• Korean journal of food and cookery science
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• v.24 no.1
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• pp.31-38
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• 2008

Sulgidduk samples made with additions of 1, 2, 3, 4, and 5% Ulmus cortex powder, and a control, were examined for quality characteristics such as moisture content, color, gelatinization properties, textural characteristics, and consumer acceptance, in order to determine the optimal ratio of Ulmus cortex powder in the formulation. The moisture contents among the samples were not significantly different, ranging from 40.57 to 42.37%, and increased as the Ulmus cortex powder content increased. For the color values, lightness decreased and yellowness and redness increased with increasing Ulmus cortex powder content. With regard to the gelatinization properties, peak viscosity (P), trough viscosity (T), final viscosity (F), breakdown, and consistency increased with increasing amounts of Ulmus cortex powder. Pasting temperature, time to peak viscosity, and setback presented decreasing tendencies with the additions of Ulmus cortex powder. For the textural characteristics, increasing Ulmus cortex powder content presented decreases in hardness, springiness, and chewiness however, adhesiveness, cohesiveness, and gumminess were not significantly different among samples. In the consumer acceptance test, the scores of all evaluated characteristics decreased as the ratio of Ulmus cortex powder increased. However, the intensity ratings for the 1 and 2% Ulmus cortex powder samples showed the opposite effect, obtaining fairly good scores. In conclusion, the results indicate that adding $1{\sim}2%$ Ulmus cortex powder to Sulgidduk is optimal, providing good physiological properties and reasonably high consumer acceptability.

• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.291-294
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• 2008

Amylogram properties such as peak viscosity, hot viscosity, cool viscosity, breakdown, pasting consistency and setback were investigated by the Rapid Visco Analyzer and interpreted by the relationship among amylogram properties according to the varietal groups classified by the rapidity of grain filling (RGF) which was calculated by the percentage of grain weight at 15 days after heading to 40 days after heading. The 164 rice recombinant inbred lines from the cross of Milyang23 and Gihobyeo were used to get the basic information regarding the amylogram properties. The used recombinant inbred lines could be grouped into 4 varietal groups such as slow maturing (less than 40% of RGF), mid-slow maturing (41-60% of RGF),mid-fast maturing (61-80% of RGF), and fast maturing (more than 81% of RGF) groups based on the RGF. The peak viscosity and setback showed regular tendency according to the varietal groups classified by the RGF. Positive significant correlations were found between pasting consistency and setback, however negative significant correlations were found between breakdown and setback in all varietal groups.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.696-703
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• 1994

The purpose of this study was to investigate the gelatinization properties of potato starch heated with microwave. Two types of potato starches were prepared; In group A raw potato starch was heated with microwave and in group B potato starch was isolated from potato heated with microwave. Both groups were exposed to the microwave energy in a 560W, 2,450 MHz oven for 60, 120, 180 and 300 seconds. Gelatinization behaviour by DSC made a few differences according to the ratio of starch to water. As the microwave heating time took longer, gelatinization temperature and gelatinization $enthalpy({\bigtriangleup}H_1)$ were decreased in and melting $enthalpy({\bigtriangleup}H_2)$ was increased in group A. Whereas they were increased in group B. In both groups, maximum viscosity in gelatinization by Brabender amylogram was decreased by microwave heating. Then the peak of the maximum viscosity was shifted to higher temperature and cold viscosity was slightly increased. In group A, viscosity in gelatinization and light transmittance by NaOH was increased in initial stage and gel volume in gelatinization by KSCN was decreased. On the other hand, in group B, viscosity by alkali was slightly decreased, but light transmittance by NaOH was almost never changed. Gel volume is decreased like group A.

• Macromolecular Research
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• v.12 no.6
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• pp.545-552
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• 2004

The long-term stability of sulfonic acid-containing polyimides has been investigated. The hydrolytic degradation of homopolyimide and the block copolyimide comprising $27\;mol\%$ of 2,2'-bis(trifluoromethyl)benzidine and $9\;mol\%$ of m-phenylenediamine (BTFMB27mPl0[7/(3+1)]), was quantified through viscosity measurements and FT-IR spectroscopic analyses. The viscosity decrease with respect to time and the degradation rate were similar. The degrees of degradation with respect to time under ambient conditions and at elevated temperature in water were monitored by FT-IR spectroscopy. A new absorption peak was observed at $1786\;cm^{-1},$ which we corresponds to the presence of anhydride end groups formed by hydrolytic scission of the imide rings.

