• Applied Biological Chemistry
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• v.38 no.5
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• pp.393-397
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• 1995

With a view to utilizing fish skin gelatin as a clearifier or chewing gum base, yellowfin sole skin gelatin was succinylated. Up to 10% succinic anhydride to gelatin, the succinylation degree of gelatin was increased linear and above this concentration a nearly constant value was reached. The succinylated gelatin treated with 15% succinic anhydride to gelatin was examined on the reactivity properties with tannic acid in the experiment. Succinylation degree of the gelatin was about 80%. Succinylation shifted the apparent isoelectric point from pH 5.54 in untreated gelatin to pH 4.08 in succinylated gelatin. The proximate composition and amino acid composition of succinylated gelatin were similar to those of untreated gelatin. However Lysine composition for succinylated gelatin was lower than for untreated gelatin. The ratio of precipitated gelatin and tannic acid became maximum at pH 4.8 in untreated gelatin, at pH 4.0 in succinylated gelatin. Regardless of the difference between untreated and succinylated gelatins, the ratio of precipitated gelatin decreased with concentration of gelatin. The ratio of precipitated tannic acid was the highest by adding $2{\sim}4$ times in succinylated gelatin to tannic acid weight, by adding $2{\sim}3$ times in untreated gelatin. The ratios of precipitated succinylated gelatin and tannic acid were scarcely affected by the presence of sucrose, however, were affected by the presence of ethyl alcohol.

• Applied Biological Chemistry
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• v.38 no.2
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• pp.147-150
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• 1995

Effects of gelation conditions on physical properties of dover sole skin gelatin prepared by fractional precipitation with ethanol were investigated. The physical properties such as gel strength, melting point and gelling point of both ethanol treated and non-ethanoltreated gelatins were improved as concentration of gelatin was increased. The physical property of 10% ethanol treated gelatin sol reached maximum at pH 6.0, whereas non-treated one showed maximum at pH 5.0. Both ethanol treated and non-treated gelatin gel showed the higher gel strength and melting point at lower temperatures and longer period of time. Generally, the physical properties of ethanol treated gelatin gel was better than those of non-ethanol treated gel.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.8
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• pp.1147-1152
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• 2016

This study evaluated the effect of the addition of pig skin gelatine powder with different levels on the chemical compositions, cooking characteristics, and sensory properties of tteokgalbi. Tteokgalbi was produced from products containing 0% (control), 1%, 2%, 3%, and 4% pig skin gelatine powder. The protein and moisture contents of samples increased with an increase of pig skin gelatin powder levels. In addition, the pH value and CIE $b^*$ values of uncooked and cooked samples increased with increasing amount of pig skin gelatin powder. However, cooking loss, diameter reduction, and thickness reduction of samples decreased with an increase of gelatin powder contents. The hardness, gumminess, and chewiness of samples increased with an increase of gelatin powder contents, and sensory evaluation of tteokgalbi containing 2~3% pig skin gelatin powder was the highest. Therefore, usages of pig skin gelatin powder can improve quality characteristics of tteokgalbi.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.483-486
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• 1995

With a view to increase utility of ethanol fractionated fish skin gelatin as a food source, the effect of gelation condition on physical properties of the gelatin was investigated. The physical properties of gelatins treated with or without ethanol were improved with a concentration of gelatin increased. The properties such as gel strength, melting point and gelling point of 10% gelatin sol or gel were reached to maximum at pH 6.0 in ethanol treated gelatin and pH 5.0 in non treated one, respectively. Gel strength and melting point of both gelatin gels chilled for long time at low temperature were superior to those of both gelatin gels chilled for short time at high temperature. Gel strength, melting point and gelling point of ethanol treated gelatin gel or sol prepared under optimized gelation conditioning were superior to those of non treated one.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.172-173
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• 2001

