• 한국식품영양과학회지
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• 제32권1호
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• pp.89-95
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• 2003

4차원 반응표면에 의한 알로에 겔상 식품의 관능적 및 물리적 특성을 모니터링 하였다. 겔상 식품의 색상에 대한 관능점수는 알로에즙의 함량 87.38 mL, 카라기난의 함량 0.19 g 및 곤약의 함량 0.16 g에서 가장 높게 나타났으며, 겔상 식품의 향에대한 관능점수는 알로에즙의 함량 83.84 mL, 카라기난의 함량 0.20 g 및 곤약의 함량 0.17 g에서, 맛에 대한 관능점수는 알로에 즙의 함량 83.20 mL, 카라기난의 함량 0.27 g 및 곤약의 함량 0.15 g에서, 조직감에 대한 관능점 수는 알로에즙의 함량 98.95 mL, 카라기난의 함량0.23 g및 곤약의 함량0.10 g에서 가장높게 나타났다. 겔상 식품이 입안에서 느껴지는 물성을 기계적으로 측정한 결과 씹힘성은 알로에즙의 함량 113.05 mL, 카라기난의 함량 0.21 g 및 곤약의 함량 0.27 g에서 가장 높게 나타났다 알로에 겔상 식품 제조의 최적 조건인 전반적인 기호도는 알로에즙의 함량 88.23 mL, 카라기난의 함량 0.19 g 및 곤약의 함량 0.15 g으로 나타났다.

• Food Science and Biotechnology
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• 제15권6호
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• pp.856-859
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• 2006

The effects of moisture content on non-fracture dynamic properties and fracture gel quality of Pacific whiting surimi were investigated to determine their relationships. Surimi samples were tested at various moisture contents (75, 78, and 81 %). Torsion test showed that shear stress decreased rapidly and strain values decreased gradually as moisture concentration increased. Dynamic storage modulus (G') also decreased as moisture content increased. A strong positive correlation ($R^2=0.90$ to 0.99) was found between the G' measured at temperatures between 10 and $45^{\circ}C$ and fracture stress values. The results indicate that dynamic rheological measurements could be used as a tool for early gel quality assessment.

• Preventive Nutrition and Food Science
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• 제2권4호
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• pp.281-284
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• 1997

Heat-induced gelation is an important functional property of whey proteins. Preheating of calcium reduced whey was reported to increase gel strength. 5% whey-protein solutions were preheated at pH7 and at various temperatures(60~8$0^{\circ}C$) for 15 minutes. The amount of soluble aggregates and denaturation enthalpy of preheated whey proteins were measured. Preheating temperature was negatively correlated with denaturation enthalpy($R^2$=0.857, P=0.08) and positive with the amount of soluble aggregates($R^2$=0.921, P=0.002). Denaturation enthalpy was negatively correlated with gel strength($R^2$=0.93, P=0.002). Soluble aggregates and gel strength were positively correlated($R^2$=0.972, P=0.0003). The formation of three dimensional gel network requires controlled protein denaturation and aggregation. Since preheating leads to the partial denaturation of proteins and the formation of soluble aggregates, preheated whey proteins have a higher gel strength than non-preheated one.

• 한국식품과학회지
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• 제20권4호
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• pp.594-599
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• 1988

냉동 저장온도에서 비동결 상태로 액란을 저장할 수 있는 방법을 연구하기 위하여 cryoprotectants를 첨가하거나 papain으로 처리하여 $-15^{\circ}C$에서 저장하면서 품질변화를 조사한 결과는 다음과 같다. Cryoprotectants로는 제품의 향미를 고려하여 fructose와 glucose를 45 : 55로 혼합하여 사용하는 것이 좋고, whole egg나 난황을 $-15^{\circ}C$에서 비동결 상태로 저장하는데 필요한 cryoprotectants의 농도는 각각 70.3%와 45.2%이었다. 그리고 액란에 cryoprotectants를 첨가하여 저장하면 gel화를 효과적으로 방지할수 있었으며, gel화가 발생한 액란에서는 consistency의 증가, 단백질 침전도의 증가 및 미세구조의 파괴를 볼수 있었다. 액란에 0.15%.papain을 처리한 후 냉동온도에서 저장하면 액란의 gel화를 상당히 방지할 수 있었다.

• Korea-Australia Rheology Journal
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• 제11권4호
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• pp.275-278
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• 1999

Soft polymeric materials have gained importance in recent years, namely in food, pharmaceuticals, photographic media, adhesives, vibration dampeners and superabsorbers (to name a few), but also as inter-mediates for selforganization of molecules or supramolecules into long range order. Many of these soft materials are close to their gel point, i.e. they are liquids just before reaching their gel point or they are solids which have barely passed the gel point. New rheological methods need to be developed for the understanding of these soft materials; the typical liquid properties (viscosity) and typical solid properties (modulus) are not applicable since they diverge at the gel point. This will be discussed in the following. Fortunately, chemical gelation experiments with model polymers has given insight into the behavior at the gel point (Winter and Mours, 1997). This knowledge of the critical gel provides us with a reference state when working with soft polymeric materials. Chemical gels will serve as model materials for the exploration of physical gels. A novel method for detecting the gel point has been proposed: the instant of liquid-to-solid transition(gel point) is marked by the crossover of the normalized dynamic moduli G'/cos($n_c$$\pi$/2) and G"/sin($n_c$$\pi$/2).>/2).

