• 한국식품과학회지
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• 제38권3호
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• pp.444-447
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• 2006

마를 냉동건조, 선풍기건조, 열풍건조, 연탄건조한 후 이들의 현탁액과 상징액의 점도와 첨가물에 따른 점도변화를 조사하였다. 선풍기건조한 마 현탁액(7.5%)의 점도는 43 mPa s로 냉동건조한 것의 58.1 mPa s보다는 낮았지만 시중에서 많이 사용하는 열풍건조한 것의 17.2 mPa s보다는 높았다. 이는 농가에서 저렴한 방법으로 점성이 상당히 유지되는 건조마를 생산할 수 있음을 말해준다. 건조방법 별로 점도차이가 나는 것은 건조 중 점질물의 단백질이 열변성되었기 때문이었다. 마현탁액과 상징액에 설탕을 첨가하면 점도가 상승하였으나 소금의 첨가로는 별 영향이 없었다. 구연산은 0.5% 첨가하였을 때 점도가 감소하였다.

• 한국식생활문화학회지
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• 제21권1호
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• pp.76-80
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• 2006

This study investigated the quality characteristics of demi-glace sauce that is used widely in western cuisine depending on adding volume of basil which has a specific aroma, taste and some functional ability. Analysis of color differences of demi-glace sauce was showed that a-value of demi-glace sauce decreased with adding basil, whereas viscosity of the demi-glace sauce was decreased. There were no significant differences in color, aroma, taste, appearance, viscosity, feel in mouse and general acceptability with sex and age of subjects. Demi-glace sauce with 2% basil showed best score in sensory evaluation. From theabove results, our data suggest that addition of 2% basil to demi-glace sauce is recommend for commercial use.

• 한국식품과학회지
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• 제26권6호
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• pp.696-703
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• 1994

The purpose of this study was to investigate the gelatinization properties of potato starch heated with microwave. Two types of potato starches were prepared; In group A raw potato starch was heated with microwave and in group B potato starch was isolated from potato heated with microwave. Both groups were exposed to the microwave energy in a 560W, 2,450 MHz oven for 60, 120, 180 and 300 seconds. Gelatinization behaviour by DSC made a few differences according to the ratio of starch to water. As the microwave heating time took longer, gelatinization temperature and gelatinization $enthalpy({\bigtriangleup}H_1)$ were decreased in and melting $enthalpy({\bigtriangleup}H_2)$ was increased in group A. Whereas they were increased in group B. In both groups, maximum viscosity in gelatinization by Brabender amylogram was decreased by microwave heating. Then the peak of the maximum viscosity was shifted to higher temperature and cold viscosity was slightly increased. In group A, viscosity in gelatinization and light transmittance by NaOH was increased in initial stage and gel volume in gelatinization by KSCN was decreased. On the other hand, in group B, viscosity by alkali was slightly decreased, but light transmittance by NaOH was almost never changed. Gel volume is decreased like group A.

• Preventive Nutrition and Food Science
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• 제9권2호
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• pp.133-137
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• 2004

This study was carried out to establish a method for the detection of irradiated glutinous rice by measuring pulsed photostimulated luminescence (PPSL) and viscometric properties. Viscosity was determined using a Brookfield DV-III rotation viscometer at 3$0^{\circ}C$ and measured at 30, 60, 90, 120, 150, 180, and 210 rpm. All irradiated samples indicated a decrease in viscosity with increasing stirring speeds (rpm) and irradiation doses. Treatments with 2∼5 kGy significantly decreased the viscosity. The photon counts of the irradiated glutinous rice were measured by PPSL and the photon counts of the non-irradiated and irradiated glutinous rice measured immediately after irradiation exhibited an increase with increasing irradiation dose. The photon counts of irradiated glutinous rice almost disappeared with the lapse of time when stored under normal room conditions, but was still possible to detect after 12 months of darkroom storage. Consequently, these results indicate that the detection of irradiated glutinous rice is possible by both viscometric and PPSL methods.

• 한국식품영양과학회지
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• 제23권5호
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• pp.822-826
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• 1994

Effects of concentration(6-9%, db) , heating temperature (80-95$^{\circ}C$), cooking time (10-50min) and heating method (continuous and instantaneous) on the apparent viscosity of cowpea sediment dispersions at 6$0^{\circ}C$ were investigated. The instantaneous heating resulted in higher apparent viscosity than continuous heating regardless concentrations and heating temperatures. The activation energy of the increase rate constant of the apparent viscosity was about 8 kcal/mole. The apparent viscosity of the cowpea sediment dispersion heated to 95$^{\circ}C$ and held for 20 min showed a linear relation with the 20 min height at 92.5$^{\circ}C$ by viscoamylograph.

• Preventive Nutrition and Food Science
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• 제19권3호
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• pp.242-245
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• 2014

The flow behaviors of three thickened fruit juices (orange, apple, and grape juice) prepared with a commercial instant xanthan gum (XG)-based thickener that is marketed in Korea were investigated at different thickener concentrations (1.0%, 1.5%, 2.0%, 2.5%, 3.0%, and 3.5%) and setting times (5 and 30 min) using a rheometer and a line-spread measurement method. The flow distance values measured by the line-spread test (LST) were compared with the apparent viscosity (${\eta}_{a,50}$) values measured with a sophisticated computer-controlled rheometer. The ${\eta}_{a,50}$ values of the juices increased as thickener concentration increased, whereas their flow distances decreased. The ${\eta}_{a,50}$ values at the 30-min setting time were much higher than those at the 5-min setting time, indicating that the setting time before serving or consuming thickened juices can affect viscosity values. Plots comparing ${\eta}_{a,50}$ values to LST flow distances revealed strong exponential relationships between the two measures ($R^2$=0.989 and $R^2$=0.987 for the 5- and 30-min setting times, respectively). These results indicate that the LST can be a suitable instrument for evaluating the viscosity of thickened fruit juices prepared with different XG-based thickener concentrations and setting times for the dysphagia diet.

