• Korean Journal of Food Science and Technology
• /
• v.30 no.6
• /
• pp.1350-1356
• /
• 1998

An attempt was made to investigate the effects of additives (3%) such as egg white, soybean protein, corn starch and Read Amity-N (green bean starch 85%+psyllium husk 10%) on the thermal properties and gel structures of mackerel surimi and to examine the quality of surimi by using differential scanning calorimetry (DSC), rheometry and scanning electron microscopy (SEM). The thermal transition temperatures of mackerel surimi protein were 40, 52, 67 and $79^{\circ}C$ after those temperatures were changed to 37, 46, 57 and $76^{\circ}C$ after adding salt (3% NaCl). Addition of Read Amity-N and corn starch to surimi showed new peak at the temperature of $90^{\circ}C\;and\;92^{\circ}C$, respectively. The enhancing effects of gel strengths of mackerel surimi cooked gels prepared from adding four kinds of additives, respectively, were egg white > soybean protein > Read Amity-N > corn starch in order. Scanning electron microscopy showed a difference in fine structures between the cooked gels which were prepared with and without additives. Dispersion profiles of protein were more thick in cooked gel prepared with additive than in cooked gel prepared without additive.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.31 no.3
• /
• pp.438-444
• /
• 2002

Interactions between meat proteins and hydrocolloids in a model system may play an important role for the improvement of textural properties in low-fat sausage mixtures. The objective of this study was to determine gel properties as affected by the type and level of hydrocolloid, various pH values of meat protein-hydrocolloid mixture before cooking, and internal cooking temperatures. The desirable heat-induced gels (HIGs) were formed at least pH values above 6.0. The addition of konjac flour (KF), kappa-carrageenan (CN) and locust bean gum (LBG) to extracted salt soluble proteins (2%) improved the gel strength with increased levels (0.5∼1.5%) and HIGs containing CN had the highest (p<0.05) gel strength. The increase of cooking temperature increased gel strength, depending on pH and type of hydrocolloid. However, the minimun internal cooking temperature to make viscoelastic HIGs was 70$^{\circ}C$. These results indicated that desirable HIGs were manufactured with each hydrocolloid concentration of 1% and minimum cooking temperature of 70$^{\circ}C$ with pH values higher than 6.0.

• Journal of Embryo Transfer
• /
• v.28 no.4
• /
• pp.355-360
• /
• 2013

Precise, rapid and simple methods for species identification in animals are among the most important techniques in the livestock industry and research fields including meat classification. In this study, polymerase chain reaction (PCR) based molecular identification using inter species polymorphisms were examined by PCR-restriction fragment length polymorphism (RFLP) analysis for mitochondrial DNA (mtDNA) cytochrome b (CYTB) gene sequences among four mammalian livestock animals (cattle, horse, goat and pig). The results from PCR-RFLP analysis using the AluI restriction enzyme were also provided for the species-specific band patterns among CYTB gene sequences in these four species. The AluI-digestion for CYTB genes provided interesting migration patterns differentially displayed according to each species. Cattle and horse had one AluI-recognition site at different nucleotide positions and their AluI-digested fragments showed different band patterns on the gels. Pig had two AluI-recognition sites within the amplified CYTB sequences and produced three bands on the gels. Goat had no AluI-recognition site and was located at the same position as the uncut PCR product. The results showed the species-specific band patterns on a single gel among the four livestock animal species by AluI-RFLP. In addition, the results from blind tests for the meat samples collected from providers without any records showed the identical information on the species recorded by observing their phenotypes before slaughter. The application of this PCR-RFLP method can be useful and provide rapid, simple, and clear information regarding species identification for various tissue samples originating from tested livestock species.

