• 한국식품조리과학회지
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• 제15권4호
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• pp.418-425
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• 1999

찰전분을 0.1 N HCl로 산처리하여 약산처리 전분의 특성과 효소저항전분의 수율 및 특성을 비교한 결과 가수분해율은 0.32~0.88%로 낮았으며 약산처리에 의해 처리시간에 따라 가수분해율이 직선적으로 증가하지는 않았다. 효소저항전분의 수율은 보통 옥수수전분은 24시간까지 RS수율이 증가하였고. 찰옥수수전분과 찰보리전분은 산처리 12시간에, 찹쌀전분은 산처리 8시간에 최대 RS 수율을 보여, 찰전분의 종류와 품종에 따라 가수분해정도와 수율이 차이가 났다. 옥수수전분의 형태는 약산처리에 의해 형태변화가 없었으며, 효소저항전분 생성전분은 보통옥수수전분의 경우 그물망 같은 형태를 나타내었으나 찰옥수수전분은 표면이 강한 결정 입자를 보였으며, 약산처리에 의해 생성전분과 분리된 효소저항전분의 형태는 차이가 없었다. X선 회절기에 의한 전분의 형태는 생전분의 경우 전형적인 A형을 나타내었으며 산처리에 의한 변화는 없었다. 형성된 효소저항전분은 보통옥수수전분의 경우 약산처리시 2$\theta$=16.5$^{\circ}$피크가 강해졌으며 찰옥수수전분의 경우 무정형의 피크를 나타내었고, 분리된 효소저항 전분은 형성전분과는 다른 경향을 보여 완전한 결정형을 나타내었다.

• Preventive Nutrition and Food Science
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• 제16권4호
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• pp.339-347
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• 2011

Flour and isolated starch from chickpea (desi type, 328S-8) were evaluated for their in vitro digestibility and physicochemical properties. The protein content, total starch content and apparent amylose content of chickpea flour and isolated starch were 22.2% and 0.6%, 45.8% and 91.5%, and 11.7% and 35.4%, respectively. Chickpea starch granules had an oval to round shape with a smooth surface. The X-ray diffraction pattern of chickpea starch was of the C-type and relative crystallinity was 24.6%. Chickpea starch had only a single endothermic transition (13.3 J/g) in the DSC thermogram, whereas chickpea flour showed two separate endothermic transitions corresponding to starch gelatinization (5.1 J/g) and disruption of the amylose-lipid complex (0.7 J/g). The chickpea flour had a significantly lower pasting viscosity without breakdown due to low starch content and interference of other components. The chickpea starch exhibited significant high setback in the viscogram. The average branch chain length, proportion of short branch chain (DP 6~12), and long branch chains (DP${\geq}$37) of isolated chickpea starch were 20.1, 20.9% and 9.2%, respectively. The rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) contents of chickpea flour and starch were 9.9% and 21.5%, 28.7% and 57.7%, and 7.1% and 9.3%, respectively. The expected glycemic index (eGI) of chickpea flour (39.5), based on the hydrolysis index, was substantially lower than that of isolated chickpea starch (69.2).

• 한국작물학회지
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• 제38권6호
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• pp.513-523
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• 1993

쌀의 이용성 증진과 쌀 가공적성 육종을 위한 기초자료를 얻고자 쌀의 아밀로스함량 및 호화특성이 크게 다른 벼 24품종에 대한 쌀 배유전분의 구조 및 물성의 차이를 비교 분석한 결과를 요약하면 다음과 같다. 1. 쌀 전분-요-드 정색반응의 최대흡수파장이 찰은 520nm, 메는 560nm～600nm까지로서 이밀로스 함량이 높은 품종일수록 길어지는 경향이 있었고 비슷한 아밀로스함량 수준에서도 품종에 따라 최대흡수파장에 다소 차이가 있었다.2. 쌀 품종별 전본의 글루코오스쇄장분포 비교에 의하면 Fr. I에서 가장 큰 품종간 차이를 나타내었고 다음으로 중간분획(Int. Fr).과 Fr. III/Fr. II율에서 품종간 차이가 크게 나타났으며, 특히 아밀로펙틴의 미세구조를 나타내는 Fr.III/Fr. II율은 찹쌀이 멥쌀보다 높은 경향이었으나 멥쌀간에는 아밀로스함량과는 관계없이 품종간 차이를 나타내었다. 3. 알칼리 붕괴도가 낮은 품종일수록 전분입자의 50% 산 가수분해 소요시간이 길었으며, 호응집성이 경질인 품종과 연질이 품종들 모두에서 50% 산 가수분해 소요시간에 품종간 차이를 나타내었다. 또한 호응집성이 경질인 품종일수록 Fr. III의 분포가 낮고 Fr. I의 분포 및 아밀로스 함량은 높은 경향이었다. 4. 쌀의 전분구조 및 특성과 쌀의 이화학적특성에 따라 주성분분석에 의하여 공시품종들을 6개군으로 분류할 수 있었는데 이는 주로 아밀로스관련 성분과 아밀로펙틴 구조성분에 따라 군집화 되었다.

