• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.4
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• pp.476-483
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• 1993

The moisture sorption characteristics of commercially produced seasoned dried layer (Porphyra yezoensis) was investigated by measuring sorption isotherms. The laver and two kinds of desiccant (silica gel and zeolite based desiccant) were used at temperatures of 30, 40 and 5$0^{\circ}C$ respectively using the method of saturated salt solution. Time to reach the equilibrium moisture content at each temperature and relative humidity varied from 4~6hr for the laver to 20~25hr for the silica gel and 43~46hr for the zeolite. The isotherms of the layer and the desiccants showed the characteristic sigmoidal curve. Monomolecular layer moisture content calculated using the BET equation at each temperature (30, 40, 5$0^{\circ}C$) were 5.26, 4.46 and 3.49% (d.b.) for the laver, 17.32, 15.24 and 12.89% (d.b.) for the silica gel, 16.89, 14.92 and 14.44% (d.b.) for the zeolite, respectively, Both desiccants showed higher values of the monomolecular layer moisture content than the laver. In all cases, the monomolerular layer moisture contents were decreased linearly as the temperature was increased in the experimental ranges. Water vapor transmission rate of the packaged material was also influenced by the temperature, which could be explained by the Arrhenius equation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.1
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• pp.18-24
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• 2011

This study investigated the physicochemical and enzymatic properties of unmarketable cultured bastard halibut (Paralichthys olivaceus) of different weights as a potential source of surimi and surimi gel. The proximate composition of cultured bastard halibut of different weights did not differ significantly at P<0.05 (light weight (LBH) 400~500 g, medium weight (MBH) 600~800 g, and heavy weight (HBH) > 1,000 g). Compared to Alaska pollock muscle, the bastard halibut muscle had a 4% higher crude protein content and 6% lower moisture content. The collagen content of LBH bastard halibut muscle was 1.58 g/100 g, which was lower than or no different from bastard halibut weighing different amounts. Regardless of fish weight or pH, the enzymatic activities of crude fish extracts ranged from 0.34~0.48 U/mg for casein and hemoglobin, 11.0~12.7 U/mg for LeuPNA, 5.4~6.1 U/mg for ArgPNA, 2.3~2.9 U/mg for SAAPFNA, and 0.1~0.2 U/mg for BAPNA. The yield of surimi gel from LBH was 24.4%, which was similar to that from MBH and lower than that from HBH. The surimi gel from LBH was similar to that from HBH, while weaker than that from MBH. The surimi gel from LBH gel was stronger than grade SA gel from commercial Alaska pollock.

• Food Science of Animal Resources
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• v.26 no.1
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• pp.20-27
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• 2006

Effects of addition level of sodium chloride (NaCl) on gel properties of surimi-like pork (SLP) were investigated. Porcine semimembranosus muscle was used to manufacture SIP contained 1, 2, 3 and 4% NaCl to measure moisture content, pH, color, gel strength, micro-structure and sensory evaluation. The pH and moisture content of SLP were decreased as increasing of NaCl level. However, the gel strength of SLP was increased with increasing of NaCl level. Values of yellowness and chroma were lower in SLP of 2% and 3% NaCl compared with those of 1% and 4% NaCl. Amorphus protein particles size in micro-structure of SLP was decreased and coagulated as increasing level of NaCl. SLP of 1% NaCl had a structure formed by aggregates of densely packed globular proteins and arranged in clusters, whereas a well-structured matrix with a highly interconnected network of strand was observed in SLP of 4% NaCl. Result suggested that the increasing gel strength with NaCl level might be due to lower moisture content and denser micro-structure of gel.

• Applied Chemistry for Engineering
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• v.20 no.6
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• pp.685-691
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• 2009

Dispersions of fumed silica are made in 6 kinds of mono-solvents and mixed solvents which have hydroxyl group, non hydroxyl group, different polarity, and different molecular size. The viscosity and rheology behaviors of the each dispersion are investigated according to the viewpoint of solvent characteristic. The silica dispersion in polar solvent with hydroxyl group is stable and low viscous sol. The silica dispersion in non-polar solvent with non-hydroxyl group is high viscous gel. When the solvent with hydroxyl group is added to the silica dispersions with non-polar solvents, they show the reduction of viscosity with solvent content. They have minimum critical content which shows no viscosity change. The minimum critical solvent content is decreased according to the polarity of solvents with no hydroxyl group. The solvation layer which is formed on the silica surface through hydrogen bonding between hydroxyl-containing solvent and the silanol group of silica surface is the reason of stable and low viscous sol. In case of non-polar solvent, silanol on adjacent silica particles interacted directly by hydrogen bonding show high viscous and flocculated gel.

