• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1125-1129
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• 2008

Polypropylene (PP)/corn starch master batch(starch-MB) blends with different PP compositions of 90, 80, 70, and 60 wt% were prepared by melt compounding at $200^{\circ}C$, using lab scale Brabender mixer. The chemical structures, thermal properties and non-isothermal crystallization behavior of the PP/starch-MB blends were investigated by FT-infrared spectrometry (FT-IR), differential scanning calorimetry (DSC), and thermogravimetric analyzer (TGA). The fabrication of the PP/starch-MB blend was confirmed by the existence of hydroxy group in FT-IR spectrum. There was no district change in melting temperature and melting enthalpy, and TGA curve indicates a decrease in degradation temperature with starch-MB content. The non-isothermal crystallization process was analyzed using by Avrami equation. The Avrami exponents were in the range of 2.71-3.97 for PP and 1.48-1.99 for PP/starch-MB blonds. The activation energies calculated by Kissinger method were 233 kJ/mol for PP, 484 kJ/mol for PP90, 541 kJ/mol for PP80, 553 kJ/mol for PP70, and 422 kJ/mol for PP60.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.928-933
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• 1995

Sensory and instrumental characteristics of mixed starch gels of defatted corn starch and mung bean starch were examined in terms of the effects of various additives such as textured soy protein(TSP), soybean oil(S0), carboxymethyl cellulose(CMC) and pectin(PC). Gels were prepared by storing the paste at room temperature for 24 hrs and 72 hrs. The additives were used 1% or 2% on the starch basis. The ratio of defatted corn starch and mung bean starch was selected 60 : 40(to, w/w), where the acceptability was the highest. The cohesiveness and springiness of the mixed starch gels stored 24 hrs increased, but the brittleness and acceptability decreased with all the additives. Textural characteristics of the mixed gels stored 72 hrs were different according to the type and content of additives, whereas hardness and cohesiveness increased in all case. Unlike the sensory evaluation, the textural properties of mixed gels tested by a Instron Universal Testing Machine showed no difference in hardness, but the cohesiveness and springiness increased.

• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.11-16
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• 1984

Rheological properties of waxy and non-waxy rice starch solutions were evaluated with a narrow gap rotational and Cannon Fenske viscometers. The gelatinized rice starch solutions containing 0.2-1.0% starch displayed pseudoplastic flow behavior. At higher starch level, degree of pseudoplasticity of waxy rice starch solutions increased, while that of non-waxy rice did not changed apparently. The consistency coefficient (K) of non-waxy rice starch solutions increased with increasing gelatinization temperature, but waxy rice starch solutions remained constant, and in alkaline aqueous solutions both of them showed increasing K values. The value of K increased exponentially with an increase in concentration. The effect of the temperature on the viscosity of the solutions followed Arrhenius' type equation, and the activation energies were in the range of 3.675-3.775 kcal/g-mol that were near to that of pure water. The changes of reduced viscosity with concentration were followed Huggin's equation and the values of intrinsic viscosity and interaction coefficient were 0.78-1.59 dl/g and 0.67-2.75, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.8
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• pp.1102-1105
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• 2006

The effect of heat treatments on in vitro starch hydrolysis of proso millet, sorghum, Job's tears, and buckwheat by pancreatic ${\alpha}-amylase$ was investigated. Grain samples were tested raw, boiled in water, or steamed/roasted. Starch content of the grains varied from 59.5% in Job's tears to 65.5% in proso millet, and amylose content varied from 5.3% in Job's tears to 36.3% in buckwheat. The in vitro starch hydrolysis of raw and heat-treated grains continuously increased during 60 min of hydrolysis. The starch hydrolysis (%) of raw grains after 60 min incubation was in the order of buckwheat (5.7%), proso millet (33.0%), Job's tears (51.2%), and sorghum (57.6%). Grains treated with steaming/roasting appeared to have higher starch hydrolysis rates than those with boiling except proso millet. Hydrolysis rates of buckwheat with a high amylose content appeared to be lower, compared to proso millet, sorghum, and Job's tears containing low amylose contents.

• Korean Journal of Food Science and Technology
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• v.53 no.5
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• pp.521-526
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• 2021

This study characterized the chemical structure and physical properties of domestic commercial wheat starch and compared them with those of imported commercial wheat starch. Three varieties of domestic commercial wheat starch (DWS) were compared to three types of imported wheat starch (IWS). The morphology of DWS granules was spherical with diameters 17.0-18.3 ㎛; the IWS granules exhibited various diameter sizes (16.6-17.7 ㎛). The amylose content of both DWS and IWS was between 23.2-23.8%. DWS exhibited smaller gelatinization temperature ranges and gelatinization enthalpies compared to IWS. These results suggest that IWS-PW (plain wheat starch) is a mixture of many types of wheat starch. In conclusion, the quality of domestic wheat flour and imported wheat flour was related to gluten content as well as to the starch properties.

• Applied Biological Chemistry
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• v.37 no.2
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• pp.77-84
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• 1994

Sweetpotatoes were baked (BK), microwaved (MW), microwaved/baked (MWBK), and microwaved/hold/microwaved (MWHO). Sugars, Huntercolors, compression and shear forces, sensory scores, moisture content, starch, and alcohol insoluble solids (AIS) were determined for each treatment. The BK roots contained higher (p<0.05) amount of sugars and less (p<0.05) starch. The MW roots contained higher (p<0.05) amount of starch, AIS, and less (p<0.05) sugar. The BK product resulted in the least (p<0.05) compression and shear forces needed to break it. The MW product demanded the greatest (p<0.05) force. The MWHO showed very similar results to the BK. Sensory scores for the BK and the MWHO sweetpotatoes were very acceptable. In color scores, the MWHO products were very acceptable and similar to the BK in flavor.

