• Preventive Nutrition and Food Science
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• 제16권4호
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• pp.283-290
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• 2011

The recent increase of colon, breast, and prostate cancer incidence in Korea has been attributed to a diet pattern change to a more Western style, in which the foods eaten are higher in protein and fat. Whether high protein intake itself stimulates tumor cell growth and exacerbates disease status has been investigated, however, many epidemiological studies have inconsistent results between meat intake and the risk of certain cancers. These inconsistent results are partly because of the difficulty of studying the effects of just the meat intake. Other factors, such as overall meal context, could not be completely excluded in the study. To address the question of whether high protein itself is independently associated with carcinogenesis, we initiated ICR mice with 200 nmol ($50{\mu}g$) 7,12-dimethylbenz[a]anthracene (DMBA) and fed animals either a normal diet (ND, 14% casein) or a high protein diet (HPD, 50% casein) for 15 weeks with 12-O-tetradecanoylphorbol-13-acetate (TPA) promotion in two-stage skin carcinogenesis protocol. There was no significant difference between ND and HPD group in food intake and body weight throughout the experiment. However, tumor multiplicity of the HPD group was decreased by 75.5% compared to that of the ND group. In addition, HPD inhibited skin hyperplasia and epidermal cell proliferation. Western analyses with whole skin lysates showed that HPD inhibited TPA-induced Akt (S473), S6K (T389), 4E-BP1 (Thr 37/46) and Erk1/2 (Thr202/Tyr204) phosphorylation as well as COX-2 expression. Taken together, these data suggest that a high protein diet has an anticarcinogenic effect by inhibiting the TPA-induced Akt signaling pathway.

• 산업식품공학
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• 제14권3호
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• pp.263-270
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• 2010

Xylanase를 생산하는 호알칼리성 균주를 토양으로부터 분리하여 동정하였다. 토양으로부터 분리한 호알칼리성 균주 3000여종 중 xylanase 활성이 가장 높은 균주인 strain DK-2386 균주를 선별하였다. Gram 염색과 SEM을 통한 형태학적 특성을 관찰하였으며, Methods for General and Molecular Bacteriology와 Bergey's manual of systematic bacteriology, 그리고 Biochemical tests for identification of medical bacteria에 준하여 생화학적 특성을 확인한 결과 배양액의 색은 붉은 빛을 나타내었으며, Gram양성 간균, 내생포자형성, catalase 양성, oxidase 양성, 혐기성 양성, glucose로부터 gas 형성 양성, casein 가수분해 양성, starch 가수분해 양성, CMC 가수분해 양성, xylan 가수분해 양성, nitrate 환원능 양성이며 10% NaCl 농도에서도 생육하는 것을 확인하였다. 균체의 지방산 조성 분석 결과 $C_{15:0\;ISO}$ 27.35%와 $C_{15:0\;ANTEISO}$ 31.54%, $C_{16:0}$ 9.70%로 이루어져 Bacillus속으로 동정되었으며, 16S rDNA 염기서열 분석결과 B. agaradhaerens와 100%의 유사성을 갖는 것을 확인하였다. (사)한국종균협회로부터 분양받은 Bacillus agaradhaerens 40952, B. alcalophilus와 strain DK-2386 균주사이의 생화학적 특성을 비교한 결과 B. agaradhaerens와 속과 종이 같으나 미세하게 특성이 다른 균주로 판단되어 B. agarad haerens DK-2386이라 명명하였다.

• Journal of Nutrition and Health
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• 제19권6호
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• pp.363-373
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• 1986

