• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.717-724
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• 2013

To characterize the food components of two mussels (wild hard-shelled mussel (HM) Mytilus coruscus, and cultured sea mussel (SM) Mytilus edulis) in Korea, we examined the proximate composition, fatty composition, amino acid/mineral content, texture, collagen content and chemical and taste compounds. Regarding the proximate composition, HM had lower moisture levels and higher crude protein and carbohydrate contents than SM. The amino nitrogen, volatile basic nitrogen and total amino acid contents of HM and SM were 250.6 and 227.3 mg/100 g, 11.2 and 12.0 mg/100 g, and 17,451.1 and 15,334.8 mg/100 g, respectively. The major amino acids were glutamic acid, aspartic acid, glycine, alanine, lysine and arginine. The major fatty acids of HM and SM were 14:0, 16:0, 16:1n-7, 20:5n-3, and 22:6n-3, which did not differ significantly between the two mussels. HM had a higher n-3 polyene ratio, and a lower saturate and monoene ratio than SM. Regarding the taste-active compounds, the free amino acid contents of HM and SM were 1,116.5 and 961.8 mg/100 g, respectively, and the major free amino acids were taurine, glutamic acid, glutamine, glycine, citrulline, lysine and arginine. The primary minerals in both HM and SM were Na, Cl, K and P which did not differ significantly between the two mussels. The soluble and insolube collagen contents of HM and SM were 265.8 and 228.4 mg/100 g, and 119.5 and 121.8 mg/100 g, respectively.

• Food Science and Preservation
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• v.17 no.6
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• pp.820-825
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• 2010

We investigated changes in the quality characteristics of soy sauce made using salts from deep ocean water; such salts are more economic to obtain than sun-dried salt. pH level and buffer action both decreased as fermentation proceeded. The content of the pure extract after 120 d of fermentation was 7.5%(w/w), and increased as fermentation proceeded. Total and amino acid nitrogen levels after 120 d of fermentation were 1.4% and 0.75%, respectively (both w/w). Of the free amino acids (179.8-315.7 mg%), glutamic acid was the most abundant, followed by alanine, lysine, and leucine. The glutamic acid/total free amino acid ratio was 21.0-23.2%. The content of essential amino acids was 78.0-142.3 mg%; this level increased as fermentation progressed.

• The Korean Journal of Food And Nutrition
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• v.30 no.5
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• pp.916-922
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• 2017

This study was conducted to investigate changes in organoleptic properties and taste components including free sugar, organic acid and free amino acid with addition of walnut. Changes in total nitrogen were insignificantly different with addition of walnut. Amino type nitrogen content was decreased in proportion to supplemental level of walnut. Content of organic acids, of which three kinds were detected, such as citric acid, malic acid and lactic acid increased more than two times with addition of walnut. Contents of free sugar and amino acid were decreased with addition of walnut. The proportion of essential amino acid was 40.6~41.4 percent. Glutamic acid in total amino acid was increased in proportion with addition of walnut. The highest sensory evaluation score was recorded in soy sauce with addition of 2 percent walnut. Together, it was expected that 2 percent addition of walnut to soy sauce has a positive effect on the taste of soy sauce.

• Applied Biological Chemistry
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• v.12
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• pp.43-51
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• 1969

The purpose of this study was to determine protein amino acid contents of some Korean foods by gas-liquid chromatography, and to evaluate this technique as a procedure for the quantitative determination of amino acids in foods. The crude protein content of foods was also estimated from the nitrogen content. 1. Nitrogen content of each food sample was determined previously to adjust the amount of sample for GLC analysis 2. In the analysis of 17 known amino acids, a linear relationship was found between the weight of 13 amino acids of 17 amino acids, the internal standard as well as the injection volume of a mixture and the detector responses for the derivatives of the amino acids. No response for arginine, cystein, histidine, and tyrosine was observed. 3. The relative molar response (RMR) values for the 13 amino acids of standard solution relative to glutamic acid as '1.00' were obtained under normal operating conditions with a hydrogen flame ionization detector. 4. The recovery of amino acids from their mixtures with natural food materials was carried out. The recoveries were essentially quantitative except threonine and serine. An overall mean recovery of 11 amino acids was $101.4{\pm}8.4$ per cent before hydrolysis and $98.1{\pm}8.7$ per cent after hydrolysis of samples. 5. The comparative analysis of the acid hydrolysates of two food samples by gas-liquid and ion-exchange chromatographic analysis were carried out. In white-bait pemmican, only threonine and asparagine amounts by GLC analysis had similar values to those obtained by ion-exchange chromatography. The other seven amino acids gave higher values as measured by GLC than by ion-exchange. With the food sample, soybean, alanine, valine, asparagine, and glutamic acid were in good agreement in two analysis, while leucine, proline, threonine, phenylalanine, and lysine were found in slightly higher concentrations in the GLC analysis. 6. Grant variations of amino acid content were found among samples analyzed. The amino acid contents of each sample were compared with the values found in the literature.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.3
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• pp.371-377
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• 2009

