• Asian-Australasian Journal of Animal Sciences
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• 제25권11호
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• pp.1559-1567
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• 2012

The objective of this study was to evaluate ruminal degradability and intestinal digestibility of crude protein (CP) and amino acids (AA) in hempseed cake (HC) that were moist heat treated at different temperatures. Samples of cold-pressed HC were autoclaved for 30 min at 110, 120 or $130^{\circ}C$, and a sample of untreated HC was used as the control. Ruminal degradability of CP was estimated, using the in situ Dacron bag technique; intestinal CP digestibility was estimated for the 16 h in situ residue using a three-step in vitro procedure. AA content was determined for the HC samples (heat treated and untreated) of the intact feed, the 16 h in situ residue and the residue after the three-step procedure. There was a linear increase in RUP (p = 0.001) and intestinal digestibility of RUP (p = 0.003) with increasing temperature during heat treatment. The $130^{\circ}C$ treatment increased RUP from 259 to 629 g/kg CP, while intestinal digestibility increased from 176 to 730 g/kg RUP, compared to the control. Hence, the intestinal available dietary CP increased more than eight times. Increasing temperatures during heat treatment resulted in linear decreases in ruminal degradability of total AA (p = 0.006) and individual AA (p<0.05) and an increase in intestinal digestibility that could be explained both by a linear and a quadratic model for total AA and most individual AA (p<0.05). The $130^{\circ}C$ treatment decreased ruminal degradability of total AA from 837 to 471 g/kg, while intestinal digestibility increased from 267 to 813 g/kg of rumen undegradable AA, compared with the control. There were differences between ruminal AA degradability and between intestinal AA digestibility within all individual HC treatments (p<0.001). It is concluded that moist heat treatment at $130^{\circ}C$ did not overprotect the CP of HC and could be used to shift the site of CP and AA digestion from the rumen to the small intestine. This may increase the value of HC as a protein supplement for ruminants.

• Molecules and Cells
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• 제27권5호
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• pp.533-538
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• 2009

Heat shock protein 27 (Hsp27) is a molecular chaperone protein which regulates cell apoptosis by interacting directly with the caspase activation components in the apoptotic pathways. With the assistance of the Tat protein transduction domain we directly delivered the Hsp27 into the myocardial cell line, H9c2 and demonstrate that this protein can reverse hypoxia-induced apoptosis of cells. In order to characterize the contribution of Hsp27 in blocking the two major apoptotic pathways operational within cells, we exposed H9c2 cells to staurosporine and cobalt chloride, agents that induce mitochondria-dependent (intrinsic) and -independent (extrinsic) pathways of apoptosis in cells respectively. The Tat-Hsp27 fusion protein showed a greater propensity to inhibit the effect induced by the cobalt chloride treatment. These data suggest that the Hsp27 predominantly exerts its protective effect by interfering with the components of the extrinsic pathway of apoptosis.

• Journal of Dairy Science and Biotechnology
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• 제26권1호
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• pp.27-36
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• 2008

This review was written to introduce updated data on the structure and function of the major milk proteins identified as allergens, the characterization of their epitopes in each allergenic milk proteins, and the reduction of milk protein allergenicity. Most mammalian milk protein, even protein present at low concentration, are potential allergens. Epitopes identified in milk proteins are both conformational(structured epitope) and sequential epitopes(linear epitope), throughout the protein molecules. Epitopes on casein and whey proteins are reported to be sequential epitope and conformational epitopes, respectively. Conformational epitopes on whey protein are changed into sequential epitope by heat denaturation during heat treatment. Several methods have been proposed to reduce allergenicity of milk proteins. Most ideal and acceptable method to make hypoallergenic milk or formula, so far, is the hydrolysis of allergenic milk proteins by enzymes that has substrate specificity, such as pepsin, trypsin, or chymotrypsin. Commercial formulas based on milk protein hydrolysate are available for therapeutic purpose, hypoantigenic formula for infants from families with a history of milk allergy and hypoallergenic formula for infants with existing allergic symptoms.

