• Title, Summary, Keyword: gelatinization

Search Result 618, Processing Time 0.042 seconds

A study on Reducing Power, Degree of Gelatinization and Retrogradation Rate of Soybean Jeolpyon (콩절편의 소화율, 호화도 및 노화속도)

  • 정해옥
    • Korean journal of food and cookery science
    • /
    • v.12 no.2
    • /
    • pp.162-165
    • /
    • 1996
  • Various kinds of jeolpyon (cubed rice cake) differing in roasted soybean flour. content (0, 5, 10, 15, 20%) were prepared to study digestibility, degree of gelatinization and retrogradation rate. Digestibility slightly in creased as soybean content increased. Degree of gelatinization also increased as soybean content increased. Retrogradation rate obtained from the changes in hardness of soybean jeolpyon with the control was 0.528 day and time constant (1/k) was 1.89 days.

  • PDF

Physicochemical Factors Affecting Cooking and Eating Qualities of Rice and the Ultrastructural Changes of Rice during Cooking (쌀의 취반 및 식미특성에 영향을 주는 요인들과 취반 시 쌀의 배유 조직의 변화)

  • 이영은;오스만엘리자베쓰엠
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.20 no.6
    • /
    • pp.637-645
    • /
    • 1991
  • Physicochemical factors affecting cooking and eating quality of rice and their mechanisms were investigated. The stickiness of cooked rice was negatively correlated with amylose content(r=0.58, p<0.05) and protein content(r=-0.72, p<0.01), but not affected by crude fat content of rice. The ultrastructure of cooked rice grain showed the progressive gelatinization of starch from the periphery toward the center of the endosperm as water and heat energy diffused into. The rate of water diffusion appears to be dependent on the cell arrangement in the endosperm and the protein content of milled rice. Once water and heat reach the starch granules, the rate of in situ gelatinization of starches appears to be dependent on their own gelatinization temperature range and amylose content. Protein acts as a barrier for the swelling of starch and water diffusion in two ways : 1) by encasing starch granules in the starchy endosperm, and 2) by forming a barrier between the subaleurone layer and the starchy endosperm. Therefore, the separation and fragmentation of the outermost layers of the endosperm occurred more easily in the low-protein content rices, and was associated with increases of solids lost in cooking-water at 95$^{\circ}C$ and stickiness of cooked rice.

  • PDF

Factors Affecting Gelatinization Temperature of Rice Starch (쌀 전분의 호화온도에 영향을 주는 요인들)

  • 이영은;오스만엘리자베쓰엠
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.20 no.6
    • /
    • pp.646-652
    • /
    • 1991
  • Factors affecting gelatinization temperature of rice starches from different varieties were investigated. Birefringence end-point temperature(BEPT), amylose content, granule size distribution and degree of crystallinity of rice starches showed the significant varietal differences at ${\alpha}\;=0.01$. Susceptibility of the granule to gelatininzation was dependent mainly on the degree of crystallinity, as indicated by the significant positive correlation between BEPT and the relative crystallinity(r=0.67, p<0.01). However, granule size distribution did not affect the GT(gelatinization temperature) range, nor did amylose electron microscopy (SEM). SEM also confirmed that there is no relationship between the size and the shape and the amylose content of the rice starch.

  • PDF

Physicochemical Properties of Japonica Non-Waxy and Waxy Rice during Kernel Development

  • Kim, Sung-Kon;Jung, Sun-Ok
    • Food Science and Biotechnology
    • /
    • v.15 no.2
    • /
    • pp.289-297
    • /
    • 2006
  • In this study we examined the changes in weight and dimension, protein and amylose contents, and pasting properties of brown rice flour, as well as the gelatinization properties of starch, from two non-waxy japonica cultivars and one waxy japonica cultivar planted in an experimental field in 2002 under the same fertilizer conditions. The weight of both rough and brown rice increased consistently up to 42 days after flowering (DAF) for the non-waxy rice and to 35 DAF for the waxy rice. The changes in dimension of the brown rice kernel indicated that the length was maximized first, followed by breadth and then thickness. The protein content of the non-waxy rice remained fairly constant, but that of the waxy rice decreased by about 1% after 14 DAF. The amylose content of the non-waxy brown rice flour increased, but that of the waxy brown rice flour decreased during kernel development. As the kernel developed, the peak viscosity of the non-waxy rice flour increased up to 35 DAF, after which it decreased, whereas that of the waxy brown rice flour increased consistently. The gelatinization temperature of starch also increased in the waxy rice during kernel development up to 21 DAF. The gelatinization enthalpy of starch, however, increased in all rice cultivars throughout the kernel development.