This study was devised to elucidate whether soused shrimp exhibits a digestive action on boiled pork meats. and the mechanism by which sousing with a high concentration of sodium chloride preserves nutrients in foods for a prolonged pe\ulcornerriod. Protease was isolated from soused shrimp using a combination of ammonium sulfate fractionation. DEAE - cellulose ion exchange chromatography and gel filtra\ulcornertion. The isolated protease had specific activity of 1.560 units. 210 purification fo\ulcornerld with an yield of 38%. Its optimum pH and temperature were 8.0 and $43^{\circ}C$ respectively. The molecular weight of the enzyme was 35.000. The Km value of the enzyme for casein was 1.6 x $10^{-6}$ M The e=yme required the presence of cu\ulcornerpric ion to exhibit its full activity. Eighty eight percent of the enzyme activity was in\ulcornerhibited by 3.5M NaCI showing a reversibly linear decrease of the enzyme activity as NaCI concentration increased. The nature of the inhibition by NaCl was rever\ulcornersible and noncompetitive. The protease activity in soused shrimp was well preser\ulcornerved with the elapse of time at least in part due to NaCI induced suppression of autodigestion. The enzyme was denatured by acid easily. i.e. 1% of the original activity remained after staying at pH 2 for 10 minutes. which is within the norm\ulcorneral range of pH of the human stomach. Soused shrimp was observed to be one of those containing the highest protease activity compared with the other soused foo\ulcornerds such as soused oyster. squid. clam. and Pollack intestine with respect to spec\ulcornerific activities of dialized 1:4 whole homogenates(w/v) in 5 mM sodium phospha\ulcornerte - 2.4 mM j3 - mercaptoethanol buffer. pH 8.0. Casein and boiled meats including pork, beef, and chicken appeared to be the good substrates for the protease. Casein was the best. Therefore. the ingestion of boiled meats including pork together with soused sh\ulcornerrimp would help digestion of boiled pork in human not only by increasing appe\ulcornertite also by the direct proteolytic digestion of boiled meats by soused shrimp to\ulcorner some extent. And a high concentration of sodium chloride inhibited the protease activity reversibly in a remarkable degree, which ensued in a significant retardat\ulcornerion of autodigestion of protein in foods by proteases, and hereby contributed to the preservation of foods for an extended period.

• Journal of Nutrition and Health
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• 제34권5호
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• pp.485-492
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• 2001

The prevalence of type 2 diabetes mellitus has been rapidly increased in parallel with the westernization of eating behavior in Korea. Increased consumption of animal fat and simple sugar can be potential contributors for insulin resistance. The purpose of the study was to determine whether Western-(WD) and Korean-style(KD) diets altered insulin secretion and insulin resistance in male Sprague Dawley rats. Rats weighing 98$\pm$5g were provided by KD(77 En% of starch, 5 En% of corn oil and 13 En% of gluten plus 5 En% of casein), WD(42 En% of starch, 40 En% of butter and 18% of casein) or control diet(62 En% of starch, 20 En% of corn oil and 18% of casein) for 12 weeks. Body weights were lower in KD compared to WD. Fasting blood glucose levels were not different among diets. Insulin secretion from the beta cells was higher by 2.2$\pm$0.4 folds in WD than KD at baseline. In hyperglycemic clamp insulin secretion was higher in WD than KD and CD. Whole body glucose disposal rates referred to the state of insulin sensitivity were lowest in WD among groups. Glycogen deposits in soleus and quadriceps muscles were lowest in WD among all groups, but their triglyceride contents were highest. GLUT4 contents and glycogen synthase were lowest in WD in both muscles. In conclusions, westernization of diets needed more insulin to normalization of blood glucose levels due to increased insulin resistance. Thus, WD would lead to increased prevalence of diabetes mellitus when increased insulin resistance could not be compensated by insulin secretion in the case of elevated blood glucose levels. (Korean J Nutriton 34(5) : 485~492, 2001)

• 한국식품영양과학회지
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• 제14권3호
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• pp.265-273
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• 1985

한국산 10종의 패류단백질을 선정하여 이들의 in vitro 소화율과 trypsin 비소화성 물질을 정량하고, 아미노산 분석결과를 같이 이용하여 이들 단백질의 품질을 C-PER technique 으로 평가하였으며 이를 토대로 패류단백질 품질평가를 위하여 적용가능 한 in vitro technique이 선정되었다. In vitro 소화율은 대부분의 시료가 어류단백질보다 낮은 $80{\sim}85%$ 정도였다. 내장을 제거한 시료의 경우에는 내장을 제거하지 않은 시료에 비하여 $2{\sim}3%$ 정도 상승하는 동시에 trypsin 비소화성물질의 함량이 내장제거시료에 적은 것으로 보아, 패류의 소화율은 내장에 존재하는 trypsin 비소화성물질과 색소단백질등의 영향을 받는 것으로 되어진다. 우럭, 개조개, 새고막 및 피조개의 lysine 함량은 표준단백질인 ANRC casenin 보다 떨어지나 다른 시료는 이와 비슷하였고, 특히 재첩, 가무락 및 내장 제거 담치는 현저히 높아 약 10.0g/16g N.을 나타내었다. 전 시료의 tryptophan과 cystein 함량은 다른 어류단백질보다 월등히 높았다. 전반적인 패류의 C-PER은 2.0미만이었으나 내장을 제거한 바지락, 새고막, 피뿔고둥과 피조개 전 시료의 C-PER은 $1.6{\sim}2.9$ 전후로 나타났다. 전 시료의 DC-PER은 2.5이상으로 계산되었는데, 새고막과 피조개 내장제거 시료는 3.0이상이었다. in vitro 소화율이 높거나 내장을 제거한 패류단백질의 품질 측정은 DC-PER과 예측소화율(Predicted digestibility)이 유리할 것이며, 내장을 제거하지 않은 시료나 효소 비소화성물질이 많은 시료는 DC-PER 및 in vitro 소화율 측정법이 보다 정확하게 품질을 측정할 수 있을 것으로 기대되었다.

