• Title/Summary/Keyword: staling rate

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Staling Rate of Cooked Rice Stored at $21^{\circ}C$ and $72^{\circ}C$ (실온 및 고온 저장시 쌀밥의 노화 속도)

  • Kim, Sung-Kon;Pyun, Yu-Ryang
    • Korean Journal of Food Science and Technology
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    • v.14 no.1
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    • pp.80-81
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    • 1982
  • Staling rates of cooked rice from Akibare (Japonica) and Milyang 23 (Indica) stored at $21^{\circ}C$ and $72^{\circ}C$ were analyzed using the expression ${\theta}={\exp}\;(-kt^n)$, where ${\theta}$ in the fraction of uncrystallized material remaining after time t. The values for the rate constant (k) indicated that the firming process for both rices was not dependent on the variety, but was dependent on the storage temperature. The Avrami exponent (n) was found to be unity at two temperatures, suggesting that the staling of cooked rice is characterized by instantaneous nucleation followed by rod-like growth of starch crystals.

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Effects of Flour Brew with Bifidobacterium bifidum as a Natural Bread Improver (Bifidobacterium bifidum을 첨가한 밀가루 Brew의 천연제빵개량제로서의 효과)

  • 조남지;김혁일;김성곤
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.6
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    • pp.1275-1282
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    • 1999
  • To investigate the effect of flour brew with bifidobacteria on bread characteristics, flour brew with bifidobacteria was added to baking after 16 hour incubation at 37oC. The more addition of flour brew, the higher gassing power, the better machinality of dough were obtained, resulting in the larger specific volume of bread. Flavor profile analyzed by Electronic Nose System showed that flavor components of 30% flour brew were decreased comparing with those of control and there was shown definite difference in sensory characteristics between them. Staling studies of bread containing flour brew indicated had a definite effect in retarding the staling rate of bread, with time constant calculated in 30% treatment being 3.09 days and in control being 2.08 days. The enthalphy of gelatinization was decreased from 2.51J/g to 0.61J/g with increment of flour brew, suggesting that starch crystallization is delayed. conclusion, Flour brew fermented by bifidobacteria can be used as a natural bread improver with so many benefits as better machinality, one more day storage period, slower staling rate, better bread volume and more appealing bread flavor.

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Effect of the Addition of Dietary Fiber on Satling of Cakes (식이성 섬유의 첨가가 케익의 노화에 미치는 영향)

  • Kang, Kyoo-Chan;Baek, Sang-Bong;Rhee, Kyu-Soon
    • Korean Journal of Food Science and Technology
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    • v.22 no.1
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    • pp.19-25
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    • 1990
  • A study was undertaken to examine the effect of the addition of dietary fiber on quality attributes of cakes during 12-days storage period at $21^{\circ}C$. Moisture content, degree of gelatinization and hardness determinations were carried out. Addition of dietary fiber increased water holding capacity and decreased hardness and staling rate. Crumb color and sensory quality of cakes with and without dietary fiber was not significantly different.

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Rheological and Baking Studies of Composite Flour from Wheat and Naked Barley (밀-쌀보리 복합분의 물리적 성질 및 제빵 시험)

  • Kim, S.K.;Cheigh, H.S.;Kwon, T.W.;D'Appolonai, B.L.;Marston, P.E.
    • Korean Journal of Food Science and Technology
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    • v.10 no.1
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    • pp.11-15
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    • 1978
  • Barley (variety, Bangsa No. 6) was milled on a stone mill with 60% flour extraction. Rheological and baking properties of composites containing 5 and 10% of the barley flour with wheat flour (11.4% protein) were investigated. As the barley flour level was increased, amylograph paste viscosities increased at all reference points and farinograph stability decreased. However, no significant differences were noted in the proportional number measured with extensigraph with the various flours. Loaf volume and the staling rate of bread decreased and increased respectively as the barley flour level was increased.

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Feasible Scaled Region of Teleoperation Based on the Unconditional Stability

  • Hwang, Dal-Yeon;Blake Hannaford;Park, Hyoukryeol
    • Transactions on Control, Automation and Systems Engineering
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    • v.4 no.1
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    • pp.32-37
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    • 2002
  • Applications of scaled telemanipulation into micro or nano world that shows many different features from directly human interfaced tools have been increased continuously. Here, we have to consider many aspects of scaling such as force, position, and impedance. For instance, what will be the possible range of force and position scaling with a specific level of performance and stability\ulcorner This knowledge of feasible staling region can be critical to human operator safety. In this paper, we show the upper bound of the product of force and position scaling and simulation results of 1DOF scaled system by using the Llewellyn's unconditional stability in continuous and discrete domain showing the effect of sampling rate.

Physical Properties and Sensory Evaluation of Muffins with Trehalose (트레할로스를 첨가한 머핀의 물리적 특성 및 관능평가)

  • Heo, Soo-Jin;An, Hye-Lyung;Lee, Kwang-Suck
    • Culinary science and hospitality research
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    • v.16 no.1
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    • pp.13-23
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    • 2010
  • The principal objective of this study was to develop the optimal recipe for muffins prepared with replacement of sucrose with trehalose. The effects of trehalose on properties and staling of muffins during storage days(0, 1, 3, 5 days) were evaluated in terms of height, volume, weight, specific volume, baking loss rate, crumbscan, colorimeter, texture analyzer and sensory evaluation. Crust thickness of muffins containing trehalose evaluated with crumbscan decreased as the content of trehalose increased. Lightness(L value) of muffins with trehalose increased for the storage days, but muffins without trehalose decreased. yellowness(b value) increased significantly as the trehalose content increased. Hardness value of muffins was reduced by adding trehalose; however, the resilience value of muffins with trehalose increased significantly. Finally, the sensory evaluation revealed that muffins with 25% of trehalose showed the best result in texture, taste and overall preference.

