• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1128-1133
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• 1998

Extrusion cooking treatment was compared with autoclaving/cooling treatment for formation of enzyme resistant starch of high amylose corn starch (HACS). Effects of barrel temperature $(100^{\circ}C,\;120^{\circ}C,\;140^{\circ}C)$ and feed moisture content (25%, 35%, 45%) on extrusion processing in a co-rotating twin-screw extruder under fixed screw speed (100 rpm) were investigated by measuring enzyme resistant starch (RS) yield. RS yield were estimated by in-vitro pancreatin digestion method and enzymatic-gravimetric method using termamyl. Barrel temperature and yield of RS were negatively correlated and feed moisture content and yield of RS was positively correlated as determined by in-vitro pancreatin method. The highest yield (38.4%) of RS was obtained from HACS extrudate processed at the barrel temperature of $100^{\circ}C$ and the feed moisture content of 45%, while the yield of RS by 5 times of autoclaving/cooling was 25%. The yield of RS by in vitro pancreatin digestion method was 20.7% with high amylose corn starch and 8.2% with ordinary corn starch (CS), respectively, under the same extrusion condition (barrel temperature $120^{\circ}C$, feed moisture content 35%). At the same condition, the yields of RS by enzyme-gravimetric method were 14.6% with HACS and 6.8% with CS, respectively. The yield of RS increased during the storage at $4^{\circ}C$ for 4 weeks and the highest yield (60%) was obtained by the storage of HACS extrudates extruded at $100^{\circ}C$ and 45% feed moisture content.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2003.07a
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• pp.85-85
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• 2003

본 연구는 저열량 기능성 탄수화물 소재(저항전분, 식이섬유)를 이용하여 당뇨병 환자의 혈당과 지방대사를 조절하는데 도움을 줄 수 있는 치료식을 개발하기 위해 동물실험과 임상실험을 수행하여 제품의 혈당 및 지방대사 조절, 혈당조절호르몬, 장내기능조절 효과를 검증하였다. 또한 동물실험을 통해 대장에서 염증을 일으키는 것으로 알려진 deoxycholate (DOC)를 식이무게의 2%로 첨가하고, HAS는 일반전분의 50%로 대체시켰을 때 HAS가 DOC의 염증작용에 어떠한 영향을 미치는지 살펴보아 HAS의 장기능 개선에 대한 기능성을 환인해보았고 저항전분이 혈당 및 혈액내 지질조성에 미치는 영향을 살펴보았다. 인체실험 연구결과는 저항 전분을 섭취한 군에서 체중이 유의적으로 감소하였고 비만도를 나타내는 BMI도 감소하여 개발된 선식제품의 체중감소 효과가 입증되었다. 당대사 결과는 동물실험의 경우는 저항전분을 섭취한 군에서 혈당감소를 나타내고 있으나 인체실험의 경우 선식제품 섭취 후 혈당과 인슐린의 농도가 영향을 받지 않았으며 혈액 내 지방성분은 동물실험에서는 혈액내 총지방과 중성지방이 저항전분 섭취시 감소하였고, 인체실험의 경우 저항전분 시제품 섭취 후에 혈액내 중성지방량은 약간 증가하였으나 총지방량과 총콜레스테롤량, LDL-콜레스테롤량은 감소하는 효과를 보여주었다. 또한 면역능력에 대한 지표는 저항전분 시제품 섭취 후 혈액 내 면역글로부린 G가 유의적으로 증가 하였다. 동물실험을 통한 저항전분의 장기능에 관한 연구결과는 저항전분의 한 형태인 HAS의 섭취가 대장길이와 맹장무게를 증가시키며, 맹장에서의 비피더스균의 증식을 가져와 장내 SCFA의 생산을 증가시키고, 맹장내 pH 감소를 가져오며 대장 점막에서의 PGE2의 생산을 감소시켜 장 기능개선의 효과를 나타내고 있다. 그리고 이러한 효과는 DOC섭취에 의한 부작용을 완화시키는 작용을 하였다. 또한 저항전분의 동물실험 겨로가는 혈당을 감소시키며, 혈액지방 수준을 감소시키는 효과를 나타내므로 저항전분의 섭취는 장긴\ulcorner 개선, 혈당유지, 혈액지방수준 개선의 효과가 있는 것으로 보인다.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.747-752
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• 1993

