• 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.

• 한국식품영양과학회지
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• 제23권3호
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• pp.453-458
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• 1994

체색이 다른 세종류(백색육, 황색육, 회색육)의 식용 달팽이(Giant snail, Achatine fulica)의 일반성분과 무기질을 정량하여 이의 식품학적 가능성을 예측하였으며, 효소를 이용한 단백소화율(in vitro protein digestibility), 단백효율비(C-PER, computed protein efficiency ratio) 및 typsin inibitor 함량을 측정하여 이의 단백질 품질을 평가하였다. 또한 전처리 및 가공조건을 달리한 달팽이 제품의 단백질 품질을 측정하여 바람직한 처리조건을 찾으려 했으며, 달팽이육 중에 다량 포함되어 있는 점액성 물질이 다른 단백질의 소화율에 미치는 영향도 아울러 실험하였다. 1. 식용왕달팽이의 가식부는 39% 정도로서 해산패류보다 10%정도 높았으며 가식부 100g당 11.5~13.7%의 단백질, 0.9~1.3%정도의 지질이 함유되어 있다. 무기질로서는 칼슘, 칼륨 및 마그네슘이 풍부하였고 특히 칼슘함량은 굴(oyster)에 비교하여 5~10배 높았다. 2. 아미노산의 함량과 그 조성은 백색육, 회색육, 황색육이 모두 비슷하였고, 주요 아미노산은 aspaltic acid, glutamic acid, proline과 glycine으로 총아미노산의 52.5%를 차지하였고 특히 필수아미노산 함량이 총아미노산의 45~46%를 차지하여 균형잡힌 단백질로 판별되었다. 3. 생달팽이육의 단백질 소화율은 76.6%(회색육)~81%(황색육과 백색육)였으며 단백효율비는 2.24(백색육)~2.36(황색육) 범위였으나, trypsin inhibitor함량은 체색에 따라 다양하였다(백색윤 22.7mg/g solid, 회색육 28.97mg/g solid 및 황색육 36.75mg/g solid). 4. 10% 식염수에 5분간 침지한 후 10분간 boiling한 달팽이육의 소화율은 생육에 비해 1.7%(백색육)~5.7%(회색육)로 증가하였고, trypsin inhibitor 함량은 12.62mg/g solid (백색육)과 16.40mg/g solid (회색육)로 크게 감소하였으며, C-PER은 가공조건에 따라 변동이 없었다. 5. 생달팽이육에 다량 함유된 점액성물질은 여러가지 단백질의 소화율 2% (ANRC casein)~11%(filefish protein)로 감소시켰다.

• 한국식품과학회지
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• 제21권3호
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• pp.441-445
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• 1989

인삼엽 단백질의 식량화를 위하여 엽단백질 농축물(LPC)을 조제하여 그 아미노산 조성과 인공소화율을 검토하였다. 인삼엽을 $-20^{\circ}C$ 냉아세톤으로 처리하고 0.2% NaOH(0.5% SDS, 0.5% 2-ME 함유)로 단백질을 추출하며 인삼 LPC를 얻었다. 인삼 LPC의 일반성분으로는 지방과 회분이 1% 미만이었고 단백질은 75% 내외로 많았으며 총 당은 약 5% 이었다. 총 사포닌 함량은 약 1.2%이고 panaxadiol과 panaxatriol의 비는 1.67이었다. 아미노산 조성은 aspartic acid의 함량이 약 13.4%로 가장 많았으며 methionine의 함량은 매우 낮았다. 필수아미노산토 고루 들어 있었고 총 아미노산에 대한 필수아미노산은 54.5%이였고 E/T ratio는 3.02이었다. LPC의 제 1제한아미노산은 함황아미노산이고, 그 amino acid score는 43.1이었다. Pepsin및 trypsin을 사용한 인삼 LPC의 소화율은 비교단백질인 milk casein에 비하며 낮았다.

• 한국식품영양과학회지
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• 제12권2호
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• pp.73-83
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• 1983