Effects of Various Salts on the Reheating Behavior of Retrograded Rice Starch and Cooked Rice

  • Han, Sung-Hee;Kim, Bo-Reum;Lee, Seog-Won;Rhee, Chul
    • Preventive Nutrition and Food Science
    • /
    • v.16 no.2
    • /
    • pp.157-164
    • /
    • 2011
  • The influence of sodium salts and chlorides at various concentrations (0.05, 0.10, 0.50, and 1.00%) on the reheating behavior of retrograded rice starch and cooked rice was investigated. The degree of gelatinization of the all retrograded rice starch gels and the cooked rice containing sodium salts and chlorides increased after reheating compared to the starches without salt. Gelatinization also showed an increasing trend as the concentration of sodium salts and chlorides increased. The increase of gelatinization after reheating the samples containing sodium salts and chlorides was greater than 38.0%. The reheated retrograded rice starch and cooked rice containing $Na_3PO_4$ showed the lowest set back value and retrogradation rate constant. Among all the samples, the cooked sample containing $Na_3PO_4$ showed the highest increment of gelatinization after reheating. Also, this same sample showed the lowest retrogradation degree.

Effects of Particle Size and Gelatinization of Job's Tears Powder on the Instant Properties

  • Han, Sung-Hee;Park, Soo-Jea;Lee, Seog-Won;Rhee, Chul
    • Preventive Nutrition and Food Science
    • /
    • v.15 no.1
    • /
    • pp.67-73
    • /
    • 2010
  • The effects of particle sizes (small, medium and large sizes) and gelatinization treatment on the changes of the instant properties of Job's tears powder were investigated. The degree of gelatinization on the different particle size samples of Job's tears powder was the highest in the small particle size, and it also showed an increasing trend regardless of pregelatinizing whether it is or not as the particle size decreased from large particle size to small particle size. The water solubility index of the pregelatinized samples was high compared to that of ungelatinized samples regardless of particle size and temperatures. The water absorption and swelling power increased as particle size and temperature were increased. The dispersibility and sinkability of ungelatinized sample was increased as particle size and temperature were increased and it also showed lower value regardless of particle size and temperature. However, the dispersibility and sinkability of pregelatinized samples were shown to have the opposite result, such that the smallest particle size of pregelatinized sample had the lowest sinkability (11.3%). The turbidity of the pregelatinized small particle size was the highest by a factor of 1.08.

The Influence of the Annealing of Corn Starch on the formation and Characteristics of Enzyme-resistant Starch

  • Yoon, Ji-Young;Lee, Young-Eun
    • Preventive Nutrition and Food Science
    • /
    • v.4 no.4
    • /
    • pp.215-220
    • /
    • 1999
  • The Physical properties of corn starch were investigated by scanning electron microscopy, X-ray diffractometry and differential scanning calorimetry during the formation of enzyme-resistant starch(RS). Samples were studied in their native states and after annealing at 50, 55, 60 and 65℃ in excess water(starch : water=1:3) for 48hr. Starch granules became smaller and more rounded after annealing than in their native state. Annealing did not change the X-ray profile of native corn starch. After autoclaving-cooling cycles, native starch lost most of its crystallinity but annealed ones showed some of their crystallinity left as diffuse or poor B-type, which didn't relate to increasing Rs yields. During formation of RS, however, both native and annealed starches changed their X-ray profile from A-type to poor B-type of retrograded amylose. Annealing caused an increase in gelatinization temperature and enthalpy, but a narrowing of gelatinization temperature range. Only starch annealed at 65℃, however, showed a decrease in enthalpy even though its gelatinization temperature increased, which appeared to be due to the partial gelatinization in the amorphous region during annealing. Peak height index(PHI), the ratio of ΔH to Ti-To, increased by annealing. PHI values, therefore, showed the possibility as an indicator to predict RS yield which cannot be differentiated by differential scanning calorimetry and X-ray diffraction data.

  • PDF

In-Process Control of an Infant Formula with Rice Starch using Rheology (쌀 전분의 유동성을 함유한 영.유아용 조제분유의 공정 관리)

  • Heo, Young-Suk;Konuklar, Gul
    • Journal of Dairy Science and Biotechnology
    • /
    • v.26 no.2
    • /
    • pp.45-49
    • /
    • 2008
  • We studied the feasibility of monitoring and controlling the manufacturing process of an infant formula with rice starch by testing in-process samples using rheology. We used DSC to first determine the gelatinization temperature of the rice starch, a key ingredient of this product. With this characteristic temperature and the process design known, rheological measurements were conducted on the in-process samples for detecting the presence and extent of gelatinization and retrogradation of rice starch; in-process samples were collected from the carbohydrate tank, after the homogenizer, and the finished product tank. The correlation between the rheological measurements on these samples and manufacturing performance proved that rheology is a very sensitive tool for monitoring the structural development of this infant formula during main process, and their influence on sterilization efficiency. We observed that the lower degree of gelatinization during main process, a shorter residence time in the finished product tank, and using caustic flush rather than clean-in-place additively lead to higher sterilization efficiency. These findings can be utilized for a rational design and analysis of the manufacturing process for infant formulas containing rice starch.

