• Journal of Microbiology and Biotechnology
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• v.30 no.7
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• pp.1082-1091
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• 2020

Microbial transglutaminases (MTGs) are widely used in the food industry. In this study, the MTG gene of Streptomyces sp. TYQ1024 was cloned and expressed in a food-grade bacterial strain, Bacillus subtilis SCK6. Extracellular activity of the MTG after codon and signal peptide (SP Ync M) optimization was 20 times that of the pre-optimized enzyme. After purification, the molecular weight of the MTG was 38 kDa and the specific activity was 63.75 U/mg. The optimal temperature and pH for the recombinant MTG activity were 50℃ and 8.0, respectively. MTG activity increased 1.42-fold in the presence of β-ME and 1.6-fold in the presence of DTT. Moreover, 18% sodium chloride still resulted in 83% enzyme activity, which showed good salt tolerance. Cross-linking gelatin with the MTG increased the strength of gelatin 1.67 times and increased the thermal denaturation temperature from 61.8 to 75.8℃. The MTG also significantly increased the strength and thermal stability of gelatin. These characteristics demonstrated the huge commercial potential of MTG, such as for applications in salted protein foods.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.721-724
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• 2000

The possibility of the enzymatic in vitro glycosylation using peptide-N-glycosidase F was examined. Oligosaccharide chains in the glycoproteins are important for the biological activity, solubility, immunogenecity, recognition, and prevention of degradation. After 4 h incubation of deglycosylated glycoprotein with excess glucose oligomer and ammonia in acetone at $50^{\circ}C$, upper shift of protein band was observed on SDS-PAGE. And the different deglycosylation characteristics of glucose oxidase and fetuin were investigated.

• Food Science and Biotechnology
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• v.14 no.5
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• pp.667-671
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• 2005

The aim of this study is to investigate the effects of the muscle mass and fiber number on post-mortem metabolic rates and pork quality. Carcass traits, muscle fiber characteristics, and type of fiber composition were evaluated using a sample of 200 cross-bred pigs. The muscle mass was divided into two groups according to carcass weight and loin-eye area measurements (heavy or light). In addition, the muscle histological characteristics were divided into two groups according to the muscle fiber density and total number of muscle fibers (high or low). All the carcass traits were significantly different in the muscle mass groups. Increasing weight significantly affected the cross-sectional area (CSA) of all fibers. The low group, which had a low muscle fiber number indicating a larger CSA of fibers, and especially the heavy-low group had the highest CSA levels of fibers. The fiber number percentage and the area percentage were significantly different in the groups categorized by fiber number. The heavy-high group indicated a normal rate of pH decline and the R-value. In addition, pigs with a heavy muscle mass and high muscle fiber number indicated normal drip loss, lightness, and protein denaturation. The present results suggest that increasing the total muscle fiber number has a beneficial effect on increasing the muscle mass without deteriorating the meat quality.

• Journal of Biosystems Engineering
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• v.40 no.3
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• pp.261-270
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• 2015

Purpose: Cold storage is the most popular method used to preserve highly perishable foods such as beef and fish. However, at refrigeration temperatures, the shelf life of these foods is limited, and spoilage leads to massive food waste. Moreover, freezing significantly affects the food's properties. Ice crystallization and growth during freezing can cause irreversible textural damage to foods through volumetric expansion, moisture migration induced by osmotic pressure gradients, and concentration of solutes,which can lead to protein denaturation. Methods: Although freezing can preserve perishable foods for months, these disruptive changes decrease the consumer's perception of the food's quality. Therefore, the development and testing of new and improved cold storage technologies is a worthwhile pursuit. Results: The process of maintaining a food product in an unfrozen state below its equilibrium freezing temperature is known as supercooling. As supercooling has been shown to offer a considerable improvement over refrigeration for extending a perishable product's shelf life, implementation of supercooling in households and commercial refrigeration units would help diminish food waste. Conclusions: A commercially viable supercooling unit for all perishable food items is currently being developed and fabricated. Buildup of this technology will provide a meaningful improvement in the cold storage of perishable foods, and will have a significant impact on the refrigeration market as a whole.

• Food Science and Biotechnology
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• v.16 no.4
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• pp.549-556
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• 2007

The study was carried out to examine on the refiner discharge from Alaska pollock as a collagen resource by characterizing biochemical and functional properties of collagen. The refiner discharge from Alaska pollock surimi manufacturing was a good resource for collagen extraction according to the results of total protein, heavy metal, volatile basic nitrogen, collagen content, amino acid composition, and thermal denaturation temperature (TDT). TDT of acid soluble collagen from refiner discharge showed $20.7^{\circ}C$, which was similar to that of collagen from Alaska pollock muscle and was higher than that of collagen from Alaska pollock skin. TDT of acid-soluble collagen from refiner discharge was, however, lower than those of skin collagens from warm fish and land animal. Acid-soluble collagen from refiner discharge of Alaska pollock could be used as a functional ingredient for food and industrial applications according to the results of water and oil absorption capacities, and emulsion properties. In addition, if the thermal stability of the acid-soluble collagens is improved, collagen from refiner discharge from Alaska pollock could be more effectively used.