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Effect of Leek(Allium tuberosum) Powder on Physicochemical and Sensory Characteristics of Breads (부추의 첨가가 식빵의 물리화학적 및 관능적 특성에 미치는 영향)

  • 송영선;정현실;노경희;고미경
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.1
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    • pp.113-117
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    • 1999
  • Physiological and sensory characteristics of breads prepared with the flour substituted with leek powder were evaluated. Leek powder contained 34.6% total dietary fiber. Substitution of wheat flour with 2% and 3% of leek powder decreased loaf volume by 13 and 27%, respectively. Moisture content was slightly increased and staling rate during storage at 25oC decreased in breads with leek powder. The addition of leek powder slighty increased hardness of fresh bread, but did not affect hardness of stored breads. Breads with leek powder turned into greenish and had characteristic flavor. Nontheless, no significant differences were observed between control and that with 2% of leek powder in sensory evaluation.

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Effect of Wheat Flour Brew with Bifidobacterium bifidum on Rheological Properties of Wheat Flour Dough (Bifidobacterium bifidum을 이용한 밀가루 brew가 반죽의 이화학적 성질에 미치는 영향)

  • Cho, Nam-Ji;Lee, Si-Kyung;Kim, Sung-Kon;Joo, Hyun-Kyu
    • Korean Journal of Food Science and Technology
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    • v.30 no.4
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    • pp.832-841
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    • 1998
  • In order to economically utilize flour brew with Bifidobacterium bifidum as a bread improver, the effect of flour brew on the rheological properties of dough, growth curve and acid production, and symbiosis with yeast were investigated. Growth of bifidobacteria was not increased more than initial seed volume but was consistent during 24 hours of incubation. pH was decreased and T.T.A was increased up to 12 hours of incubation. Symbiosis between bifidobacteria and yeast was little. Bifidobacteria produced more lactic acid than acetic acid in flour brew and the opposite in skim milk broth. This result was inferred from Lactobacillus sp. inherent in flour. On rheological properties of dough, farinograms of flour showed progressively decreasing baking absorption, mixing time and stability as the amount of flour brew increased. The validation of extensograms showed that R/E ratio linearly increased with increment of flour brew, and nearly doubled in all treatments comparing to that of control, which suggest the reduction of actual fermentation time. On visco/amylograms, malt index increased with addition of flour brew, accordingly showing the decrease in viscosity. Break down and set back value decreased with increment of flour brew, suggesting that staling rate of bread can be delayed.

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Study on the Texture and Staling of Breads with Addition of Various Hydrocolloids (Hydrocolloids를 첨가한 식빵의 텍스쳐와 노화에 관한 연구)

  • Lee, Seung Ju;Cho, Sook-Kyung;Lee, Seung-Joo
    • Korean journal of food and cookery science
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    • v.24 no.5
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    • pp.636-644
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    • 2008
  • The principal objective of this study was to assess the effects of hydrocolloids(xanthan gum, guar gum, sodium alginate, k-carrageenan, carboxy-methyl cellulose) on the suppression of retrogradation in the bread. The pasting properties of the doughs and the sensory properties were determined in the bread samples, to which xanthan gum, guar gum, sodium alginate, k-carrageenan, and CMC, were added at different ratios(0.2%, 0.6%, 1%). CMC and k-carrageenan with 0.6% level were selected for the further retrogradation studies. Changes in the firmness of the bread samples at room temperature for 15 days were assessed using a texture analyzer, and the type of retrogradation was calculated via the Avrami equation. The thermal properties of the samples were also determined via differential scanning calorimetry (DSC). The addition of hydrocolloids was shown to increase the viscosities of the doughs. Setback and breakdown viscosity were reduced significantly via the addition of CMC(0.6%, 1%), xanthan gum(1%), and k-carrageenan(1%). Sensory hardness was significantly increased when 1% hydrocolloids were added. Our textural analysis showed that the addition of CMC reduced the firmness of the bread, whereas k-carrageenan didn't. However, the retrogradation rate was reduced via the addition of k-carrageenan, as was also demonstrated in the results of our DSC analysis.

Effect of Certain Additives on Bread-Making Quality of Wheat-Purple Sweet Potato Flours (밀 및 자색고구마 가루의 제빵성에 대한 첨가제의 영향)

  • 김선영;유정희
    • Korean journal of food and cookery science
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    • v.13 no.4
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    • pp.492-499
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    • 1997
  • The effect of oxidants, gluten and gums on breadmaking quality of wheat-purple sweet potato(Ipomoea batatas) composite flour were studied. Alveograph tests of doughs showed that all additives increased the P, L and W values. Of these additives, L-Ascorbic acid, gluten, carboxy methyl cellulose have a significant effect on alveogram indexes. SEM showed that the dough added with additives changed some what in appearance when compared with the control. When oxidants was added, the doughs discontinuous gluten film were observed. No significant differences ,were evident in bread crumb color among the additives. And textural characteristics of bread crumb were influened by adding additives. Breads containing additives showed an increase in max weight, strength and hardness and a decrease in springness and cohesiveness. Average enthalpy values for all bread crumb after 7days increased with storage time. However, addition of additives decrease the rate of staling slightly more than that of the control. Addition of L-Ascorbic acid, L-Cystine, carboxy methyl cellulose and hydroxy propyl methyl cellulose increased the loaf volume significantly, and with except potassium bromate bread scores were acceptable.

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