• Title/Summary/Keyword: Viscosity difference

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A Study on the Viscosity Changes and Palatability of Potato Soup by Different Variety and Consistency (감자의 품종과 농도에 따른 수우프의 점도변화 및 식미기호에 관한 연구)

  • 이승교;안홍석
    • Korean journal of food and cookery science
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    • v.1 no.1
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    • pp.45-52
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    • 1985
  • For the knowledge of characteristics of the cooking condition of different varieties of patato, 4 kinds of spring cultivated (Namjak, Sumi, Daiji, and Dowon) and 4 kinds of summer cultivated (Namjak, Sumi, Bintze, Radosa) were selected. The quality of potato starch, the viscosity, and the palatability of each potato soup were measured respectively. The amylograph characteristics of potato starch showed great difference not only between the spring and the summer cultivated, but also among the various kinds of potatoes. The amylograph of the spring cultivated didn't show the breakdown and the set back largely but showed the gradual increase of the viscosity and the high gelatinization temperature. Bintze and Namjak among the summer cultivated were gelatinized easily and in low temperature, and showed the beakdown. The low gelati-nization temperature of the summer cultivated infers that the starch granules of the summer cultivated are less compact then those of the spring ones. Sumi, Daiji and Dowon of the spring products showed the soup was falling down, but the viscosity of Namjak and 4 summer cultivated increased only slightly. The taste of soup is different according to the consistency of soup, and so the taste of soup of Daiji, Dowon, and Sumi of the spring cultivated products was good at the consistency 19.8% and 23.5%. All the summer cultivated products and Namjak of the spring cultivated were good at 27%.

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Quality Characteristics of cream soups added with rice flour and potato as a thickening agent (쌀가루와 감자를 농후제로 사용한 크림스프의 품질 특성)

  • Koh Seung-Jeong;Park Hong-Hyun;Lee Kyung-Hee
    • Korean journal of food and cookery science
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    • v.20 no.6 s.84
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    • pp.568-574
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    • 2004
  • In order to seek the possibility of using rice flour and potato as thickening agent instead of roux, sensory evaluations of cream soups manufactured from 3 different thickening agents were conducted. The viscosity, moisture and lipid contents, and the color affecting the quality of the soup were investigated. The results were as follows: 1. As thickening agents for 200g of the cream soups, rice flour and potatoes at 20.5 and 20g, respectively, were needed in order to make soup with a similar concentration to that manufactured using 20g of roux. 2. In the sensory tests, the soup made with rice flour had the most preferred overall acceptability, with a significantly preferable taste. The soup made with rice flour had the strongest whiteness and savory taste, but that made with roux had the strongest viscosity and smooth feeling in the mouth feel. There was no difference between the samples with regard to nutty flavor. The whiteness, palatability, viscosity and smooth feel sensory properties were positively correlated with the overall acceptability. Among these properties, the palatability showed the highest correlation (r=0.538) with overall preference. 3. The cream soup made using potatoes as the thickening agent had a $76.20\%$ water content, whereas those made with rice flour and roux had 73.00 and $64.00\%$ respectively The fat content of the cream soup made with roux was $10.24\%$, which was twice as high as those of the rice flour and potato soups. 4. Among the 3 kinds of cream soup, the one made with rice flour had the whitest color.

Analysis of Empirical Constant of Eddy Viscosity by Zero- and One-Equation Turbulence Model in Wake Simulation

