofibrillar proteins by proteases contained in the minced meat, which result in non-interlinkage.

• Animal Bioscience
• /
• 제37권7호
• /
• pp.1185-1195
• /
• 2024

Objective: This meta-analysis aimed to evaluate the impact of wilted and unwilted silage on various parameters, such as nutrient content, fermentation quality, bacterial populations, and digestibility. Methods: Thirty-six studies from Scopus were included in the database and analyzed using a random effects model in OpenMEE software. The studies were grouped into two categories: wilting silage (experiment group) and non-wilting silage (control group). Publication bias was assessed using a fail-safe number. Results: The results showed that wilting before ensiling significantly increased the levels of dry matter, water-soluble carbohydrates, neutral detergent fiber, and acid detergent fiber, compared to non-wilting silage (p<0.05). However, wilting significantly decreased dry matter losses, lactic acid, acetic acid, butyric acid, and ammonia levels (p<0.05). The pH, crude protein, and ash contents remained unaffected by the wilting process. Additionally, the meta-analysis revealed no significant differences in bacterial populations, including lactic acid bacteria, yeast, and aerobic bacteria, or in vitro dry matter digestibility between the two groups (p>0.05). Conclusion: Wilting before ensiling significantly improved silage quality by increasing dry matter and water-soluble carbohydrates, as well as reducing dry matter losses, butyric acid, and ammonia. Importantly, wilting did not have a significant impact on pH, crude protein, or in vitro dry matter digestibility.

• 대한가정학회지
• /
• 제23권2호
• /
• pp.29-36
• /
• 1985

This experiment was conducted to investigate changes of the components in steamed and roasted green tea after 10 min, 20 min and 30 min of heat treatment of heat treatment at $110^{\circ}C$. Vitamin C and tannin were determined by spetrophotometry. Total nitrogen, water-soluble nitrogen and water-soluble non protein nitrogen were determined by Kjeldahl analysis system. Aromas were identified by gas chromatography. After heat treatment, contents of most compounds decreased. Tannin and caffeine decreased a little bit, while vitamin C decreased considerably. There were both decreases and increases in aromas. Aromas which increased were geraniol, trans-2-hexenol, linalool, $\alpha$-ionone and $\beta$-ionone. From these results, it was concluded that the highest quality of green tea was one steam- treated for 10 min at $110^{\circ}C$.

• Asian-Australasian Journal of Animal Sciences
• /
• 제24권5호
• /
• pp.616-622
• /
• 2011

This study evaluated the fermentation characteristics and protein degradation dynamics of wet green tea grounds (WGTG) silage. The WGTG was ensiled with distilled water (control), or lactic acid bacteria (LAB), enzyme (E), formic acid (FA) and formaldehyde (FD) prior to ensiling. Three bag silos for each treatment were randomly opened at 0, 3, 7, 14, 28 and 60 days after anaerobic storage. For all the treatments, except for FA, there was a rapid decline in pH during the first 7 days of ensiling. LAB treatment had higher lactic acid content, lower ammonia-N ($NH_3$-N) and free-amino nitrogen (FAA-N) contents than other treatments (p<0.05). E treatment had higher lactic acid, water-soluble carbohydrates (WSC) and non-protein nitrogen (NPN) content than the control (p<0.05). FA treatment had higher $NH_3$-N and FAA-N content than the control (p<0.05). FD treatment had lower NPN and FAA-N content than the control, but it did not significantly inhibit the protein degradation when compared to LAB treatment (p>0.05). Results indicate that LAB treatment had the best effect on the fermentation characteristics and protein degradation of WGTG silage.

• Archives of Pharmacal Research
• /
• 제19권5호
• /
• pp.423-428
• /
• 1996

Optimum conditions for hydrolysis were investigated to enhance water-solubilities of protein-bound polysaccharides in the basidiocarps of Ganoderma lucidum by treating chymotrypsin. We also attempted with Ganoderma lucidum residue remaining after extracting hot water-soluble compoents in Ganoderma lucidum. After hydrolyzing under optimum conditions (20 ppm chymotrypsin, 2% Gampderma lucidum or 6% Ganoderma lucidum residue, at pH 10 and at $ 40^{\circ}C$), the amounts of total protein and carbohydrate of hydrolysate were measured. Michaelis constant, $K_{m}$, and maximum rate, $V_{max}$, calculated by Lineweaver-Buck plot for the hydrolysis of Ganoderma lucidum were 1.73% and 0.073%/min respectively and those for hydrolysis of Ganoderma lucidum residue were 2.40% and 0.033%/min respectively. The amount of polysaccharide isolated from Ganoderma lucidum (100 g) treated with chymotrypsin was only 3.07 g, but significantly increased amount (14.34 g) of polysaccharides was isolated from Ganoderma lucidum residue (100 g) treated with chymotrypsin. The protein-bound polysaccharide was isolated from the non-hydrolyzed and hydrolyzed sample and molecular weights of the polysaccharide were measured by Sepharose CL-48 gel filtration.

• 한국식품과학회지
• /
• 제21권3호
• /
• pp.364-369
• /
• 1989

본 실험은 냉동저장 중에 법동변성 방지제의 첨가가 우육과 돈육의 품질에 미치는 영향을 알아본 것으로 냉동변성 방지제 종류는 sorbitol, mono sodium glutamate와 sodium tripolyphosphate를 혼합하여 사용한 CP-A, sorbitol, sucrose와 sodium tripolyphosphate를 섞은 CP-B 그리고 sorbitol, sucrose, sodium citrate와 sodium tripolyphosphate를 사용한 CP-C세 종류이었고 시료는 $-20^{\circ}C$에서 12주간 저장되었으며 분석항목으로는 pH변화, TBA가, 유리지방산 함량의 변화, 수용성 및 염용성 단백질의 추출성이었다. 그 결과를 요약하면 다음과 같다. 1. 냉동변성 방지제 첨가구의 pH는 무첨가구의 pH보다 0.2-0.5unit 정도의 상승효과를 보였으며 TBA가 및 유리지방산 함량은 저장기간이 길어짐에 따라 무첨가구에 비해 증가하는 경향을 보였다. 2. 수용성 단백질의 추출성은 냉동변성 방지제를 처리할 때 돈육이 우육에 비해 높은 추출율을 보였는데 특히 돈육의 CP-B 처리구에서 무첨가구에 비해 우수하였다. 3. 염용성 단백질의 추출성에 대한 냉동변성 방지제의 효과는 우육의 CP-A 처리구와 돈육의 CP-B 처리구에서 무첨가구에 비해 약 10-25%의 높은 추출성 향상을 나타내었다.