A curd yogurt was prepared from milk added with skim milk powder or four kinds of starch such as rice starch, wheat starch, corn starch and potato starch. The effects of starch addition at 2%(w/v) level on acid production by lactic acid bacteria in milk was investigated. The effects of starch addition on quality of curd yogurt in terms of apparent viscosity, sensory property and volatile aroma compounds were also examined. Addition of starch markedly stimulated the acid production by lactic acid bacteria. Among four organisms tested, Lactobacillus jugurti produced the highest amount of acid. Apparent viscosity of curd yogurt added with starch was significantly higher than that of control. Curd yogurt fermented with L. jugurti showed pseudoplastic and thixotropic characteristics. Sensory property of curd yogurt added with corn starch or rice starch was evaluated as slightly better than reference sample, but that with potato starch was evaluated as the worst among all samples. Acetaldehyde, acetone, ethanol and butanol were detected by gas chromatographic analysis.

• Korean journal of food and cookery science
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• v.5 no.2
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• pp.43-50
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• 1989

Physicochemical properties on defatted potato starches, Irish Cobbler and Dejima, were investigated. The average diameter of the Irish Cobbler and Dejima starch were $22.5-29.8\mu\textrm{m}$, and both the starches had birefringence. Irish Cobbler starch was lower than that of Dejima starch in water binding capacity, swelling power and solubility. Relative crystallinity of both the starches was decreased after defatted. The blue value of Irich Cobbvler and Dejima starch was measured 0.37 and 0.35 respectively Transmittnace of 0.1% starch suspensions was higher on defatted starch than on untreated starch. Differential Scanning Calorimetry of untreated potato starch showeed higher gelatinization temperature in Irish Cobbler starch than in Dejiam starch. The gelatinization enthalpy of untreated starch was higher in Irisch Cobbler starch than in Dejima starch, but, after defatted, it was decreased.

• Korean journal of food and cookery science
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• v.19 no.1
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• pp.65-71
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• 2003

The objective of this study was to compare the textural properties and sensory evaluation of Injulmi, a traditional Korean waxy rice cake, added with 10, 20 and 30% of RS3-type resistant starch. RS3-type resistant starch was prepared from nonwaxy rice(Odaebyeo) starch by autoclaving-cooling cycle. The RS yield of RS3-type resistant starch was 9.10%. By increasing the addition level of RS3-type resistant starch, the hardness and adhesiveness of Injulmi increased as measured by using a rheometer. Hunter color L and a values of Injulmi added with RS3-type resistant starch were increased, but b value was decreased. In case of sensory evaluation, the hardness of Injulmi added with RS3-type resistant starch was higher than that of non-added Injulmi. The overall duality of Injulmi added with RS3-type resistant starch by sensory evaluation was negatively correlated with the hardness measured by rheometer(p＜.0.05).

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.514-520
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• 1996

The purpose of this study was to develop the production technology of modified starch. Corn starches were gamma irradiated at 0-110 kGy and the effect of irradiation dose levels on the physicochemical properties of corn starches were investigated. Blue value linearly decreased, while alkali number and solubility markedly increased as irradiation dose levels were increased. The optical transmittance increased as applied irradiation dose levels were increased in the temperature range of $65-95^{\circ}C.$ Water binding capacity and swelling power showed maximum value at 30 and 10 kGy, respectively and they tended to decrease thereafter. Gelatinization viscosity of the gamma irradiated starch considerably decreased as compared to that of the non-irradiated starch. Irradiation at 110kGy resulted in a marked reduction of peak viscosity and cooling viscosity at $30^{\circ}C$ by 100 and 300 times, respectively. The physicochemical properties of corn starch irradiated at 30 kGy were similar to those of commercial acid-modified starch, while those of corn starch irradiated at 100 kGy were similar to those if oxidized starch.