• Food Science and Biotechnology
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• 제18권3호
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• pp.618-623
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• 2009

Synergistic interactions between xanthan (X) and carob (C) were investigated by studying the linear viscoelastic behavior of X, C, and X/C mixtures at sol and gel states. At the solution state, storage modulus (G') dominates the linear viscoelastic properties of X/C mixtures. The gelation temperature (52 to $57^{\circ}C$) was weakly dependent on the xanthan fraction (${\phi}x$) in the mixture. The ${\phi}x$ also had a strong effect on G' until ${\phi}x=0.5$. The elastic active network concentration (EANC) of X/C gels was estimated from the pseudo-equilibrium modulus. The EANC for systems with ${\phi}x=0.25$, 0.5, 0.75, and 1 at 1% total concentration was 2.3, 4.4, 4.1, and 0.32 (${\times}10^{-3}\;mol/m^3$), respectively. The maximum synergistic effect was observed at about ${\phi}x=0.5$. The G' at the transition state of X/C mixed gel was proportional to ${\omega}^{3/2}$ at ${\omega}$>${\omega}_{tr}$ (the onset transition frequency) compared to the theoretical limit of ${\omega}^{1/2}$.

• 한국식품영양학회지
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• 제1권2호
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• pp.50-55
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• 1988

B-Amylase was obtained from sweet potato extract in a crystalline state by dialysis against water after precipitated with acetone according to the method reported previously followed by DEAE Sephadex A-50 ion exchange chromatography plus gel chromatography of Sephadex G-200. The purified enzyme was homogeneous by SDS PAGE. The efforts had done to remove the miner bands in SDS PAGE by Sephadex G-200 gel chromatography, DATE Sephadex A-50 ion exchange chromatography. isoelectrophocusing, affinity chromatography, hydroxyapatite chromatography, recrystallizstion and HPLC on a column of TSK gel SW 3000 but have given any result. But, N -terminal amino acid of the enzyme was revealed mainly alanine and trace of glycine and glutamic acid. Therefore, it seems that the miner bands in SDS PAGE have a role of subunit.

• Applied Biological Chemistry
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• 제30권4호
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• pp.305-310
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• 1987

대두 및 고구마로부터 얻은 ${\beta}-Amylase$의 단백질 구조를 CD Spectra, 항체반응, 화학적 절단을 통하여 비교하였다. 고구마 ${\beta}-Amylase$는 4개의 동일한 subunit로 구성되어 있으며 대두 ${\beta}-Amylase$는 Subunit구조를 하고 있지 않았다. 또한 두 효소는 변성시킨 상태에서 SDS-gel전기영동, gel filtration한 결과 분자량은 동일하였다. 그리고 대두 및 고구마 ${\beta}-Amylase$는 CD spectra상 유사한 2차구조를 나타내고 있으나 방향족 측쇄가 상이함을 나타냈다. 한편 cyteine 잔기 및 methionine 잔기의 화학적 절단한 결과 두 효소는 동일한 아미노산 배일을 나타냈다. 또한 면역학적인 방법에 의해서도 두 효소는 유사성이 인정되었다. 한편 대두 ${\beta}-Amylase$에 대한 항체는 고구마 ${\beta}-Amylase$의 활성을 억제하였으나 밀, 보리, 무우 ${\beta}-Amylase$에 대해서는 활성 억제가 나타나진 않았다.

• Journal of Microbiology and Biotechnology
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• 제5권4호
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• pp.181-187
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• 1995

The cells of Vibrio vulnificus can be induced to the viable but nonculturable (VBNC) state by natural environmental parameters. The V. vulnificus cells in the VBNC state can not be recovered by ordinary laboratory techniques. This nonculturability could often hamper development of effective processing strategies to minimize the number of V. vulnificus in seafoods. Even with V. vulnificus cells in a culturable state, the length of time required to identify the bacteria in contaminated food by phenotyphic characterization may prevent appropriate in-time responses by public health agencies to infections of the bacteria. In the present study, we used polymerase chain reaction (PCR) to develop a rapid and direct detection method for V. vulnificus in small octopus (Octopus variabilis) which is consumed as a raw food in Korea. The region targeted was a 704-base pair (bp) portion of the hemolysin gene, vvhA, of V. vulnificus. The primers designed for PCR amplification were specific for all V. vulnificus sp. tested. Several methods were examined to extract total DNA directly from V. vulnificus seeded into the octopus homogenate and the guanidine isothiocyanate (CITC) method appeared to be most effective. From the octopus homogenate seeded by V. vulnificus at an initial level of $10^2$ CFU/ml of the homogenate and then incubated for 12 h, the targeted sequence was successfully amplified by PCR and the 704-bp DNA fragment was observed by gel electrophoresis. The total completion of this assay requires less than one day.

• 한국축산식품학회지
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• 제34권2호
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• pp.230-237
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• 2014

This study was designed to find the most suitable method and wall material for microencapsulation of the Lactobacillus plantarum to maintain cell viability in different environmental conditions. To improve the stability of L. plantarum, we developed an encapsulation system of L. plantarum, using water-in-oil emulsion system. For the encapsulation of L. plantarum, corn starch and glyceryl monostearate were selected to form gel beads. Then 10% (w/v) of starch was gelatinized by autoclaving to transit gel state, and cooled down at $60^{\circ}C$ and mixed with L. plantarum to encapsulate it. The encapsulated L. plantarum was tested for the tolerance of acidic conditions at different temperatures to investigate the encapsulation ability. The study indicated that the survival rate of the microencapsulated cells in starch matrix was significantly higher than that of free cells in low pH conditions with relatively higher temperature. The results showed that corn starch as a wall material and glycerol monostearate as a gelling agent in encapsulation could play a role in the viability of lactic acid bacteria in extreme conditions. Using the current study, it would be possible to formulate a new water-in-oil system as applied in the protection of L. plantarum from the gastric conditions for the encapsulation system used in chicken feed industry.