• Food Science and Biotechnology
• /
• 제16권6호
• /
• pp.902-909
• /
• 2007

Granular maize starch was treated with Thermus scotoductus 4-${\alpha}$-glucanotransferase (${\alpha}$-GTase), and its physicochemical properties were determined. The gelatinization and pasting temperatures of ${\alpha}$-GTase-modified starch were decreased by higher enzyme concentrations. ${\alpha}$-GTase treatment lowered the peak, setback, and [mal viscosity of the starch. At a higher level of enzyme treatment, the melting peak of the amylose-lipid complex was undetectable on the DSC thermogram. Also, ${\alpha}$-GTase-modified starch showed a slower retrogradation rate. The enzyme treatment changed the dynamic rheological properties of the starch, leading to decreases in its elastic (G') and viscous (G") moduli. ${\alpha}$-GTase-modified starch showed more liquid-like characteristics, whereas normal maize starch was more elastic and solid-like. Gel permeation chromatography of modified starch showed that amylose was degraded, and a low molecular-weight fraction with $M_w$ of $1.1{\times}10^5$ was produced. Branch chain-length (BCL) distribution of modified starch showed increases in BCL (DP>20), which could result from the glucans degraded from amylose molecules transferred to the branch chains of amylopectin by inter-/intra-molecular transglycosylation of ${\alpha}$-GTase. These new physicochemical functionalities of the modified starch produced by ${\alpha}$-GTase treatment are applicable to starch-based products in various industries.

• 한국식품조리과학회지
• /
• 제28권6호
• /
• pp.871-881
• /
• 2012

To compare the physicochemical and gel properties of mung bean starches prepared by different purification methods, starches from Korean Eohul variety and Chinese mung bean (MB) with or without hull using alkaline solution or water as solvent were purified. The optimum conditions for making muk were investigated. Apparent amylose and total dietary fiber contents, water binding capacity, solubility and pasting properties by RVA were analyzed. The characteristics of starch gels (10% dry basis) were measured for 0 and 4 day stored at $4^{\circ}C$. The protein and ash contents were significantly different (p<0.05) and lowered in starch from dehulled MB using alkaline solution. The starches from dehulled MB using alkaline solution showed the lowest color differences. Apparent amylose contents of Eohul and Chinese starches showed 37.06-39.03% and 31.57-32.74%, respectively. Chinese starch was higher in water binding capacity but lower in solubility at $85^{\circ}C$ than others. Peak, trough, cold, and breakdown viscosities of Eohul starch were higher than those of Chinese one. Mung bean starch gel made immediately exhibited clear and glossy appearance but became whiter like milk. The crystallinities of starch and starch gel showed A and B types, respectively. The hardness, gumminess, and resilience of starch gel made immediately and hardness, cohesiveness, gumminess, and resilience of 4 day stored gels were different significantly (p<0.05). Especially, Eohul starch gels purified from hulled MB showed higher resilience (bending property) and hardness. Therefore, it was suggested that high quality muk would be made using MB starch purified from hulled Korean mung bean using water as solvent.decreased in contain more than 20% of SGP added groups. The optimal concentration of SGP was found in the range of less than 10%.

• 한국식품조리과학회지
• /
• 제31권6호
• /
• pp.696-702
• /
• 2015

Rice dumpling shells were prepared with different levels of hydrocolloids, such as hydroxypropyl methyl cellulose (HPMC), and potato starch. After steaming, the physical, sensory, and cooking properties of the shells were measured. Increasing the amount of potato starch decreased the pasting temperature and increased the peak viscosity. With the addition of hydrocolloids, water absorption and cooking loss for the rice dumpling shells decreased significantly. For the textural properties, the rice dumpling shells with hydrocolloids showed lower hardness and higher springiness than the control, and especially, 10% potato starch and 3% HPMC addition (P10H3) improved the texture of the rice dumpling shells the most. The sensory results seemed to be affected more by the addition of potato starch than HPMC, and over 15% addition of potato starch significantly decreased the quality of the rice dumpling shells. By addition of adequate amount of hydrocolloids (3% HPMC and 10% potato starch), the sensory quality of rice dumpling shells can be effectively improved.