단백질(蛋白質)의 상호보충(相互補充) 및 제한(制限)아미노산 보충(補充)이 흰쥐(Sprague Dawley계(系) 이유(離乳)한 숫쥐)의 성장(成長), 체내대사(體內代謝) 및 체조성(體組成)에 미치는 영향(影響)을 규명하기 위하여 사양(飼養) 및 대사실험(代謝實驗)을 실시(實施)하였다. 실험사료(實驗飼料)의 에너지 및 단백질(蛋白質) 수준(水準)은 각각 3,600kcal/㎏ 및 20%로 고정하였고, 단백질(蛋白質)의 공급원(供給源)으로 카제인과 대두단백질(大豆蛋白質)을 택(擇)하여 각각 100:0, 80:20, 50:50, 20:80, 0:100의 비율(比率)로 혼합(混合)하였으며 각각에 methionine을 0% 또는 0.3%로 보충(補充)하였던 결과를 요약(要約)하면 다음과 같다. 흰쥐의 체중(體重)과 증체량(增體量)은 대두단백질(大豆蛋白質) 단독(單獨) 급여(給與) 때 가장 낮았고 카제인의 혼합비율(混合比率)을 증가(增加)시킬 수록 증가(增加)되었다. 대두단백질(大豆蛋白質)에 methionine을 보충급여(補充給與)했을 때 증체량(增體量)은 무보충(無補充) 혼합(混合) 급여(給與)했을 때와 동일(同一)했으며 카제인 단독(單獨) 급여(給與)때 보다 카제인 혼합(混合) methionine 보충(補充) 급여(給與)에서 증체량(增體量)은 더 높았다. 사료섭취량(飼料攝取量)은 카제인 단독급여(單獨給與) 때나 카제인의 혼합비율(混合比率)을 증가(增加)시킬 때 높았으나 meihionine을 보충(補充)했을 때 저하(低下)되었으며 대두단백질(大豆蛋白質) 단독급여(單獨給與)에서 낮았으며 methionine을 보충(補充)해도 증가(增加)되지 않았다. 사료효율(飼料效率)은 카제인이나 대두단백질(大豆蛋白質)의 단독(單獨) 급여(給與)때보다 두 단백질(蛋白質)의 혼합급여(混合給與) 때 더 높았으며 단독급여(單獨給與)에 methionine을 보충(補充)함으로써 사료효율(飼料效率)이 증가(增加)되었으나 혼합급여(混合給與)에 보충(補充)했을 때에는 같은 효과(效果)를 보이지 않았다. 성장실험기간중(成長實驗期間中) 총(總)에너지섭취량(攝取量)은 사료(飼料) 섭취량(攝取量)과 관계가 있었고 카제인 단독급여(單獨給與) 때나 그의 혼합비율(混合比率)을 증가(增加)시킬 때 증가(增加)했다. 에너지효율(效率)과 단백질효율(蛋白質效率)은 두 단백질(蛋白質)을 단독급여(單獨給與)할 때에는 methionine보충(補充)에 의해 증가(增加) 되었으며 또한 혼합급여(混合給與) 때에는 대두단백질(大豆蛋白質)의 비율(比率)을 증가(增加)시킬 수록 methionine에 의한 개선효과(改善效果)를 보였다. 질소섭취량(窒素攝取量) 및 카제인 뇨질소량(尿窒素量)은 단독급여(單獨給與) 했을 때 가장 높았고, 대두단백질(大豆蛋白質) 단독급여(單獨給與) 때 가장 낮았으며 카제인의 비율(比率)을 증가(增加)시킬 수로 증가(增加)되었다. 질소균형(窒素均衡) 및 축적율(蓄積率)은 처리(處理)에 의한 차이(差異)에 통계적(統計的) 유의성(有意性)은 없었다. 대사실험기간중(代謝實驗期間中) 총(總)에너지섭취량(攝取量)과 분(糞) 및 뇨(尿)에너지는 카제인 단독급여(單獨給與) 때 높았고, 가소화(可消化) 에너지와 대사(代謝)에너지, 에너지의 소화율(消化率) 및 리용율(利用率)은 처리(處理)에 의한 유의차(有意差)는 없었다. 체지방(體脂肪)은 methionine보충(補充)에 의해 증가(增加)되었으나, 체단백질(體蛋白質)은 감소(減少)했다(r=0.65, p<0.01). 체지방(體脂肪)과 체수분(體水分)과도 부(負)의 상관관계(相關關係)(r=-0.83, p<0.01)가 있었다. 간(肝)의 무게는 도체(屠體)의 무게의 변화(變化)와 일치(一致)했고 (r=0.79, p<0.01) methionine보충(補充)에 의해 증가(增加) 되었으며 카제인의 비율(比率)을 증가(增加)시킬 수록 증가(增加)되었다.

