• 한국미생물·생명공학회지
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• 제19권5호
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• pp.514-520
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• 1991

Extrusion시켜 구조변형시킨 전분(질)을 기질로 cyclodextrin glucanotransferse(CGTase)를 활용하여 액화과정을 거치지 않고 직접 cyclodextrin을 합성하는 불용성 extrusion된 전분-수용성 CGTase로 구성된 불균일상 효소반응계에 관하여 연구하였다. Extrusion된 전분을 기질로 이용할 경우 기존의 액화전분을 기질로하는 균일상 효소반응계에서 보다 현저히 증가된 CD 농도, 수율 그리고 합성속도를 얻을 수 있었으며, extrusion된 전분 기질농도가 100g/l일 때 CD생성량과 수율은 각각 54g/l와 0.54였다.

• 한국미생물·생명공학회지
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• 제22권1호
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• pp.106-113
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• 1994

A novel method for production of concentrated purity maltose using swollen extruded corn starch was investigated. Degree of gelatinization of extruded starch suitable for maltose formation was found to be around 70%. The optimal amiunt of enzyme was 400 unit fungal $\alpha $-amylase per g of starch, and the reaction time was 12 hours. At extruded starch concentration of 300 g/l(w/v), maltose concentration and content were reached up to 220 g/l(w/v) and 77%(w/w), respectively. The maltose forming reaction was also successfully proceeded at high starch concentration of 700 g/l(w/v), however, the conversion yield and content were decreased. By the addition of extruded starch by fed-batch wise, the maltose concentration, purity, and conversion yield could be improved up to 465 g/l(w/v), 70%(w/w), and 0.63, respectively. The investigated maltose production process seems to have many potential advantages over the conventional process utilizing liquefied starch, and the feasibility for industrial application needs to be evaluated.

• 한국미생물·생명공학회지
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• 제16권3호
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• pp.231-237
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• 1988

Tapioca 전분으로부터 ethanol을 생산하기 위한 여러 방법을 비교한 결과 extrudate를 이용하는 것이 460.5ι/ton의 alcohol 수율을 보여 가장 효과적이었다. Rhizopus sp. glucoamylase로 69시간 반응시켰을 때 extrudate로부터는 108.7mg/$m\ell$, 생 tapioca chip에서는 43.8mg/$m\ell$의 환원당이 생성되어 생전분보다 extrudate에 대한 glucoamylase의 분해력과 분해속도가 월등함을 알 수 있었다. Extrudate를 이용한 alcohol 발효를 수행한 결과 발효 초기에 alcohol 농도가 높아져 세균 오염방지 및 발효시간을 단축시키는 효과를 얻을 수 있었으나 extrusion 온도가 alcohol 발효에 미치는 영향은 크지 않았다. Glucoamylase가 생tapioca 보다는 extrudate에 더 용이하게 작용할 수 있는 것은 전분입자의 구조적 차이 때문임을 전자현미경으로 확인하였으며 extrudate와 생전분에 대한 분해력은 Rhizopus sp. glucoamylase 가 Aspergillus usamii glucoamylase보다 높았다.

• 한국미생물·생명공학회지
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• 제22권3호
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• pp.283-289
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• 1994

The production of maltose utilizing swollen extrusion starch seems to have many technical advantages, such as, high reaction rate and high yield, production of high purity concentrated maltose, and low energy consumption, over the conventional method utilizing liquefied starch. The characteristics of maltose formation in heterogeneous enzyme reaction system comtaining swollen extrusion starch was investigated using fungal $\alpha $-amylase. The influence of extrusion conditions on structure of extruded starch, such as, degree of gelatinization, water absorption index, and water solubility index was analyzed. The relationship between the structural features and maltose forming reaction was investigated, and the result was analyzed in terms of surface reaction of insoluble extruded swollen starch. The characteristics of maltose formation from swollen sxtrusion starch was compared using endo-type fungal $\alpha $-amylase and exo-type $\beta $anylase, and the structural trasformation of extruded starch was also observed to clarify the reaction mechanism.

• 한국식품영양과학회지
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• 제26권3호
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• pp.436-442
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• 1997

Corn starch was extruded under relatively low shear, high moisture, and low temperature. Puffing of corn starch dough was induced by injecting $CO_2$gas in the range from 0MPa to 0.09MPa. Piece density and compressive modulus for puffed corn starch were decreased by increasing the injection pressure to 0.07MPa, and increased above 0.07MPa. the microstructure of corn starch puffed with $CO_2$gas showed thick cell size, compared with those puffed with steam. RVA paste viscosity curves of corn starch puffed with $CO_2$had different patterns from those puffed with steam, probably resulted from partial gelatinization of starch. Water absorption and solubility were not significantly changed by $CO_2$injection pressure, but the average degree of polymerization was reduced by higher $CO_2$injection. The water absorption, water solubility, and the average degree of polymerization for corn starch puffed with $CO_2$were significantly lower than those puffed with steam.

