• Title/Summary/Keyword: gelatinization

Search Result 621, Processing Time 0.128 seconds

Effects of Heating Temperature, Time and Additives on Gelatinization of Potato Starch (가열온도(加熱溫度), 시간(時間) 및 첨가제(添加劑)가 감자 전분(澱粉)의 호화(糊化)에 미치는 영향(影響))

  • Chang, Young Il;Chang, Kyu Seob;Yoon, Han Kyo
    • Korean Journal of Agricultural Science
    • /
    • v.16 no.1
    • /
    • pp.102-110
    • /
    • 1989
  • Surface structure and X-ray diffractogram of gelatinized potato starch on heating temperature, time and additives were investigated by Scanning Electron Microscopy (SEM) and X-ray diffractometry. The results obtained are as follows; Potato starch had an amylose content of 23.5%, and blue value of 0.41. Raw potato starch granuls showed egg form. Destruction of starch granuls increased as gelatinizing time and temperature increased. The degree of gelatinization of potato starch showed to be 90% by X-ray diffractomertry at $70^{\circ}C$. There were no significant differences in degree of gelatinization of potato starch on gelatinizing time and phosphate concentration at $70^{\circ}C$. The degree of gelatinization of sample prepared was higher in presence of phosphate than in absence of phosphate.

  • PDF

Differential Scanning Calorimetry of Rice Starch (쌀 전분의 Differential Scanning Calorimetry)

  • Hyun, Chang-Kee;Park, Kwan-Hwa;Kim, Young-Bae;Yoon, In-Hwa
    • Korean Journal of Food Science and Technology
    • /
    • v.20 no.3
    • /
    • pp.331-337
    • /
    • 1988
  • The thermal properties of typical five Indica and five Japonica rice varieties were investigated by Differential Scanning Calorimetry (DSC). There was no significant difference in gelatinization temperature between Indica and Japonica varieties, but the average enthalpy of gelatinization was larger in Indica types than that in Japonica. However, the enthalpy of melting of amylose-lipid complex was larger in Japonica types than that in Indica types. The DSC thermogram of hydrolyzed rice residue included a smaller peak of gelatinization with narrow range of temperature. Retrogradation of gelatinized rice kernel was also determined with DSC theremograms. The endothermic peak areas clearly increased with increasing storage time at $4^{\circ}C$ so that the area could be used as a measure of the relative degree of retrogradation. The results indicated that Samgang variety(Indica) retrograded more rapidly than Chuncheong variety(Japonica).

  • 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.

Molecular Structure and Gelatinization Properties of Turnip Starch (Brassica rapa L.)

  • Kim, Nam-Hee;Yoo, Sang-Ho
    • Food Science and Biotechnology
    • /
    • v.14 no.4
    • /
    • pp.470-473
    • /
    • 2005
  • Starch was isolated from turnip (Brassica rapa L.), and to elucidate the structure-function relationship its structural and physical properties were characterized. Morphological structure of the starch was analyzed by SEM (Scanning Electron Microscopy). Most of the starch granules were spherical in shape with diameter ranging from 0.5-10mm. Apart from larger granules ($<10\;{\mu}m$) which dominated the population size of turnip starch, significant amount of small ($0.5-2\;{\mu}m$) and mid-size granules (${\sim}\;{\mu}m$) were also detected. It was revealed that presumably, erosion damages occurred due to the attack of amylase-type enzymes on the surface of some granules. Branch chain-length distribution was analyzed by HPAEC (High-Performance Anion-Exchange Chromatography). The chain-length distribution of turnip starch revealed a peak at DP12 with obvious shoulder at DP18-21. The weight-average chain length ($CL_{avg}$) was 16.6, and a large proportion (11.8%) of very short chains (DP6-9) was also observed. The melting properties of starch were determined by DSC (Differential Scanning Calorimetry). The onset temperature ($T_o$) and the enthalpy change (${\Delta}H$) of starch gelatinization were $50.5^{\circ}C$ and 12.5 J/g, respectively. The ${\Delta}H$ of the retrograded turnip starch was 3.5 J/g, which indicates 28.2% of recrystallization. Larger proportion of short chains as well as smaller average chain-length can very well explain relatively lower degree of retrogradation in turnip starch.

