• 한국식품과학회지
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• 제26권6호
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• pp.683-689
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• 1994

With a view to utilizing effectively fish skin wastes from marine manufactory, a gelatin solution extracted from yellowfin sole skin was fractionated by precipitation with ethanol, and then the functional and physico-chemical properties for the fractionated gelatin were determined. Ethanol was added up to 50% of ethanol content to a gelatin solution extracted from yellowfin sole skin, then the mixture was left to stand at $0^{\circ}C$ for 12 hours. Finally, the precipitates were dried by hot-air ($40^{\circ}C$). The gel strength and melting point of a 10% gel of gelatin prepared from yellowfin sole skin by precipitation with ethanol has 322.4g and $23.3^{\circ}C$, respectively. The physico-chemical properties of the ethanol treated fish skin gelatin were superior to those of fish skin gelatin prepared without ethanol treatment. Besides, the functional properties of the ethanol treated gelatin were lower in solubility and higher in water holding capacity, oil binding capacity, emulsifying activity, emulsifying stability, foam expansion and foam stability than those of pork skin gelatin sold on market as well as gelatin prepared without ethanol treatment. It may be concluded, from these results, that the fish skin gelatin prepared by precipitation with ethanol can be effectively utilized as a human food by improving the functional properties.

• International Journal of Industrial Entomology and Biomaterials
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• 제15권2호
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• pp.171-174
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• 2007

Sericin beads were prepared from ethanol-precipitated sericin. The addition of ethanol into hot-water extracted sericin solution induced precipitation of sericin and thereby some sericin could be fractionated. The ethanol-precipitated sericin (EpSS) had narrower molecular weight distribution than original sericin. The EpSS had mainly random coil structure with small portion of ${\beta}-sheet$ structure. With the EpSS, spherical beads could be prepared at lower concentration than with original sericin due to higher viscosity. The EpSS beads had better compressive strength than the original sericin beads and had rubber-like property. Our results suggest that EpSS is more compatible in the polymeric field, since it has better mechanical strength than original sericin.

• 대한수의학회지
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• 제4권1호
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• pp.19-22
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• 1964

The alcohol precipitation test(APT) is widely used in the inspection of cow milk, whereas the APT in goat milk inspection is not specifically known. The APT is used to determine the precipitating ability of milk by heat used in sterilization and evaporating process at the milk plant. The APT may also be used to detect abnormal milks such as acid milk, colostrum, and any milk in which the salt balance is disturbed so that it may be more subject to precipitation than normal milk. In the experiments the applicability of the APT of goat milk was studied. The results obtained by using 87 sample of goat milk are as follows: 1. As all the fresh samples(100%) were APT positive by using 70% ethanol which is used in the practice of cow milk and 3 out of 87 samples(3.7%) were positive by using 45% ethanol, it is suggested that 45% ethanol may be applied in the APT of goat milk. 2. The distribution of natural acidity (apparent acidity) was between 0.12%-0.30% and the amount of natural acidity did not significantly affect the precipitating ability of goat milk by APT. 3. The freshness of goat milk cannot be detected sharply by APT even though 45% ethanol is applied.

• Applied Biological Chemistry
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• 제38권2호
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• pp.129-134
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• 1995

수산가공부산물인 어류껍질로부터 식용으로 이용 가능한 고품질의 젤라틴을 제조할 목적으로 알코올처리에 의한 찰가자미류껍질 젤라틴의 제조를 시도하였고, 아울러 제조한 젤라틴을 목적에 맞게 효율적으로 식품산업에 이용하기 위해 필요한 몇가지 기능 특성도 검토하였다. 알코올처리 조건은 추출 및 탈색 처리한 찰가자미류껍질 젤라틴용액에 최종농도가 30%가 되도록 에탄올을 가하고 $0^{\circ}C$에서 12시간동안 분별침전한 젤라틴의 품질이 가장 우수하였고, 이 때의 겔강도, 졸화온도, 겔화온도 및 수율은 각각 223.0 g, $17.7^{\circ}C$, $12.0^{\circ}C$ 및 5.1%로서 에탄올 무처리한 젤라틴에 비해 물리적 특성이 개선되었으나 가축껍질에서 추출한 시판 젤라틴에 비하여 물리적 특성이 낮아 겔화제 등으로 이용하기에는 미흡하였다. 그러나 기능성의 경우 에탄올 처리한 어류껍질 젤라틴이 에탄올 무처리한 어류껍질 젤라틴에 비하여 용해도는 약간 낮았지만 보수력, 지방흡수력, 유화성 및 유화안정성, 거품성 및 거품안정성 등은 훨씬 높았고, 뿐만 아니라 시판되는 가축껍질 젤라틴에 필적하는 수준이었다. 따라서 겔화성 이외에의 기능성을 고려한 식품가공소재로서 에탄올로 처리한 찰가자미껍질 젤라틴을 사용하면 제품의 기능 특성은 다소 향상되리라 판단되었다.

