• Title/Summary/Keyword: Rheological Properties

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Effect of Chlorella Addition on the Quality of Processed Cheese (Chlorella첨가가 가공치즈 품질에 미치는 영향)

  • Jeon, Jeong-Ki
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.3
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    • pp.373-377
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    • 2006
  • The effect of chlorella addition on the quality characteristics of processed cheese was investigated. Chlorella processed cheese was prepared in the different ratio of chlorella (0.5% (w/w) and 1.0% (w/w)). Chlorella processed cheese was stored at $10{\pm}1^{\circ}C$ and evaluated for the quality characteristics including general composition, pH, the number of microorganisms, oiling off, meltability, rheological properties, color, and sensory evaluation. Contents of moisture, protein, fat, fat in dry matter, and pH values were not different from those of control cheese. Microorganisms were not detected. The degree of oiling off showed no significant difference, but meltability decreased significantly (p<0.05). Hardness and springiness gradually increased significantly (p<0.05), while cohesiveness gradually decreased significantly (p<0.05). The L (lightness) values and the a (redness) values decreased with increasing chlorella contents, but the b (yellowness) values increased with increasing chlorella contents, so color expressed yellowish green. Compared to control cheese made by conventional way, QDA scores of color and mouthfeel of chlorella processed cheese were significantly higher (p<0.05) and the most favorite quality characteristics were shown in the processed cheese with 0.5% (w/w) chlorella (CPC1). These results suggested that health-oriented chlorella processed cheese would be made by the addition of the chlorella.

Product Characteristics as Factors of Process Parameters in Starch Phosphates Preparation by Twin-screw Extruder (이축압출성형기로 인산전분 제조시 Process Parameters에 따른 제품의 특성)

  • Kim, Chong-Tai;Kim, Dong-Chul;Kim, Chul-Jin;Kim, Hae-Sung
    • Korean Journal of Food Science and Technology
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    • v.23 no.2
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    • pp.235-240
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    • 1991
  • Starch phosphates were prepared from the corn starch mixed with 2% sodium tripolyphosphate by twin-screw extruder with a feed rate of 20 kg/hr and an extrusion temperature of $130^{\circ}C$, and the effects of extrusion variables on the physicochemical properties (target parameters) of starch phosphates were investigated. Interrelations of system parameters (specific mechanical energy and extrudate moisture) and rheological properities of starch was analyzed by using the response surface analysis. Degree of substitution (DS) was increased with increasing the feed moisture, and showed the maximum value at the screw of near 250 rpm, Degree of gelatinization was proportionally increased with increasing the screw speed and decreasing the feed moisture. Apparent viscosity of the paste was increased with increasing the feed moisture, but it was not significantly affected by the screw speed. It was found by scanning electron microscopy that the starch microgranules were much more degradaded, and as consequent result, the intrinsic viscosity was decreased, whereas, water solubility index was increased. The rate of retrogradation of the gels was retarded with increasing DS and decreasing viscosity.

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Rheological Properties of Dough and Quality Characteristics of Bread Containing Whey Ferment Cultured by L. acidophilus KCCM 32820 and P. freudenreichii KCCM 31227 (L. acidophilus KCCM 32820과 P. freudenreichii KCCM 31227로 배양한 유청발효물을 첨가한 반죽 레올로지 및 식빵의 품질특성)

  • Lee, Jeong-Hoon;Choi, Mi-Jung;Chung, Koo-Chun;Lee, Si-Kyung
    • Food Science of Animal Resources
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    • v.32 no.6
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    • pp.803-809
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    • 2012
  • This study was carried out to evaluate the effects of whey ferment containing L. acidophilus KCCM 32820 and P. freudenreichii KCCM 31227 on the quality characteristics of white pan bread. Instrumental analysis such as alveograph, gelatinization temperature, texture analysis, retrogradation rate was determined. In an alveograph test, $P_{max}$ value in the treatment was higher than that in the control, but extensibility of dough in the control showed to be higher than in the treatment, so test dough showed more strength than the control. In terms of DSC analysis for gelatinization, temperature there were no significant differences of $T_p$ and ${\Delta}H$ between the control and the treatment. In hardness analysis by rheometer, dough containing whey ferment revealed lower values than the control. From the analysis of the organic acid contents, propionic acid was not detected in the control, however 1.13 mg/g of propionic acid was detected in the treatment. In the retrogradation analysis by DSC, the test delayed slightly compared to the control.