젤라틴은 일반적으로 콜라겐의 가수 분해로 생성되어지는 단백질로서 대부분 동물의 결합 조직이나 피부, 배에 존재한다. 젤라틴은 젤리, 제빵 및 제과, 유화제 및 chewing gum base 등과 같은 식품용은 물론이고, 의약용, 사진용, 미생물 배양용 등으로도 사용되어 지고 있다. 젤라틴은 대부분 돼지나 소와 같은 육상 동물에서 얻어지고 있으나 최근 들어 광우병과 구제역과 같은 안전상의 문제가 대두되는 시점에서 그들의 대체 원료가 필요로 하게 되었고 이들을 대신하기 위해 어류에서 추출한 젤라틴에 많은 관심을 보이고 있다. (중략)

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.547-559
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• 1994

To effectively utilize fish skin wastes from marine manufactory, the optimal extraction conditions to prepare gelatin from fish skins of Alaska pollack, cod and yellowfin sole were investigated. In addition, the physical properties of the fish skin gelatins prepared under the optimal extraction conditions were compared with the commercial animal skin gelatin. The conditions for extraction of gelatins from fish skins were as follows ; The skins were limed with 1.0~1.5%(w/v) calcium hydroxide solution. The fish skin gelatins were extracted with 6~7 volumes of water(pH 6.0~7.0) for 5hrs at $40{\sim}50^{\circ}C$, and the yield of Alaska pollack skin gelatin extracted under the above conditions was higher than those of cod and yellowfin sole skins. The heavy metal contents, jelly strength and electric conductivities of fish skin gelatins were lower than those of a commercial gelatin(bovine skin), but the viscosity and isoelectric point were higher. The amount of amino acid in fish skin, such as gelatin, glutamic acid, serine, threonine, methionine and cysteine, were higher than those in pig and ox skin. However, the contents of hydroxyproline and proline were lower.

• Applied Biological Chemistry
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• v.38 no.2
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• pp.129-134
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• 1995

With a view to utilizing effectively fish skin wasted from marine manufactory, an extracted dover sole skin gelatin was fractionated by further ethanol fractional precipitation method, and then the functional and physicochemical properties for the modified gelatin were determined. Ethanol was added to the concentration of 30% in an extracted dover sole skin gelatin solution, and then the mixture was left to stand at $0^{\circ}C$ for 12 hours. Finally, the precipitates were dried by hot-air$(40^{\circ}C)$ blast. The yellowfin sole skin gelatin prepared by further ethanol fractional precipitation has 223.0 g in gel strength, $17.7^{\circ}C$ in the melting point, and $12.0^{\circ}C$ in the gelling point. The physicochemical properties of the ethanol treated fish skin gelatin were superior to those of fish skin gelatin prepared without ethanol adding, whereas inferior to those of animal skin gelatin. The functional properties of the ethanol treated fish skin gelatin were superior to those of fish skin gelatin prepared without ethanol adding, and were more similar to animal skin gelatin. It may be concluded, from these results, that the dover sole skin gelatin prepared by further ethanol fractional precipitation can be effectively utilized as a human food by improving the functional properties.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.830-834
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• 2002