  • Park, Il Heum;Cho, Young Jun;Kim, Tae Yun;Lee, Moon Ock;Hwang, Sung Su
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.3
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    • pp.323-333
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    • 2014
  • In this paper, the wakes behind a square cylinder were simulated using two kinds of different turbulence models for the eddy viscosity concept such as the zero- and the one-equation model in which the former is the mixing length model and the latter is the k-equation model. For comparison between numerical and analytical solutions, we employed three skill assessments: the correlation coefficient(r) for the similarity of the wake shape, the error of maximum velocity difference(EMVD) for the accuracy of wake velocity and the ratio of drag coefficient(RDC) for the pressure distribution around the structure. On the basis of the numerical results, the feasibility of each model for wake simulation was discussed and a suitable value for the empirical constant was suggested in these turbulence models. The zero-equation model, known as the simplest turbulence model, overestimated the EMVD and its absolute mean error(AME) for r, EMVD and RDC was ranging from 20.3 % to 56.3 % for all test. But the AME by the one-equation model was ranging from 3.4 % to 19.9 %. The predicted values of the one-equation model substantially agreed with the analytical solutions at the empirical mixing length scale $L=0.6b_{1/2}$ with the AME of 3.4 %. Therefore it was concluded that the one-equation model was suitable for the wake simulation behind a square cylinder when the empirical constant for eddy viscosity would be properly chosen.

Characteristic of yoghurt containing puffed rice flour (팽화미의 첨가가 요구르트 특성에 미치는 영향)

  • Kim, Moon-Suk;Ahn, Eun-Suk;Shin, Dong-Hwa
    • Korean Journal of Food Science and Technology
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    • v.25 no.3
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    • pp.258-263
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    • 1993
  • New type yoghurts were prepared by fermenting milk containing puffed rice flour(PRF) with some commercial lactic acid bacterial starters. The yoghurts were evaluated for pH, tillable acidity, viscosity and color with sensory evaluation for final quality. The optimum moisture content of rice for puffing was over or less 14%. Increasing addition level of PRF, lightness decreased and, redness and yellowness increased with increasing viscosity greatly. There was no quality difference among commercial starters but pH, acidity and viscosity of yoghurt were affected. During the storage at $5^{\circ}C$, pH dropped, acidity and viscosity increased gradually. The number of lactic acid bacteria was increased until 6 days storage to $3{\times}10^8$ and dropped after on. The yoghurt containing PRF was inferior in flavor texture and taste comparing with commercial yoghurt.

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Studies on the Thin Rubber Coated Fabrics. (Part 2) Physical Properties of the Coated Fabric with Rubber Compounds Having Different Viscosity (박막(薄膜) Rubber Coated Fabrics에 관(關)한 연구(硏究)(제2보(第2報)) Viscosity가 다른 배합(配合)고무를 각종(各種) 원반(原反)에 도포(塗布)했을때의 물리적(物理的) 성능(性能)에 대(對)하여)

  • Kim, Joon-Soo;Lee, Myung-Whan;Yum, Hong-Chan;Lee, Sook-Ja;Rhim, Kwang-Kew
    • Elastomers and Composites
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    • v.1 no.1
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    • pp.49-55
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    • 1966
  • Based upon the results of the previous work, the experiments are concentrated on the improvement of the durability of rubber coated fabrics as a rain garment material. To obtain a much lighter and durable coated fabric, several kinds of light weight cotton prints having almost equal density in warp and fillingwise were chosen. Rubber coating on these prints was made by topping and spreading process using rubber compound of various viscosity, and the physical properties of final product were analysed and interpreted in terms of adhesion and durability. The results are as follows. 1. Any noticeable difference between two coating processes was not found in terms of physical properties. 2. Base fabrics should be dipped once into a dilute rubber compound before coating operation in order to obtain a uniform adhesion and physical properties, and the optimum range of the viscosity of dipping paste are from 100 poise to 200 poise. 3. Generally, the tearing strength of the coated fabrics is inversely proportional to the adhesion. 4. It was assumed that the increase of the water proofness after water immersion on the finished material which have dense base fabric is chiefly due to the swelling of the cellulosic fiber.