• Applied Biological Chemistry
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• 제38권4호
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• pp.330-333
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• 1995

알코올처리 찰가자미류껍질 젤라틴을 식용단백소재로 이용하기 위한 기초자료를 얻을 목적으로 첨가제에 의한 알코올처리 젤라틴의 물리적 특성치의 변화를 검토하였다. 겔강도, 졸화온도, 겔화온도 및 점도와 같은 물리적 특성치는 에탄올처리의 유무에 관계없이 두 젤라틴 모두가 철이온, 당 및 에탄올을 첨가한 경우는 증가하였으나, 염화나트륨 및 유기산을 첨가한 경우는 감소하는 경향을 나타내었고, 첨가물에 의한 물리적 특성치의 증감폭은 에탄올 처리 유무에 따라 차이가 없었다.

• KSBB Journal
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• 제26권1호
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• pp.13-18
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• 2011

본 연구에서는 $Ca(LA)_2$의 침전조건을 최적화하고 침전된 $Ca(LA)_2$ 용액에 황산을 처리하여 고순도, 고수율의 lactic acid를 회수할 수 있는 방법을 개발하고자 하였다. 특히 $Ca(LA)_2$의 용해도를 낮추기 위하여 여러 종류의 유기용매 첨가에 따른 영향을 평가하였다. 모델용액의 경우 침전을 위한 최적의 석회종류, 석회량, 교반속도, 시간, 온도, 유기용매 첨가량은 각각 CaO, 0.0175 g/mL, 220 rpm, 24 h, $5^{\circ}C$, ethanol 25% (v/v)이었으며 최적 조건 하에서 가장 높은 순도 (98%)와 수율(69%)을 얻을 수 있었다. 발효배양액 (lactic acid 순도: 69%, pH: 7.3)의 경우, 모델용액으로부터 얻은 최적의 조건 하에서 $Ca(LA)_2$ 회수 과정에서 64%, 회수된 $Ca(LA)_2$에 황산을 첨가 ($Ca(LA)_2/H_2SO_4$ molar ratio = 1:1)하여 lactic acid를 회수하는 과정에서 86%의 회수율을 각각 얻어 발효배양액으로부터 총괄 수율 55%로 lactic acid (순도: 88.6%)를 얻을 수 있었다.

• Applied Biological Chemistry
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• 제40권2호
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• pp.107-111
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• 1997

Protopectinase(PPase)는 식물 세포벽의 protopectin을 분해하는 효소로서 식품의 가공에 이용될 수 있는 효소이다. PPase의 산업적 응용을 위하여 PPase를 생산하는 미생물 Bacillus subtilis IFO 12113의 배양여액에 acetone, methanol, ethanol을 각각 처리하여 PPase를 회수하는 연구를 수행하였다. Acetone의 경우, 배양여액 대 acetone을 1:1 (v/v) 비율로 첨가했을 때 효소는 59.2%가 회수되었으며 정제도는 1.7배 이었다. Methanol의 경우, 1:2(v/v) 비율로 처리하였을 때, 효소는 100% 회수되었으며 비활성도로 본 정제도는 4.0배 증가하였다. Ethanol의 경우에 1 :0.5 (v/v) 비율로 처리한 것을 원심분리시켜 침전물을 제거하고, 그 상등액에 최종 ethanol 비율을 1:1(v/v)까지 처리했을 때, 효소의 회수율은 68%를 나타냈으며 비활성도는 13.5배 증가하였다. 세균의 배양여액으로부터 PPase의 회수에는 methanol 처리가 가장 효율적이었으나, 산업적 응용을 위하여 정제효과까지 고려하면 ethanol처리가 가장 적절하였다.