• Korean Journal of Food Science and Technology
• /
• v.32 no.6
• /
• pp.1291-1297
• /
• 2000

Particle size distribution, pasting properties by Rapid Visco Analyser, and textural properties of acorn, mungbean and buckwheat starches, which are the basic raw materials for mook, are compared. The major particle size of mungbean starch was $10{\sim}30$ micron, whereas acorn and buckwheat starches were $5{\sim}20$ micron. At the same starch concentration, mungbean starch had the highest peak viscosity, breakdown and setback. Acorn starch showed the lowest peak viscosity and breakdown. The peak viscosity of buckwheat starch was close to that of mungbean, however the trough and final viscosity were comparable to those of acorn starch. At the same peak viscosity, mungbean starch showed the lowest trough and final viscosity and the highest breakdown and setback. Acorn starch was differentiated from buckwheat starch in that the former had the higher value of setback. The textural properties of mungbean starch gel were significantly different from others. The texture of gels from acorn and buckwheat starches revealed that only the hardness and gumminess were different each other. The hardness of starch gels were negatively correlated with trough and final viscosity, and positively correlated with setback.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.26 no.3
• /
• pp.230-234
• /
• 1993

In order to obtain the fundamental factors influencing on gelation of Alaska pollack meat paste during processing, the states of water in gel from meat paste were studied using differential scanning calorimetry(DSC) and thermogravimetry(TG). In the differential scanning calorimetry, the calorimetric curves of gels were characterized by single peak through the evaporation of water. Each curve was divided into two divisions below and above $105^{\circ}C(Q_1\;and\;Q_2)$, and a quotient, $R_{105}[={Q_2/(Q_1+Q_2)}+100]$ was adopted to represent the amount of immobilized water in the total water of gels. There was a good correlationships between gel strength values and those quotients($R_{105}$), the correlation coefficient was 0.93. Three types of water(A, B, C) differentiated by evaporating velocity were regarded as free water and it was abundant among the three types of water. The type C water was regarded as the water in so-called mono-molecular layer region. The ratio of the content C versus total water content showed good correlationships with the gel strength and its correlation coefficient was 0.99.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.22 no.2
• /
• pp.83-93
• /
• 2011

Biochemical and enzymatic characterization for extracellular protease isolated from Cordyceps militaris cultivated on rice bran medium was investigated. C militaris produced proteolytic enzymes from 10 days after inoculation, maximum enzyme production was found at 25 days. The optimum temperature and pH of proteases production was at $25^{\circ}C$ and pH 7.0, respectively. The protease activity was observed in the four peaks (Pro-I, Pro-II, Pro-III, and Pro-IV) separated through Sephadex G-100 column chromatography. The separated protease was optimally active at $25^{\circ}C$. Optimum pH of the protease was between 7 and 8. Enzyme was also stable over at $30-80^{\circ}C$. The enzyme was highly stable in a pH range of 4-9. Protease activity was found to be slightly decreased by the addition of $Mg^{2+}$, $Mn^{2+}$, $Zn^{2+}$, $Fe^{2+}$ and $Cu^{2+}$, whereas inhibited by the addition of $Ca^{2+}$ and $Co^{2+}$ Protease activity was inhibited by protease inhibitor PMSF. On the other hand, the partially purified protease was investigated on proteolytic protease activity by zymogram gel electrophoresis using three substances (casein, gelatin and fibrin). Four active bands (F-I, FII, F-III, and F-IV) of fibrin degradation were revealed on fibrin zymogram gels. Both of F-II and FIII showed caseinolytic, fibrinolytic and gelatinolytic activities in three gels. Thermostability, pH stability, and pH-thermostability of the enzyme determined the residual fibrinolytic activity also displayed on fibrin zymogram gel. The only one enzyme (F-II) displayed over a broad range of temperature at $30-90^{\circ}C$. The FII displayed fibrinolytic activity in the pH range 3-5, but was inactivated in the range of pH 6-11. The F-I and F-III showed enzyme activity in the pH range of 6-11. In the pH-thermostability, the F-II only kept fibrinolytic activity after heating at $100^{\circ}C$ for 10, 20 and 30 min at pH 3 and pH 7, respectively. On the other hand, the F-II was retained activity until heating for 10 min under pH 11 condition. By using fibrin zymogram gel electrophoresis, extracellular fibrinolytic enzyme F-II from C. militaris showed unusual thermostable under acid and neutral conditions.

