• Food Science and Biotechnology
• /
• v.15 no.6
• /
• pp.856-859
• /
• 2006

The effects of moisture content on non-fracture dynamic properties and fracture gel quality of Pacific whiting surimi were investigated to determine their relationships. Surimi samples were tested at various moisture contents (75, 78, and 81 %). Torsion test showed that shear stress decreased rapidly and strain values decreased gradually as moisture concentration increased. Dynamic storage modulus (G') also decreased as moisture content increased. A strong positive correlation ($R^2=0.90$ to 0.99) was found between the G' measured at temperatures between 10 and $45^{\circ}C$ and fracture stress values. The results indicate that dynamic rheological measurements could be used as a tool for early gel quality assessment.

• Korean Journal of Food Science and Technology
• /
• v.18 no.5
• /
• pp.364-371
• /
• 1986

High-ester pectin was demethylated by the treatments of HCl alone and a combination of HCl and $NH_4OH$. The low-ester pectin prepared were analyzed for chemical composition and the pectin gels were evaluated for firmness by sag values and strength by puncture stress. Gels made from HCl demethylated sample showed brittle, weak and poor elastic characteristics while the $HCl-NH_4OH$ treated samples generally resulted in a smooth and elastic gels except those samples having very low content of ester group or acid amide group. Statistical analysis showed that significant correlations were found between sag values and ester content or molecular weight, and puncture stress and ester content, acid amide groups or molecular weight. The equations derived for sag, puncture stress and sag/puncture stress from chemical data could be useful for prediction of some of the physical properties of low-ester pectin gel.

• Journal of the Korean Ceramic Society
• /
• v.28 no.12
• /
• pp.943-952
• /
• 1991

Lead zirconate titanate(PZT) powders and thin films were prepared from an alkoxide-based solution by sol-gel method. Gelation of synthesized complex solutions, pyrolysis and crystallization behaviors of the dried powder were studied in accordance with a water content and a catalyst. PZT thin films were formed by spin-casting method on silicon and platinum substrates, and characterized. Ester produced from the reactions was completely removed when drying of the gel was finished. Pyrolysis property of the dried PZT gels were changed in order water content, class of catalyst, and quantity of catalyst. Crystalline Pb phase was transiently formed near 250$^{\circ}C$. Basic catalyst is good additive for a formation of perovskite phase in the films, and acidic catalyst for a densified film structure. By the analysis of RBS, Pb element in the PZT films were diffused into silicon substrate, and the pores, may be produced due to local densification around some grains in the films, make an origin of fault in microstructure when holding time goes to be longer at 700$^{\circ}C$.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.46 no.1
• /
• pp.12-16
• /
• 2001

In order to develop near isogenic lines (NILs) the heterozygous rice plants for alkali digestibility value(ADV) were selected and tested in every generation from $F_5$to $F_9$ of a cross, Seratus malam/Suwon 345. Finally several sets of NILs, which were six low ADV lines and four medium-high ADV lines, were selected among $F_{10}$ lines. No differences of the plant growth characteristics, amylose content and protein content of rice grain were found between low and medium-high ADV lines. Rice flour of low ADV lines showed longer gel length in gel consistency test than medium-high ADV lines, and also showed different gelatinization characteristics measured by rapid visco analyzer compared with medium-high ADV lines. The result of genetic analysis indicated that ADV-NILs developed were differed in a pair of major gene controlling ADV, and low ADV was dominant over medium-high ADV.

• Journal of the Korean Society of Food Culture
• /
• v.29 no.1
• /
• pp.84-90
• /
• 2014

This study investigated the effects of ginkgo nut powder on the antioxidant activity and quality characteristics of mung bean starch gel. Mung bean starch gels were prepared with different amounts of ginkgo nut powder (0, 1, 3, 5, and 7%). The antioxidant activity of ginkgo nut powder and mung bean starch gel was estimated through measuring DPPH free radical scavenging activity and total phenolic acid content. For analyzing quality characteristics several factors were considered: syneresis, pH, color, texture profile analysis, and sensory evaluations. In the results, syneresis in the treated group was higher than the control group. The pH, b values, total phenolic acid content, and DPPH free radical scavenging activity of mung bean starch gels also significantly increased with increasing ginkgo nut powder. In contrast, the L values and a values of mung bean starch gels significantly decreased with increasing ginkgo nut powder. In the texture profile analysis, the mung bean starch gels with 5% and 7% ginkgo nut powder showed significantly lower degrees of hardness, chewiness, and gumminess. On the other hand, cohesiveness was highest in the mung bean starch gels with 5% and 7% ginkgo nut powder. The consumer acceptability score for the mung bean starch gel prepared with 5% and 7% ginkgo nut powder ranked significantly higher than the other groups in flavor and taste. Overall, these results suggest that ginkgo nut powder is a good ingredient for increasing the consumer acceptability and functionality of mung bean starch gel.