• Fisheries and Aquatic Sciences
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• v.26 no.2
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• pp.145-157
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• 2023

Surimi has been traditionally used as the main ingredient in gelling foods, such as imitation crab sticks. However, it can also be used to manufacture snacks without gelling properties. To assess the properties of surimi as a snack ingredient, we prepared fried fish snacks with different surimi grades of Alaska pollack (AP) and threadfin bream (TB) and evaluated their quality characteristics. AP had significantly higher protein and gel strength values than TB did. Regarding color, TB showed significantly lower lightness (L) values and higher redness (a) and yellowness (b) values than AP did, consistent with the appearance of a brown color. TB had significantly lower hardness values, higher thickness expansion, and higher oil content than AP did. Hardness was found to be positively correlated with gel strength and negatively correlated with oil content. In the micro-structure images, more blistering was formed in TB, indicating higher expansion and crispiness. In the sensory evaluation, TB showed higher overall sensory acceptance than AP did, which is the result of its high color content, crispiness, taste, and aroma. Principal component analysis of the electronic nose and tongue revealed that the samples were clearly separated. In particular, TB had more aromatic components than AP in the electronic tongue. Our findings indicate that gel strength, which determines the quality properties of surimi, does not need to be considered in snack manufacturing. In fact, surimi with low gel strength is a more suitable ingredient for snack manufacturing.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.2
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• pp.157-163
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• 1985

Various cell wall polysaccharides and related enzyme activities in hot pepper fruit were determined at different stages of maturity. The uronic acid content of cell walls decreased between immature green and turning stage fruit and then increased by red ripe stage. In contrast, cellulose content of cell walls changed only a little during ripening. Total neutal sugar content of cell wall material decreased 50% and galactose content of the walls decreased about 80% by the turning stage. Polygalacturonase and ${\beta}-galactosidase$ activities, as well as total hemicellulose from isolated cell walls of ripening hot pepper fruit were studied using gel filtration chromatography. Polygalacturonase activity was not detectable but 5 isozymes of ${\beta}-galactosidase$ were resolved. The activities of the enzymes were relatively high and gel filtration showed that they differed in molecular weight. Hemicellulose content decreased during ripening and softening. The molecular weight profiles shifted from high molecular weight to low molecular weight polymers during ripening. The changes in cell walls that may be associated with fruit softening involve the alteration of hemicellulose prior to the degradation of wall-bound uronic acid. It is suggested that the decrease in cell wall galactose involved changes in turnover of new cell wall components.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.422-427
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• 2012

A giant squid has not been utilized in the manufacture of the surimi-based product because of its strong fishy smell and weak gel forming ability. In this study, Amorphophallus konjac flour (AKF) was used to improve the quality of giant squid surimi-based products. The response trace plots showed that the gel texture and water retention ability (WRA) of surimi gel increased as the contents of AKF and surimi increased, whereas the water content decreased. Meanwhile, the whiteness of surimi gel increased as the contents of water and surimi increased, and AKF content decreased. Based on a sensory evaluation, giant squid surimi-products with AKF was inferior in color and taste compared to commercial surimi-based products, This inferiority could be improved by the addition of seasoning ingredients such as sweeteners. AKF successfully removed the fishy smell and improved the surimi gel properties. Therefore, AKF could be used as a food ingredient in surimi-based products.

• Korean journal of food and cookery science
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• v.13 no.5
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• pp.627-634
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• 1997

The purpose of this study is to examine the effect of protein content on the physicochemical properties, gelatinized characteristics and textural properties of cowpea precipitate gels stored for 24 hrs and 48 hrs at room temperature. The contents of protein, total fat, and ash ranged from 0.35%∼1.38%, 0.54%∼0.64%, and 0.21%∼0.25%, respectively. The X-ray diffraction patterns were all Ca-type, showing no difference according to the protein content. Protein content did not make any difference in the blue values of cowpea precipitate. The blue value of cowpea precipitate powder as protein content was decreased. The water-binding capacity of cowpea precipitate powder increased as the protein content increased. Swelling power and solubility of cowpea precipitate powder increased as protein content decreased. The transmittance of cowpea precipitate powder was not different according to the protein content. The initial pasting temperature of cowpea precipitate powder by differential scanning calorimetry (DSC) and rapid visco analyser (RVA) showed no differences according to the protein content. In sensory evaluation, the color and clarity of cowpea precipitate gels stored for 24 hrs and 48 hrs at room temperature as the protein content increased, and the hardness, cohesiveness, springiness, acceptability were greater when the gels were stored for 48 hrs. Instrumental analyses using a rheometer showed that the hardness, gumminess, and chewiness of cowpea precipitate gels stored for 24 hrs, which was increased as the high protein content increased. For the gels stored for 48 hrs, all other factors are significantly different except cohesiveness as the protein content increased.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.608-612
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• 2012

We investigated the cycling behavior of $Li_4Ti_5O_{12}$ electrode in a cross-linked gel polymer electrolyte based on non-flammable ionic liquid consisting of 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide and vinylene carbonate. The $Li_4Ti_5O_{12}$ electrodes in ionic liquid-based gel polymer electrolytes exhibited reversible cycling behavior with good capacity retention. Cycling data and electrochemical impedance spectroscopy analyses revealed that the optimum content of the cross-linking agent necessary to ensure both acceptable initial discharge capacity and good capacity retention was about 8 wt %.

• Journal of the Korean Ceramic Society
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• v.29 no.5
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• pp.335-340
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• 1992

Undoped PbTiO3 ceramics was successfully prepared by using sol-gel process, which had not been fabricated due to its microcracks created by anisotropic stress during phase transition from cubic to tetragonal phase. Fabrication of undoped PbTiO3 ceramics via sol-gel processing was very much affected by the PbO content of the samples as well as PbO vapor from sintering atmosphere. Excess PbO was found to promote rapid grain growth in PbTiO3 ceramics. After sintering at 1100$^{\circ}C$ average grain size of PbTiO3 ceramics with excess PbO was about 8 times greater than that of stoichiometric composition, which may be due to PbO liquid phase from excess PbO.