  • PDF

Physicochemical Characteristics of Starches in Rice Cultivars of Diverse Amylose Contents

  • Yoon, Mi-Ra;Chun, A-Reum;Oh, Sea-Kwan;Hong, Ha-Cheol;Choi, Im-Soo;Lee, Jeong-Heui;Cho, Young-Chan;Kim, Yeon-Gyu
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.57 no.3
    • /
    • pp.226-232
    • /
    • 2012
  • Through the sampling four rice cultivars with differing amylose contents, the relationship between the structural and gelatinization properties of endosperm starches was analyzed. These rice varieties exhibited different chain length distribution ratio within the amylopectin cluster as well as varing amylose levels. The proportion of amylopectin short chains of in Goami cutlivars was higher than the other varieties, whereas the Goami 2 which shows amylose extender mutant properties in the endosperm showed the highest proportion of long chains. In X-ray diffraction analysis of rice starches, the Goami 2 variety displayed a B-type pattern whereas the other varieties were all A-type. Among the cultivars with high and normal rice starch levels, those with the higher amylose contents showed distinctly lower swelling. Goami 2 rice was found to have the highest onset and peak gelatinization temperature from the differential scanning calorimetry results. The four rice cultivars under analysis also showed different rates of hydrolysis by amyloglucosidase. These findings suggest that the composition and chemical structure of the starch content is a major determinant of both the gelatinization and functional properties of rice.

Gelatinization Properties of Starch Dough with Moisture Content, Heating Temperature and Heating Time (수분함량, 가열온도 및 가열시간에 따른 전분 반죽의 호화특성)

  • Lee, Boo-Yong;Lee, Chang-Ho;Lee, Cherl-Ho
    • Korean Journal of Food Science and Technology
    • /
    • v.27 no.3
    • /
    • pp.428-438
    • /
    • 1995
  • The gelatinization properties of corn and waxy corn starch doughs were examined at various moisture contents, heating temperatures and heating times. The onset temperatures of gelatinization with 1% CMC using Brabender Amylograph were $64^{\circ}C$ for both corn and waxy corn starch. In the gelatinization properties using DSC, onset temperature$(T_o)$, maximum peak temperature$(T_p)$, completion temperature$(T_c)$ and enthalpy of the corn starch were $68.15^{\circ}C,\;74.01^{\circ}C,\;85.65^{\circ}C$ and $3.2\;cal/gram$ respectively. While those of the waxy corn starch were $68.24^{\circ}C,\;75.43^{\circ}C,\;93^{\circ}C$ and $4.2\;cal/gram$ respectively. In enzymatic analysis, when the moisture content increased from 36% to 52% and heating temperature from $60^{\circ}C$ to $100^{\circ}C$, the gelatinization degree of starch dough increased from about 10% to about 62%. The gelatinization degree of waxy corn starch dough was $15{\sim}20%$ higher than that of corn starch dough under the same gelatinization conditions. The regression equations of gelatinization degree (Y) of starch dough in the range of $36{\sim}52%$ moisture content $(X_1)\;60{\sim}100^{\circ}C$ heating temperature $(X_2)\;and\;0{\sim}2.0$ min heating time $(X_3)$ were examined using response surface analysis. The regression equation of corn starch dough was: $Y=28.659+8.638\;X_}+15.675\;X_2+7.770\;X_3-1.620\;{X_1}^2+10.790\;X_1X_2-4.220\;{X_2}^2+0.510\;X_1X_3+1.980\;X_2X_3-6.850\;{X_3}^2\;(R^2=0.9714)$ and that of waxy corn starch dough was: $Y=32.617+12.535\;X_1+20.470\;X_2+8.608\;X_3+4.093\;{X_1}^2+13.550\;X_1X_2-4.467\;{X_2}^2+1.560\;X_1X_3+2.160\;X_2X_3-9.527\;{X_3}^2$\;(R^2=0.9621)$. As the moisture content, heating temperature and heating time increased, the reaction rate constant(k) of gelatinization increased. The greatest reaction rate constant was observed at initial 0.5 min heating time of 1st gelatinization stage. At the heating temperature of $90^{\circ}C$, gelatinization of starch dough was completed almost in the initial 0.5 min heating time. The reaction rate constant of waxy corn starch dough was higher than that of corn starch dough under the same gelatinization conditions. At the 52% moisture content, the regression equation between reaction rate constant(k) and heating temperature(T) for corn starch dough was $log\;k=11.1140-4.1226{\times}10^3(1/T)$ (r=-0.9520) and that of waxy corn starch dough was $log\;k=10.1195-3.7090{\times}10^3(1/T)$ (r=-0.9064).

  • PDF