• 한국식품과학회지
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• 제47권3호
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• pp.345-349
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• 2015

자숙 게살을 우유, 두유, 요구르트, 카세인에 침지하여 유제품의 이취 제거효과를 전자코를 이용하여 비교 분석해보았다. 우유와 자숙 게살의 반응시간이 길어질수록 이취저감 효과가 나타나는 것을 알 수 있었고 두유, 요구르트와의 반응에서 또한 비슷한 경향으로 나타났다. 우유, 두유, 요구르트의 효과를 비교하기 위하여 2차원 막대그래프로 표현하여 나타내었을 때 요구르트에 비해 우유와 두유에서 이취 저감화 효과가 큰 것으로 나타났다. 또한 유제품의 주요 단백질 성분인 카세인과 반응에서 비슷한 경향을 나타내었다. 이는 자숙 게살의 이취 성분이 유제품의 단백질과 결합하여 이취제거 효과가 나타났을 것으로 예상된다. 이를 토대로 일반가정에서 활용되고 있는 우유에 생선 및 게살을 재워 비린내를 제거하는 방법의 효과를 과학적으로 입증할 수 있을 것으로 여겨지며 가정에서 손쉽게 유제품을 활용하여 이취저감화가 가능할 것이고 자숙게살의 품질관리 및 조리에 활용될 수 있을 것이다.

• Fisheries and Aquatic Sciences
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• 제1권2호
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• pp.180-186
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• 1998

A 10-week feeding experiment was conducted to determine the phosphorus requirement of juvenile Korean rockfish (Sebastes schlegeli). Three replicate groups of fish initially averaging 4.2g were fed the semipurified experimental diets containing graded levels of $NaH_2PO_4\;\cdot\;2H_2O$ to provide from $0.1\%$ to $1.32\%$ total phosphorus level in a flow-through seawater system. Korean rockfish muscle and casein were used as the protein sources of the basal diet. Weight gain, feed efficiency and protein retention of fish fed the $0.35\%$ phosphorus were higher than those of fish fed the $0.1\%$ phosphorus, although no significant improvements $(P>0.01)$ were observed above the level. Determined phosphorus requirement using the broken line model was found to be $0.3\%$ for weight gain. Moisture, protein and lipid contents of whole body and muscle were not affected by dietary phosphorus levels $(P>0.01)$. Lipid contents of liver in fish fed the $0.1\%$ phosphorus were lower than those in fish fed the $0.35\%$ and $1.32\%$ phosphorus $(P<0.01)$. Dietary phosphorus increased ash and phosphorus contents of the whole body, while those of bone were not affected $(P>0.01)$. The data obtained in this study indicate that a $0.3\%$ dietaryphosphorus level could be recommended for the optimum growth and efficient nutrient utilization of juvenile Korean rockfish.

• 한국축산식품학회지
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• 제18권2호
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• pp.185-191
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• 1998

Human milk and bovine milk in normal stage were fractionated four parts : whey, skimmilk membrane, and casein pellet. The specific activity (nmole / mim / mg protein) and distribution ratio(%) of suborganella marker enzymes in each separated milk fraction were determined. Especially, neutral $Ca^{2+}$-ATPase, acid $Ca^{2+}$-ATPase, NADH-cytochrome C reductase, and acid phosphatase were higher in human milk. However, both $Ca^{2+}$-ATPases were not detected in all fractions of bovine milk. On the other hand, 5'-nucleotidase, phosphodiesterase I, alkaline phosphatase, and $\gamma$-glutamyl transpeptidase activities in bovine milk were higher than in human milk. Most of the marker enzymes were highly distributed in cream fraction of either human milk or bovine milk, and their specific activities were high to 24 fold from 3 fold when compared with that of whole milk. These results suggest that marker enzymes in mammary epitherial cell are transfered into cream fraction by the membrane rearrangement, and different biochemical reaction between human and bovine exists for milk secretion in mammary gland.

