• Microbiology and Biotechnology Letters
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• v.14 no.5
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• pp.407-413
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• 1986

In an agitated bead reaction system, the enzymatic saccharification of uncooked starch was substantially enhanced. The enhancement mechanism was investigated front the view of the structural aspect of starch. The mechanical impact caused by the movement of the attrition-milling media resulted neither the destruction of microcrystalline structure nor the fragmentation of starch granule. instead, the most distinct phenomenon was the swelling of starch granule up to about 2.5 times, and the swelling mechanism was not similar with that caused by cooking. However, in the case of the enzyme addition in the attrition coupled reaction system, the swollen starch was easily fragmented into the large number of small particles by the synergistic action of the enzyme and milling-media. The exposed surface area of the fragmented particles plays the major role in enhancing the saccharification. The saccharification rate was quite different depending on the source of starch, the reason was discussed in terms of the granular structure of uncooked starches.

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.290-296
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• 2008

This study examined the physicochemical properties of chemically and enzymatically cross-modified waxy rice starches. The waxy rice starch was cross-linked using phosphorous oxychloride, and then partially hydrolyzed with four commercial ${\alpha}$-amylases (Fungamyl, Termamyl, Liquozyme, Kleistase). Swelling power and the moisture sorption isotherm did not change with cross-modification. Two cross-modified waxy rice starches (hydrolyzed with Termamyl and Liquozyme) showed higher solubilities than native starch and the two other cross-modified starches (hydrolyzed with Fungamyl and Kleistase). In terms of RVA characteristics, the two cross-modified waxy rice starches hydrolyzed with Termamyl and Liquozyme, respectively, had lower peak viscosity, holding strength, and final viscosity than the native starch. However, the two starches hydrolyzed with Fungamyl and Kleistase, respectively, revealed higher peak viscosity, holding strength, and final viscosity than the native starch. No differences were displayed in the X-ray diffraction patterns and DSC thermal characteristics of the cross-modified waxy rice starch as compared to both the native and cross-linked starches, indicating that cross-linking and enzymatic hydrolysis occurred in the amorphous region and did not alter the crystalline region.

• Microbiology and Biotechnology Letters
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• v.19 no.5
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• pp.497-503
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• 1991

The catalytic activities of immobilized gIucoamylase in a packed bed column and a continuous stirred tank reactor have been compared. Rapid production of glucose from liquefied starch have been studied through, the continuous liquefaction and saccharification using settling chamber. The immobilized glucoamylase with chitin gave the saccharification yield of 20% with the dextrin concentration of 100 g/l in a residence of 20 min. in a packed bed column. The half-life of immobilized glucoamylase with chitin was 19 days. The glucoamyalse immobilized in chitin and encapsulated with Ca-alginate gave the saccharification yield of 6% with the dextrin concentration of 50 g/l in a residence of 20 min. in a packed bed column. The Ca-alginate encapsulated and chitin immobilized glucomylase had a half-life of 25 days, which is 6 day larger than that of the immobilized glucoamylase with chitin only. In continuous liquefaction and saccharification, the glucose yield was 17% for the liquefied starch with naked barley concentration of 50gA in a residence of 20 min.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.4
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• pp.403-409
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• 1997

To obtain information on the accumulation of (1-3, 1-4)-$\beta$-glucans during kernel maturation, (1-3, 1-4)-$\beta$-glucan contents and (1-3, 1-4)-$\beta$-glucanase activities were determined in developing kernels of the two Korean cooking barley varieties, Neulssalbori and Saessalbori. (1-3, 1-4)-$\beta$-Glucan contents in kernels at 5 and 10 days after anthesis(DAA) were very low and the contents increased rapidly in kernels at 15 to 25 DAA. (1-3, 1-4)-$\beta$-Glucan content in kernels at harvest was about 3.5 to 4% of kernel dry matter. (1-3, 1-4)-$\beta$-Glucanase activities were relatively higher in younger kernels but the levels of the activity were very low compared with those in germinating kernels. A significant negative correlation was observed between (1-3, 1-4)-$\beta$-glucan contents and (1-3, 1-4)-$\beta$-glucanase activities. Low levels of (1-3, 1-4)-$\beta$-glucanase activites in kernels at 15 to 30 DAA, however, may indicate that (1-3, 1-4)-$\beta$-glucanases have little effect on the final content of (1-3, 1-4)-$\beta$-glucans in barley kernels. Starch contents and $\alpha$-amylase activities were also determined in developing barley kernels. Starch contents increased rapidly as kernels matured and the content at harvest was about 60% of kernel dry matter. Relativley higher levels of $\alpha$-amylase activities in kernels at the earlier developmental stage decreased rapidly as kernels matured.