본 연구는 동적 전단진동(dynamic shear oscillation) 측정방법을 이용하여 농도가 젤라틴의 동적 레올로지 특성에 미치는 영향에 대하여 관찰하였다. $5^{\circ}C$에서의 젤라틴의 저장 탄성률(storage modulus, G#)과 손실 탄성률(loss modulus, G@)은 농도가 증가함에 따라 증가하는 경향을 보였다. 0.9%를 제외한 모든 농도(2.0-4.9%)에서 젤라틴의 G#은 G@보다 매우 높은 값을 나타냈으며, G#과 G@이 ${\omega}$ 의존성이 없는 true 겔과 같은 거동을 나타냈다. 젤라틴의 농도와 K#(G#에 대한 절편)와의 관계에서는 높은 결정계수$(R^2=0.99)$를 보여주면서 좋은 상관관계를 나타냈다. 여러 온도범위$(-5,\;0,\;5,\;10^{\circ}C)$에서 각 온도별로 측정된 K#값은 $-5^{\circ}C(59.5Pa)\;>\;0^{\circ}C(4.09Pa)\;>\;5^{\circ}C(1.41Pa)\;>\;10^{\circ}C(0.35Pa)$의 순으로 가장 낮은 온도에서 K#값이 가장 높은 것으로 나타났다. 또한 냉각과정에서 최종냉각온도인 $5^{\circ}C$에서 측정된 젤라틴의 최대 G#수치는 4.9%(2399Pa)>4.1%(1744Pa)>3.0%(1159Pa)>2.0%(519.3Pa)>0.9%(3.15Pa)의 순으로 높은 농도에서 높게 나타났다. Aging 10시간 동안 젤라틴 겔의 구조형성은 겉보기 first-order kinetics로부터 겉보기 구조형성 속도상수(K)를 결정함으로써 파악될 수 있다. 젤라틴의 농도가 증가함에 따라 K값은 증가하였으며, 농도와 K값과의 관계는 높은 결정계수$(R^2)$를 나타내면서 좋은 상관관계를 보여주었다(Fig. 7). 10시간 aging 후 G#은주파수$({\omega})$ 의존성이 없이 독립적인 것으로 나타났다. 따라서 이들 젤라틴 겔은 aging하는 동안에 탄성이 점점 강해지고 10시간 후에는 가교결합의 밀도가 증가하여 강한 탄성을 가진 고무질 망상구조(rubber network)를 형성했음을 알 수 있다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.2
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• pp.209-214
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• 2016

The aim of this study was to investigate the effects of pork skin gelatin on the physicochemical properties (pH, CIE color value, water holding capacity, cooking yield, viscosity, proximate composition, and texture profile analysis) of emulsion-type sausage. Emulsion-type sausages were manufactured with 0% (control), 1%, 3%, and 5% pork skin gelatin. Moisture contents of samples containing 3% and 5% pork skin gelatin were significantly higher than those of the control and samples containing 1% pork skin gelatin (P<0.05). Protein contents were the highest in samples containing 5% pork skin gelatin (P<0.05). The pH values of uncooked and cooked samples increased with increasing pork skin gelatin level (P<0.05). The lightness and yellowness values of cooked samples containing pork skin gelatin were higher than those of the control (P<0.05). In addition, redness values of cooked samples containing 3% and 5% pork skin gelatin were significantly lower than those of the control and samples containing 1% pork skin gelatin (P<0.05). Water holding capacity (WHC) was the lowest in control, and samples containing 3% and 5% pork skin gelatin had significantly higher WHC compared to the other samples (P<0.05). Cooking yield of samples increased with increasing concentration of pork skin gelatin (P<0.05). Samples containing 3% and 5% pork skin gelatin showed higher viscosity than the control and sample containing 1% pork skin gelatin (P<0.05). Springiness, cohesiveness, and chewiness of samples were not significantly different among the samples. Hardness values of the control and sample containing 1% pork skin gelatin were lower than those of other samples (P<0.05), and samples containing 5% pork skin gelatin had the highest hardness (P<0.05). Gumminess of sample containing 5% pork skin gelatin was significantly higher than that of the control (P<0.05). The results show that pork skin gelatin could improve the potential of emulsion-type sausage physicochemical properties.

• Korean Journal of Food Science and Technology
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• v.49 no.1
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• pp.80-84
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• 2017

Physicochemical properties of spent hen chicken-thigh sausage manufactured with 0 (control), 1, 3, and 5% pork skin gelatin were determined. The moisture contents of samples containing pork skin gelatin were higher than control samples. The pH value of cooked samples increased with increasing pork skin gelatin level (p<0.05). The lightness and yellowness values of cooked samples containing gelatin were higher than lightness and yellowness values of the control (p<0.05). The cooking yield of samples increased with increasing concentration of pork skin gelatin (p<0.05). The samples containing 3 and 5% pork skin gelatin showed higher viscosity than control and gelatin 1% sample (p<0.05). Hardness values were lowest in the of control group and highest in samples containing 5% pork skin gelatin (p<0.05). Overall acceptability of 5% gelatin samples was higher than acceptability of the control samples (p<0.05). The results showed that the pork skin gelatin could improve the physicochemical properties of spent hen chicken-thigh sausage.