• Title, Summary, Keyword: gelatinization

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Comparison of Differential Scanning Calorimetry with Enzymatic Method for the Determination of Gelatinization Degree of Corn Starch (DSC에 의한 전분의 Endothermic peak와 효소분석법에 의한 호화도 비교)

  • Lee, Boo-Yong;Mok, Chul-Kyoon;Lee, Cherl-Ho
    • Korean Journal of Food Science and Technology
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    • v.25 no.4
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    • pp.400-403
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    • 1993
  • Gelatinization degrees of torn and waxy corn starches in the low-moisture environment were determined by DSC thermogram and enzymatic analysis, the results were compared each other As the moisture content increased from 20% to 70%, the enthalpy of endothermic peak of starch increased linearly in DSC thermograms. When the moisture content exceeded above 70%, the DSC enthalpy of starch remained constant in DSC thermogram. The enthalpies for gelatinization of corn and waxy corn starches were 3.23 cal/g and 4.2 cal/g, respectively. When gelatinization degrees of starches were measured by enzymatic analysis, the gelatinization degree increased linearly as the moisture content increased from 20% to 80%. A linear correlation between DSC and enzymatic analysis was obtained only when the moisture content was under 70%.

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Effects of Rice Bran Dietary Fiber Extract on Gelatinization and Retrogradation of Wheat Flour (미강 식이섬유 추출물이 밀가루의 호화 및 노화에 미치는 영향)

  • Kim, Young-Soo;Ha, Tae-Youl;Lee, Sang-Hyo;Lee, Hyun-Yu
    • 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.

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Physicochemical Properties of Extruded Rice Flour and Gelatinization Popped Rice Flour (제조 방법이 다른 팽화미 분말의 이화학적 특성)

  • Lee, Jung-Eun;Kim, Yu-Jin;Cho, Mun-Gyeong;Park, Shin-Young;Kim, Eun-Mi;Cho, Yong-Sik;Choi, Yoon-Hee
    • The Korean Journal of Food And Nutrition
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    • v.25 no.4
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    • pp.850-854
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    • 2012
  • This study is carried out in order to develop food materials for the promotion of rice consumption. In this study, we researched the physicochemical properties of extruded rice flour (ER) and gelatinization popped rice flour (GPR) by the extrusion process and by the popped method with milled rice and brown rice. The extrusion process used a couple of screw extruders. The extrusion parameter was kept constant at a feed moisture content of 25%, barrel temperature of $120^{\circ}C$ and screw speed of 400 rpm. GPR was prepared by batch popping machine after gelatinization of rice. In order to evaluate the physicochemical properties of ER and GPR, as well as the gelatinization rate, water soluble index (WSI), water adsorption index (WAI), DPPH radical scavenging activity and total dietary fiber content, the color value was carried out. The gelatinization rate was similar to 71.1~73.8%. Further, the results of WSI and WAI were increased at ER and GPR compared to the raw materials; ER was also higher than GPR. DPPH radical scavenging activity and total dietary fiber content showed a tendency to reduce after extrution and popping. As a result of the color value, the L value of ER decreased more than the raw materials, whereas GPR increased at a and b values.

Effect of Ohmic Heating on Thermal and Water Holding Property of Starches (옴가열이 전분의 열적 특성과 흡수력에 미치는 영향)