• 한국미생물·생명공학회지
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• 제2권2호
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• pp.95-101
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• 1974

Studies on the optimum conditions of acid hydrolysis of sweet potato starch cake and its utilization on the production of Saccharomyces cerevisiae as a carbon source were conducted and the results showed as follows; 1.The highest hydrolysis rate, 62.7 ％ of the reducing sugar based on the weight of the dry matter, was obtained when the starch cake was hydrolyzed with 1.0％ of hydrochloric acid at 2.0 kg/$\textrm{cm}^2$ for 30 minutes. 2. But the yeast grew most favorably on the hydrolyzate obtained by treating the starch cake with 0.5％ of hydrochloric acid at 2.0 kg/$\textrm{cm}^2$ for 10 minutes. Reducing sugar content of hydrolyzate was 51.4％. 3. The optimum pH of the culture medium was 7.0, Cell growth reached to the maximum at 36 hours of cultivation time. 4. According to the vitamin requirement tests, Ca-pantothenate was found to be a promoting factor for the growth of the yeast cells. 5. "Gluten acid hydrolyzate" was most effective to the cell growth when added to the medium at the concentration of 0.1％ as a nitrogen source. 6. Sacch. cerevisiae could assimilate the sugars in the hydrolyzate about 89.1％, and the yields of the yeast cells showed 23.2mg/ml of culture medium.

• Journal of Microbiology and Biotechnology
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• 제2권1호
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• pp.56-65
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• 1992

The complete nucleotide sequence of the Bacillus circulans F-2 RSDA gene, coding for raw starch digesting a-amylase (RSDA), has been determined. The RSDA structure gene consists of an open reading frame of 2508 bp. Six bp upstream of the translational start codon of the RSDA is a typical gram-positive Shine-Dalgarno sequence and the RSDA encodes a preprotein of 836 amino acids with an Mr of 96, 727. The gene was expressed from its own regulatory region in E. coli and two putative consensus promoter sequences were identified upstream of a ribosome binding site and an ATG start codon. Confirmation of the nucleotide sequence was obtained and the signal peptide cleavage site was identified by comparing the predicted amino acid sequence with that derived by N-terminal analysis of the purified RSDA. The deduced N-terminal region of the RSDA conforms to the general pattern for the signal peptides of secreted prokaryotic proteins. The complete amino acid sequence was deduced and homology with other enzymes was compared. The results suggested that the Thr-Ser-rich hinge region and the non-catalytic domain are necessary for efficient adsorption onto raw substrates, and the catalytic domain (60 kDa) is necessary for the hydrolysis of substrates, as suggested in previous studies (8, 9).

• Journal of Applied Biological Chemistry
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• 제66권
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• pp.90-97
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• 2023

The effect of citric acid on rice starch gelatinization and low-temperature (4 ℃) storage was studied in order to produce rice cake with a lower retrogradation rate. A citric acid solution in the ratio of 0, 0.5, 1.0, and 1.5% (w/w) of the water used during production was utilized. The gelatinization properties, gel strength, thermal properties, and texture analysis were evaluated to determine the retrogradation rate. The result showed that acid hydrolysis occurred in samples treated with citric acid. Thus, increasing citric acid decreased gelatinization temperature (58.63±1.98 to 45.84±1.24 ℃). The moduli of elasticity increased with increasing citric acid concentration, indicating an increased gel strength. Thermal analysis of starch showed that the onset, peak, and conclusion temperatures of retrogradation were increased significantly with the storage period and decreased with citric acid concentration. After 72 h of low-temperature storage (4 ℃), the retrogradation rate was lowest in the rice cake with 1.5% citric acid solution, with an increased ratio of 12.01 to 13.60% compared to the control sample, with a ratio of 12.99 to 43.54%. This shows a high retrogradation rate in the control sample. Additionally, sensory properties and retrogradation ratio suggest that the addition of 1.0% citric acid solution during rice cake production is efficient in retarding the retrogradation without an adverse effect on the rice cake modeling and acceptance.

• 한국환경과학회지
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• 제14권3호
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• pp.359-366
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• 2005

Starch was crosslinked with epichlorohydrin. Crosslinked starch-filled waterborne acrylate (CSWAC) films were prepared by blending this crosslinked starch with waterborne acrylate. The thermal and mechanical properties of these films were investigated by thermogravimetric analysis (TGA), tensile strength and elongation test. The biodegradability was also studied by determination of reduced sugar products after enzymatic hydrolysis and the surface morphology was investigated by scanning electron microscopy (SEM). The CSW AC film showed significantly higher tensile strength and elongation than those of starch-filled waterbonre acrylate (SWAC). The biodegradability of this film was higher than that of native starch-filled acrylate film, and was increased by the addition of crosslinked starch to the acrylate film.

