• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.28-32
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• 1993

In order to elucidate the temperature and pressure effect on the oil expression of perilla seed, recovery of expressed oil (REO) and volumetric strain of both roasted and unroasted perilla seeds were observed at different temperature, pressure and for different periods of press. In this experiment, moisture content of perilla seed was adjusted to 2.5% and temperature used were 30, 40, 50 and $60^{\circ}C$. Pressure applied were 10, 30, 50 and 70 MPa, and periods of press were 5, 7, 9 and 11 min. As temperature and pressure were increased or periods of press was lengthened, REO and volumetric strain of pressed cake were increased. Maximum REO of unroasted perilla seeds were found to be 85.59% and those of roasted perilla seeds be 85.30%, at 70 MPa, $60^{\circ}C$, and for 11 min. Viscosity of expressed oil were exponentially dependent on temperature and REO were increased as viscosity was decreased. From statistical analysis between effects of expression factors and REO and volumetric strain of pressed cake, importance of their effects was decreased in the order of pressure, temperature, $temperature{\times}pressure$ and periods of press. The multiple regression equation between REO(Y) and temperature (T), pressure (P), and periods of press (D) were as follows; $Y=7.95+36.85P+1.12T^2-0.55TP-5.08P^2\;r^2=0.97$ for unroasted perilla seed (p<0.01), $Y=4.50T+39.23P+0.83T^2-1.71P-5.07P^2\;r^2=0.99$ for roasted perilla seed (p<0.01).

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.524-536
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• 1994

Chitosan is known to be a good biocompatible natural polymer. Polyethyleneglycol monomethacrylates(PEGM) were grafted onto chitosan and their reaction conditions and properties of the graft polymers obtained were estimated. Using ceric ammonium nitrate(CAN) as the initiator, the optimum condition for graft polymerization was determined amount of the initiator and monomer concentrations and reaction time. Grafting yields such as total conversion, the percentage of grafting and the efficiency of grafting were calculated and examined the optimum reaction condition for high grafting yields. The percentage of grafting and total conversion were maximum at condition that the concentration of initiator was $4{\sim}5{\times}10^{-3}M$, the concentration of monomer was 0.5~0.6M, the reaction time was 2~3 hours and the reaction temperature was about $40^{\circ}C$. Thermal characteristics, solubility for chitosan solvents and inherent viscosity of synthesized graft copolymers were investigated. In high initiator concentration, characteristics of chitosan were greatly diminshed. In case of inherent viscosities, chitosan-g-PE-90 was 2.81 dl/g, chitosan-g-PE-200, 3.01dl/g and chitosan-g-PE-350, 4.93dl/g. And a tendency of viscosity increase depending on the length of ethylene oxide residue was confirmed. Degree of swelling, tensile strength, elongation of membrane prepared from graft copolymers were determined. Properties of graft copolymers were affected by percentage of grafting and length of ethylene oxides residue in polyethylene glycol monomethacrylates. Tensile strength, elongation and degree of swelling of graft copolymers were remarkably improved than chitosan. As percentage of grafting increased, the amount of drug permeation was also increased.

• Korean journal of food and cookery science
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• v.3 no.2
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• pp.59-67
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• 1987

In order to make use of Job's tears widely, Job's tears starch was analyzed and determinded the contents of amylose, amylographical and other physicochemical properties. And also the yeast breads and rice cakes were made from flour and rice flours with various mixing ratios of Job's tears flour and then they were tested for suitability to preparation of bread and rice cake. 1. The starch contents of Job's tears showed 12~20%. Which was about one third of rice or waxyrice starch. But amounts of crude proteins, fats, and total ashes in Job's tears were higher than rice or waxyrice. Job' tears starch was composed of amylopectins only, and was similar to that of waxyrice starch. 2. Depends upon the Amylogram of each starch, initial gelatinization temperature of Job's tears starch was the highest among three starches of rice, waxyrice, and Job's tears. Maximum viscosity of Job's tears starch was 860BU, then it was about two times of rice starch viscosity. 3. By the sensory evaluation results, the taste of bread prepared with mixing of 10% Job's tears flour was better than flour bread and the volume and grains of the bread made from mixing of 10%, 20% Job's tears flour were similar to that of flour bread, but the taste, volume and grains of bread made from 30% mixed flour were undesirable. The rice cake Prepared from mixed flour with 25% Job's tears flour has shown to be desirable.