• Korean Journal of Food Science and Technology
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• v.18 no.6
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• pp.421-426
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• 1986

The carbohydrate characteristics and storability of two Korean traditional confections Seban-kangjeong (a Korean fried waxy-rice cookie) and starch-dashik (a Korean pressed starch cookie) were studied as compared with two Western confections fried cookie and biscuit. Seban-kangjeong showed lower contents of starch and sucrose and higher content of reducing sugar whereas starch-dashik showed higher contents of starch and sucrose and lower content of reducing sugar. Moisture content was higher in Korean confections than in Western confections. The degree of gelatinization was higher in Seban-kangjeong and fried cookie which were made through a frying process. Moisture adsorption isotherms were constructed for the four products. In storage test for 6 months under different temperature and humidity conditions, the relative humidity maintaining the initial moisture content of products was 68% for Seban-kangjeong and starch-dashik and 20% for fried cookie and biscuit. The ratio of retrogradation in storage was 15% in Seban-kangjeong, 20% in starchdashik and 28% in fried cookie and biscuit, showing the lowest progress in freezer storage.

• The Korean Journal of Food And Nutrition
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• v.9 no.4
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• pp.424-429
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• 1996

In an attempt to evaluate the effect of six starch sources-potato starch acetate, corn starch acetate, waxy corn starch, corn starch, potato starch, and wheat starch on properties of frozen noodle, amylograph characteristics of starch-wheat flour composites, cooking quality, maximum cutting force and sensory properties of cooked frozen noodles were examined. Compared with 100% wheat flour as control, potato starch acetate and potato starch-wheat flour composites had slightly lower initial pasting temperature and wheat flour composites with acetylated starches, waxy corn starch and potato starch had slightly higher maximum peak viscosity. At cooking quality examination of noodles made from wheat flour-starch composites, volume and weight of cooked noodles were increased and cook loss was decreased with the addition of acetylated starches and waxy corn starch. Maximum cutting forces of cooked frozen noodles containing more than 15% of potato starch acetate and only 15% of corn starch acetate were higher than that of control. Other starches except potato starch improved sensory properties of cooked frozen noodles and the greatest positive effect was acetated potato starch.

• Applied Biological Chemistry
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• v.33 no.4
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• pp.293-300
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• 1990

The physical and chemical properties of dry acorn starch(DS), defatted acorn starch (DFS) and reincorporated acorn starch(RIS) were investigated. Swelling power and solubility of all starch sample, were exhibited two stage behavior. It had a little change on the pasting temperature of DS and DFS but the peak viscosity and breakdown value of DFS was somewhat higher than those of DS and RIS. Flow behavior of gelatinized starch pastes showed a pseudoplastic behavior and flow behavior index was lower than unit The consistency coefficient showed concentration and temperature dependency. The activation energies of DS, DFS and RIS were from $1.70Kca1/g\;{\cdot}\;mol$ to $3.75Kca1/g\;{\cdot}\;mol$.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2001.11a
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• pp.45-45
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• 2001

종이 표변에 전분 사이징을 하는 목적은 종이가 액체에 대하여 침투저항성을 부여하 여 종이의 인쇄적성을 향상시키며 아울랴 종이의 표면적성과 종이강도 등의 물리적 특 성을 향상시키기 위해서 사용된다. 표면 사이징은 기본적으로 종이 표면에 전분을 이용 한 필름을 형성하여 종이 표면의 공극크기를 줄여 인쇄잉크 등과 같은 액체의 침투속 도를 늦여준다. 현재 국내에서 널리 사용되는 표면 사이징용 전분으로는 산화전분과 자 가변성용 일반전분이 있다. 자가변성용 전분은 효소나 APS로 전분의 chain 길이를 적 당한 점도로 잘라주는 것으로 전분 호액의 노화가 쉽게 일어나는 경향이 있다. 산화전 분은 전분회사에서 산화제를 이용하여 전분의 점도를 사용자의 요구에 따라 조절한 것 으로 water holdout이 개선되고 자가변성용 전분보다는 노화 안정성이 개선되지만 종 이 내부로의 칩투가 많이 일어나 전분 필름 강도가 약해지며 표면 강도 향상 효과가 적고 종이의 광학적 특성을 저하시키는 단점을 지니고 있다. 또한 약 10 ~ 20% 정도 사 용되는 파지의 재활용시 펄프 섬유에 흡착되지 않는 전분으로 인해 백수 내의 COD 및 B BOD를 증가시키는 원인이 된다.따라서 본 연구에서는 펄프 섬유와 친화력이 높아 지료 내첨용 지력증강제로 널리 사용되고 있는 양성 전분의 양이온 치환도 및 점도를 사이즈 프레스에 적합하게 조절 하여 백상지 제조업체의 라언에 적용하였다. 결과분석 항목으로는 파지 재활용에 따른 백수내 COD, 칼숨 이온함량 등의 백수 시스템의 변화와 종이의 물리적, 광학적 특성 및 ink jet 용지의 인쇄적성 등을 측정하여 산화전분과 비교하였다. 그 결과 약 20%의 C COD 감소 효과와 10%정도의 OPR 향상 효과를 얻을 수 있었다. 종이 물성의 경우 인 장강도와 뺏뺏이(stiffness) 및 지분 등을 측정한 결과 산화전분 보다 향상되었다. 특히 지분의 경우, 참여한 회사의 지분관련 complain이 약 80% 정도 감소하는 결과를 나타 내었다. 또한 백상지의 경우 ink jet 프린터에 많이 사용됨으로 ink jet 프린터의 인쇄 적성을 image analyzer로 측정한 결과 산화전분 보다 향상된 결과를 나타내었다.