• KSBB Journal
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• 제13권5호
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• pp.621-625
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• 1998

The raw starch hydrolysis by amylase prepared from alkaline-tolerant Bacillus sp. were investigated. Degree of hydrolysis(%) of 5%(w/v) raw rice, corn and potato starch by this enzyme were about 40, 25 and 20%, respectively. The hydrolysis action on raw starch by change of blue value was similar to the action pattern of exo ${\beta}$-amylase. The hydrolysis products of rice starch were mainly glucose and maltose. Oligosaccarides were also detected. From the above results, this enzyme was considered as exo type ${\alpha}$-amylase. This enzyme activity on the raw starch and the gelatinized starch were 28.40 and 86.60 IU/mg protein, respectively, and the ratio of raw starch-digesting activity to gelatinized starch-digesting activity (raw starch digestivity) was about 32%. The Km values for the raw and the gelatinized starch were 4.22 and 3.0mg/mL, respectively, and the VmaX values were 0.20 and 0.31mg/mL/min, respectively.

• 한국환경과학회지
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• 제13권9호
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• pp.827-833
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• 2004

The biodegradability of vinyl acetate acrylate resin and com starch blend was studied by determination of the reduced sugars produced after enzymatic hydrolysis. The starch hydrolysis reaction by $\alpha-amylase$ was achieved within 5 minutes. Optimal ranges of temperature and pH for the starch hydrolysis by $\alpha-amylase$ were around $80^{\circ}C$ and 6.5-7.2, respectively. The biodegradability of the starch-filled acrylate films increased as the content of starch increased. The biodegradation of starch in the starch-filled acrylate film by $\alpha-amylase$ was about 48.6% of that of pure starch. This value of biodegradable starch-filled acrylate film gave a good result with enzymatic shortcut test. The surface morphologies of the starch-filled acrylate film after enzymatic hydrolysis were investigated by scanning electron microscopy (SEM).

• Journal of Microbiology and Biotechnology
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• 제4권3호
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• pp.230-232
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• 1994

The enzymes $\alpha$-amylase and glucoamylase used in starch hydrolysis were found active in the supercritical carbon dioxide solvent Higher hydrolysis of starch sluny in supercritical $CO_2$ was achieved by operating the reactor for the first two hours with $\alpha$ -amylase and to subsequent addition of glucoamylase for continued hydrolysis.

• 한국미생물·생명공학회지
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• 제10권4호
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• pp.259-265
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• 1982

Bacillus circulans F-2 $\alpha$-amylase에 의한 각종 oligosaccharide의 분해산물을 조사하고, Bacillus circulans F-2 $\alpha$-amylase, Bacillus amyloliquefaciens $\alpha$-amylase, Rhizopus niveus glucoamylase에 의한 각종 생전분의 분해율을 비교 검토한 결과를 요약하면 다음과 같다. 1. 공시 oligosaccharide중 Bacillus circuians F-2 $\alpha$-amylase는 maltose와 maltotriose를 분해시키지 못하였으나 meltotetraose이상의 oligosaccharide는 분해시켰다. maltotetraose, maltopentaose, maltoheraose, maltoheptaose, maltooctaose중 maltotetraose의 분해가 가장 미약하였다. 2. soluble starch, amylopectin, amylose, oyster glycogen중 oyster glycogen의 분해율이 약간 낮았다. 3. corn starch의 분해율은 진탕반응이 정치반응보다 높았으나 potato starch에 대하여는 효소의 종류에 따라 일정치 않았다. 4. corn, rice, arrowroot, high amylose corn, banana, sago, yam, potato starch에 대하여 Bacillus circulans F-2 $\alpha$-amylase가 Bacillus amyloquefaciems $\alpha$-amylase, Rhizopus niveus glucoamylase보다 월등하게 높은 분해율을 나타내었다.

• 한국식품영양과학회지
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• 제35권8호
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• pp.1102-1105
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• 2006

잡곡류인 수수, 기장 율무, 메밀의 가열처리에 따른 in vitro 전분가수분해율을 원곡과 비교하여 분석하였다. 잡곡류의 가열처리로서 열탕처리 또는 증자 후 볶음처리를 하였으며 원곡 상태 또는 가열처리한 후 $pancreatic\;{\alpha}-amylase$를 사용하여 60분간 배양하면서 in vitro 전분가수분해율을 측정하였다. 잡곡류는 ${\alpha}-amylase$ 가수분해가 진행됨에 따라 전분가수분해율(%)이 지속적으로 증가하였다. 원곡의 경우 60분후 전분가수분해율이 메밀 5.4%, 기장 31.3%, 율무 48.3%, 수수 54.7% 순으로 큰 차이가 있었다. 전분가수분해율은 원곡 상태에 비해 가열처리한 곡물에서 $48.6{\sim}99.2%$로 현저히 높았으며 증자 후 볶음처리 방법이 열탕처리에 비해 수수를 제외하고 전분가수분해율이 높은 경향이었다. 본 실험에 사용한 잡곡류 중 amylose 함량이 낮은 기장, 수수, 율무가 amylose 함량이 높은 메밀에 비해 원곡 상태와 가열처리후의 전분가수분해율이 높게 나타났다.