• Korean Journal of Food Science and Technology
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• v.19 no.4
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• pp.366-370
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• 1987

Rheological properties of gelatinized rice starch solutions (5%) were examined with a Brookifield viscometer. Gelatinized rice starch solutions showed pseudoplastic flow having yield stress, i.e., Binghamplastic flow behavior. The yield stress of gelatinized rice starch solutions was reduced by the phosphate. Phosphate increased the pseudoplasticity of gelatinized nonwaxy rice starch solutions. but decreased that of gelatinized waxy rice starch solution. The yield stress of gelatinized nonwaxy rice starch solutions held for one hour at $90^{\circ}C$ was slightly decreased, but that of waxy starch solution was reduced by 10-fold. Phosphate reduced the yield stress for both gelatinized nonwaxy and waxy rice starch solutions. Phosphate decreased the consistency index, but did not affect the flow behavior index of the gelatinized rice starch solutions.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.749-755
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• 2021

The objective of this study was to investigate the physicochemical properties of rice starch extracted from stale rice using alkaline steeping (AKL) and improved enzymatic digestion (iENZ) methods. The crude protein content (0.5-0.7%) of stale rice starch (SRS) was less than 1% by iENZ, but not so when measured by the existing ENZ methods. SRS is an intermediate amylose rice starch. AKL-SRS and iENZ-SRS exhibited typical A-type crystal packing arrangements with similar relative crystallinities. iENZ-SRS showed higher gelatinization onset and peak temperatures with a narrower gelatinization temperature range, compared to those of AKL-SRS, indicating that iENZ annealed SRS. Thus, iENZ-SRS exhibited lower swelling power and solubility, and higher pasting viscosities with delayed viscosity development. Overall, the use of stale rice as a rice starch source could make economical production of rice starch possible, and iENZ may diversify rice starch characteristics, which expands the utilization of rice starch in food and non-food industries.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.3
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• pp.474-483
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• 2015

The textural properties of breads containing midified starches such as pregelatinized waxy corn starch, acetylated potato starch and hydroxypropylated tapioca starch, were investigated to determine the optimum addition level of modified starches. Effects of modified starches on dough properties were investigated through a farinogram and amylogram based on the different additional levels of modified starches (3%, 6%, 9%, 12% and 15% of flour content). Moisture contents and firmness values were measured to investigate the degree of retrogradation at 0 h, 36 h and 72 h after production. The levels of moisture contents were highest upon addition of pregelatinized waxy corn starch followed by acetylated potato starch and lowest upon addition of hydroxypropylated tapioca starch. Overall, higher moisture contents resulted in lower firmness levels. The preference scores by type of modified starch were highest upon addition of 9% hydroxypropylated tapioca starch, 3% pregelatinized waxy corn starch, and 6% acetylated potato starch, respectively. Preference scores were significantly correlated with textural properties such as volume, absorption, stability and weakness (p<0.01).

• Applied Biological Chemistry
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• v.37 no.6
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• pp.463-471
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• 1994

Physicochemical properties, gelatinization and retrogradation characteristics of surfactant added sweet potato starches were investigated. Three different surfactants, SSL (sodium stearoyl-2-lactylate), Dimodan (mono/diglyceride) and SE1670 (sucrose fatty acid ester 1670) were used. Shapes and crystallinities of starch granules were not changed by the addition of surfactants. Total lipid contents increased and the amylose content decreased by the addition of surfactants and the order was as follows: SE1670>SSL>Dimodan. The swelling power and solubility at $80^{\circ}C$ decreased in the surfactant added starches. By amylograph, initial gelatinization temperature of untreated sweet potato starch was $72.5^{\circ}C$, and did not change by the addition of surfactants, but SE1670 or Dimodan added starch showed the peak viscosity. The peak temperature of gelatinization and enthalpy of untreated starch by DSC were $53.9^{\circ}C$ and 1.3cal/g, respectively. The peak temperature increased by the addition of surfactants, while the enthalpy decreased. In gelatinization by alkali, the viscosity was lower in surfactant added starches than in untreated starch at concentration. The degree of retrogradation by ${\alpha}-amylase-iodine$ method was a lower in SSL and SE1670 added starches than untreated starch and the enthalpy by DSC also decreased in surfactant added and retrograded starches.