• 한국수산과학회지
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• 제39권5호
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• pp.384-390
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• 2006

To improve the extractability of carnosine and the levels of pro-oxidants such as iron in eel (Anguilla japonica) extracts, we examined the effects of extraction time, temperature, ion exchange chromatography and ultrafiltration (UF). The respective protein and total iron were reduced approximately 55 and 60% at 60$^{\circ}C$, 63 and 70% at 80$^{\circ}C$, 68 and 76% at 100$^{\circ}C$ and 82 and 48% with ion exchange chromatography, respectively, compared to the untreated extract. However, there was no significant difference in the carnosine levels in the eel extracts. Ultrafiltration reduced the protein content of the extract by 52% compared with the untreated extract. UF reduced the protein contents of the samples from 60, 80, and 100% heat treatment and ion exchange chromatography treatment by 27, 50, 46 and 47%, respectively. UF reduced the total iron contents of the identical four treatments by 14, 22, 23, and 43%, respectively, while UF increased the carnosine by 23, 17, 20, and 6%, respectively.

• 한국식품과학회지
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• 제23권5호
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• pp.627-632
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• 1991

본 실험에서는 국산 유아용 조제분유의 열처리 정도를 파악하기 위하여 HMF 함량, lactulose 함량, 유청단백질 변성율 등을 측정하였다. 조제분유의 HMF 함량은 $21.0{\sim}43.9{\mu}mol/l$로 분말상의 경우 각종 영양성분의 함량이 더 강화된 (ii)단계 제품에서 많은 HMF 함량을 보였으나, 액상의 경우 can 포장용 제품에서 더 많았다. 조제분유의 lactulose 함량은 분말상에서 $2.5{\sim}11.4mg/100ml$였고 액상에서 $27.0{\sim}164.8mg/100ml$으로 제품의 형태에 따라 많은 차이가 있었다. ADPI에서 제시한 열처리 등급을 기준으로 분류했을 때 대부분의 조제분유 제품이 medium-heat 등급에 해당되었으며, 조제분유의 유청단백질 열변성율을 측정한 결과, 분말상에서는 $1.1{\sim}69.4%$였고 액상에서는 $37.4{\sim}71.3%$이었다.

• 한국식품과학회지
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• 제36권1호
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• pp.38-43
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• 2004

대두 단백질의 기능성 변형 방법의 하나로 대두를 열처리 함에 의해 대두 단백질의 기능 특성에 어떠한 변화가 있는지 알아보기 위하여 대두를 $60^{\circ}C$에서 30, 60, 90과 120분 침지한 후 대두 분리 단백(SPI)을 제조하여 열처리하지 않은 대조군과 여러 가지 기능성을 비교하였다. 용해도 특성은 pH 4.5의 등전점 부근에서 최소의 용해도를 보였고 등전점 이하와 이상에서는 비교적 90% 넘는 높은 용해도를 나타내었다. 만리와 태광에서 모두 열처리 시간이 증가함에 따라 등전점 이하의 pH에서 용해도가 증가하였다. 수분흡수력도 열처리 시간이 증가함에 따라 증가하였고 만리의 경우 90분 시료에서 가장 높은 수분흡수력을 나타내었다. 유지흡수력은 만리의 경우 열처리 시간이 증가함에 따라 감소하였고 태광의 경우에는 60분 시료에서 최대값을 나타내었다. 유화 특성은 만리의 경우 열처리에 의해 유화활성도, 유화안정성과 유화형성력이 모두 대조군보다 유의하게 증가하였고, 태광의 경우에는 열처리에 의해 유화활성도와 유화형성력이 유의적으로 증가하였다. 만리의 경우 기포 팽창력과 기포안정성이 열처리에 의해 증가하였고, 만리와 태광 모두 기포팽창력이 90분 시료에서 최대값을 보였으며, 태광은 열처리에 의해 매우 불안정한 기포 안정성을 보였다. 겔의 TPA결과, 열처리 시간이 증가함에 따라 경도, 부착성, 탄성, 검성 및 씹힘성이 증가하였고 특히 모든 특성이 대체로 90분 시료에서 최고값을 보였다. 그러나 응집성은 열처리 시간이 증가함에 따라 감소하였다. 이상의 결과로 대두의 열처리에 의해 대두 단백질의 기능성이 변화하는 것을 알 수 있었고. 대두를 첨가물이나 식품가공재료로 사용할 때 이러한 변화를 고려하여 유용하게 활용할 수 있으리라 생각된다.