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Analysis of Empirical Constant of Eddy Viscosity by k-ε and RNG k-ε Turbulence Model in Wake Simulation

  • Park, Il Heum;Cho, Young Jun;Lee, Jong Sup
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.3
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    • pp.344-353
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    • 2019
  • The wakes behind a square cylinder were simulated using two-equation turbulence models, $k-{\varepsilon}$ and RNG $k-{\varepsilon}$ models. For comparisons between the model predictions and analytical solutions, we employed three skill assessments:, the correlation coefficient for the similarity of the wake shape, the error of maximum velocity difference (EMVD) of the accuracy of wake velocity, and the ratio of drag coefficient (RDC) for the flow patterns as in the authors' previous study. On the basis of the calculated results, we discussed the feasibility of each model for wake simulation and suggested a suitable value for an eddy viscosity related constant in each turbulence model. The $k-{\varepsilon}$ model underestimated the drag coefficient by over 40 %, and its performance was worse than that in the previous study with one-equation and mixing length models, resulting from the empirical constants in the ${\varepsilon}-equation$. In the RNG $k-{\varepsilon}$ model experiments, when an eddy viscosity related constant was six times higher than the suggested value, the model results were yielded good predictions compared with the analytical solutions. Then, the values of EMVD and RDC were 3.8 % and 3.2 %, respectively. The results of the turbulence model simulations indicated that the RNG $k-{\varepsilon}$ model results successfully represented wakes behind the square cylinder, and the mean error for all skill assessments was less than 4 %.

Enzyme-Resistant Starch Content, Physical and Sensory Properties of Tarakjuk (Milk-Rice Porridge) with Different Amylose Content (아밀로즈 함량별 타락죽의 효소저항전분 함량, 물리적 및 관능적 특성)

  • Lee, Gui-Chu;Kim, Jung-Eun;Kim, Yoon-Sun
    • Journal of the Korean Society of Food Culture
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    • v.21 no.2
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    • pp.171-178
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    • 2006
  • Tarakjuk with different amylose content was made up using roasted rice flours that consisted of the highest enzyme-resistant starch (RS), while differential scanning calorimetry (DSC) was also utilized to measure the gelatinization temperature of these roasted rice flours in order to establish cooking temperature of tarakjuk. The following qualities of tarakjuk with different amylose content were studied: color, viscosity, spreadability, starch fractions involving total starch (TS), rapidly digestible starch (RDS), slowly digestible starch (SDS) and RS, in vitro starch digestibility (IVSD) and sensory properties. During experimentation, it was found that as the amylose content of the rice flour decreased, the L value of tarakjuk decreased, whereas a value increased significantly (p<0.05). Also, while viscosity showed to increase significantly (p<0.05), on the opposite end, the property of spreadability decreased. TS ranged from $15.95{\sim}17.31%$, RDS $9.36{\sim}10.16%$, SDS $5.46{\sim}6.91%$ and RS $0.33{\sim}1.07%$, on a dry basis. Although the amylose content of rice flours decreased, IVSD increased, however showing no significant difference. When testing the sensory properties of tarakjuk, color and viscosity increased, whereas clumpiness decreased. Ilpum tarakjuk showed the highest score for nutty taste and overall acceptance levels. In fact a high correlation was shown between nutty taste and overall acceptance level (p<0.01), which leads one to believe that nutty taste is a prime factor that greatly influences overall acceptance. Furthermore, viscosity was positively correlated with both a and b values, however negatively correlated with L value (p<0.05). Moreover, roasted nutty taste and overall acceptance were positively correlated with a value (p<0.05), respectively. In conclusion, the above results suggest that tarakjuk could be made by choosing the appropriate rice flour based on the nutritional or sensory purpose.