• Analytical Science and Technology
• /
• v.37 no.4
• /
• pp.251-260
• /
• 2024

As polymers became very important in our lives, their negative impact on general health and the environment raised a serious issue. Here, enhancing their life term is presented as a compromise solution between the need and harm. In the study, six PVC films, the plain and five filled with improvers, underwent radiation exposure for 300 hours at room temperature to investigate their photodegradation rates. The modified films were embedded with organotin(IV) complex derivatives (Ph₃SnL, Ph₂SnL₂, Bu₃SnL, Bu₂SnL₂, and Me₂SnL₂ (where L is levofloxacin)), and their effectiveness was evaluated. The PVC films were compared before and after exposure to various tests including UV-Vis spectroscopy, gel content analysis, theoretical calculations, and EDX microscopy. Findings indicated that the presence of organotin(IV) complex derivatives, particularly Ph3SnL, notably decreased UV light absorbance and the amount of gel content in PVC sheets in comparison to untreated PVC. Furthermore, EDX analysis showed that the PVC-Ph₃SnL blend exposed to radiation exhibited the highest chlorine content, reaching 30 %. This blend demonstrated superior efficacy in stabilizing the polymeric materials.

• Electrical & Electronic Materials
• /
• v.7 no.6
• /
• pp.496-503
• /
• 1994

In recent years Sol-Gel processing provides an interesting alternative method for the fabrication of ferroelectric thin layers and powder. PZT powder was prepared from an alkoxide-based solution by a Sol-Gel method. Gelation of synthesized complex solutions, microstructure, thermal analysis and crystallization behaviors of the calcined powder were studied in accordance with a water content and a catalyst. Especially gelation and crystallization behavior were analysed with the change of pH. The gelation time decreased as the pH of the mixed solution increased. For PZT powder with 650.deg. C heat treatment, 100% perovskite phase was formed by using either acidic or basic catalyst. By using either acidic or basic catalyst, we were able to get very fine powders of uniform shape with an average particle size of 0.8-1.mu.m.

• Korean Journal of Pharmacognosy
• /
• v.21 no.4
• /
• pp.274-283
• /
• 1990

This study was conducted to further characterize mucilages from Dioscoreae Rhizoma, which have been known to be proteoglycans. We chose the two types of yams, Dioscorea batatas Dec. (club-like) and D. japonica Thunb. (cane-like). Repeated gel filtration of a dialyzed water extract of each fresh yam on Bio-gel P-100 and then Sephadex G-150 columns completely separated the mucilage from protein. Furthermore, gel filtration of a water extract from each yam processed by steaming and drying on the Bio-gel P-100 column gave only one polysaccharide peak without protein. These results revealed that the mucilages of yams were only composed of polysaccharide. Then we assessed some properties of the mucilages under three kinds of criteria: a complex-forming capacity between mucilage and alcian blue, mannose content in the mucilage, and viscosity. The complex-forming capacities of two types of fresh yams were closely similar with each other, but the processing of two types of the fresh yams greatly lowered the complex-forming capacity and viscosity.

• Archives of Pharmacal Research
• /
• v.21 no.5
• /
• pp.514-520
• /
• 1998

Simple and accurate methods to detect the adulteration of commercial aloe gel powder were developed. Crude polysaccharide in aloe gel powder was isolated by precipitating with excess ethyl alcohol and total hexose in isolated polysaccharide was determineded by dubois assay. After hydrolysis of non-dialysable polysaccharides, resultant free sugar was determined by gas chronmatography for sugar recogniton and ash contents was very low while the content of total hexose was very high. And polysaccharides of these products revealed typical dextran pattern, therefore, these products could be identified that adulterated with commercial maltodextrin. The content of maltodextrin in adulterated product was determined by HPLC and TLC analysis which could be adopted as a part of a certification process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.11 no.7
• /
• pp.535-540
• /
• 1998

Thin films of PLZT were prepared on indium tin oxide(ITO) coated glass substrates by sol-gel process and annealed by rapid thermal annealing(RTA) at $750^{\circ}C$ for 5 minutes. The crystal structure of PLZT thin films were investigated for a different Zr mol% content. XRD results showed that the crystallographic structure was transitted from tetragonal to rhombohedral structure as Zr mol% increased. Raman spectroscopy results showed that the bands of spectra became broader as the amount of Zr mol% increased and two crystal phase coexisted at 2/55/45 PLZT film. Raman spectroscopy was useful for crystal structure analysis of PLZT thin films.