• Composites Research
• /
• v.35 no.2
• /
• pp.98-105
• /
• 2022

In this study, polyvinyl alcohol (PVA)/graphene oxide (GO)/iron oxide (Fe₃O₄) magnetic microgels were prepared using a microfluidic approach and the dye adsorption capacity of the microgels was confirmed. The adsorption capacity (q_e) of the gels was evaluated by varying the dye concentration, pH, and contact time with the microgels. The dyes used in this work were methylene blue (MB), crystal violet (CV), and malachite green (MG), and microgels showed the highest adsorption capacity (191.1 mg/g) in methylene blue. The microgels exhibited the highest adsorption capacity in the dye aqueous solution at pH 10 due to the presence of atomic nitrogen ions (N⁺) on the dye molecules. The adsorption isotherm studies revealed that the Langmuir isotherm is the best fit isotherm model for the dye adsorption on the microgels, indicative of monolayer adsorption. The kinetic analysis exhibited that the pseudo-second order model fits better than the pseudo-first order model, confirming that the adsorption process is chemisorption. In addition, the magnetic microgels showed good reusability and recovery efficiency. It was confirmed that the adsorption capacity of the gels maintains more than 70% of the initial capacity after 5 times of cycle experiments.

• Journal of Microbiology
• /
• v.35 no.4
• /
• pp.341-346
• /
• 1997

In order to express recombinant porcine TGF-${\beta}1$ protein in a baculovirus expression system the entire TGF-${\beta}1$gene containing extra amino acids at the N terminus was cloned into pFBa and pFBb of the Bac-To-$Bac^{TM}$ baculovirus expression system. One of the clones contained 106 extra amino acids and was designated pFBa-106 TGF-${\beta}1$, and the other had 28 extra amino acids and was designated pFBb-28 TGF-${\beta}1$. The orientation of the gene was identified with restriction enzyme mapping and PCR with internal TGF-${\beta}1$ primers. Sf-9 cells were infected at a m.o.i. of 10 by the recombinant viruses generated from the two expected sizes of 55 kD and 46.4kD. these precursor forms of TGF-${\beta}1$ with a polyclonal antibody against human TGF-${\beta}1$. No mature form of TGF-${\beta}1$ protein was detected on SDS gels and an immunoblot indicated that TGF-${\beta}1$ precursor is not properlu processed in insect cells.

• KIEE International Transactions on Electrophysics and Applications
• /
• v.4C no.4
• /
• pp.176-180
• /
• 2004

This paper presents the fabrication and test of a micro cell exciter actuated by an electromagnetic force for the study on the chondrogenic differentiation of rabbit mesenchymal stem cells (MSCs). The micro cell exciter is designed to apply compressive loading to the alginate gel mixed with the MSCs. The magnetic cell exciter consists of an actuator component and a cartridge-type chamber component. An actuator is composed of a permanent magnet, a core and a coil. The chamber has seven PMMA wells and a cell culture Petri dish. Two types of alginate gels were stimulated by the cell exciters for 10 minutes every 12 hours for 7 days. In order to determine the expression of these matrix components during differentiation, RT-PCR analysis was performed. Collagen type II was expressed in the MSCs subjected to the compressive stimulation.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.8
• /
• pp.1292-1296
• /
• 2007

To investigate the gel properties of surimi-like materials (SLM) made from pig heart (PH), psoas major muscle (PM) and semimembranosus muscle (SM) of pigs, the three muscles were diced, chopped and washed with 25 mM sodium phosphate buffer (pH 7.0) to extract myofibrillar protein. SLM from SM had significantly (p<0.05) higher moisture content and lower crude protein content compared with PH and PM samples. The cooked SLM from PH was darker than that from PM and SM. Gel from PH had significantly (p<0.05) lower L* and hue values, and higher b* and chroma values compared to gels from PM and SM. The cooked SLM from PH had poor water-holding capacity (WHC) resulting in higher cooking loss. SDS-PAGE showed that the bands of myosin and tropomyosin/troponin had reduced staining intensity in the PH sample, and some unidentified bands that were not in PM and SM samples were observed in PH samples.