Effect of Xylanase Pre-and Post-Treatment on oxygen Bleaching of Oak Kraft Pulp

  • Kim, Dong-Ho;Paik, Ki-Hyon
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 1999.11a
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    • pp.194-204
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    • 1999
  • The use of genetically cloned xylanase acquired from Bacillus strearthermophillus improves bleachability for oak kraft pulps. Combination of xylanase(X). oxygen(O), ozone(Z). peroxide(P), alkaline extraction(Eo. Eop), and chlorination(C/D, D) have been tested in a variety of bleaching sequences. The effectiveness of xylanase pre-treatment(XO) and post-treatment(OX) in oxygen bleaching is mainly compared. With xylanase treatment the brightness increase by 1.5-2.1% ISO in OZEP, OZEoP, OZEopP and OPZP sequences. There is only numerically difference of brightness gains between OX and XO sequences. With xylanase treatment chemical requirements for bleaching decrease by 42.6-48.6% in OC/DEoD sequence and 47.9-54.7% as active chlorine in OC/DEopD sequence at the same brightness. the reduction of bleaching chemicals is higher in XO sequence than those in OX sequence. Following xylanase treatment the viscosity increases from 11.7-12.0 mPa·s to 12.4-13.5 mPa·s and the brightness stability is considerably improved however the difference of effectiveness between XO and OX sequence is not present. Compared to tensile index vs tear index, the physical properties are similar for TCF bleaching sequences with and without xylanase treatments. However in OC/DEoD and OC/DEopD sequences the physical properties decrease with xylanase treatment. There is no difference in the physical properties between XO and OX sequences. COD, BOD and color of bleaching effluents increase slightly with xylanase treatment, however the discharge of COD end-load into environmental impact decrease.

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Quality Characteristics of Frying Mix added with Brown Rice Fiber (현미 식이섬유를 첨가한 튀김가루의 품질 특성)

  • Choi, Seung-Il;Kim, Tae-Jong;Park, Jin-Hee;Lim, Chun-Son;Kim, Mun-Yong
    • Korean journal of food and cookery science
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    • v.27 no.6
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    • pp.671-680
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    • 2011
  • In this study, frying mix was prepared containing 0.5, 1.0, 1.5 or 2.0% brown rice fiber(BRF). The samples along with a control were then compared regarding their quality characteristics, including pasting properties, spreadability, pick-up ratio, color, textural characteristics, moisture and oil contents, and sensory qualities, all to determine the optimal ratio of BRF. For the pasting properties of frying mix, the control group was evidenced by a significantly higher peak viscosity, through viscosity, and final viscosity than that observed in the BRF samples. Breakdown was the highest at the 1.0% addition level, and time to peak viscosity and pasting temperature were maximal with the 0.5% addition. There was no significant difference in setback among the experiments. Spreadability and pick-up ratio of frying batter were not significantly different among the samples. As the BRF content increased, the lightness, greenness decreased, whereas yellowness increased. The BRF samples presented significantly higher hardness of fried batter than the control group and there was no significant difference in crispiness among the samples. Moisture content of fried sweet potato decreased with increasing BRF and oil content was the maximum on the control group. In the sensory evaluation, appearance, color, flavor, savory taste, yellowishness, coating thickness, off-flavor, and oiliness were not significantly different among the fried sweet potato samples. Bindingness, crispiness, and chewiness were highest in the control samples but minimal at a addition level of 2.0%. The control group evidenced significantly higher overall acceptability than were observed in the BRF samples. In conclusion, the results demonstrated that 0.5~1.0% BRF may prove quite useful as a additive for frying mix in the preparation of fried sweet potato and may provide favorable textural and functional properties.

The Flow Analysis of Past Flow a Circular Cylinder By Direct Numerical Simulation (DNS에 의한 원주후류에 대한 유동해석)

  • ;Mamoru TANAHASHI;Toshio MIYAUCHI
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2001.05a
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    • pp.52-57
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    • 2001
  • Laminar two-dimensional time-dependent flow past a circular cylinder is numerically investigated using direct numerical simulation for the low Reynolds number (Re=164∼280). The higher-order finite difference scheme is employed for the spatial distributions along with the second order Adams-Bashforth and the first order backward-Euler time integration. The convection term is applied by the 7th order up wind scheme and the pressure and viscosity terms are applied by the 4th order central difference. The grid system makes use of the regular grid system and it is generated by an equation. The calculated results of drag coefficients, lift coefficients, pressure distributions, and vorticity contours and other information are compared with experimental and numerical ones. These results obtained by the present DNS show good agreement with the previous studies.

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