• Food Engineering Progress
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• v.15 no.2
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• pp.155-161
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• 2011

The aim of this study was to determine the effects of different extrusion conditions on the saccharification characteristics( initial reaction velocity, reaction rate constant, yield) of extruded corn starch. Extruded corn starch-water slurries were mixed with alpha-amylase for the enzymatic saccharification. The saccharification yield of extruded corn starch was high at lower feed moisture content and higher barrel temperature. The solubility of extrudates increased with increase in the SME input which increased with increase in the feed moisture content. Starch hydrolysates having DE 63.8 was obtained after 2 hr reaction. The initial reaction velocity of the extrudate slurry with alpha-amylase was higher with decrease in the feed moisture content. The initial reaction velocity of extruded corn starch was the highest ($2.26{\times}10^{-3}mmol/mL{\cdot}min$) at 25% feed moisture content and $120^{\circ}C$ barrel temperature, 250 rpm screw speed. The pregelatinized starch was $1.83{\times}10^{-3}mmol/mL{\cdot}min$ as a control. Reaction rate constant was a similar trend to initial reaction velocity.

• KSBB Journal
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• v.20 no.5 s.94
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• pp.355-358
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• 2005

Bacteroides is the most predominant bacteria in the human large intestinal tract. Bacteroides fragilis RoidB isolated from a Korean faecal sample showed high $\alpha-fucosidase$ activity compared to other bacterial species. The optimized meidum for the production of $\alpha-fucosidase$ from 8. fragilis contained BHI 37g, hemin 10mg, cysteine 0.5g, resazurin 1mg, vitamin K1mg, and starch 5g per 1 L. The crude $\alpha-fucosidase$ obtained through DEAE-sepharose and CM- cellulose chromatography showed optimum temperature and pH at $40^{\circ}C$ and 7.0, respectively. Among several metals, $Co^{++}\;and\;Zn^{++}$ showed strong inhibition on enzyme activity.

• Korean Journal of Human Ecology
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• v.2 no.2
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• pp.29-38
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• 1999

저항전분(RS)은 건강한 사람의 소장에서 소화되지 않는 전분이나 전분질 식품의 부분이다. 저항전분은 4가지 형태로 구분하는데 RS 1은 물리적으로 효소와 만나지 않는 부분, RS 2는 생전분으로 감자, 바나나와 고아밀로오스 옥수수전분, RS 3는 노화된 전분 그리고 RS 4는 화학적으로 변성시킨 전분이다. RS 함량은 열에 안정한 $\alpha$ -아밀라아제나 pancreatin, pancreatic $\alpha$ -아밀라아제와 미생물에서 분리된 아밀라아제 등을 이용한 몇 가지 방법에 의해 분석되고 있다. RS는 대장에서 미생물에 의해 발효되어 단쇄지방산을 생성하는데 특히 부티릭산이 생성된다. 아세트산이나 프로피온산은 간의 대사에 영향을 주며 부티릭산은 항 종양(항 대장암) 특성이 있다. RS는 소화가 되지 않아 저열량원이므로 당뇨병 환자나 운동에 의한 혈당 조절이 필요할 때 조절능력을 갖는다. RS가 건강에 중요한 인자임이 알려지면, 건강을 위해 매일 섭취량의 증가를 권장해야 할 것이다.

• Journal of Aquaculture
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• v.22 no.1
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• pp.105-111
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• 2009