Quality Characteristics of Chalduk according to the Soaking Time of Glutinous Rice in Water (수침 시간을 달리한 찹쌀가루로 제조한 찰떡의 품질 특성)

  • Jung, Eun-Jin;Woo, Kyung-Ja
    • Journal of the East Asian Society of Dietary Life
    • /
    • v.16 no.6
    • /
    • pp.677-683
    • /
    • 2006
  • Glutinous rice cake(Chalduk) was made by varying the hours of soaking time of glutinous rice in the water(0, 4, 8, 12, 24 hours). After storage for various periods, the sensory and physical characteristics and the degree of gelatinization were examined in order to determine the effect of glutinous rice soaking period on the quality of Chalduk. The results of the study are summarized as follows. In the sensory test, 8-hour water soaking produced the significantly highest score for salty taste, while 0-hour water soaking had the lowest score. Four-hour water soaking had the significantly highest score for the degree of chewiness. Eight-hour water soaking had the significantly highest score for overall desirability. For the moisture content of Chalduk covered with bean flour, 8-hour water soaking produced the highest moisture content but the difference was not significant. For the degree of gelatinization, 8-hour water soaking had the highest maltose content, which confirmed the suitability of 8-hour water soaking glutinous rice. Eight-hour water soaking had the lowest hardness. With increasing storage period, the hardness sharply increased. Elasticity was higher for the long-period immersed samples than for the non-immersed samples. In conclusion, an 8-hour soaking time for glutinous rice in water was proposed to maximize the Chalduk quality.

  • PDF

Study on the Structure of Expanded Rice with Deep-Frying for Salyeotgangjung (유탕처리된 쌀엿강정용 팽화쌀의 조직학적 연구)

  • Kim, Myoung-Ae
    • Journal of the Korean Society of Food Culture
    • /
    • v.16 no.4
    • /
    • pp.323-329
    • /
    • 2001
  • This study was carried out to observe the character change of expanded rice grain for Salyeotgangjung at various gelatinization methods. The expansion and structure change of rice grain was different at conditions of heating methods and gelatinization, respectively. The boiling showed good expansion compared to other heating methods by electric rice-cooker, pressure cooker, and steam cooker. There was not difference in expansion of rice grain between the boiling and the boiling after soaking. Rice grain did greatly expand as the boiling time was extended. But the quality for Salyeotgangjung would be not good because of crack of expanded rice grain surface when the boiling time was too long.

  • PDF

The Quality and Storage Characteristics of Jeung-Pyun prepared with Opuntia ficus-india var. Sabolen powder (백년초 분말의 첨가비율과 저장에 따른 증편의 품질 특성)

  • 김기숙;이소영
    • Korean journal of food and cookery science
    • /
    • v.18 no.2
    • /
    • pp.179-184
    • /
    • 2002
  • This study was carried out to investigate the effects of adding prickly pear (Opuntia ficus-india var. Sabolen) on the quality characteristics of Jeung-Pyun, a traditional fermented Korean rice cake, and to find out an appropriate ratio of prickly pear powder to give a favorable color. Changes in the quality characteristics of prickly pear-added Jeung-Pyun during storage period were also studied. As the addition of prickly pear powder was increased from 1 to 3%, the degrees of expansion and gelatinization of Jeung-Pyun were increased. The degree of gelatinization and hardness were changed slowly during storage at room temperature (20$^{\circ}C$). In sensory evaluation, control Jeung-Pyun samples without prickly pear powder was preferred to that with prickly pear powder, but it was not significant up to 2% prickly pear powder. In the case of Jeung-Pyun containing 2% prickly pear powder, those stored for 12 hr received higher sensory scores than those right after being manufactured. In general, Jeung-Pyun samples with 2% prickly pear powder was favored. The addition of prickly pear powder was likely to improve the preservation property of Jeung-Pyun.