Effects of the Water Quality on the Dispersion Properties of Bentonites Used for Drilling Fluid (시추이수용 벤토나이트의 분산 특성에 미치는 수질의 영향)

  • Akther, Shamima;Hwang, Jin-Yeon;Lee, Hyo-Min
    • Journal of the Mineralogical Society of Korea
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    • v.20 no.1 s.51
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    • pp.21-33
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    • 2007
  • The dispersion/flocculation behavior of bentonite is a major concern in performance of drilling fluid. We studied the dispersion/flocculation characteristics of three commercial bentonites [two CMC (carboxymethyl cellulose) treated and one untreated] in waters of different pHs and salt concentrations. We also examined changes in the viscosity of bentonite suspensions in such waters as a major rheological property of drilling fluid. The dispersion/flocculation behaviors of bentonites were measured by two methods: colorimetric and light scattering method. Light scattering method allows estimating the floc diameter and flocculation rate. The dispersion and flocculation behaviors were diverse with the different bentonites and water qualities. In distilled water, all the bentonites were well dispersed up to first 10 minutes. After that, the CMC-bearing bentonites were flocculated. In salt waters, all the samples were flocculated and the flocculation rate is varied with salt concentration and polymer content. The volume of settled flocs decreased with increasing salt concentration. The flocculation rate and floc diameter increased with decreasing pH of solutions, whereas the volume of settled flocs increased with increasing pH of solutions. The bentonites of fast flocculation behavior had low viscosity. The results of the present study will be helpful in applying bentonites to drilling fluids in diverse environments.

SLUMPING RESISTANCE AND VISCOELASTICITY OF RESIN COMPOSITE PASTES (치과용 복합레진의 중합 전 slumping resistance와 점탄성)

  • Suh, Hee-Yeon;Lee, In-Bog
    • Proceedings of the KACD Conference
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    • 2008.05a
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    • pp.235-245
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    • 2008
  • The aim of this study was to develop a method for measuring the slumping resistance of resin composites and to relate it to the rheological characteristics. Five commercial hybrid composites (Z100. Z250. DenFil, Tetric Ceram. ClearFil) and a nanofill composite (Z350) were used to make disc-shaped specimens of 2 mm thickness. An aluminum mold with square shaped cutting surface was pressed onto the composite discs to make standardized imprints. The imprints were light-cured either immediately (non-slumped) or after waiting for 3 minutes at $25^{\circ}C$ (slumped). White stone replicas were made and then scanned for topography using a laser 3-D profilometer. Slumping resistance index (SRI) was defined as the ratio of the groove depth of the slumped specimen to that of the non-slumped specimen. The pre-cure viscoelasticity of each composite was evaluated by an oscillatory shear test and normal stress was measured by a squeeze test using a rheometer. Flow test was also performed using a flow tester. Correlation analysis was performed to investigate the relationship between the viscoelastic properties and the SRI. SRI varied between the six materials (Z100 < DenFil < Z250 < ClearFil < Tetric Ceram < Z350). The SRI was strongly correlated with the viscous (loss) shear modulus G' but not with the loss tangent. Also. slumping resistance was more closely related to the resistance to shear flow than to the normal stress. Slumping tendency could be quantified using the imprint method and SRI. The index may be applicable to evaluate the clinical handling characteristics of composites.

