• Mycobiology
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• v.40 no.2
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• pp.138-141
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• 2012

We measured physiological functionalities, including antihypertensive angiotensin I-converting enzyme inhibitory activity and immun-stimulating ${\beta}$-glucan content for sixty kinds of Makgeolli that is commercially available from the market. As a result, we selected R-12 commercial raw Makgeolli, with a high content of immuno-stimulating ${\beta}$-glucan, and R-14 commercial raw Makgeolli, exhibiting high antihypertensive activity. Due to the similarities in their overall physicochemical properties and raw materials used for fermentation, we compared the microbial flora in order to investigate the reason for the differences in their functionalities. Nested PCR and denaturing gradient gel electrophoresis for yeasts and bacteria were performed for analysis of microbial diversity of two different kinds of Makgeolli (i.e., R-12, R-14), which showed immuno-stimulating ${\beta}$-glucan content and exhibited a very high level of antihypertensive activity, respectively. Analysis of the 18S rDNA amplicon revealed a major presence of the yeast strain Pichia burtonii in every Makgeolli sample. Analysis of the 16S rDNA amplicon revealed a predominance of lactic acid bacteria, and the most frequent lactic acid bacteria were Lactobacillus ingluviei, L. fermentum, and L. harbinensis, and Lactobacillus sp. Among these, L. harbinensis was detected only in R-12 and L. ingluviei was found only in R-14. Different functionalities from the individual commercially available Makgeolli may be attributed to actions of different microbial flora during fermentation.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1262-1267
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• 1999

Optimum reaction conditions for gel formation of rapeseed, Brassica napus, protein catalyzed by microbial TGase(transglutaminase) were evaluated by measuring breaking strength and deformation of gel. The polymerization of the protein gel was ascertained by SDS-PAGE and content of GL crosslinking$[{\varepsilon}-({\gamma}-glutamyl)lysine]$. In the reaction between rapeseed protein and TGase at $45^{\circ}C$ for 60 min, the breaking strength and deformation of the gel was the maximum at the ratio of 1 : 40 of enzyme to substrate. 10%(w/v) of rapeseed protein concentrate was optimum for gel production. The maximum breaking strength and deformation was shown at $45^{\circ}C$ The breaking strength increased linearly up to 90 min of the reaction time and remained unchanged. The breaking strength and deformation by TGase treatment was pH dependent and pH 7 was optimum for 10% rapeseed protein solution. SDS-PAGE analysis indicated that new band of highmolecular polymers were formed by the enzyme reaction, with disappearing the original bands of rapeseed protein. According to HPLC analysis. the content of GL crosslinking was increased from 0 to $7.14\;{\mu}mol/g$ gel for 90 min of the reaction time.

• Food Science and Preservation
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• v.20 no.3
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• pp.372-378
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• 2013

The objective of this study was to evaluate the quality characteristics of mungbean starch gels that were prepared with different concentrations (0, 0.5, 1.0 and 1.5%) of peach seed powders (PSP), which exhibit antioxidant characteristics. Mungbean starch gel samples were prepared and subjected to quality characteristics such as moisture content, general components, color, texture profile analysis, total polyphenol contents, DPPH radical scavenging activity, and sensory qualities. The L-value and the a-value for color decreased significantly, whereas the b-value increased significantly as the PSP concentration increased (p<0.05). In the texture profile analysis, the mungbean starch gel with 1.5% PSP showed significantly lower degrees of hardness, cohesiveness, springiness, gumminess and brittleness (p<0.05). The total polyphenol content was highest in the 1.5% PSP to which mungbean starch gel was added, which also showed a higher than 70% DPPH radical scavenging activity level in a dose-dependent manner (p<0.05). In the sensory test of the mungbean starch gel, its sensory scores for flavor and taste were highest in the 0.5% PSP to which mungbean starch gel was added.

• Journal of Radiation Industry
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• v.5 no.4
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• pp.377-382
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• 2011

Poly(vinyl alcohol) (PVA) is an interesting material with good biocompatibility, high elasticity and hydrophilic chacrateristics. In this study, crosslinked hydrogels based on PVA, and poly(acrylic acid) (PAAc) were prepared by gamma-ray irradiation. PVA and PAAc powders were dissolved in deionized water, and then irradiated by a gamma-ray with a radiation dose of 50 kGy to make hydrogels. The hydrogels were then annealed in an oven at $120^{\circ}C$ for 10 min, 30 min and 50 min under nitrogen atmosphere. The properties of a hydrogel such as gel fraction, swelling behavior, thermogravimetric analysis (TGA) and adhesive strength as a function of PAAc content and annealing time were investigated. The gel fraction decreases with decreasing PAAc content and increasing annealing time. The thermal behaviors have shown different patterns according to the annealing time. The adhesive strength increases with increasing PAAc content.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.8
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• pp.1285-1291
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• 2007

This research investigated variation in the improvement of the texture of chicken and pork sausages induced by microbial transglutaminase (MTG). The extractability of myofibrillar proteins from these sausages as well as the ${\varepsilon}-({\gamma}-glutamyl)$lysine (G-L)　content were also investigated. MTG treatment of sausages significantly increased the breaking strength values in both meat types, especially for samples incubated at $40^{\circ}C$. However, values of the breaking strength in both meat types were increased differently. The variation in protein extractability of samples incubated at $40^{\circ}C$ for both meat types could lead to some consideration of the mechanisms and the high accessions of myosin heavy chain (MHC) to MTG. SDS-PAGE analysis showed significant changes in the density of the bands after adding MTG, especially for the pork samples in which the bands disappeared totally. The G-L content in the presence of MTG was double that in control samples of both meat types. This study suggests that the binding ability of myofibrillar proteins with MTG is strong. This leads us to suggest that MTG functions positively with different improvements in the texture of chicken and pork products that are treated mechanically, such as sausages. Variability in gel improvement level between chicken and pork sausages was observed; this resulted from the variation in meat proteins in response to MTG, as well as to the original glutamyl and lysine content.