In this study, we carried out an experiment for estimation the larval digestibility in aspects which digestive enzymatic activities and nutrition of the rotifers, Brachionus rotundiformis. Thus we enhanced the digestive enzymatic activity through the addition of starch for the increase of digestibility of rotifer (starch-rotifer), and compared with the feed efficiency through rearing of the olive flounder, Paralichthys olivaceus used rotifer lipid-enriched with Algamac $2000^{(R)}$ (CE-rotifer). The digestive enzyme activities (except for TG-lipase), total protein contents, total essential amino acid, essential amino acids (methionin and phenylalanine) of starch-rotifer (the rotifer used a starch as additive, and enriched not) was assayed significantly higher than CE-rotifer (P<0.05). And total lipid, lipid classes (except for sterol) and fatty acids as DHA and EPA showed higher in CE-rotifer than starch-rotifer (P<0.05). But, sterol contents and ST/TG ratio were shown significantly higher in starch-rotifer (P<0.05). The flounder larvae supplied the two rotifers showed standard length and body weight that not significantly differed with ranges $3.72{\sim}3.79\;mm$ and $32.9{\sim}37.8\;mg$/larva on 6 days after hatching (DAH), respectively (P>0.05). However, these of 12 DAH showed the values of significantly higher to $5.94{\pm}0.249\;mm$, $144.0{\pm}23.86\;mg$/larva and $26.2{\pm}12.13%$ in standard length, body weight and survival in CE-flounder than that of starch-flounder (P<0.05). The hydrolytic enzymatic activities of flounder larvae severally supplied the two rotifers showed the significantly higher activities in acidic -amylase, neutral -amylase, TG-lipase, lysozyme and acidic phosphatase in starch-flounder on 5 DAH (P<0.05). But neutral $\alpha$-amylase, three proteases and two phosphatases of CE-flounder on 11 DAH showed the significantly higher activities than that of starch-flounder (P<0.05). Therefore, for the flounder, Paralichthys olivaceus larvae just depleted yolk was more beneficial to supply the feed, rotifer, enhanced the digestibility than to supply the feed lipid-enriched for aspect of larval digestibility up to 6 DAH, thereafter nutrition of absorption due to the development of digestive organs suggested that enrichment effect appeared with larval somatic growth. Consequently, investigation more detailed about the larval digestive physiological and nutritional requirement variations after 6 DAH will be necessary, thereafter.

• Microbiology and Biotechnology Letters
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• v.10 no.2
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• pp.123-132
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• 1982

These experiments were conducted to investigate the enzymatic characteristics of the purified $\alpha$-amylase (F-2A) of Bacillus circulans F-2 and the digestion rate of various starches. 1. The molecular weight was estimated to be 93000 by SDS-polyacrylamide disc gel electrophoresis. The isoelectric point was about pH 5.0. The optimum pH for the enzyme action was 6.0-6.5 and the stable pH ranged pH 5.5-12.0. The optimum temperature was 6$0^{\circ}C$, and the purified $\alpha$-amylase was stable below 4$0^{\circ}C$. 2. The purified $\alpha$-amylase was activated by Mn$^{＋＋}$ and Co$^{＋＋}$, whereas it was inhibited by Ag$^{＋}$, HT$^{＋＋}$, Cu$^{＋＋}$ and Pb$^{＋＋}$. 3. The purified $\alpha$-amylase is considered to have no sulfhydryl residue essential for its catalytic activity. 4. Michaelis constant (Km) was 1.704 mg/$m\ell$. Activation energy between 25-4$0^{\circ}C$ was 12.297 Kcal/mole, and between 40-6$0^{\circ}C$, it was 7.831 Kcal/mole. 5. The hydrolysis product from soluble starch, amylose and amylopectin in the early stage of hydrolysis was G$_{6}$, and as hydrolysis proceeds, G$_4$and G$_2$appeared. 6. Products from each oligosaccarides are as follows: G$_4$longrightarrow G$_2$＋ G$_2$,G$_3$ ＋G$_1$,G$_{5}$longrightarrow G$_4$＋G$_1$,G$_{6}$longrightarrowG$_4$＋ G$_2$,G$_{7}$ G$_4$,G$_{8}$longrightarrow G$_4$＋G$_4$, 7. On raw potato starch, raw sago starch and raw yam starch, the purified enzyme exhibited a remarkably high digestion rate than Porcine pancreatic amylase and Streptococcus bovis amylase.

• Journal of Microbiology
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• v.37 no.2
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• pp.80-85
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• 1999

The purification system of glucoamylase (glucan 1,4-${\alpha}$-glucosidase, EC 3. 2. 1. 3), some characteristics of the purified enzyme and hydrolysis rate of various raw starch were investigated through several experiments. The enzyme was produced on a solid, uncooked wheat bran medium of Aspergillus oryzae NR 3-6 isolated from traditional Korean Nuruk. The enzyme was homogeneously purified 6.8-fold with an overall yield of 28.3% by the criteria of disc- and SDS-polyacrylamide gel electrophoresis. The molecular weight was estimated to be 48 kDa by SDS-PAGE. The optimum temperature and pH were 55$^{\circ}C$ and 4.0, respectively. The enzyme was stable at a pH range of 3.0∼10.0 and below 45$^{\circ}C$. Enzyme activity was inhibited about 27% by 1mM Hg2+. The hydrolysis rate of raw wheat starch was shown to be 17.5-fold faster than the hydrolysis rate of soluble starch. The purified enzyme was identified as glucoamylase because the product of soluble starch by the purified enzyme was mainly glucose by thin layer chromatography.