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Studies on the Preparation and Utilization of Filefish Protein Concentrate (FPC) -IV. The Production and Characteristics of Bread using FPC-Wheat Composite Flour- (말쥐치 농축단백질(濃縮蛋白質)의 제조(製造) 및 이용(利用)에 관(關)한 연구(硏究) -제 4 보 : 말쥐취 농축단백질(濃縮蛋白質)-밀가루 복합분(複合粉)을 이용(利用)한 제빵시험(試驗)-)

  • Yang, Han-Chul;Lim, Wang-Jin;Paik, Soon-Young
    • Korean Journal of Food Science and Technology
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    • v.15 no.3
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    • pp.269-276
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    • 1983
  • Experiments were performed to study the rheological and baking properties of bread fortified with various amounts of filefish protein concentrate (FPC). Doughs were prepared from mixtures containing wheat flour and 5,10,15 and 20% of FPC. Standard methods were used to evaluate the rheology of doughs and characteristics of bread. The results were as follows. 1. The water absorption of the fortified doughs increased as FPC increased. FPC caused an increase in development time and stability as measured by Farinograph. 2. In the extensigraph test, FPC yielded a decrease in extensibility and an increase in resistance to extension. 3. Baking tests demonstrated that addition of FPC decreased the volume of loaf and made the crumb darker and coarser. 4. Additional tests were made to examine effect of sodium stearoyl lactylate (SSL) added at 0.25, 0.50, 1.00 and 2.00% on doughs containing 10% headed & gutted FPC. The most appropriate amount of SSL as an additive was 0.5%. 5. In the farinograph, adding 0.5% SSL could delay dough development time and greatly increase stability. 6. When 0.5% SSL was added on doughs containing 5,10,15 and 20% headed & gutted FPC, baking quality was greatly improved. The breads containing up to 10% were acceptable by the addition of SSL, but not in higher level of FPC. 7. The results of sensory evaluations of bread showed that the color, texture and taste of bread containing 5% whole FPC and 5, 10% headed & gutted FPC were reasonably gacceptable.

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Processing of Fermented Squeezed-type Pen Shell By-product by Proteolytic Enzyme (효소분해법에 의한 키조개부산물 젓갈의 제조)

  • KANG Hoon-I;KANG Tae-Joong;BAE Tae-Jin;KIM Hyun-Ju
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.27 no.5
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    • pp.509-514
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    • 1994
  • A processing method for fermented paste of favorable flavor and texture using pen shell by-product was investigated. The pen shell by-product was homogenized with the addition of water and hydrolyzed with $5\%$ of Protin P(105 PU/g) at $55^{\circ}C$ for 1 hour. Flavor of the hydrolysate could be improved by thermal treatment at $100^{\circ}C$ for 40 minutes with $10\%$ of invert sugar. $2\%$ of agar-agar and $6\%$ of starch added to hydrolysate emulsified by $8\%$ of polyglycerol condensed ricinoleate(PGDR) were significantly effective for the improvement of rheological properties such as hardness, springiness and chewiness of the fermented paste. $15\%$ of table salt was finally added to the product of fermented pen shell paste. The contents of moisture, protein, lipid, carbohydrate and salinity of the product were $62.7\%,\;3.2\%,\;4.4\%,\;10.6\%\;and\;15.6\%$, respectively. The major free amino acids were glutamic acid, arginine, aspartic acid, leucine, lysine, glycine and alanine. The product was stable for the storage of 60 days at $23{\pm}3^{\circ}C$ on bacterial growth.