• 한국식품영양학회지
• /
• 제29권5호
• /
• pp.692-697
• /
• 2016

This study was aimed to develop a gruel using rice extrudates and to evaluate physicochemical properties of Tarakjuk (milk porridge; MP) prepared with milk (M) and rice powder (RP, control), rice extrudate (RE), or enzyme treated rice extrudates (ETR). Pasting property of ETR was significantly different from those of RP or RE with significantly low peak viscosity, breakdown and setback values in the ETR sample. Viscosity of MP prepared with ETR was also significantly low, as compared to that of control (> 900 cP). The total solids and spreadability of MP with ETR was higher than those with RP or RE. Hunter color values varied significantly depending on enzyme treatment levels in ETR samples with enzyme dose-dependent increase in b-value. Average starch digestibility of ETR sample was higher by 10.2% than that of control sample. DPPH radical scavenging activities of ETR samples were greater than those of RE or RP. These results indicated that ETR could be beneficial for preparing easy-drink and diet food with higher starch digestibility and fluidity, especially for gastric tube-fed patients.

• Food Science and Biotechnology
• /
• 제17권2호
• /
• pp.234-240
• /
• 2008

The optimal conditions for the production of branched dextrin from com starch (CSBD) using branching enzyme (BE) were established by investigating the degree of retrogradation of the gelatinized starch. The physicochemical properties of CSBD prepared using the established process were evaluated. It was found that physicochemical properties of com starch were greatly modified by BE treatment. CSBD had a higher dextrose-equivalent value and water solubility than the corresponding control. On the other hand, the viscosities in gelatinized solution and amylose contents of CSBD were lower than those of the control. A high-performance size-exclusion chromatography/multiangle laser light scattering/retractive index (HPSEC/MALLS/RI) system showed that the average molecular weight of CSBD was lower than that of the control. The pasting viscosities of CSBD were stable during the entire temperature cycle. In general, the BE treatment resulted in the retrogradation during storage being lower for CSBD than for the control.

• 한국식품과학회지
• /
• 제52권4호
• /
• pp.409-414
• /
• 2020

시중에 분쇄된 상태로 판매되는 CFBF와 faba bean 원물을 직접 분쇄하여 제조한 FBF, 그리고 분쇄한 faba bean 가루에서 알칼리 추출법으로 추출한 FBS의 물리화학적 특성을 확인하였다. FBS의 녹말 입자는 타원형에 표면에 갈라짐이 있으며 CFBF와 FBF는 일정하지 않은 크기의 입자를 보였다. FBS는 상대적으로 낮은 용해도와 겉보기 점도를 보여주었다. CFBF와 FBF는 호화 특성을 나타내지 못한 반면 FBS는 비교적 낮은 trough와 높은 setback값의 호화 특성을 보여주어 차이를 나타냈다. FBS의 호화 엔탈피는 12.9 J/g으로 CFBF와 FBF 보다 높은 값을 나타내었다. 상대결정화도에서도 역시 FSB가 CFBF와 FBF와 비교하여 상대적으로 높은 값을 나타내었다. CFBF와 FBF는 여러 실험들의 결과에서 서로 크게 차이 나지 않고 비슷한 경향의 특성을 확인하였으나 FBS는 CFBF, FBF와는 크게 다른 물리화학적 특징들을 보였다. 이는 서로 다른 단백질 함량 때문이라 판단된다. FBS는 녹말 추출을 위하여 NaOH 용액을 이용하여 단백질을 제거하여 단백질 함량이 CFBF, FBF와 비교했을 때 상당히 낮고 단백질을 제거하기 위한 공정 중 녹말의 변화가 있으며 CFBF와 FBF의 단백질은 녹말과 수분의 반응에 관여하여 물리화학적 특성에 영향을 끼쳤다고 판단되었다. 한국에서는 faba bean 가루와 녹말을 다양하게 사용하고 있지 않은데 이 연구의 결과는 식품산업에 faba bean을 적용하기 위한 기초자료로 사용될 수 있을 것이다.

• Food Science and Biotechnology
• /
• 제16권6호
• /
• pp.943-947
• /
• 2007

The acid modification of waxy rice starch was conducted to improve the yugwa production process. The intrinsic viscosity, paste viscosity, and differential scanning calorimetry characteristics of acid modified starch were measured, and bandaegi and yugwa prepared from acid modified starch were evaluated. The intrinsic viscosities of acid thinned starches were 1.48, 1.27, 1.15, and 0.91 mL/g after reaction times of 1, 2, 3, and 4 hr, respectively. The gelatinization enthalpy was reduced from 16.3 J/g in native starch to 15.8, 15.3, 14.7, and 14.5 J/g in acid thinned starches as the time of acid thinning increased. The peak viscosity and final viscosity decreased with increasing the time of acid thinning, but the pasting temperature was slightly increased in acid thinned starches. The hardness of bandaegi from acid thinned starches under high pressure greatly decreased relative to the control, typical yugwa. Yugwa from acid thinned starch under high pressure maintained a homogeneous structure containing tiny and uniform cells similar to that of native waxy rice starch used for typical yugwa. Acid thinning under high pressure appears to be a good alternative to the existing steeping process for better yugwa quality.