• Journal of Nutrition and Health
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• 제18권3호
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• pp.234-241
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• 1985

사료(飼料) 단백질(蛋白質)의 질(質)을 향상시키기 위해 미생물(微生物)을 배양(培養)하여 제조한 발효사료(醱酵飼料)의 질적(質的)인 개선효과를 알아보고자 밀기울에 Aspergillus oryzae를 배양(培養)한 발효(醱酵)밀기울을 제조하여 그 화학적(化學的) 조성(組成)과 동시에 쥐 사료(飼料)에 첨가한 후 사육하여 성장률(成長率)과 사료효율을 측정하였으며, NPU, PER 및 NPR과 같은 단백질(蛋白質)의 생물학적(生物學的) 이용성(利用成)을 조사하여 다음과 같은 결과(結果)를 얻었다. 1) 발효(醱酵)밀기울의 제조과정 중에 밀기울건물(乾物)의 절대량이 15% 감소되었다. 2) 발효(醱酵)밀기울의 일반성분(一般成分)은 원료인 밀기울에 비해 조(粗)단백질, 조(粗)섬유, 조(粗)회분 및 조(粗)지방은 증가하였고 가용성무실소물(可溶性無室素物)은 감소하였으며 amino-nitrogen과 riboflavin의 함량은 각각 3.6배와 12배씩 현저히 증가되었다. 아미노산 함량은 발효(醱酵)밀기울에서 18.6% 증가 하였다. 3) 쥐의 사료(飼料) 섭취량(攝取量)과 체중(體重) 증가량(增加量)에서는 각 군간에 별다른 차이가 나타나지 않았으며, 사료효율은 모든 FWB군이 50% WB군보다 좋았으나 통계적 유의성(有意性)은 없었다. 4) 대체적으로 모든 FWB군은 50% WB군보다 PER, NPR 및 NPU수치가 높은 경향(傾向)이었는데 그 중(中) 50% FWB군의 NPU 수치는 100% Casein 군과는 거의 유사하고 50% WB군에 비해서는 유의(有意)하게 더 높았다(P< 0.05).

• 한국수산과학회지
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• 제31권2호
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• pp.245-251
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• 1998

조피볼락 사료의 각종 미네랄 필수성을 조사하기 위해 주요 mineral 함량이 낮은 조피볼락 근육과 casein을 사료 단백질원으로 선정하여 영양연구용으로 자체 설계된 reference premix중에 P, Ca, Zn, Mg, Fe, K, Mn 및 Se을 각각 첨가하지 않은 premix와 mineral 전부를 첨가하지 않은 사료를 설정하여 모두 10종 실험사료를 제조하였다. 평균체중 4.2g의 조피볼락 치어를 각 수조에 25마리씩 실험사료마다 3반복으로 수용하여 10주간 사육실험하였다. 성장, 사료효율, 영양소이용률, 전어체의 지질 함량에서 mineral premix를 첨가하지 않은 사료가 가장 낮은 것 (P<0.01)으로 나타났다. Reference mineral premix에 P, Ca, Zn, Mg, Fe, K, Mn 및 Se을 각각 첨가하지 않은 실험 사료의 증체율은 모두 reference premix를 첨가한 대조구보다 유의하게 낮았다 (P<0.01). 사료효율은 Mg, Fe, K 및 Se을 첨가하지 않은 실험구가 대조구와 통계적으로 차이가 없었으며, 그외 실험구는 대조구보다 낮은 값을 보였다 (P<0.01). 일일 사료섭취율은 실험구간에 유의차가 없었지만 (P>0.01), P, Ca 및 Zn 무첨가구들의 단백질축적률은 대조구보다 저조한 성적을 보였으며, 지질축적률은 Zn 무첨가구만 대조구와 차이를 보였다 (P<0.01). 각 미네랄을 첨가하지 않은 실험구들의 어체성분은 대조구와 통계적인 차이가 없었다.