• Journal of Nutrition and Health
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• 제17권2호
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• pp.94-100
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• 1984

The effect of methionine supplementation to the isolated soyprotein(ISP) diet on the growth, body metabolism and composition of the Albino male rats was studied. Three levels(0.3,0.6 and 0.9%) of methionine were supplemented to the ISP diet with the constant levels of energy and protein of 3,600 kcal/kg and 20%, respectively. The body weight and weight gain of the growing rats were significantly increased by 0.3% methionine supplementation to the ISP diet compared to the ISP diet(P< 0.05).The effects of methionine supplementation to the ISP diet tended to be larger with increasing of the level of methionine supplementation, 0.6 and 0.9%, were statistically insignificant. Food and gross energy intake of growing rats fed the ISP diet or the ISP supplemented with methionine diet were lower than those fed the casein diet(P< 0.05). FER and PER of all the methionine supplemented diets were higher than those of the ISP or casein diet (P< 0.05) without significant differences among the supplementation levels of methionine to the diets. The weight gain of adult rats fed 0.9% methionine supplemented ISP diet were higher than those of the other treatments with significant difference. The effects of methionine supplementation to the ISP diet on the protein digestibility, BV, NPU, N-balance, N-retention, and body and liver compositions were not significant.

• Asian-Australasian Journal of Animal Sciences
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• 제30권6호
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• pp.797-803
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• 2017

Objective: Effects of nitrogen supplementation associated with different levels of starch on voluntary intake, digestibility, and rumen and metabolic characteristics of cattle fed low-quality tropical forage (Brachiaria decumbens hay, 7.4% crude protein, CP) were evaluated using ruminal and abomasal cannulated steers. Methods: Five European${\times}$Zebu young bulls (186 kg body weight, BW) were distributed according to a $5{\times}5$ Latin square. The following treatments were evaluated: control, supplementation with 300 g CP/d (0:1), supplementation with 300 g starch/d and 300 g CP/d (1:1), supplementation with 600 g starch/d and 300 g CP/d (2:1), and supplementation with 900 g starch/d and 300 g CP/d (3:1). A mixture of nitrogenous compounds provided 1/3 from true protein (casein) and 2/3 from non-protein nitrogen (mixture of urea and ammonium sulphate, 9:1) was used as the nitrogen supplement. In order to supply energy a unique source of corn starch was used. Results: Supplements increased (p<0.05) dry matter intake, but did not affect (p>0.05) forage intake. There was a cubic effect (p<0.05) of starch on voluntary intake. This was attributed to the highest forage intake (g/kg BW) when using the 2:1 starch:CP ratio. Supplements increased (p<0.05) organic matter (OM) digestibility, but did not affect (p>0.05) neutral detergent fibre corrected for ash and protein (NDFap) digestibility. There was a positive linear effect (p<0.05) of the amount of starch supplemented on OM digestibility. Total NDFap digestibility was not affected (p>0.05) by the amount of supplemental starch. Ruminal ammonia nitrogen concentrations were higher (p<0.05) in supplemented animals, however, a negative linear effect (p<0.05) of amount of starch was observed. Supplements increased (p<0.05) the nitrogen balance (NB) and efficiency of nitrogen utilization. These effects were attributed to increased body anabolism, supported by higher (p<0.05) serum concentration of insulin-like growth factor 1. Increasing the amount of starch tended (p<0.06) to linearly increase the NB. In spite of this, there was a highest NB value for the 2:1 starch:CP ratio amongst the treatments with supplementation. Conclusion: Nitrogen supplementation in cattle fed low-quality tropical forage increases nitrogen retention in the animal's body. An additional supply of starch increases nitrogen retention by increasing energy availability for both rumen and animal metabolism.

• 한국축산식품학회지
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• 제36권4호
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• pp.516-522
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• 2016

Goat milk is highly nutritious and is consumed in many countries, but the development of functional foods from goat milk has been slow compared to that for other types of milk. The aim of this study was to develop a goat milk protein hydrolysate (GMPH) with enhanced digestibility and better hypoallergenic properties in comparison with other protein sources such as ovalbumin and soy protein. Goat milk protein was digested with four commercial food-grade proteases (separately) under various conditions to achieve the best hydrolysis of α_s -casein and β-lactoglobulin. It was shown that treatment with alcalase (0.4%, 60℃ for 30 min) effectively degraded these two proteins, as determined by SDS-PAGE, measurement of nonprotein nitrogen content, and reverse-phase high-performance liquid chromatography. Hydrolysis with alcalase resulted in a significant decrease in β-lactoglobulin concentration (almost to nil) and a ~40% reduction in the level of α_s-casein. Quantification of histamine and TNF-α released from HMC-1 cells (human mast cell line) showed that the GMPH did not induce an allergic response when compared to the control. Hence, the GMPH may be useful for development of novel foods for infants, the elderly, and convalescent patients, to replace cow milk.