  • Cha, Yun-Hwan
    • The Korean Journal of Food And Nutrition
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    • v.27 no.1
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    • pp.112-119
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    • 2014
  • Ohmic heating uses electric resistance heat which occurs equally and rapidly inside food when the electrical current is transmitted into. Prior to the study, we have researched the potato starch's thermal property changes during ohmic heating. Comparing with conventional heating, the gelatinization temperature and the range of potato starch treated by ohmic heating are increased and narrowed respectively. Herein, we have studied thermal property changes of wheat, corn, potato and sweet potato starch by ohmic heating as well as conventional heating. And then we measure the water holding capacity of starches. Annealing of starch is a heat treatment method heated at 3~4% below the gelatinization point. This treatment changes the starch's thermal property. In the DSC analysis of this study, the $T_o$, $T_p$, $T_c$ of all starch levels have increased, and the $T_c$-$T_o$ narrowed. In the ohmic heating, the treatment sample is extensively changed but not with the conventional heating. From the ohmic treatment, increases from gelatinization temperature are potato ($8.3^{\circ}C$) > wheat ($5.3^{\circ}C$) > corn ($4.9^{\circ}C$) > sweet potato ($4.5^{\circ}C$), and gelatinization ranges are potato ($7.9^{\circ}C$), wheat ($7.5^{\circ}C$), corn ($6.1^{\circ}C$) and sweet potato ($6.8^{\circ}C$). In the case of conventional treatment, water holding capacity is not changed with increasing temperature but the ohmic heating is increased. Water holding capacity is related to the degree of gelatinization for starch. This result show that when treated with below gelatinization temperature, the starches are partly gelatined by ohmic treatment. When viewing the results of the above, ohmic treatment is enhanced by heating and generating electric currents to the starch structure.

Varietal Variation of Alkali Digestion Value and Its Relationship with Gelatinization Temperature and Water Absorption Rate of Milled Rice Grain (쌀 알칼리붕괴반응의 품종간 변이와 호화온도 및 수분흡수율과의 관계)

  • Kwang-Ho Kim
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.37 no.1
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    • pp.28-36
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    • 1992
  • Fifty rice varieties were tested for alkali digestibility of milled rice grain at four different KOH levels, and twenty-four varieties selected were tested again for alkali digestibility at different degrading times and KOH levels. Gelatinization rate at several heating times and heating temperatures, and water absorption rate at 21$^{\circ}C$ and 77$^{\circ}C$ water temperatures were observed using rice samples of twenty-four varieties to clarify the relationship between alkali digestibility response, gelatinization rate and water absorption rate. Varietal difference of ADV in Japonica and Tongil tye rices was biggest at KOH 1.2%, but it was better to test at KOH 1.2% and 1.4% levels to know the exact alkali digestibility response of rice varieties. Rice varieties tested could be classified into three groups, low, intermediate and high, based on their alkali digestibility response at four KOH levels, and most of Korean cultivated rice varieties were belonged to intermediate or high ADV group. Varietal variation was also found in alkali degrading response at different soaking times in alkali solution. Low ADV varietal group showed higher gelatinization temperature and needed longer heating time for complete gelatinization compared with intermediate or high ADV group. Same trends was found between intermediate and high ADV groups, but varietal variation in the same ADV group was also found in gelatinization temperature and heating time needed for complete gelatinization of rice grain. Water absorption rate of low ADV group was lower than intermediate or high ADV group both at 21$^{\circ}C$ and 77$^{\circ}C$ water temperatures, and intermediate ADV group showed lower absorption rate than high ADV group only in initial water absorption stage at 21$^{\circ}C$.

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Comparative Degree of Gelatinization and Retrogradation on Gamkugsulgie with Added of Gamkug (감국 첨가에 의한 감국설기의 호화 및 노화도 비교)

  • 박금순;최미애;임정교
    • Journal of the East Asian Society of Dietary Life
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    • v.10 no.6
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    • pp.514-521
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    • 2000
  • This study was induced to compare retrogradation and gelatinization in sulgie with added powder and flower of gamkug, which had been stored in 4$^{\circ}C$, 1$0^{\circ}C$ and 3$0^{\circ}C$, respectively. The addition of 5% powdered gamkug showed the highest degree of gelatinization while the control did the lowest. The degree of hardness of gamkugsulgie was lower than control and the following order 4$^{\circ}C$>1$0^{\circ}C$>3$0^{\circ}C$. Gamkugsulgie showed a little lower degree of retrogradation than control group. The degree of retrogradation at 4$^{\circ}C$ was far greater comparing with the other group. The degree of retrogradation were delayed as the storing temperature rose tran 4$^{\circ}C$ to 3$0^{\circ}C$, temperature namely, gamkugsulgie retrogradation time constant of the test group was slower 1.18 times at 4$^{\circ}C$. 1.24 times at 1$0^{\circ}C$ and 2.58 times at 3$0^{\circ}C$ than that of the control group.