• Proceedings of the Korea Concrete Institute Conference
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• 1993.10a
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• pp.108-112
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• 1993

The term Alkali-Silica Reaction (ASR) is used to describe a reaction between certain siliceous aggregates and hydroxyl ions present in the pore fluid of a concrete. The ASR is affected by the content of alkali, the particle size and the content of reactive aggregate, water-cement ratio, humidity, temperature and so on. In this paper, the fluence of alkali content and kind of added alkali to the ASR was studied. As a result, the more the content of alkali was increased, the more the mortar-bar was expand and the expansion of mortar-bar was showed differently with the added alkali kinds, The reaction products by ASR were observed by SEM(Scanning Electron Microscope) and analyzed by EDXA(Energy Dispersive X-ray Analysis) also and showed a gel composed of alkali(Na+, K+), silica and calcium.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.623-626
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• 2004

[ $Ba_{0.6}Sr_{0.4}TiO_3$ ] (BST) dielectric thin films doped by Cr were prepared using an alkoxide-based sol-gel method on the Pt/Ti/SiO2/Si substrate. Atomic force microscopy and x-ray diffraction analysis showed that increasing the Cr doping ratio causes increased grain size while the surface remains smooth and crack-free. It was also found that compared with undoped films the increase of Cr content in BST improves the dielectric constant and the leakage-current characteristics. The figure of merit reached the maximum value of 72.3 at the 5 mol % of Cr doping. This composition showed the dielectric constant of 426, the loss factor of 0.0065, tenability of 47.7%, and leakage-current density (at the electric field of 100 kV/cm) of $5.31{\times}10^{-8}A/cm^2$. The results show that the Cr-doped BST thin films are prospective candidates for applications in tunable devices.

• Fire Science and Engineering
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• v.22 no.5
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• pp.61-66
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• 2008

In this research, gel compounds containing thermochromic ingredients were manufactured and evaluated to prevent the transition hazards of fire and explosion, which they are one of the methods for detecting abnormal conditions caused by overheating of special materials early. And also, compounds of viscoelastic and brushing types were manufactured as the kind and content of raw materials, and manufacturing process to enlarge the application for overheat-detecting targets. Test methods were conducted as chromism test, viscosity profile, starting time of thermochromism, and FT-IR analysis. Thermochromic gel materials exhibit chromism properties that can detect abnormal conditions effectively, and then they are possible to various applications.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.6
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• pp.513-523
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• 1993

Varietal difference in structural and physical characteristics of rice starch and interrelationships between these starch properties and the physicochemical components of rice grains were investigated for twenty four rice varieties, which were considerably different in amylose content, gelatinization temperature and gel consistency, to obtain the basic informations for diversifying the utility of rice grains and for developing various rice cultivars adaptable to rice food processing. Wave length of maximum absorbance for blue color reaction of starch-I$_2$ complex was 520nm for glutinous rice and 560～600nm for nonglutinous rice. The higher amylose rice showed the longer wave length but there was considerable difference of the wave length among rice materials with similar amylose content. Varietal difference in frequency distribution of debranched starch molecules by isoamylase hydrolysis was largest in amylose fraction, the longest fraction(Fr. I), and was next bigger in intermediate fraction(Int.Fr.) and the ratio between short and long glucose chain of amylopectin fraction(Fr. III /Fr. II). The Fr. III / Fr II ratio was higher in glutinous rice than in nonglutinous one but it was considerably different among nonglutinous rice varieties without any connection with amylose content. The lower alkali digestible rice showed the longer half-hydrolysis time in acid solution. Both soft and hard gel rice varieties in gel consistency test revealed significant varietal difference of 50% acid hydrolysis time. The harder rice in gel consistency exhibited the less frequency of short branch fraction of amylopectin (Fr. III) and the higher amylose content. Twenty four rice varieties were cleary classified by upper two principal components contracted from structural or physical traits of rice starch and some physicochemical properties of rice grain by principal component analysis. The 1st and 2nd principal components can be characterized to components related with amylose and amylopectin structure respectively.

• Food Science of Animal Resources
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• v.38 no.1
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• pp.14-25
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• 2018

Chemical compositions, trypsin inhibitory activity, and gelling properties of albumen from duck egg during salting of 30 days were studied. As the salting time increased, moisture content decreased, the salt content and surface hydrophobicity increased (p<0.05). Trypsin inhibitory activity and specific activity were continuously decreased throughout the salting time of 30 days (p<0.05). This coincided with the decrease in band intensity of inhibitor with molecular weight of 44 kDa as examined by inhibitory activity staining. Nevertheless, no differences in protein patterns were observed in albumen during the salting of 30 days. Based on texture profile analysis, hardness, springiness, gumminess, chewiness, and resilience of albumen gel decreased with increasing salting time. Conversely, salted albumen gels exhibited higher cohesiveness and adhesiveness, compared to those of fresh albumen. Scanning electron microscopic study revealed that gel of salted albumen showed the larger voids and less compactness. In general, salting lowered trypsin inhibitory activity and gelling property of albumen from duck egg to some extent. Nevertheless, the salted albumen with the remaining inhibitor could be an alternative additive for surimi or other meat products to prevent proteolysis.