• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.3
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• pp.265-273
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• 1985

To predict the nutritional quality of seafood proteins using a newer in virto model, 10 species of shellfish protein samples were used in determining the extent of in vitro digestibility, trypsin indigestible substrate (TIS), computed protein efficiency ratio (C-PER), discriminant computed protein efficiency ratio (DC-PER) and predicted digestibility which calculated solely from amino acid profile. The content of TIS in eviscerated samples were ranged from 1.10 to 5.09 mg/g solid, whereas the whole samples were ranged from 1.26 to 7.30 mg/g solid expressed quantitatively as mg of soybean trypsin inhibitor. The in vitro digestibility showed $82{\sim}86%$ for eviscerated samples in contrast with $78{\sim}84%$ for whole ones. Therefore, the results suggested that in vitro digestibility of shellfish was influenced by the present of viscera. The lysine content of Mya arenaria, Saxidomus purpuratus, Anadara subcrenata, and Anadara broughronii were lower than that of ANRC casein, but Corbicula fluminea, Cyclina sinensis, and eviscerated Mytilus edulis, were showed the value about 10.0 g/16g N. In all samples, the content of tryptophan and cystein were more higher than those of ANRC casein. The C-PER of whole samples showed the value below 2.0 while the values above 2.5 noted in the eviscerated samples. DC-PER of most samples were greater than those of C-PER and a greater discrepancies were revealed in whole shellfish which possesses the lower in vitro digestibility. The shellfish sample showed a high in vitro digestibility and a low TIS content such as eviscerated ones may need the DC-PER and predicted digestibility procedures rather than C-PER and four-enzyme in vitro digestibility procedure could offer more advantages in predicting the protein quality of whole shellfish samples which have poor in vitro digestibility and high TIS content.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.3
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• pp.453-458
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• 1994

The nutrient content and protein quality of Giant snalil (Acchatina ) meats (white, yellow, and gray) were determined for fresh and processed products. Fresh snail meats contained 81~82% moisture, 11~14% protein, 0.9~1.3% fat, and 1.2-1.4% ash. Proximate composition of fresh meat varied (p<0.05) with meat colour and gray meat had the lowest protein and highest ash content among samples. The major minerals of fresh snail meats were calcium (318~570mg%), potassium (170~190mg%), and magnesium (74~103mg%).Gray meat showed the higher calcium and lower sodium level than the other snail meats. No differences were found between fresh snail meats on amino acid profile, and total essential amino acid was 46% of total amino acids in all snail meats. In vitro protein digestibility of fresh snail meats were ranged from 76 to 81% which were lower than that of marine moulusks. Processing resulted in some increase(1.7~5.7%) in protein digestibility but no differences were found in C-PER after processing. The 25% saline water extractable mucous materials from fresh snail meat influenced in decreasing digestibility of other protein sources from 2% (casein) to 11% (filefish protein).

• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.441-445
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• 1989

This study was investigated to evaluate the feasibility of protein concentrate for human food from ginseng leaf. The protein concentrate was prepared from ginseng green leaf by treating with cold acetone , followed by protein extraction with 0.2% NaOH containing 0.5% 2-mercaptoethanol and 0.5% sodium dodecyl sulfate. Proximate composition of the ginseng leaf protein concentrate (LPC) showed that fat and ash was less than 1%, protein was about 75%, total sugar and total saponin was 5% and 1.2%, respectively. As compared to the provisional amino acid pattern reported by FAO/WHO, ginseng LPC was found to be poor in S-containing amino acids, which were the first limiting amino acid. The amino acid score and E/T ratio of ginseng LPC were 43.1 and 3.02, respectively. Digestibility of ginseng LPC by pepsin and trypsin was lower than that of milk casein.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.2
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• pp.73-83
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• 1983

This experiment was conducted to study effects of different sources of protein, and of the different combination ratios of the two protein supplemented or unsupplemented with methionine on the growth and body metabolism of the growing male rats. Casein and isolated soyprotein (ISP) were combined at different ratios of 100:0, 80:20, 50:50, 20:80 and 0:100 to supply the constant levels of dietary energy and protein of 3,600kcal/kg and 20%, respectively. Each combination was supplemented with either 0 or 0.3% methionine. Results obtained in these experiments were summarized as follows: The body weight and weight gain in the ISP diet were the lowest, but were increased with the increase of ratios of casein to ISP. The body weight gain in the ISP diet supplemented with methionine was similar to that in the combination diets of casein and ISP. The combination diets of casein and ISP supplemented with methionine had the higher weight gain than the casein diet. The food intake in the casein diet was the highest, and was increased with the increase of ratios of casein to ISP, and was lowered with methionine supplementation. The food intake in the ISP diet was the lowest and was not increased with methionine supplementation to the ISP diet. The food efficiency ratio of the combination diets of casein and ISP was improved compared to those of either the casein or the ISP diets. The food efficiency ratio was improved in the diet of either casein of ISP supplemented with methionine, but was not improved in the combination diets of casein and ISP with methionine supplementation. The gross energy intake had direct relation with the food intake of rats and the relation was increased either in the casein diet of with the increase of the ratios of casein to ISP. The energy efficiency and protein efficiency ratios were improved in the diet of either casein of ISP by the supplementation of methionine, and the effect of methionine supplementation of the energy efficiency and protein efficiency atio was increased with the increase of the ratios of ISP to casein. The nitrogen intake and urinary nitrogen excretion of the casein diet were the highest and those of the ISP diet were the lowest. They were increased with the increase of ratios of casein to ISP. The nitrogen balance and retention were not significantly among the treatments. The gross energy intake and fecal and urinary energy were the highest in the casein diet but the digestible and metabolizable energy and the digestibility and metabolizability of energy were not significantly different among the treatments. The body fat content of rats was increased by supplementation of methionine but the body protein content was decreased (r=-0.65, p<0.01). The body fat content of rats was negatively correlated with body moisture content (r=-0.83, p<0.01). The liver weight was highly correlated with the carcass weight (r=0.79, p<0.01), and was increased by the methionine supplementation and by the increase of the ratios of casein to ISP.

• Journal of Nutrition and Health
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• v.17 no.2
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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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• v.30 no.6
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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.

• Food Science of Animal Resources
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• v.36 no.4
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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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• v.14 no.7
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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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• v.35 no.2
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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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• v.28 no.2
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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.