• Korean Journal of Food Science and Technology
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• v.13 no.1
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• pp.6-14
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• 1981

In an attempt to make dried noodles with composite flours utilizing rice and wheat flours, noodle-making characteristics were improved by the addition of popped rice and wheat flours to rice flour. Their quality was studied in terms of physical properties, noodle-making characteristics, cooking quality test and sensory evaluation. Dried noodle of the composite flour was produced by the conventional method. The results are summerized as follows; 1. In comparing the composite flours, the rice flour containing 30% popped rice flour had a lower maximum viscosity than that with 40% popped rice flour by method of amylograph. The composite flour(20% rice+30% popped rice+50% wheat flour) with added 2% xanthan gum showed the viscosity characteristics which was similar to that of wheat flour. 2. Addition of $1.5{\sim}2.0%$ xanthan gum and $40{\sim}50%$ wheat flour to rice and popped rice flour mixture helped to improve the noodle making properties and the cooking quality, and the noodle making properties and the cooking quality of the mixed flour were almost the same as those of wheat flour alone. 3. The composite flour (rice+popped rice+wheat flour) with xanthan gum showed a higher score in sensory evaluation than that without xanthan gum. The general acceptability scores obtained with the noodle products made of the composite flours with 30% popped rice flour was not significantly different from that of noodle products made of wheat flour alone. However, the noodle products made of the composite flours showed rather higher scores in odor and palatability than the products made of wheat flour alone.

• Korean journal of food and cookery science
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• v.15 no.6
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• pp.652-658
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• 1999

Arrowroot Mook was prepared as a trial to develop new food items from natural resources, and its rheological properties were measured. 1. The starting point of gelatinization of 7% arrowroot starch solution was $67.5^{\circ}C$ as measured by amylograph. The viscosity of arrowroot starch reached the maximum 375 B.U. at $95^{\circ}C$ and decreased to 315 B.U. while holding at $95^{\circ}C$ for 15 min. When the temperature dropped to $50^{\circ}C$, the viscosity increased again to 530 B.U. 2. The gelatinization enthalpy of arrowroot starch was 15.603 J/g. 3. For the color, there were significant differences in b value for the arrowroot Mook made of arrowroot starch and in L value for the Mook made by the addition of arrowroot juice. 4. In descriptive analysis, $S_3$(14% arrowstarch) was most favored in color, and $S_1$(10% arrowstarch)was most favored in transparency, brittleness, fineness, and shininess. There were no significant differences in hardness, adhesiveness, and astringency. 5. On the contrary to mechanical measurement, there were no significant differences in hardness of samples as the addition of arrowroot juice increased, although there appeared a tendency to be softer in descriptive analysis. 6. The Mook prepared with 12% arrowroot starch was most favored by sensory evaluation. In case of adding arrowroot juice, the Mook containing 3% of arrowroot juice was most favored. Overall, arrowroot Mook showed a potential as a new food item.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.436-441
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• 2003

The physiochemical properties of wheat flour dough added with onion powder were investigated. The color value of mixed onion powder was added and had low values of lightness and redness, as well as high value of yellowness. Water absorption of the wheat flour dough decreased with the increase in the onion powder. Both development time and stability of the wheat flour dough with onion powder added were less than those of the control. An increase in the added amount of onion powder resulted in an increase of weakness. The maximum viscosity gradually decreased with the increase the amount of onion powder, while the temperature of gelatination did not change. The wheat flour dough extensibility decreased, and the resistance of extension and area under the curve increased in the onion powder. It is of considerable note that the pH of the wheat flour dough decreased in the process of fermentation with an increase in the amount of onion powder.