The objectives of the present study were to investigate the effects of different dietary ratios of whole-crop corn silage and alfalfa hay on nitrogen (N) digestion, duodenal flow and metabolism across the portal-drained viscera (PDV) of growing beef steers, and to elucidate their relationships. Four steers (236${\pm}$7 kg BW) fitted with duodenal cannulae and chronic indwelling catheters into the portal and mesenteric veins and abdominal aorta were used in a 4${\times}$4 Latin square design. Animals were fed (at 12-h intervals) the 4 diets consisting of whole-crop corn silage (C) and alfalfa hay (A) in 80:20 (C8A2), 60:40 (C6A4), 40:60 (C4A6) and 20:80 (C2A8) ratios of which dietary crude protein (CP) was 10.5, 12.0, 13.5 and 15.0% of dry matter (DM), respectively. Feeding level was restricted to 95% of ad libitum intake to measure N digestion, blood flow and net flux of N across the PDV. Digestibility of DM and neutral detergent fiber and digestible energy intake linearly increased as the ratio of alfalfa hay increased. The N intake, duodenal flow and intestinal disappearance increased linearly with increasing alfalfa hay. Arterial and portal concentrations of ${\alpha}$-amino N showed a quadratic response to increasing levels of alfalfa hay and were the highest in steers fed the C6A4 diet. The net PDV release of ${\alpha}$-amino N and ammonia N increased linearly with increasing alfalfa hay, but urea N uptake by PDV did not differ among diets. As a percentage of apparently digested N in the total gut, net PDV release of ${\alpha}$-amino N linearly decreased from 66 to 48% with increasing alfalfa hay. Conversely, net PDV recovery of ${\alpha}$-amino N to intestinal N disappearance varied with increasing alfalfa hay accounting for 49, 50, 58 and 61% on C8A2, C6A4, C4A6 and C2A8 diets, respectively. Net PDV uptake of urea N, relative to apparently digested N, linearly decreased from 81 to 25% as alfalfa hay increased from 20 to 80% of DM intake. Considering PDV uptake of urea N, microbial efficiency and conversion of total tract digested N to PDV ${\alpha}$-amino N net supply, a diet consisting of 80% whole-crop corn silage and 20% alfalfa hay (10.5% CP) was the best, while considering the quantities of intestinal N disappearance and ${\alpha}$-amino N absorption, a diet of 20% whole-crop corn silage and 80% alfalfa hay (15% CP) would be preferred. The proportion of ${\alpha}$-amino N recovered by PDV relative to the intestinal N disappearance may vary with energy intake level of mixed forage diets.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.6
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• pp.838-844
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• 2013

This study was conducted to evaluate chemical composition, nitrogen-corrected true metabolizable energy (TMEn) and true amino acids digestibility of corn distillers dried grains with solubles (DDGS) produced in China. Twenty five sources of corn DDGS was collected from 8 provinces of China. A precision-fed rooster assay was used to determine TMEn and amino acids digestibility with 35 adult cecectomized roosters, in which each DDGS sample was tube fed (30 g). The average content of ash, crude protein, total amino acid, ether extract, crude fiber and neutral detergent fiber were 4.81, 27.91, 22.51, 15.22, 6.35 and 37.58%, respectively. TMEn of DDGS ranged from 1,779 to 3,071 kcal/kg and averaged 2,517 kcal/kg. Coefficient of variation for non-amino acid crude protein, ether extract, crude fiber and TMEn were 55.0, 15.7, 15.9 and 17.1%, respectively. The average true amino acid digestibility was 77.32%. Stepwise regression analysis obtained the following equation: TMEn, kcal/kg = -2,995.6+0.88${\times}$gross energy+$49.63{\times}a^*$ (BIC = 248.8; RMSE = 190.8; p<0.01). Removing gross energy from the model obtained the following equation: TMEn, kcal/kg = 57.88${\times}$ether extracts+$87.62{\times}a^*$ (BIC = 254.3, RMSE = 223.5; p<0.01). No correlation was found between color scores and lysine true digestibility (p>0.05). These results suggest that corn DDGS produced in China has a large variation in chemical composition, and gross energy and $a^*$ value can be used to generate TMEn predict equation.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.9
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• pp.1361-1368
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• 2006

