• KSBB Journal
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• v.23 no.2
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• pp.169-176
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• 2008

The concentration of fresh gel from Aloe vera L. by using ulfrafiltration (UF) process was investigated and analyzed. The two membranes (organic and ceramic) with different molecular weight cut-off (MWCO) and modules (flat sheet and tubular) was used. Under optimum operation conditions, ceramic (zirconium dioxide) tubular membrane with MWCO of 50 kDa resulted in higher flux, less fouling, more turbid, higher total solid, higher polysaccharide and less aloin content. Optimum operation conditions were transmembrane pressure of 1.0 bar, feed velocity of 240 L/hr and temperature of $23^{\circ}C$. Volume concentration factor of aloe gel was 3.13 at permeate flux of $51.1\;L/m^2{\cdot}hr$ after processing time of 1.66 hr. Aloin in fresh aloe gel by UF process was effectively removed as permeate and bioactive polysaccharide content was 2.1 times higher than that of fresh aloe gel. These results allowed a very good level of concentration degree and polysaccharide content. Thus, ultrafiltration process of this study was suitable for the concentration of fresh aloe gel though the aloe concentrate showed both the viscosity decrease and partially separation of liquid layer during storage at $4^{\circ}C$.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.5
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• pp.555-566
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• 2023

In this study, a composite phase change material (CPCM) produced using the SOL-GEL technique was developed as a thermal energy storage medium for low-temperature applications. Tetradecane and activated carbon (AC) were used as the core and supporting materials, respectively. The tetradecane phase change material (PCM) was impregnated into the porous structure of AC using the vacuum impregnation method, and a thin layer of silica gel was coated on the prepared composite using the SOL-GEL process, where tetraethyl orthosilicate (TEOS) was used as the silica source. The thermal performance of the CPCM was analysed using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). DSC results showed that the pure tetradecane PCM had melting and freezing temperatures of 6.4℃ and 1.3℃ and corresponding enthalpies 226 J/g and 223.8 J/g, respectively. The CPCM exhibited enthalpy of 32.98 J/g and 27.7 J/g during the melting and freezing processes at 7.1℃ and 2.4℃, respectively. TGA test results revealed that the AC is thermally stable up to 500℃, which is much higher than the decomposition temperature of the pure tetradecane, which is around 120℃. Moreover, in the case of AC-PCM and CPCM thermal degradation started at 80℃ and 100℃, respectively. The chemical stability of the CPCM was studied using Fourier-transform infrared (FT-IR) spectroscopy, and the results confirmed that the developed composite is chemically stable. Finally, the surface morphology of the AC and CPCM was analysed using scanning electron microscopy (SEM), which confirmed the presence of a thin layer of silica gel on the AC surface after the SOL-GEL process.

• Korean journal of food and cookery science
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• v.19 no.4
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• pp.511-520
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• 2003

This study was carried out to determine the effects of various contents of kiwifruit contents on the quality characteristics of mixed polysaccharide gels made from $\kappa$-carrageenan and locust bean gum. The color value, gelling temperature, melting temperature, break down rate, syneresis, rupture properties, TPA properties and sensory properties of mixed polysaccharide gels with various contents of kiwifruit contents were measured. As the kiwifruit contents was increased, the lightness (L), yellowness (b) and greenness (-a) of the mixed polysaccharide gels increased. There were no differences in the color values of gels during storage. As the kiwifruit content was increased, the gelling and melting temperatures of the mixed polysaccharide gels also increased. The mixed polysaccharide gels with high kiwifruit contents were difficult to melt, and it seemed that the addition of kiwifruit to the mixed polysaccharide gels could improve the thennal stability of the gels. The syneresis of the gel increased with increasing storage time, whereas the addition of kiwifruit to the gel resulted in suppression of syneresis. With regard to the rupture properties, stress, energy and strain, they were all decreased with increasing kiwifruit contents. The TPA properties, adhesiveness, hardness and chewiness increased and cohesiveness decreased with increasing kiwifruit contents. The results showed that the gel became tough and adhesive, and could be easily broken under small deformation, with increasing kiwifruit contents. The sensory evaluation showed that the green color, aroma, sweetness and sourness increased with increasing kiwifruit contents. The texture, adhesiveness, springiness and cohesiveness decreased, and brittleness and hardness increased, with increasing kiwifruit contents. The overall acceptability of the gel with 30% kiwifruit content was the highest. Thus, mixed polysaccharide gels made from kiwifruits could be useful, as the addition of kiwifruit to a mixed polysaccharide gel results in a good aroma, taste and stability, despite a lowering of the textural properties.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.1
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• pp.115-122
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• 2014