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SLUMPING RESISTANCE AND VISCOELASTICITY OF RESIN COMPOSITE PASTES (치과용 복합레진의 중합 전 slumping resistance와 점탄성)

  • Suh, Hee-Yeon;Lee, In-Bog
    • Restorative Dentistry and Endodontics
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    • v.33 no.3
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    • pp.235-245
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    • 2008
  • The aim of this study was to develop a method for measuring the slumping resistance of resin composites and to relate it to the rheological characteristics. Five commercial hybrid composites (Z100, Z250, DenFil, Tetric Ceram, ClearFil) and a nanofill composite (Z350) were used to make disc-shaped specimens of 2 mm thickness. An aluminum mold with square shaped cutting surface was pressed onto the composite discs to make standardized imprints. The imprints were light-cured either immediately (non-slumped) or after waiting for 3 minutes at $25{\circ}C$ (slumped). White stone replicas were made and then scanned for topography using a laser 3-D profilometer. Slumping resistance index (SRI) was defined as the ratio of the groove depth of the slumped specimen to that of the nonslumped specimen. The pre-cure viscoelasticity of each composite was evaluated by an oscillatory shear test and normal stress was measured by a squeeze test using a rheometer. Flow test was also performed using a flow tester. Correlation analysis was performed to investigate the relationship between the viscoelastic properties and the SRI. SRI varied between the six materials (Z100 < DenFil < Z250 < ClearFil < Tetric Ceram < Z350). The SRI was strongly correlated with the viscous (loss) shear modulus G' but not with the loss tangent. Also, slumping resistance was more closely related to the resistance to shear flow than to the normal stress. Slumping tendency could be quantified using the imprint method and SRI. The index may be applicable to evaluate the clinical handling characteristics of composites.

Development of Jelly Fortified with Lactic Acid Fermented Prickly Pear Extract (백년초 젖산 발효액을 이용한 젤리의 제조)

  • Son, Min-Jung;Whang, Ki;Lee, Sam-Pin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.3
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    • pp.408-413
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    • 2005
  • Rheological properties and sensory characteristics of prickly pear jelly made from κ-carrageenan and glucomannan were examined. Prickly pear extract (PPE) fermented by Lactobacillus casei LS (isolated from soy milk curd residue) exhibited pH 3.12, 1.15% acidity (lactic acid) and 2.7 × 10/sup 9/ CFU/mL lactic acid bacteria. In the effect of concentration of fermented PPE, the jelly containing 4% fermented PPE had higher springiness and slightly lower hardness than that without fermented PPE, and was superior to color and taste. The hardness and brittleness of jellies were enhanced by the addition of 0.25% citric acid. The addition of 0.25% ascorbic acid resulted in the production of soft jelly like pudding. In the effect of concentration of κ-carrageenan, the hardness and springiness of jellies were increased by adding 0.75% κ-carrageenan, but was decreased by adding at the 0.9% level. In the overall preference of jellies including sweet and sour taste, higher score was obtained by the fortification of 0.6% and 0.75% κ-carrageenan, 0.25% citric acid and 30% fructose syrup.

Evaluation of Rheological and Functional Properties of Roasted Soybean Flour and Mixed Cereals Fermented by Bacillus sp. (고초균을 이용한 볶은 콩과 곡류 혼합 발효물의 물성 및 기능성 평가)

  • Son, Se-Jin;Lee, Sam-Pin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.3
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    • pp.450-457
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    • 2011
  • Roasted soybean flour (RSF) and mixed cereals were fermented by the solid state fermentation using Bacillus subtilis HA to optimize the production of biologically active compounds. The RFS fermented with 52.7% moisture content showed higher production with protease activity of 42.6 unit/g and 10% mucilage content after fermentation for 24 hr. Tyrosine content and protease activity after 48 hr fermentation time were the highest values with 445.5 mg% and 55.1 unit/g, respectively. However, the wholesome fermented RSF (FRSF) was obtained by fermentation for 24 hr because of the production of unpleasant flavors after fermentation for 48 hr. The RSF fermented with various types and contents of cereals has no effects on tyrosine content and protease activity. However, the addition of brown rice significantly increased mucilage content, especially indicating 24.55% at the addition of 80% (w/w). For addition of barley, fibrinolytic activity was increased to 11.82 unit/g by the fortification of 60% barley. It is concluded that biologically active compounds including fibrinolytic activity and mucilage content in FRSF were dependent upon the type and content of various cereals.