• Applied Biological Chemistry
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• 제34권2호
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• pp.187-189
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• 1991

Gelatinization temperatures of upland and lowland waxy brown rice starches annealed at $25^{\circ}C$ and $60^{\circ}C$ for 24hr were investigated with differential scanning calorimetry No annealing effect was observed at low temperature. The upland rice starch showed narrower range of gelatinization temperature upon annealing treatment at $60\circ}C$ compared with the lowland rice starch. The enthalpy of gelatinization was not changed in case of the upland rice starch but was increased in case of the lowland one upon annealing.

• 펄프종이기술
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• 제39권4호
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• pp.14-20
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• 2007

The effects of blending starches with different gelatinization temperatures on the development of ply-bond strength were systematically investigated using a three component mixture design technique. Oxidized corn starches with different gelatinization temperatures were blended with natural corn starch and sprayed for plybonding. Optimum blend ratio for maximizing plybond strength improvement for the starch blends was 40% of natural starch, 27% of oxidized starch with low gelatinization temperature and 33% of oxidized starch with high gelatinization temperature. Starch granules with the lowest gelatinization temperature gelatinizes at the lowest temperature, while the natural corn starch gelatinizes at later stage of drying. The improvement of plybond strength with starch blends were verified on machine trial as well. Plybond strength improvement obtained from the machine trial was lower than that achievable with handsheets, which was attributed to the lower internal bond strength of the linerboards made from recycled fibers.

• 한국식품과학회지
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• 제24권1호
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• pp.70-73
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• 1992

옥수수 전분을 하이드록시프로필화 및 가교화시켜 변성 전분을 제조한 후 DSC, Amylograph 등을 이용하여 호화특성을 연구하고 호화액의 gel 특성을 조사하였다. 하이드록시프로필화에 의하여 옥수수 전분의 호화온도는 크게 떨어졌으며 가교화만을 시킨 전분은 호화온도가 약간 상승하였으며 호화엔탈피는 약간 감소하였다. 하이드록시프로필화와 가교화를 동시에 시켰을 때는 호화온도가 크게 떨어져 하이드록시프로필화만 시킨 것보다는 약간 높았으나 팽윤이 억제되었고 gel 조직강도는 증가하였다.

• Preventive Nutrition and Food Science
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• 제4권4호
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• pp.215-220
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• 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.

• 한국식품과학회지
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• 제27권3호
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• pp.428-438
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• 1995

Corn starch와 waxy corn starch를 사용하여 중간수분계의 수분함량으로 반죽을 제조하고 수분함량과 가열온도, 가열시간에 따른 전분 반죽의 호화양상을 밝혀 보고자 하였다. Corn starch와 waxy corn starch의 amylograph 호화 특성은 1% CMC를 첨가하여 측정한 호화개시 온도가 모두 약 $64^{\circ}C$로 나타났다. DSC특성은 corn starch호화 개시 온도가 $68.15^{\circ}C$, 최대호화온도가 $74.01^{\circ}C$, 호화종결 온도가 $85.65^{\circ}C$, 호화엔탈피는 3.2 cal/gram이었으며, waxy corn starch의 호화개시온도는 $68.24^{\circ}C$, 최대호화온도 $75.43^{\circ}C$, 호화종결온도 $93^{\circ}C$, 호화엔탈피는 4.2 cal/gram으로 나타났다. 수분함량$(X_1)\;36{\sim}52%)$, 가열온도$(X_2)\;60{\sim}100^{\circ}C$, 가열시간$(X_3)$ $0{\sim}2.0$분으로 가열시 corn starch와 waxy corn starch 반죽의 호화도(Y) 변화를 실험계획법으로 조사한 반응표면 회귀 방정식은 corn starch 반죽의 경우 $Y=28.659＋8.638\;X_1+15.675\;X_2+7.770\;X_3-1.620\;{X_1}^2+10.790\;X_1X_2-4.220\;{X_2}^2+0.510\;X_1X_3+1.980\;X_2X_3-6.850\;{X_3}^2$ $(R^2=0.9714)$ 이었고 waxy corn starch 반죽의 경우는 $Y=32.617+12.535\;X_1+20.470\;X_2+8.608\;X_3+4.093\;{X_1}^2+13.550\;X_1X_2-4.467\;{X_2}^2+1.560\;X_1X_3+2.160\;X_2X_3-9.527\;{X_3}^2$ $(R^2=0.9621)$이었다. 즉 수분함량과 가열온도, 가열시간이 증가할수록 반죽의 호화도는 모두 증가하는 경향을 나타내었고 같은 조건에서는 waxy corn starch가 corn starch 반죽보다 $10{\sim}20%$ 정도 더 호화되는 것을 알 수 있었다. Corn starch 와 waxy corn starch 반죽의 호화 속도를 보면 가열온도 $70^{\circ}C$와 $80^{\circ}C$에서는 가열시간 0.5분 이내에서 비교적 빠른 속도로 반죽이 호화되고 가열시간이 그 이상으로 증가할 때도 반죽의 호화가 약간은 진행되지만 $90^{\circ}C$ 이상의 가열온도에서는 가열시간 0.5분 이내에 반죽의 호화가 급속히 일어나고 가열 시간을 증가시켜도 더이상의 호화는 일어나지 않았다. 같은 조건에서는 waxy corn starch 반죽의 호화 속도가 corn starch보다 더 빠른 것으로 나타났다. 대표적으로 52% 수분함량에서 반응속도상수(k)와 가열온도(T)사이의 관계식은 corn starch의 경우 $logk=11.1140-4.1226{\times}10^3(1/T)$, waxy corn starch의 경우 $logk=10.1195-3.7090{\times}10^3(1/T)$이었다.