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Studies on the Processing Properties and Interactions Between Porcine Blood Proteins and Waxy Rice Starch During Making Porcine Blood Cake

  • Lin, Chin-Wen;Yang, Jeng-Huh;Chu, Hsien-Pin;Su, Ho-Ping;Chen, Hsiao-Ling;Huang, Chia-Cheong
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.3
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    • pp.358-364
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    • 2001
  • The physiochemical properties and interactions between porcine blood and waxy rice were determined. Addition of calcium chloride (0.15%) improved acceptability of blood cake and increased the gelatinization degree of waxy rice. The water-holding capacity of porcine blood gel (blood/water=60/40, v/v), extent of absorption and gelatinization of waxy rice, and scanning electron microscopy showed that blood protein matrix and waxy rice are competitors for holding water in the cooking procedure. Non-haem iron content increased linearly (R=0.95) when heating temperature rose. The presence of blood proteins caused increasing of peak temperature (Tp) of gelatinization in differential scanning calorimetric thermal gram, The microstnlcture of plasma proteins and haemoglobin appeared continuous changes, and interacted with surface of waxy rice flour in terms of network and mosaic form, respectively. The electrophoretic patterns revealed an interaction between plasma proteins and waxy rice glutelin and haemoglobin when heated could be found at temperatures above $60^{\circ}C$.

Gelatinization Properties of Heat-Moisture Treated Potato and Sweetpotato Starches (수분 열처리한 감자 및 고구마전분의 호화 특성)

  • Kim, Sung-Kon;Lee, Shin-Young;Park, Yong-Kon
    • Korean Journal of Food Science and Technology
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    • v.19 no.5
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    • pp.435-440
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    • 1987
  • Gelatinization properties of heat-mositure treated potato and sweet potato starches were investigated. Water-binding capacity of starch was increased by heat-mositure treatment, which was more pronounced in sweet potato starch. Blue value was not affected by the treatment. Amylograph viscosities were decreased by heat-mositure treatment, which was more pronounced in potato starch. Critical concentration of NaOH for gelatinization of starch increased as moisture level increased. Gel volume of starch upon KSCN gelatinization was higher in potato starch. Gelatinized starches showed Binghamapseudoplastic behavior. Consistency index and yield stress were drastically decreased upon heat-moisture treatment.

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Rheological Properties of Gelatinization of Rice Starch (쌀 전분 호화중의 리올로지 특성)

  • Lee, Shin-Young;Cho, Hyung-Yong;Kim, Sung-Kon;Lee, Sang-Kyu;Pyun, Yu-Ryang
    • Korean Journal of Food Science and Technology
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    • v.16 no.3
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    • pp.273-278
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    • 1984
  • Changes in rheological properties of rice starch-water systems during the gelatinization were evaluated with the tube viscometer at temperatures between 50 and $85^{\circ}C$ and for the concentrations ranging from 3-5% rice starch. The flow consistency index increased exponentially with time at a particular temperature while being linearly dependent upon the concentration. The gelatinization rate measured by rheological method followed Arrhenius type equation. The value of activation energy of gelatinization for 5% rice starch was about 25 kcal/g mol.

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Characteristics of Dry and Moist Type Sweet Potato Starches (분질 및 점질 고구마 전분의 특성)

  • Shin, Mal-Shick;Ahn, Seung-Yo
    • Korean Journal of Food Science and Technology
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    • v.20 no.3
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    • pp.412-418
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    • 1988
  • Granular shapes and sizes, physicochemical priperties and gelatinization patterns of sweet potato starches from Wonki(the dry type) and Chunmi(the moist type) were investigated. Starch granules of sweet potatoes were round. Granule sizes of Wonki starch were mainly $11{\mu}m$ and those of Chunmi starch were $12{\mu}m\;and\;17{\mu}m$. Wonki starch had lower water binding capacity and swelling power than Chunmi starch. But Wonki starch had higher amylose content, gelatinization temperature, miture content for gelatinization and temperature for gelatinization than Chunmi starch.

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