Amino acid imbalances refer to the deleterious effects that occur when a second-limiting amino acid or mixture of amino acid lacking a particular limiting amino acid is supplemented in diets marginal in one or more indispensable amino acids. In spite of variation in the conditions that have been used to induce amino acid imbalances, such as protein level in the diet, the extent of difference in total nitrogen content between basal and imbalanced diets, and kinds of amino acids used as imbalancing agents, the conspicuous common features of amino acid imbalances have been a decreased concentration of the limiting amino acid in blood, depression of feed intake and weight gain, and increased dietary content of the limiting amino acid needed to correct the imbalances. There is strong evidence that a decrease in the concentration of a limiting amino acid detected in the anterior prepyriform cortex of the brain is followed by behavioral effects, especially a decrease in feed intake. This might be due to the competition between the limiting amino acid and the amino acids in the imbalancing mixture for transport from blood into brain. One of the biochemical responses of animals fed amino acid imbalanced diets is a rapid decrease in the concentration of the limiting amino acid, which are due in part to an increase in catabolism of the limiting amino acid by the increased activities of enzymes involved in the catabolism of the amino acid. Practically, specific amino acid imbalances could be induced in swine and poultry diets that have been supplemented with lysine, methionine, tryptophan when threonine, isoleucine, valine, etc. are potentially third- or fourth-limiting in diets. In these cases supplementation of the limiting amino acid could be beneficial in preventing the decrease of feed intake that could otherwise occur as a result of amino acid imbalance.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.98-102
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• 2000

To investigate quality characteristics of southeast asian salt-fermented fish sauces, various chemical properties were examined against 13 kinds of southeast asian salt-fermented fish sauces. The range of chemical compositions were $60.6{\~}72.8{\%}$ moisture, $18.2{\~}25.8{\%}ash,\;0.9{\~}13.7{\%}$ crude protein and $14.1{\~}338.6\;mg/100 ml$ VBN. The pH and salinity were $4.66{\~}5.91,\;24.1{\~}30.6{\%}$, respectively. Total nitrogen, amino nitrogen, total free amino acid, and total ATP related compounds (sum of $ATP{\~}IMP$, HxR, Hx and uric acid) were in the ranges of $0.140{\~}2.199g,\;115.4{\~}1,643.0 mg,\;46.4{\~}9,056.3\;mg\;in\;100 ml,\;and\;0.829{\~}9.564 {\mu}mol\;in\;1\;ml$, respectively. Southeast asian salt-fermented lish sauces were rich in tree amino acids, such as glutamic acid, Iysine, leucine, alanine, aspartic acid, valine and isoleucine in the order.

• Korean Journal of Ecology and Environment
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• v.50 no.4
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• pp.432-440
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• 2017

Compound specific isotope analysis of amino acids (CSIA-AAs) is being highlighted as an alternative approach for overcoming some restrictions in application of stable isotope analysis of bulk tissue (SIA) for trophic position (TP) estimation. However, this approach has rarely been applied in Korea. The present study determines TP of two Polychaeta (Nephtyidae and Glyceridae) and two fish species(Platycephalus indicus and Lophius litulon) collected from the Geum River estuary using nitrogen isotope ratio of amino acid and compared with the TP values estimated by SIA. The Polychaeta species, sampled in two sites, showed similar TP between SIA(2.7 and 3.1) and CSIA-AAs (2.6 and 3.1). However, for both fish species, TP values displayed a large difference between SIA (3.1 and 2.3) and CSIA-AAs (3.8 and 3.7). In this study TP values estimated by CSIA-AAs showed more similar to the previously reported gut content analysis of both fishes compared with the results of SIA. Current study suggests the applicability of nitrogen isotope ratio of amino acid to understand coastal ecosystem structure and trophic ecology.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.471-477
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• 1995

Extractive nitrogen, free amino acids, oligopeptides, nucleotides and related compounds, quaternary ammonium bases, and guanidino compounds were analyzed to evaluate quality of anchovy sauce. The commercial products contained low proximate composition, extractive nitrogen and other extractive components, than the experimentally prepared anchovy sauce. Both samples, commercial products and experimentally prepared anchovy sauce, were rich in free amino acids, such as glutamic acid, leucine, alanine, lysine, and aspartic acid. The extractive nitrogenous components which consist of total nucleotides and related compounds, total free amino acids, methionine, isoleucine, valine, taurine, tyrosine, histidine, leucine, aspartic acid, cystine, and lysine, showed significant correlation(p<0.01) with extractive nitrogen. Possibly, seven kinds of free amino acids such as methionine, isoleucine, valine, taurine, tyrosine, histidine, and leucine, might be recommend as quality indices of standardization for anchovy sauce.