• 한국환경과학회지
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• 제13권12호
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• pp.1131-1138
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• 2004

The starch-filled waterborne acrylate (SWAC) films were prepared. The structures and properties of SWAC films were investigated by infrared spectroscopy, thermogravimetric analysis, and strength test. The biode­gradability of SWAC film was also studied by determination of reduced sugar products after enzymatic hydrolysis. The surface morphology of the SWAC film was investigated by scanning electron microscopy (SEM). The results showed that the tensile strength and elongation of SWAC film decreased with the increase of starch content. The SWAC film showed significantly higher water absorbed content than waterbonre acrylate film. The biodegradability of SWAC film increased as the content of starch increased. The biodegradation of starch in SWAC film by ${\alpha}-amylase\;was\;about\;77{\%}$ of that of pure starch.

• Applied Biological Chemistry
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• 제40권5호
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• pp.395-399
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• 1997

아밀로오스 함량이 다른 옥수수전분을 2.2N HCl로 산처리하여 산가수분해 특성 및 효소저항전분의 수율을 비교하였다. 산 가수분해경향은 아밀로오스 함량이 0%인 Amioca는 7일을 경계로, 그외의 전분은 4일을 경계로 2단계로 진행되었으며, 산가수분해 속도상수는 초기에 $4.01{\sim}9.21{\times}10^{-3}hr^{-1}$, 후기에는 $1.60{\sim}5.01{\times}10^{-3}hr^{-1}$로 아밀로오스 함량이 낮을수록 옥수수전분의 가수분해 속도가 빨랐다. 생전분의 X-선 회절양상은 아밀로오스 함량이 적은 Amioca, PFP, CMS(commercial maize starch)는 A형 , 고아밀로오스 함량인 Amaizo 5, Amylomaize VII은 B형의 전형적인 결정형을 보였으며, 산처리 후에도 모든 시료의 결정형은 그대로 유지하였으나 상대적인 결정화도는 증가하였다. 효소저항전분의 수율은 Amioca, CMS, Amylomaize VII이 각각 1.8%, 20.8%, 37.9%로 아밀로오스 함량이 높을수록 수율도 증가하였으며, 가열-냉각 횟수를 4회 반복한 후 분리한 산처리 한 옥수수전분의 효소저항전분의 수율은 1일 산처리한 CMS, Amylomaize VII이 각각 4.5%, 29.1%였으며 7일 산처리시에는 1.5%와 19.4%로 산처리에 의해 효소저항전분의 수율이 감소하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권2호
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• pp.171-180
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• 2017

Objective: This study investigated the association of enzyme-producing microbes and their enzymes with starch and hemicellulose degradation during fermentation of total mixed ration (TMR) silage. Methods: The TMRs were prepared with soybean curd residue, alfalfa hay (ATMR) or Leymus chinensis hay (LTMR), corn meal, soybean meal, vitamin-mineral supplements, and salt at a ratio of 25:40:30:4:0.5:0.5 on a dry matter basis. Laboratory-scale bag silos were randomly opened after 1, 3, 7, 14, 28, and 56 days of ensiling and subjected to analyses of fermentation quality, carbohydrates loss, microbial amylase and hemicellulase activities, succession of dominant amylolytic or hemicellulolytic microbes, and their microbial and enzymatic properties. Results: Both ATMR and LTMR silages were well preserved, with low pH and high lactic acid concentrations. In addition to the substantial loss of water soluble carbohydrates, loss of starch and hemicellulose was also observed in both TMR silages with prolonged ensiling. The microbial amylase activity remained detectable throughout the ensiling in both TMR silages, whereas the microbial hemicellulase activity progressively decreased until it was inactive at day 14 post-ensiling in both TMR silages. During the early stage of fermentation, the main amylase-producing microbes were Bacillus amyloliquefaciens (B. amyloliquefaciens), B. cereus, B. licheniformis, and B. subtilis in ATMR silage and B. flexus, B. licheniformis, and Paenibacillus xylanexedens (P. xylanexedens) in LTMR silage, whereas Enterococcus faecium was closely associated with starch hydrolysis at the later stage of fermentation in both TMR silages. B. amyloliquefaciens, B. licheniformis, and B. subtilis and B. licheniformis, B. pumilus, and P. xylanexedens were the main source of microbial hemicellulase during the early stage of fermentation in ATMR and LTMR silages, respectively. Conclusion: The microbial amylase contributes to starch hydrolysis during the ensiling process in both TMR silages, whereas the microbial hemicellulase participates in the hemicellulose degradation only at the early stage of ensiling.