• Proceedings of the Membrane Society of Korea Conference
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• 1997.04b
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• pp.45-47
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• 1997

정밀여과 및 한외여과에 의해 단백질 등과 같은 거대분자 물질을 분리정제할 경우 피할 수 없는 문제점은 막에 의해 분리된 거대부자들이 막표면에 쌓이는 농도분극(concentration polarization)현상과 이 누적된 거대분자가 막과의 상호작용에 의해 막표면 또는 막세공 내에 비가역적으로 침적되는 막오염(membrane fouling)현상이 일어난다는 점이다. 특히 막표면 또는 막세공 내에 분리대상 물질이 비가역적으로 침적되어 발생되는 막오염은 상대적으로 가역적 침적 과정인 농도분극보다 제어 또는 억제가 어려워 최근의 막분리 분야 연구의 상당 부분이 막오염 유발요인의 해석, 막오염을 효율적으로 제어 또는 억제하기 위한 방법의 연구에 집중되고 있다. 본 연구에서는 단백질 용액의 정밀여과시 단백질 변성이 막오염에 미치는 영향을 체계적으로 규명하기 위한 연구의 일환으로서 BSA를 분리대상 물질로하여, BSA용액을 미리 기계적 Shear(펌프 및 sonification), 열, 화학적 방법(pH 및 변성제)으로 변성시킨 후, 이 용액을 대상으로 회분식 정밀여과 실험을 수행하여 단백질 응집체 형성이 막투과량 감소에 미치는 영향을 실험적으로 검토하였으며, 각각의 막투과량 감소 특성을 아래의 4가지 blocking filtration law로서 해석하였다: complete blocking law, intermediate blocking law, standard blocking law, cake filtration law.

• Bulletin of the Korean Chemical Society
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• v.20 no.10
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• pp.1159-1164
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• 1999

The study investigated the effect of carrier composition (ionic strength and pH) on the retention of various proteins in flow field-flow fractionation (Flow FFF) as well as the conformational change of Bovine Serum Albumin (BSA) with urea concentration, storage time and temperature. The study found that the retention of protein in Flow FFF increased with the ionic strength of the carrier liquid. Most proteins were well solubilized at pH = 7-8. The hydrodynamic diameters obtained from Flow FFF retention data agree well with theoretical values. The retention increased and the peak shape became distorted at extreme pH conditions of the carrier solution. The selected carrier composition for comparison between the literature value of proteins was 0.05 M tris buffer solution with a pH of 8. Storing BSA at 4 ±2℃ over a period of three months resulted in slow dimerization. Also, in case of the storage of BSA at 37 ±5℃ for one week, the retention of both BSA monomer and dimer increased with the urea concentration. Finally, the structural composition of specific enzymes: malonyl-CoA decarboxylase (MCDC) and malonyl-CoA synthesis (MCS) was determined by using Flow FFF at specific carrier solutions. The molecular weight of the natural MCDC was determined to be 208 kDa, which means it is a homotetramer, while that of the MCS was determined to be 47 kDa, which means it is a monomer.

• Archives of Pharmacal Research
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• v.6 no.1
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• pp.17-23
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• 1983

By tracing albumin stabilizing activity an anti-inflammatory component, continentalic acid was isolated from ether-soluble acidic fraction of Aralia continentalis. Continenetalic acid in a concentration of 0.115mg/3ml gave 50% inhibition for heat denaturation of albumin. The protein stabilizing potency of it was approximately three and eleven times that of phenylbutazone and that of salicylic acid, respectively. The anti-inflammatory actions of it and its methylester were investigated employing carrageenin-induced edema in rat paw. Continentalic acid administered s. c. showed an activity of about three times of hydrocortisone. When administered p. o., it was still active, but its methylester was more active than phenylbutazone, suggesting the poor absorption of it in gastorointestinal tract. Its chemical structure was identified by chemical and spectral studies as (-) pimara 8(14), 15-diene-19-oic acid, which was already isolated from A. dordata, but not reported for its biological activity.

• Korean Journal of Materials Research
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• v.32 no.4
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• pp.186-192
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• 2022

Collagen is one of the most widely used biological materials in medical design. Collagen extracted from marine organisms can be a good biomaterial for tissue engineering applications due to its suitable properties. In this study, collagen is extracted from fish skin of Ctenopharyngodon Idella; then, the freeze drying method is used to design a porous scaffold. The scaffolds are modified with the chemical crosslinker N-(3-Dimethylaminopropyl)-N'-ethyl carbodiimide hydrochloride (EDC) to improve some of the overall properties. The extracted collagen samples are evaluated by various analyzes including cytotoxicity test, SDS-PAGE, FTIR, DSC, SEM, biodegradability and cell culture. The results of the SDS-PAGE study demonstrate well the protein patterns of the extracted collagen. The results show that cross-linking of collagen scaffold increases denaturation temperature and degradation time. The results of cytotoxicity show that the modified scaffolds have no toxicity. The cell adhesion study also shows that epithelial cells adhere well to the scaffold. Therefore, this method of chemical modification of collagen scaffold can improve the physical and biological properties. Overall, the modified collagen scaffold can be a promising candidate for tissue engineering applications.

• Journal of the Korea Organic Resources Recycling Association
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• v.6 no.1
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• pp.43-52
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• 1998

The objective of this study is to investigate the optimum conditions of extracting collagen without chrome ion from the leather waste. The effect of temperature, pH, and the concentration of alkaline solution on the collagen extraction has been studied. The result indicated that the incipient denatured temperature of collagen measured by viscosity was $25^{\circ}C$ and the complete denatured temperature was $31.5^{\circ}C$. The optimum solubilization condition for temperature was between $15^{\circ}C$ and $20^{\circ}C$, pH was 1.5, the concentration of alkaline solution was 3% of sodium hydroxide. The almost complete chrome ion separation was possible around the pH of 1.5. The separation efficiency of chrome ion from tannery waste was more than 99.5%. Extraction efficiency of crude protein from leather waste was about 89.5%. The hydroxyproline and collagen content in the extracted crude protein were 8.53% and 63.62%, respectively.