• Asian-Australasian Journal of Animal Sciences
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• 제14권7호
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• pp.986-993
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• 2001

In balance experiments with rats either 25 or 50% of the casein protein in the control diet was replaced with one of the following eight sun-dried tropical biomass products: water spinach plants (WS) (Ipomoea aquatica Forsk), leucaena leaves (LL) (Leuceana leucocephala), duckweed plants (DW) (Lemma minor L.), groundnut foliage (OF) (Arachis hypogaea L.), trichantera leaves (Tric) (Trichantera gigantea), indicago leaves (Ind) (Indigofera hirsuta), mungbean foliage (Mb) (Phaseolus aureus), and cassava leaves (CL) (Manihot esculenta Crantz). The experiment included 102 rats with six individuals per treatment group. In three of the 16 biomass treatment groups, feed intake and weight gain of the rats were unacceptably low, and therefore they were excluded from the statistical evaluation, The crude protein (CP) content of the biomass products varied between 20.9% (Tric) and 33.2% (DW), whereas the content of NDF varied between 18.5% (Ind) and 32.2% (DW) of dry matter (DM). The total content of essential amino acids (g/16 g N) was comparable with that of alfalfa meal, except for GF and Tric, which were inferior. Between plant species, differences in dietary digestibility of organic matter (dOM) and CP (dCP) were observed (p<0.001). Also, the replacement level negatively influenced dOM and dCP (p<0.001). The lowest values for dOM (p<0.001) were observed for diets including biomass products with the highest content of NDF (OF, Tric, Mb, LL). Digestibility of CP was negatively affected by level of protein replacement. Significant (p<0.001) differences were found in N-retention and biological value among diets with different biomass products. The most favourable overall results were obtained for DW, WS and CL. The main factors affecting the nutritive value of the diets tested were their NDF content, dCP and AA profile of the biomass. Also antinutritive component(s) may have influenced the process of digestion and metabolism of some of the biomass products.

• Animal Bioscience
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• 제35권2호
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• pp.260-271
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• 2022

Objective: We aimed to investigate the effect of the differing amino acid (AA) release dynamics of two protein sources on the growth performance, nitrogen deposition, plasma biochemical parameters, and muscle synthesis and degradation of piglets when included in their diets at normal and low concentrations. Methods: Forty-eight piglets (Duroc×Landrace×Large White) with initial body weight of 7.45±0.58 kg were assigned to six groups and fed one of 6 diets. The 6 dietary treatments were arranged by 3×2 factorial with 3 protein sources and 2 dietary protein levels. They are NCAS (a normal protein content with casein), NBlend (a normal protein content with blend of casein and corn gluten meal), NCGM (a normal protein content with corn gluten meal), LCAS (a low protein content with casein), LBlend (a low protein content with blend of casein and corn gluten meal), LCGM (a low protein content with corn gluten meal). The release dynamics of AA in these diets were determined by in vitro digestion. The digestibility, utilization and biological value of nitrogen in piglets were determined by micro Kjeldahl method. Plasma insulin was measured by enzyme-linked immunosorbent assay kits. The protein expression of mediators of muscle synthesis and degradation was determined by western blotting. Results: Although the consumption of a low-protein diet supplemented with crystalline AA was associated with greater nitrogen digestion and utilization (p<0.05), the final body weight, growth performance, nitrogen deposition, and phosphorylation of ribosomal protein S6 kinase 1 and eIF4E binding protein 1 in the muscle of pigs in the low-protein diet-fed groups were lower than those of the normal-protein diet-fed groups (p<0.05) because of the absence of non-essential AA. Because of the more balanced release of AA, the casein (CAS) and Blend-fed groups showed superior growth performance, final body weight and nitrogen deposition, and lower expression of muscle ring finger 1 and muscle atrophy F-box than the CGM-fed groups (p<0.05). Conclusion: We conclude that the balanced release of AA from CAS containing diets and mixed diets could reduce muscle degradation, favor nitrogen retention, % intake and improve growth performance in pigs consuming either a normal- or low-protein diet.

• Journal of Nutrition and Health
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• 제28권2호
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• pp.144-151
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• 1995

This study investigates the supplementing effects of milks by various heat treatment on growth performance and protein and calcium metabolism of rats. For 4 weeks, raw, LTLT-HTST-and UHT-processed milks were given to rats which fed on a calcium free, semi-synthetic diet containing 5%casein. There were no significant differences among the experimental groups in weight gain, feed efficiency ratio and the serum level of total protein and calcium. Also, no significant differences were showed in protein efficiency, nitrogen balance, apparent protein digestibiltiy and the contents of weight and calcium of the left femur as well as 2 incisors. However, the biological value of protein in the UHT-milk group was significantly higher than that of the raw-milk group. The apparent calcium digestibility and calcium balance in the UHT-milk group were higher than those in the raw-, LTLT- and HTST-milk groups. The weight of left femur in all the groups supplemented with various heat-treated milks was significantly impair the nutritive value of protein and calcium in milk. Futhermore, UHT-processing may improve the bioavailability of protein and calcium in milk.