• Food Science and Biotechnology
• /
• 제17권1호
• /
• pp.52-57
• /
• 2008

The effects of transglutaminase (TG) on the pasting and rheological properties of different wheat cultivars ('Sharpshooter', 'Russ', and 'AcAriss') blended with barley (40%) or soy (20%) flour were investigated. In the rapid visco-analyzer (RVA) pasting profile, the addition of barley or soy flour to wheat flour samples induced a decrease in peak, trough, final viscosity, breakdown and setback values. However, TG treatment of these blends significantly increased peak viscosity and breakdown (p<0.05). In particular, TG treatment greatly increased the breakdown of wheat flour blended with soy flour, indicating that the cross-linking of proteins through TG may somehow be related to an increase in starch granule rupturing in pastes. Storage (G') and loss (G") moduli of the sample pastes increased with an increase in frequency ($\omega$), while complex viscosity (${\eta}*$) decreased. In all wheat cultivars, G', G", and $\eta$ were decreased by the addition of barley or soy flour, or TG treatment. Results suggest that protein cross-linking by TG can produce unique and improved properties in wheat flours blended with barley or soy flour.

• Journal of Applied Biological Chemistry
• /
• 제50권4호
• /
• pp.234-238
• /
• 2007

The effects of ultra-fine pulverization on the physicochemical properties of rice starch (RS) were investigated using a high impact planetary mill. After pulverization, RVA characteristics, peak viscosity, break down, and set back values of RS decreased from 274.75 to 9.42 RVU, 214.46 to 6.17 RVU, and 87.80 to 17.00 RVU, respectively. The pasting properties also changed significantly. X-Ray diffractogram revealed RS had four A-type peaks, which disappeared after pulverization. The peak temperature and gelatinization enthalpy of RS using differential scanning calorimetry (DSC) were 13.99 J/g at $75.14^{\circ}C$, whereas the pulverized RS (PRS) had two peaks, 0.13 J/g at $63.88^{\circ}C$ and 1.23 J/g at $101.24^{\circ}C$. DSC measurement showed the retrogradation degree of PRS was lower than that of RS after storage at 4 and $25^{\circ}C$. The enzymatic (${\alpha}$-amylase) digestibilities of RS and PRS were 72.7 and 77.3%, respectively.

• 한국식품과학회지
• /
• 제45권6호
• /
• pp.747-753
• /
• 2013

고구마의 가공공정(절단, 성형, 세척) 중 발생하는 고구마 가공슬러지로부터 고구마전분을 회수하여 전분소재로서의 활용가능성을 재고하기 위해 회수된 고구마전분들의 물리화학적 특성을 조사하였고 고구마 가공 슬러지의 냉동저장에 따른 고구마전분의 특성 변화를 비교하였다. 고구마 가공 슬러지로부터 회수된 전분들의 총전분 함량은 94.1-95.6%의 범위에 있었으나 겉보기 아밀로오스와 인 함량은 냉동 고구마 가공 슬러지로부터 회수된 고구마 전분이 다른 전분들에 비해 유의적으로 낮았다. 냉동저장 처리는 고구마전분의 아밀로펙틴 분지사슬 분포에 큰 영향을 미치지 않았으나 고구마전분 입자의 결정구조를 변형시켰으며 무정형 영역을 감소시켰다. 이로 인해 고구마전분의 팽윤력과 페이스팅 점도특성은 감소하였으며 최대호화온도와 호화종결온도는 상승하는 결과를 초래하였다. 전체적인 결과를 고려할 때 고구마 가공 슬러지를 획득한 즉시 회수한 고구마전분은 고구마로부터 직접 분리한 고구마전분과 물리화학적 특성이 유사하여 상업적인 전분소재로 사용가능할 것으로 기대되지만 냉동저장된 고구마 가공 슬러지로부터 분리 정제한 고구마전분을 상업적으로 이용하기 위해서는 가공식품에 있어 이의 가공적성 및 최종품질에 대한 영향 조사가 선행되어야 할 것 같다.