• The Korean Journal of Food And Nutrition
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• v.20 no.4
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• pp.427-432
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• 2007

The texture and descriptive sensory characteristics of a Korean rice cake(Karedduk) with added emulsifier were investigated after 2 and 24 hrs of storage at $5^{\circ}C$. The emulsifier, SP, was added at 0, 0.1, 0.5 and 1% levels to the dry rice flour. In the amylogram, the peak viscosity(P), hot paste viscosity(H) and cold paste viscosity(C) of the rice flour with added emulsifier were higher than those of the control. The texture property analysis by a Texture Analyzer revealed that the springiness, cohesiveness and adhesiveness of the Korean rice cake(Karedduk) with added emulsifier were similar to those of the control, while chewiness, gumminess and hardness were lower compared to the control. Also, the hardness by sensory characteristics was significantly different as compared to the control. Lastly, adding emulsifier to the Korean rice cake(Karedduk) was effective at retarding retrogradation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.6
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• pp.753-757
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• 1993

Pasting properties of the two commercial products of air-dried sediment of acorn were studied with viscoamylograph. The concentrations used were 7.0~9.5% and heating temperatures were 86.5$^{\circ}C$, 89.5$^{\circ}C$ and 92.5$^{\circ}C$. The viscosity increased as the heating temperature increased at a fixed concentration, but sample A at 8.5% concentration and sample B at 9.5% concentration maintained the constant peak viscosity regardless the heating temperatures. Samples heated to 92.5$^{\circ}C$ showed breakdown at all concentrations. The 15-min height and cold viscosity were negatively correlated with the heating temperature at a constant concentration. There was a 1% difference in concentration to give the same indices of amylogram between two samples.

• Korean Journal of Weed Science
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• v.32 no.3
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• pp.204-210
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• 2012

The physicochemical properties of tuber starch in water chestnut have been studied. Peak viscosity, hot paste viscosity and cooling peak viscosity were 5679, 3146 and 4262 RVU, respectively. In three transition parameters, onset temperature ($T_o$), peak temperature ($T_p$), and conclusion temperature ($T_c$) were 64.1, 68.5 and $72.3^{\circ}C$, respectively. Gelatinization enthalpy (${\Delta}H$ gel) was 4.48 J/g. A-type starch has a smaller proportion (11.4%) of short chains ($DP{\geq}12$) and a larger proportion (57.2%) of short chains ($13{\leq}DP{\geq}24$). The tuber starch of water chestnut displayed an A-type X-ray diffraction pattern showing a strong diffraction peak at $2{\Theta}$ values of $15.18^{\circ}$, $17.13^{\circ}$, and $23.1^{\circ}$, and a weak peak at $2{\Theta}$ values of $18.1^{\circ}$, $20.06^{\circ}$, and $26.69^{\circ}$. Their crystallinity was 28.6% and the mean starch granule size was 21.5 ${\mu}m$.

• Korean Journal of Food Science and Technology
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• v.49 no.5
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• pp.463-468
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• 2017

Waxy rice starch purified from Hwaseonchal white rice was modified by octenyl succinic anhydride (OSA) for use as an emulsifier. OSA-modified starches (1, 2, and 3% OSA, pH 8.5, 6 h) were investigated to understand their physicochemical and pasting properties, and emulsion stability. The degree of substitution (DS) of 1, 2, and 3% OSA starches was 0.0062, 0.0182, and 0.0214, respectively. FT-IR spectroscopy showed that OSA starches showed weak peaks at 1724 and $1572cm^{-1}$ and the peak at $3300cm^{-1}$ was reduced by an increase in the DS. Native and OSA starches showed A type crystallinity and a similar granular size. The OSA starch increased the peak viscosity, but decreased the onset and peak temperatures, and enthalpy with an increase in OSA concentration. The creaming index of emulsion of OSA starches decreased with an increase OSA concentration. It was suggested that the emulsion stabilizing capacity of OSA waxy rice starches increased with an increase in the OSA concentrations.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.464-469
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• 1997

Rapid visco-analyzer (RVA) and differential scanning calorimetry (DSC) were used to study the effect of rice bran dietary fiber extract on gelatinization and retrogradation of wheat flour. The addition of rice bran dietary fiber extracts from various heat treated bran into wheat flour caused to increase the pasting temperature, peak viscosity and final viscosity of RVA measurements. For gelatinization measured with DSC, mixtures of wheat flour and rice bran dietary fiber extract had slightly higher To (onset temperature) and Tp (peak temperature) values than those of control (wheat flour), and wheat flour/defatted rice bran dietary fiber extract mixture had the lowest enthalpy value. In comparison with gelatinization, the retrogradation endotherm of mixtures stored at $4^{\circ}C$ up to 4 weeks occurred at about $20^{\circ}C$ lower temperatures than gelatinization endotherm with broader shape and well-defined thermograms with storage time. The retrogradation of wheat flour was retarded greatly by addition of rice bran dietary fiber extract, and there was no big difference between 5% and 10% additions.

• Food Engineering Progress
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• v.15 no.4
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• pp.311-317
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• 2011

Rice bread premix was prepared from rice flour and vital wheat gluten, and the changes in the premix properties were studied during storage at 5, 25 and $35^{\circ}C$ for 4 months. Optimum level of 14-17% vital gluten could be added to the rice bread premix. The pH, sedimentation value, and Pelshenke value of the rice bread premix decreased with increasing storage period, whereas water retention capacity (WRC) and alkaline water retention capacity (AWRC) increased with increasing storage temperature. Mixograph peak time increased with increasing storage temperature. Rapid Visco Analyser (RVA) peak viscosity and setback values increased with increasing storage temperature and period. Decreased loaf volume was observed at the rice bread prepared from the premix during storage, especially at higher temperatures. Crumb hardness of the rice bread prepared from the premix increased during 4-month storage period.