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1026-1032
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• 1996

The effects of steeping temperature $(7^{\circ},\;15^{\circ},\;20^{\circ}\;and\;30^{\circ}C)$ and steeping time $(2{\sim}14\;hr)$ on the physicochemical properties of milled rice (variety; Chucheongbyeo) were investigated. The pH of the steep water decreased as the steeping time increased, which was more pronounced at higher steeping temperature. The solid loss was about 4.0% during steeping. The contents of protein, fat and ash decreased during steeping, which was greater at elevated temperature. The lightness of rice was slightly increased, and the yellowness was decreased upon steeping. The water-binding capacity of rice was increased during steeping at above $15^{\circ}C$. The slight increase of the swelling power of rice at $80^{\circ}C$ was observed upon steeping. The maximum wavelengh for the rice flour-iodine complex was moved to a higher wavelengh, but X-ray diffraction patterns remained constant regardless the steeping conditions. The pasting properties of rice flour (10%) by amylograph indicated that the peak viscosity increased as the steeping time was increased at all steeping temperatures. The steeping resulted in the greater breakdown and the 1ower setback. The log peak viscosity showed a linear relationship with the steeping time. The activation energy and $Q_{10}$ value for the visciosity increase rate was 2, 320 cal/mole and 1.14, respectively.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.247-251
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• 1993

Physico-chemical characteristics of glutinuous rice during soaking treatment at different temperature for Yu-Kwa (Korean traditional glutinous rice cake) processing were determined. Crude fat and protein contents of soaked glutinous rice decreased up to 30% to 50%, respectively, compared to raw rice, but there was a little difference in soaking periods. As the soaking period increased pH of soaking solution was decreased from 6.4 to 3.3, while Brix was increased from 0.5 to 13.6. Titration acidity of soaking solution and soaked rice were increased to 22.9 and 3.4, respectively, as the soaking period increased to 9 days at $20^{\circ}C$ soaking, but it was increased rapidly to 29.8 and 4.0, respectively, at $30^{\circ}C$. The three kinds of free sugar such as glucose, sucrose and maltose were detected. Glucose was the major produced free sugar during soaking, sucrose was not detected after 1 day soaking period. Characteristics of amylographic viscosity on soaked rice showed that there are no difference in pasting temperature by the soaking time and temperature, but the maximum viscosity was drastically increased on $1{\sim}2\;day$ soaking period and decreased rapidly after $2{\sim}3\;day$.

• Elastomers and Composites
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• v.41 no.2
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• pp.97-107
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• 2006

The recycled polyethylene composites with various ratio of ground waste tire powder were manufactured by using a fully intermeshing co-rotating twin screw extruder for the reuse of waste tire scrap. In this investigation, the ground waste tire powders (GWTP) were blended with virgin HDPE and recycled polyethylene in the weight ratio of 0 to 50 wt.%. Mechanical properties such as tensile strength, elongation at break and impact strength were measured by using ASTM standard. The experimental results for the various composite showed that the tensile strength of composites decreased with increasing GWTP ratio, while elongation at break increased with the amounts of GWTP. On the other hand, the impact strength for the three kinds of composites showed maximum at the 30 wt.% of GWTP and then decreased. Morphology of the fracture surface tends to be rough with increasing waste tire powder content. Rheological properties were investigated by measuring the shear viscosity against shear rates and softening temperatures. They showed that melt viscosity of rubber composites in this study subsequently increased with increasing GWTP content as a result of increase of flow resistance against external stress and followed a Power-law behavior.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.3
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• pp.353-360
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• 2008

This study evaluated the quality characteristics of dried noodles made of wheat flour supplemented with different concentrations of skate powder. Cooking quality, mechanical texture properties, gelatinization temperature and viscosity were measured, after which sensory evaluation was performed with prepared noodles. Water binding capacity, solubility and swelling power of the composite skate powder and wheat flours were higher than those of pure wheat flour. Gelatinization temperature of the composite skate powder and wheat flours increased, while initial, interim, and maximum-viscosity at $95^{\circ}C$, decreased, with increasing skate powder content. In relation to color values, increasing skate flour content led to decrease in L and b values and increase in a value. For the textural characteristics, the addition of skate powder increased hardness, springiness, chewiness and adhesiveness. Overall, noodles made with 3% skate powder were preferred compared to other samples.