• 한국식품조리과학회지
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• 제7권2호
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• pp.97-104
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• 1991

This study was carried out in order to study the protein functionality such as foaming and emulsifying properties by succinylation of peanut protein isolates. Succinylated and unsuccinylated peanut protein isolate was tested for to find out the effect of pH, heat treatment and sodium chloride concentration on the solubility, foam expansion, foam stability, emulsion capacity and emulsion stability. The results are summarized as follows; 1. Succinylation enhanced the solubility of peanut protein isotate (PPI). The solubility of succinylated PPI markedly increased at pH 4.5. When the protein solutions was heated, the solubility of succinylated PPI greatly increased than PPI at pH 3. With addition of NaCl, solubility of succinylated PPI increased at pH 7 and pH 9. 2. The foam expansion of PPI and succinylated PPI on pH was no difference between both proteins. Addition of NaCl and heat treatment caused steeply increased in foam expansion at pH 3. 3. The foam stability of PPI and succinylated PPI showed the lowest value at pH 4.5. When PPI and succinylated PPI was heated, foam stability of two proteins incensed at pH 3 and showed similar aspects between PPI and succinylated PPI. However, at pH 9 stability of succinylated PPI decreased by heat treatment over $60^{\circ}C$. 4. Emulsion capacity of succinylated PPI on pH was markedly increased and showed the highest value at pH 11. At pH 4.5 which is isoelectric point of PPI, emulsion capacity of PPI by succinylation improved than that of PPI. When succinylated PPI was heated, emulsion capacity was greatly increased at pH 2 and pH 7. With NaCl was added, emulsion capacity of succinylated PPI increased than that of PPI. 5. Emulsion stability of PPI and succinylated PPI was affected by pH and showed its highest value at pH 11. At pH 4.5, emulsion stability of succinylated PPI increased than that of PPI. Addition of NaCl and heat treatment caused slightly increased in emulsion stability of succinylated PPI.

• Molecules and Cells
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• 제39권2호
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• pp.163-168
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• 2016

Caffeine has both positive and negative effects on physiological functions in a dose-dependent manner. C. elegans has been used as an animal model to investigate the effects of caffeine on development. Caffeine treatment at a high dose (30 mM) showed detrimental effects and caused early larval arrest. We performed a comparative proteomic analysis to investigate the mode of action of high-dose caffeine treatment in C. elegans and found that the stress response proteins, heat shock protein (HSP)-4 (endoplasmic reticulum [ER] chaperone), HSP-6 (mitochondrial chaperone), and HSP-16 (cytosolic chaperone), were induced and their expression was regulated at the transcriptional level. These findings suggest that high-dose caffeine intake causes a strong stress response and activates all three stress-response pathways in the worms, including the ER-, mitochondrial-, and cytosolic pathways. RNA interference of each hsp gene or in triple combination retarded growth. In addition, caffeine treatment stimulated a food-avoidance behavior (aversion phenotype), which was enhanced by RNAi depletion of the hsp-4 gene. Therefore, up-regulation of hsp genes after caffeine treatment appeared to be the major responses to alleviate stress and protect against developmental arrest.

• 한국미생물·생명공학회지
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• 제21권6호
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• pp.513-519
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• 1993

The alkaline protease in the polyhedra preparation of Spodoptera litura nuclear polyhedrosis virus was successfully inactivated by heating at 100C for 20 minutes. SDS-PAGE analysis indicated that heat inactivated polyhedra is composed of major proteins of 31kDa and presumptive its polymer protein of 62kDa. However, this polyhedra was converted into several smaller molecular weight proteins when treated with midgut juice, but not by treatment with heat-inactivated midgut juice.

• 한국식품영양학회지
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• 제7권4호
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• pp.345-352
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• 1994

High protein beverage of cow-soy milk was prepared by mixing the soymilk and commercial homogenized cow milk in the various ratios. Effect of heat treatment, pH and addition of calcium and sucrose was studied on the water-soluble nitrogen of cow-soy milk The heat-treated soymilk at 10$0^{\circ}C$ were centrifuged at the range of 830~29,900xg for 30 min and 11,200xg was found to be proper for determination of the degree of protein denaturation by centrifugal method. When soymilk was heated at 70~10$0^{\circ}C$ for 30~240 min, soluble nitrogen (QA SN) in supernatant of protein was decreased to 78.0~56.8% due to protein denaturation. Most of heat denaturation of protein was found to be occurred during Initial heating 10$0^{\circ}C$ for all mixed cow-soy milk. The sedimentation of SN was maximum at pH 4.0 In the range of pH 3~8. Addition of sucrose affected little on oASN while calcium addition reduced %SN significantly to approx. 55% for soymilk(100%). The effect of Ca was less as the ratio of cow milk increased.