This study investigated on the effects of adding mechanically deboned chicken meat (MDCM) hydrolysates on the quality properties of imitation fish paste (IFP) during storage. IFP was prepared from Alaska Pollack, spent laying hens surimi and protein hydrolysates which were enzymatically extracted from MDCM. The study was designed as a $3{\times}4$ factorial design with three MDCM hydrolysate content groups (0%, 0.4%, and 0.8%) and four storage times (0, 2, 4, and 6 weeks). Addition of MDCM hydrolysates increased crude fat content but lowered water content (p<0.05). The breaking force of IFP, an indicator of gel formation, increased in treated groups compared to control (p<0.05). Angiotensin I-converting enzyme (ACE) activity was inhibited and free radical scavenging activity increased with increasing MDCM hydrolysate content (p<0.05). In conclusion, the addition of MDCM to IFP improves gel characteristics. Additionally, protein hydrolysates from MDCM serve as a potential source of ACE inhibiting peptides.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.2
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• pp.93-98
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• 1983

Apple sugaring and apple nectar gel were treated with coating agent, and then the rate of weight loss, browning reaction and fungi growth on the storage conditions of those were investigated. The results obtained were summarized as follows; The composition of sucrose, D-sorbitol, corn syrup, gelatin, arabia gum, citric acid, sodium citrate and sodium ascorbate as a nontoxic coating agent was desirable to repress weight loss browning reaction and fungi growth of apple sugaring and apple nectar gel. It was the most effective method that apple sugaring was treated with the coating agent and refrigerated with double packaging. The contraction by weight loss, browning reaction and fungi growth of apple nectar gel treated with the coating agent and freezed with double packaging were repressed.

• Korean Journal of Poultry Science
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• v.16 no.4
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• pp.233-238
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• 1989

This experiment was carried out to establish effective egg storage technology by studying the physico-chemical properties of albumen and yolk during the cold storage. The results obtained were summarized as follows：1. Egg Yolk was gelated and whipping quality and whipping stability of albumen was decreased by the freezing storage. 2. NaCl was the best anti-freezer to prevent the gelation of egg yolk among various anti-freezer (NaCl, glucose, sucrose, amides). 3. Viscosity of egg yolk and albumen was increased and color was changed but changes of colorin albumen was slight during the storage at $-5^{\circ}C$ and $-20^{\circ}C$. 4. To store the 5% NaC1 added egg yolk -at $-5^{\circ}C$ was the best way to prevent the gelation of egg yolk and save the energy. 5. Emulsion capacity of egg yolk was decreased by the cold storage with the addition of NaCl.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.2
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• pp.161-166
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• 2001

The storage proteins of the mulberry longicorn beetle, Apriona germari Hope, were purified and characterized. Three kinds of storage protein (SP1, SP2 and Sp3) were purified from the last instar larval hemolymph of A. germari by the FPLC techniques, anion exchange chromatography and gel permeation chromatography. The SP1, SP2 and SP3 have a native molecular weight of 480, 440 and 420 kDa, respectively. In the SDS-polyacrylamide gel electrophoresis analysis, these storage proteins are composed of a single protein subunit with molecular weight of 90, 85 and 80 kDa, respectively. This result showed that the storage proteins are hexameric protein. The SP1 and SP2 were stained with Schiffs reagent, but SP3 was not stained. It can be assumed that SP1 and SP2 are glycoprotein. Western blot analyses using the each of polyclonal antiserum against purified SP1, SP2 and SP3 showed that the three antibodies reacted with the each of SP bands, respectively. Also, antibodies against SP1 and SP3 cross-reacted with the SP3 and SP1, respectively. However, SP2 was not cross-reacted with these two antibodies. Also, antiserum against SP2 did not cross-reacted with the SP1 and SP3.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.6
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• pp.816-821
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• 2007