• 한국식품영양학회지
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• 제3권2호
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• pp.207-210
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• 1990

Paper chromatography and (NH4)2SO4 precipitation method were used for refinement and separation of proteins Color reaction was tested by Biuret test, Million test, Xanthoprotein test, and Ninhydrin test. Precipitation reaction and coagulation of proteins were tested by heating method (Ethanol, HNO3).

• 한국동물위생학회지
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• 제36권4호
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• pp.255-261
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• 2013

The objective of the present study was to determine the minimum alcohol (ethanol) concentration that gives rise to the coagulation of goat milk for the alcohol precipitation test, and to evaluate the physical parameters of goat milk which include alcohol and heat stability. A total of 1,295 udder-half milk samples from 648 lactating dairy goats were collected from seven farms in Jeonnam province, Republic of Korea, to determine the alcohol and heat stability. The majority (99.6%) of the samples were coagulated when 70% ethanol was added to the milk, while only 11.0% of the samples were precipitated by the addition of an equal volume of 45% ethanol. With the concentration of 65%, 60%, 55% and 50% aqueous ethanol, 99.2%, 96.8%, 81.0% and 52.8% of the milk samples were coagulated, respectively. Of 1,295 dairy goat milk samples tested for heat stability, 127 (9.8%) were coagulated by boiling. Among the 143 alcohol test-positive udder-half milk samples, 52 (4.0%) were unstable by heat test, while 1,032 (79.7%) of the 1,152 alcohol test-negative milk samples were stable by heat test. According to the results of boiling test, sensitivity and specificity of 45% alcohol precipitation test were 0.3023 (95% CI: 0.2346~0.3772) and 0.9190 (95% CI: 0.9017~0.9344), respectively. The contents of protein and the specific gravity were higher in the milk samples of 45% alcohol test-positive than in those of 45% alcohol test-negative. However, lower levels of lactose and milk urea nitrogen were observed in the milk samples of 45% alcohol test-positive compared to the alcohol test-negative milk samples. The lowest pH values ($6.73{\pm}0.20$) were shown in the 45% alcohol test-negative and heat-unstable milk samples, while the lowest values of somatic cell counts and bacterial counts were shown in the 45% alcohol test-negative and heat-stable milk samples. Results of this study suggest that the alcohol precipitation for dairy goat milk may have to be tested with ethanol concentration less than 45% for the determination of freshness and heat-stability.

• Asian-Australasian Journal of Animal Sciences
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• 제19권4호
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• pp.601-604
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• 2006

The objective of this study was to investigate technical methods for extraction of mucopolysachharide-protein containing chondroitin sulfate from keel cartilage of chickens. The chemical composition of chicken keel cartilage was determined. For the preparation of mucopolysaccharide-protein from lyophilized chicken keel cartilage, hot water extraction and alcalase hydrolysis methods were examined. Results showed that the optimum condition of hot water extraction was incubation for 120 min with a yield of 40.09% and chondroitin sulfate content of 28.46%. For alcalase hydrolysis, the most effective condition was 2% alcalase in 10 volumes of distilled water for 120 min. The yield of hydrolysate was 75.87%, and chondroitin sulfate content was 26.61%. For further separation of chondroitin sulfate from the alcalase hydrolysate, which has a higher yield than that of hot water, 60% ethanol precipitation was performed. The yield of the ethanol precipitate was 21.41% and its chondroitin sulfate content was 46.31%. The hot water extract, alcalase hydrolysate and ethanol precipitate showed similar electrophoretic migration with standard chondroitin sulfate (chondroitin sulfate A), using cellulose acetate membrane electrophoresis. These results indicated that a significant amount of mucopolysaccharide-protein containing chondroitin sulfate could be acquired form chicken keel cartilage. Therefore, keel cartilage in chicken may provide an inexpensive source of chondroitin sulfate for commercial purposes.