• 한국식품과학회지
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• 제42권2호
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• pp.240-245
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• 2010

국산 및 중국산 현미를 대상으로 방사선 조사여부 판별방법의 하나인 점도측정법 검증을 위하여 0-15 kGy 범위의 감마선을 조사하고 점도, 전분함량 및 specific parameter 측정에 의한 미지시료의 조사여부 판별을 시도하였다. 현미의 전분함량은 국산과 중국산 각각 71.52와 64.58%이었고, 국산 현미가 중국산 보다 상대적으로 높은 점도를 나타내었다. 방사선 조사된 국산 및 중국산 현미의 조사선량에 따른 점도 및 specific parameter는 유의적으로 감소하였으며, 전단속도(50, 150, 300 rpm)에 영향을 받아 낮은 속도에서 조사선량의 영향이 크게 나타났다. 점도와 specific parameter의 변화에 대한 조사선량의 상관성을 나타낸 결정계수($R^2$)는 국산 현미는 0.9423-0.9567, 중국산 현미는 0.9119-0.9387을 보였다. 또한 상기 점도측정법에 의한 미지시료(n=30)의 조사여부 판별시험에서는 90%의 정확도를 보였다. 이로써 전분질 식품의 방사선 조사여부 확인에서 점도측정법은 screening 방법의 하나로써 보조적 역할의 가능성을 보여주었다.

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

• 산업식품공학
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• 제23권2호
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• pp.125-133
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• 2019

마 분말과 생 마의 추출 용매(열수 25, 50, 75, 95℃, 에탄올 25, 50, 75 100%) 및 추출 방법(회분법, 침지법)에 따른 추출물과 추출 후 침전물에 대한 특성을 알아보았다. 추출물의 total polyphenol 대부분 생 마 보다는 마 분말에서 더 높게 나타났고 마 분말 50% 에탄올 추출에서 가장 높은 함량을 나타냈다. DPPH 라디칼 제거능은 마 분말과 생 마 모두 75% 에탄올 추출법에서 높은 제거능을 보였고, 가압 가열 추출법은 높은 압력과 온도에 의한 항상화 물질의 파괴로 인해 낮은 제거능을 보였다. 조사포닌 함량은 마 분말과 생 마 모두 95℃ 열수 추출법에서 가장 높은 함량을 나타냈다. 티로시네이즈 활성 억제능에서는 마 분말의 경우는 95℃ 열수 추출법 또는 가압 가열 추출법, 생 마의 경우에는 95℃ 열수 추출법, 25% 에탄올 추출법 또는 가압 가열 추출법으로 추출한 시료가 가장 티로시네이즈의 활성을 억제하는 것으로 나타났다. 침전물의 RVA 호화특성 결과 대부분 추출법에서 peak viscosity, trough, final viscosity 등이 control에 비해 증가하는 결과가 나온 반면 95℃ 열수 추출법과 가압 가열 추출법에서는 전분 그래뉼의 파괴를 SEM을 통하여 확인하였고 그로 인한 viscosity 감소 현상이 나타났다. 그러나 마 분말 75℃ 열수 추출의 경우 전분 그래뉼의 파괴는 SEM에서 관찰되지 않았음에도 viscosity가 감소한 것에 대한 추가 연구도 필요할 것으로 생각된다. 침전물 현탁액의 점도는 마 분말에서 5.82-9.12 cp, 생 마에서 13.88-19.10 cp로 생 마에서 더 높게 나타났으며 이는 생 마의 점액 물질에 의한 결과로 생각되었다. 본 연구를 통해 마의 추출물과 침전물의 특성을 확인함으로써 마를 활용한 소재화, 식품 및 피부미용 기능성식품 및 화장품 소재 개발을 위한 데이터 자료로써 활용될 수 있을 것이라 생각된다.

• KSBB Journal
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• 제5권4호
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• pp.403-410
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• 1990

Application of the Rheocatch Hotwire Monitoring System for food biotechnology process was evaluated. The growth of microogranism, E coli (JM 83 and Sigma) and Corynesccfertun glutamicum, were monitored. in the fermentor. The cell growth could not be detected the temperature differences between the hotwire and samples($\Delta$T) as indicated by the monitoring system during the fermentation processes. The cell concentration of less than 2g/dl was not sufficient to generate the measurable temperature difference in the fermentor. In order to calibrate the Rheocatch Monitoring System, the temperature difference as a function of solute concentration (microbial cells, sodium cholide, sucrose and dextran) was studied. The relationship between $\Delta$T and the concentration of microbial cells, sucrose and dextran can be expressed in a power series. Further studied with dextran indicated that viscosity and/or kinematic viscosity increase exponentially with an increase in $\Delta$T This is regardless of the concentration and molecular weight of dextran. $\Delta$T linearly increases with the logarithm of molecular weight, while the logarithm of viscosity and the logarithm of kinematic viscosity increase with the logarithm of molecular weight.