• Preventive Nutrition and Food Science
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• 제11권2호
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• pp.146-154
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• 2006

Structural modification of corn starch by gamma irradiation was evaluated for under dry conditions at varied intensities from 0 to 40 kGy. Under scanning electron microscopy, the granule shape of corn starch was not significantly affected by the irradiation up to 40 kGy. In addition, X-ray diffraction and melting patterns of the irradiated starches were similar to those of the native starch, indicating that crystalline regions in the starch granules were not changed by irradiation. However, the pattern of gel permeation column chromatography showed a significant increase in partial hydrolysis of gamma irradiated starch samples. The degree of polymerization and the paste viscosity of irradiated starch samples dose-dependently decreased significantly with irradiation, and increased solubility and clarity were observed in the irradiated starch solution. In addition, the degree of retrogradation decreased as irradiation dose increased. Irradiation of corn starch has advantages over the ordinary acid or the enzyme hydrolysis modification methods. It does not affect the granular shape and crystalline phase of starch during hydrolysis, and the process can be carried out in dry state.

• 한국식품조리과학회지
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• 제33권3호
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• pp.307-315
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• 2017

Purpose: To develop nano-sized starch particles for application as dietary fiber sources in liquid food system, the morphology and thermal properties of acid hydrolyzed rice starches with different amylose contents were evaluated. Methods: Rice starches purified from three Korean cultivars, including Goami, Hopyeong, and Hwaseonchal, were hydrolyzed with 2.2 N HCl solution in a $35^{\circ}C$ shaking water bath (100 rpm) for 7, 10 and 15 days. Results: Acid hydrolysis rates of rice starches increased with increasing hydrolysis duration, and rates for Goami, Hopyeong, and Hwaseonchal were 28.74-38.50%, 38.96-49.53%, and 40.24-48.88%, respectively. The granular size of acid hydrolyzed starches decreased to 122.4-479.9 nm, whereas granular aggregation increased with increasing hydrolysis duration. In particular, waxy rice starch of Hwaseonchal was composed of many tiny granules without aggregates. Gelatinization temperature and temperature range increased with increasing hydrolysis duration. All starches showed A type crystallinity using an x-ray diffractometer, regardless of acid hydrolysis. Conclusion: It is suggested that nanoparticles could be prepared by acid hydrolysis of rice starches, and waxy rice starch is the most preferred source for application.

• 한국미생물·생명공학회지
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• 제18권4호
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• pp.352-359
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• 1990

분쇄마찰매체효소반응계에서 glucoamylase와 Alpha-amylase의 보완작용에 의한 옥수수 생전분의 효소당화 mechanism을 규명코자, 분리.정제된 상기 효소의 혼합 비율에 따른 당화양상 및 생성당 조성, 전분입자 구조, 생전분입자의 particle size 분포, X-ray 회절양샹의 변화 등을 관찰하였다. 분쇄마찰매체 효소반응계에서도 효소를 분리하여 사용하였을 때보다 glucoamylase와 $\alpha$-amylase를 혼합사용할 경우 당화율이 크게 향상되었으며, 고순도의 glucose 생산에 적합한 두 효소의 혼합비율은 약 1:1-1:2(unit) 로 판명되었다.

• 한국식품영양과학회지
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• 제22권5호
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• pp.596-602
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• 1993

신선찰벼와 한강찰벼 전분을 산처리하여 이호학적 성질, differential scanning calrorimetry 및 효소에 의한 가수분해율의 차이를 비교 검토하였다. 산 가수분해율은 한강찰벼가 약간 높았으며, 산처리에 따라 가용성 선형물질이 분해되어 ${\lambda}_{max}$와 청가는 감소하였고 또 물결합능력, 용해도 및 결정도는 증가하였으나 팽윤력은 감소하였다. 요오드 반응에 의한 최대흡수파장은 한강찰벼가 높았으나 최대흡수파장 및 680nm에서 흡광도는 시료간에 차이가 없었다. 물결합 능력과 용해도는 신선찰벼가 높았으나 팽윤력은 한강찰벼가 높았다. 가열에 의한 광투과도는 신선찰벼가 낮아서 열에 대한 안정성이 높았다. KSCN에 의한 겔부피는 신선찰벼가 커서 용출물질량이 많았다. 산처리중 전분의 결정형태는 A형이 유지되었으며 상대결정도는 신선찰벼가 높았다. DSC특성값은 산처리에 따라 감소하였으며, glucoamylase에 의한 가수분해율은 산처리에 따라 증가하여 산처리 48시간에 신선찰벼는 98%, 한강찰벼는 96%로 전체적으로 신선찰벼가 높았다.

• 한국식품조리과학회지
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• 제24권3호
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• pp.273-281
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• 2008

To determine the nutritional quality and physical properties of ginseng-chicken meat porridge, 10 kinds of ginsengchicken meat porridge samples containing waxy and/or non-waxy rice were analyzed for in vitro protein digestibility and their degree of starch hydrolysis. Viscosity and spreadness were determined for the gelatinized pastes of the porridge samples. Microphotographs of the starch granules and pastes were studied to confirm structural changes in the rice starch during cooking. The starch paste from non-waxy rice porridge had higher viscosity than the starch paste from the waxy rice porridge; however, in the case of the ginseng-chicken meat porridge, the difference in viscosity was negligible. Microphotograph comparisions between the waxy rice porridge and non-waxy rice porridge indicated apparent differences in the shapes of their starch granules and gels. The granule surface of the non-waxy rice was very rough while that of the waxy rice was very smooth; this difference would lead to organoleptical discrepancy. The added ginseng increased the protein digestibility of the chicken meat; however, the protein digestibility of the ginseng-chicken meat porridge was lower than that of the chicken meat or rice porridge due to inhibited protein digestion by the gelatinized starch. Finally, the rice porridge had increased starch hydrolysis with additions of chicken meat and vegetables.