• 한국미생물·생명공학회지
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• 제23권4호
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• pp.416-424
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• 1995

Mechanism of the cyclodextrin (CD) production reaction by cyclodextrin glucanotransferase (CGTase) using swollen extrusion starch as substrate was investigated emphasizing the structural features of starch granule. The degree of gelatinization was identified to be the most representative structural characteristic of swollen starch. The most suitable degree of gelatinization of swollen starch for CD production was around 63.52%. The structural transformation of starch granule during enzyme reaction was also followed by measuring the changes of the degree of gelatinization, microcrystallinity, and accessible and inaccessible portion to CGTase action of residual swollen starch. The adsorption phenomenon of CGTase to swollen starch was also examined under various conditions. The inhibition mechanism of CGTase by various CDs was identified to be competitive, most severely by a-CD. The mechanism elucidated will be used for development of a kinetic model describes CD production reaction in heterogeneous enzyme reaction system utilizing swollen extrusion starch.

• Journal of Ginseng Research
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• 제5권2호
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• pp.114-121
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• 1981

Starch was isolated from 4-year-old and 6-year-old ginseng roots and its physical and chemical characteristics were studied. The results obtained were summarized as follows. 1. The shape of ginseng starch granules was polygonal and rounded with its granule size ranging from 2.0 to 7.5$\mu$. The swelling power of 4-year-old ginseng starch was much greater than that of 6-year old ginseng starch. Gelatinization pattern showed that 6-year-old ginseng starch gelatinized rapidly at $65^{\circ}C$, whereas 4-year-old starch continued to gelatinize, without having a definite gelatinization temperature as temperature increased 3. Amylogram of ginseng starch showed that gelatinization initiated at 61$^{\circ}C$ and was completed at 88$^{\circ}C$ with its viscosity reaching at 810 B.U. 4. The amylose contents were 32% and 9% for 4-year-old and 6-year-old ginseng starch, respectively. 5. X-ray diffraction analyses indicated that there were some structural differences between 4-year-old and 6-year-old ginseng starch.

• 한국식품영양학회지
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• 제27권1호
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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.

• 한국식품조리과학회지
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• 제16권5호
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• pp.431-436
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• 2000

Gelatinization properties of potato starches which were prepared by steeping at 10 ${\pm}$ 1$^{\circ}C$ or 25 ${\pm}$ 1$^{\circ}C$ for 11 days were investigated. The pasting and initial gelatinization temperatures measured by rapid visco-analyzer (RVA) were increased, but the peak and trough viscosities of potato starch were decreased by steeping. The onset temperature, peak temperature, conclusion temperature, and enthalpy of gelatinization were increased by steeping as measured by DSC. The contents of hot-water-soluble carbohydrate and amylose in potato starch were decreased by steeping.

• 한국식품과학회지
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• 제20권3호
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• pp.412-418
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• 1988

분질 고구마인 원기와 점질 고구마인 천미로부터 전분을 분리하여 입자의 형태, 이화학적 성질, 호화양상을 조사 하였다. 전분입자는 모두 둥근형이고 입자의 크기는 원기 전분은 $11{\mu}m$ 천미 친분은 $12{\mu}m$ 및 $17{\mu}m$의 입자가 주를 이루었다. 원기 전분은 천미 전분에 비하여 물결합 능력과 팽화력이 낮았으나 아밀로오스함량, 호화온도, 호화에 필요한 수분량 및 호화에 필요한 최저 온도등이 더 높았다.