• 산업식품공학
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• 제15권2호
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• pp.155-161
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• 2011

본 실험은 압출성형을 통한 저DE덱스트린 제조공정을 확립하기 위해서 수분함량 25, 35% 배럴온도 100, $120^{\circ}C$, 스크루 회전속도 150, 250 rpm에서 압출성형한 전분을 알 파아밀라아제로 당화시켰을 때 당화특성을 연구하였다. 수 분용해지수는 원료전분 수분함량이 25%로 감소할 경우 증 가되었으며, 수분흡착지수도 수분의 감소와 함께 전체적으 로 증가하였다. 환원당함량의 경우 수분함량이 낮고 배럴온 도 높을수록 증가되었다. 120 분간 당화 후 DE 63.8로 높 게 나타났다. 비기계적 에너지 투입량(SME)의 증가와 함께 수분용해도는 증가하는 경향이었다. 또한 수분함량의 감소 와 함께 비기계적 에너지 투입량과 수분용해도는 증가하였 다. 페이스트점도는 원료전분의 수분이 낮고, 스크루 회전 속도가 증가할수록 전분사슬의 절단에 따라 저온최고점도 가 감소하는 경향을 보였다. 초기반응속도는 수분함량이 25%로 낮고 배럴온도 $120^{\circ}C$, 스크루 회전수 250 rpm에서 $2.26{\times}10^{-3}mmol/mL{\cdot}min$로 가장 높았다. 시중 호화전분 $1.83{\times}10^{-3}mmol/mL{\cdot}min$에 비해서도 높은 결과를 보였다. 당화속도상수는 히구치모델을 응용하였으며, 수분함량이 낮 고 배럴온도가 $120^{\circ}C$일 때 전체적으로 높게 나타났다. 본 실험에서 초기반응속도, 당화속도상수, 당화수율 등을 고려 할 때, 최적조건은 수분함량 25%, 배럴온도 $120^{\circ}C$, 스크루 회전속도 250 rpm이었다.

• Preventive Nutrition and Food Science
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• 제11권1호
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• pp.61-66
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• 2006

The objective of this study was to compare the color and microstructure of powder, redness, brownness, and antioxidative activity in extruded ginseng, white ginseng and red ginseng extracts. The colors of extruded dry ginseng powder (moisture content 30%, barrel temperature $110^{\circ}C$, and screw speed 200 rpm) were similar to those of red ginseng. Intact cell wall structure was examined in dried root ginseng at $70^{\circ}C$ (A), white ginseng with skin (D), white ginseng without skin (E), and red ginseng (F) under a scanning electron microscope. The cell wall was not detected in samples B and C (dry ginsengs extruded with 25% and 30% moisture contents, respectively). Intact starch granules were detected in samples A, D, and E under a scanning electron microscope. Melted starch granules were detected in samples B, C, and F. Colors (L, a, b) of 50% EtOH extracts were similar in samples C and F. Browniness and redness of extracts were high in extruded dry ginseng and red ginseng extracts. Extruded dry ginseng (B) showed higher electron donation ability and phenolic content than the other samples.

• Preventive Nutrition and Food Science
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• 제7권2호
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• pp.133-138
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• 2002

To examine the cholesterol-towering effects of extruded products made with cassava starch (CS) and blends of cassava starch with either resistant starch (CS-RS) or oat fiber (CS-OF) hamsters were fed with diets containing a high-cholesterol (2%) and high-fat (17%) diet for 20 days. Hamsters fed with a diet containing no cholesterol were used as a control. Total cholesterol (TC) levels in the CS-RS and CS-OF groups were significantly (p>0.05) lower compared to the CS group by 11.5% and 8.5%, respectively. Also, the diets containing fibers decreased the value of low-density lipoproteins plus very low-density lipoproteins fraction by 32.4% (CS-RS diet) and 51.7% (CS-OF), respectively, as compared to the CS diet. Total lipid values were significantly (p<0.05) lower in hamsters fed the CS-RS diet (916 mg/dL) and CS-OF diet (964 mg/dL) as compared to those fed the CS diet (1661 mg/dL). The results obtained in this study suggest that extruded products containing cassava starch blended with either resistant starch or oat fleer, could prevent health problems associated with high levels of cholesterol and hypertriglyceridemia induced by a high cholesterol and fat diet.

• 한국식품과학회지
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• 제23권6호
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• pp.683-688
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• 1991

단일축 압출조리기를 이용하여 밀가루를 조리한 후 탁주발효용 기질로 사용하여 알코올 수율을 조사하였다. 또한 스팀가열과 비교하여 압출조리에 의한 밀가루 전분질의 분자구조 변화와 효소 민감성에 대하여 gel permeation chromatography(GPC)와 고유점도 측정으로 평가하였다. 밀가루의 GPC patternd은 스팀 가열이나 방출조리에 의하여 크게 변화되지 않았다. 그러나 ${\alpha}-amylase$를 30분간 처리할 경우 압출성형된 밀가루의 맥아당 생산량이 크게 증가하며 GPC pattern도 크게 변하여 저분자 전분질의 함량이 증가하며 고유점도는 감소하였다. 압출성형된 밀가루로 탁주발효를 한 결과 스팀증자된 밀가루로 탁주발효를 한 경우보다 실험실 규모 실험에서는 26%의 알콜생산 증대가 기록되었으며 공장규모 발효에서는 10% 이상의 알콜생산 증대를 얻을 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제9권1호
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• pp.1-8
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• 1999

Most carbohydrates exist in nature in an insoluble state, which reduces their susceptibility towards various carbohydrases. Accordingly, they require intensive pretreatment for structural modification to enhance an enzyme reaction. The direct conversion of insoluble carbohydrates has distinct advantages for special types of reaction, especially exo-type carbohydrase; however, its application is limited due to structural constraints. This paper introduces two novel heterogeneous enzyme reaction systems for direct conversion of insoluble carbohydrates; one is an attrition coupled enzyme reaction system containing attrition-milling media for enhancing the enzyme reaction, and the other is a heterogeneous enzyme reaction system using extruded starch as an insoluble substrate. The direct conversion of typically insoluble carbohydrates, including cellulose, starch, and chitin with their corresponding carbohydrases, including cellulase, amylase, chitinase, and cyclodextrin glucanotransferase, was carried out using two proposed enzyme reaction systems. The conceptual features of the systems, their reaction characteristics and mechanism, and the industrial applications of the various carbohydrates are analyzed in this review.