Gelatinization Properties of Pigmented Rice Varieties (유색미의 품종별 호화 특성)

  • Ha, Tae-Youl;Park, Sung-Hee;Lee, Sang-Hyo;Kim, Dong-Chul
    • Korean Journal of Food Science and Technology
    • /
    • v.31 no.2
    • /
    • pp.564-567
    • /
    • 1999
  • Gelatinization characteristics of pigmented rice varieties were determined in terms of amylose contents, amylograph, gel consistency, water absorption index (WAI) and water soluble index (WSI). Amylose contents of black and red rice were lower than those of brown rice, especially Sanghaehyanghyulla exhibited the lowest amylose contents among the pigmented rice varieties tested. There was no significant difference in WAI among the pigmented rice varieties, but WSI was lower in red rice than the others. Peak viscosity of black rice measured in a Brabender amylograph was lower than those of red and brown rice.

  • PDF

Quality Characteristics of Rice Noodles Supplemented with Turmeric, Purple Sweet Potato, or Seaweed (Hizikia fusiforme) (강황, 자색고구마, 톳을 첨가한 쌀국수의 품질 특성)

  • Hwang, Seong-Yun;Kang, Kun-Og
    • Journal of the East Asian Society of Dietary Life
    • /
    • v.23 no.2
    • /
    • pp.211-217
    • /
    • 2013
  • We investigated the quality characteristics of rice noodles supplemented with turmeric, purple sweet potato, or seaweed (Hizikia fusiforme). RVA (Rapid Visco Analyser), color, water activity, texture, and cooking properties were tested. Initial gelatinization temperature of noodles containing turmeric were the highest. Peak viscosity, holding strength, break down, final viscosity, and set back of noodles containing purple sweet potato were highest, indicating that the gelatinization state was more unstable and retrogradation would occur faster. The L value of the seaweed noodle was the lowest, while the a and b value of the turmeric noodles were $7.3{\pm}0.3$ and $40.2{\pm}1.3$ respectively, higher values than turmeric and seaweed noodles. Water activity of the seaweed noodle was 0.665, higher than turmeric and purple sweet potato noodles. Cooking properties (including weight, volume, and water absorption) and turbidity of seaweed noodles showed the highest growth rate. In terms of texture, the hardness was highest in purple sweet potato noodles, and the cohesiveness and gumminess was highest in seaweed noodles. The quality characteristics of rice noodles supplemented with turmeric, purple sweet potato, or seaweed showed that seaweed noodles were stable in gelatinization and cooking properties.

Characteristics of Dough with Red Ginseng Marc Powder (홍삼박 분말을 첨가한 반죽의 특성)

  • Han, In-Jun;Kim, Mun-Yong;Chun, Soon-Sil
    • Journal of the East Asian Society of Dietary Life
    • /
    • v.17 no.3
    • /
    • pp.371-378
    • /
    • 2007
  • Red ginseng has been considered a functional food, and many studies on red ginseng and the prevention of cancer, hypertension, arteriosclerosis and constipation have been conducted. In this study, white bread dough with 1, 2, 3, 4 or 5% red ginseng marc powder was measured by a farinograph, extensograph, amylograph, as well as for pH to evaluate the development time, stability, extensibility, resistance to extension, gelatinization temperature, and maximum viscosity temperature. The ash content of the wheat flour increased with an increasing content of red ginseng marc powder. The gelatinization maximum and the temperature for the gelatinization maximum of the flour-water suspension in the amylograph were not affected by the addition of red ginseng marc powder. The moisture absorption of the wheat flour in the farinograph increased as the content of red ginseng marc powder increased. Also, as the content of red ginseng marc powder increased, dough development time decreased. The extensibility of the dough in the extensograph showed a negative relationship with the amount of red ginseng marc powder added.

  • PDF