The physical properties and sensory characteristics of acorn starch gels (Dotori Mook), which were gamma-irradiated up to 3 kGy, were evaluated during storage at $4^{\circ}C$. Even at the dose of 2 kGy, the gamma irradiation decreased total bacteria in the Dotori Mook during 5 days of storage, to lower than the detection limit $(10^2CFU/g)$. The hardness of the control sample increased according to the days of storage, while the gamma irradiated samples had decreased hardness according to the irradiation dose. The sample irradiated at 3 kGy maintained the same hardness as the control at day 0 of storage. Irradiation did not affect the Hunter color values. No significant differences were observed in off-odor, color, springiness, and overall acceptability (p<0.05) at the irradiation dose of 2 kGy. It can be concluded that the irradiation of Dotori Mook, up to 2 kGy, does not affect the quality of the Mook during storage, with regard to texture and sensory characteristics. Moreover, the irradiated Mook was superior in maintaining hardness and had prolonged shelf-life time by sanitation.

• The Korean Journal of Rheology
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• v.9 no.1
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• pp.27-32
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• 1997

GM 은 Amorphopallus Konjac K. Koch의 tuber의 주성분으로알카리 응고제를 첨가 함에 따라 열적으로 안정한 gel을 형성한다. GM에 침전제로 메탄올을 사용하여 4단계로 분 별하였고 각 분별물(F.1, F.2, F.3, F.4)들은 Mark-Houwink 식을 이용하여 분자량을 산출하 였다. Ubbelohde를 이용한 농도에 따른 환산점도로부터 고유 점성도값을 구한 결과 분자량 이 높은 분별물이 분자량이 낮은 분별물에 비하여 직선으로부터 벗어남을 알수 있었다. 또 한 고유점성도는 분자량이 증가할수록 증가하였고, 분자량 분포 범위가 broad하게 나타났다. GM용액의 frequency와 shear rate에 따른 viscosity를 측정한결과 낮은 frequency에서는 loss modulus(G＂)가 storage modulus(G＂)보다 큰 값을 가졌으나 높은 frequency에서는 G ＇가 G＂보다 크게 나타났다. 이 현상은 분자들의 얽힘에 관한 시간 의존도로써 설명할수 있다. 즉높은 frequency에서는 탄소 사슬간의 얽힘들이 진동기간내에 분자결합이 끊어지기 에 충분한 시간을 갖지 못하여 그 조직이 교차 결합을 한 gel처럼 행동하게 되고 한편 낮은 frequency에서는 탄소사슬들의 얽힘이 풀리고 흐르기에 충분한 시간을 갖게된다. Shear rate에 따른 viscosity값과 frequency에 대한 dynamic viscosity값은 거의 유사한 변화를 나 타내었다.

• Journal of the Korean Ceramic Society
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• v.34 no.10
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• pp.1060-1066
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• 1997

In this paper, the effects of La addition of PLZT thin film prepared by sol-gel method on the capacitor characteristics are investigated for gigabit generation DRAM applications. The addition of La on the PLZT capacitor results in a trade-off between charge storage density(Qc') and leakage current density(Jl). As La content increases, Qc' and permeability(εr) at 0V are reduced while Jl is significantly decreased. It is demonstrated that 5% La doping of PZT can substantially reduce Jl and also improve resistance to fatigue while incurring only minimal degradation of Qc'. Very low leakage current density (5×10-7 A/㎠ even at 125℃) and high charge storage density (100fC/㎛2) under VDD/2=1V conditions are achieved using 5% La doped PZT thin films for gigabit DRAM capacitor dielectrics. In addition, the fatigue and TDDB measurements indicate good reliability of the PLZT capacitors.