• Preventive Nutrition and Food Science
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• v.10 no.1
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• pp.11-16
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• 2005

Enzymatic hydrolysis of dark muscle of skipjack was optimized by using response surface methodology. Three factors of independent values were pH (4.2 to 9.8), time (0.6 to 3.4 hrs) and temperature (34℃ to 76℃), and independent values were optical density and brix. The optimum conditions for enzymatic hydrolysis were pH 7.0 to 8.0, 55℃ and 3 hrs. The headspace volatile compounds of reaction flavors using the enzymatic hydrolysate, cysteine and xylose were identified by using the combination of a canister system, gas chromatography and mass selective detector. Among 67 compounds, we identified 8 sulfur-containing compounds and 7 furans which were thought to be highly related to meat-like flavors.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.837-844
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• 1994

In order to making the good quality soybean cheese, it is prepared byover growing cow's milk added soybean curd with Actinomucor elegans and the nold-overgrown curd soked in salt-brine/ethanol mixture. The physicochemical changes and sensory evaluation were investigated during the aging period. Crude protein, carbohydrate, crude fat ash contents of the pehtze were increased by elapsing the fermentation time, whereas moisture's decreased . Amino-N and ammonia -N contents of cow's milk added pehtze and soybean phetze were increased 17.25%, 7.23% and 16.16%, 8.42% respectively. Total nitrogen content of the pehtze was decreased by elaping the aging time but soaking solution's increased. Free amino acid content of soybean cheese was increased as a result of the proteolytic action of molds. As a result, sulfur containing amino acid such as methionine and cysteine of the cow's milk added soybean cheese were enriched 1.3 times more than the soybean cheese. Flavor, taste and texture of the cow's milk added soybean cheese were higher than soybean cheese.

• The Korean Journal of Food And Nutrition
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• v.13 no.6
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• pp.558-562
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• 2000

A strain of non-sulfur photosynthetic bacteria possessing large amount of ubiquinone-10 in the cell mass, was isolated from waste water collected from the Nakdong River. It was identified as Rhodobacter sp. N-2 by a series of studies on its morphological. cultural and physiological characteristics. The organism appeared to got higher cell mass under circumstances of anaerobic growth conditions than under photosynthetic aerobic cultures. Biotin and thiamin and niacin could be used as good growth factors.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.422-429
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• 1997

For the complete and accurate amino acid determination of protein and food samples, 3 different hydrolysis procedures have been conducted in parallel for each sample, which include the alkaline hydrolysis for tryptophan determination, performic acid oxidation prior to the acid hydrolysis for the determination of cysteine and cystine, and the 6N HCl hydrolysis for the determination of the rest of amino acids. In the present study, amino acid concentrations obtained from the modified single hydrolysis procedure were compared with the values from the conventional hydrolysis procedures in casein and nine food and composite dish samples. In most of the samples tested, the modified single hydrolysis procedure gave significantly higher values of cysteins and cystein compared to the performic acid oxidation method, but resulted in a considerable destruction of tryptophan in food and composited dish samples. There was no consistent difference in the rest of amino acid concentrations between the two hydrolysis systems. Therefore, for complete amino acid determination of various foods and composite dishes, the single hydrolysis method may replace the 6N HCl hydrolysis and performic acid oxidation methods, and thereby reduces 3 hydrolyses to 2 steps with much higher recoveries of the sulfur containing amino acids.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.444-449
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• 2003

To investigate the long term effect of buchu (Chinese chives) diet on ROS formation in the liver and stin tissue of ICR mice, one of control, 2% or 5% buchu-added diet was fed to ICR mice for 12 months. Superoxide anion (O2ㆍ), hydrogen peroxide($H_2O$$_2$) and hydroxyl radical (ㆍOH) contents were measured in cytosol, microsome, mitochondria of liver and skin of mice, respectively. Behu diet showed a significant decrease of superoxide anion, hydrogen peroxide and hydroxyl radical contents in liver and skin tissues compared to control diet, and this effect is especially higer at 5% than at 2% buchu diet level. ICR mice showed an age-dependent increase in ROS contents, while the group fed buchu diet decreased its ROS contents significantly and ROS contents of liver appeared to be 2 fold higher than skin. The results of the present study suggest that antioxidative components and sulfur-compounds in buchu diet appear to be responsible for the inhibition of ROS formation in ICR mice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.6
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• pp.719-724
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• 1992

Volatile components in Korean salt-fermented anchovy were analyzed by simultaneous steam distillation-solvent extraction/gas chromatography/mass spectrometry. Seventy-three volatile compounds were detected in sample. Among these, 58 compounds were positively identified and were composed mainly of aldehydes, ketones, alcohols, nitrogen-containing compounds, esters, sulfur-containing compounds, furans and miscellaneous compounds. The amounts of aldehydes was the highest in flavor compounds detected in sample and next followed by alcohols, furans, esters and ketones. In particular, the following high ratios were observed : 3-methylbutanal, 1-penten-3-ol, ehtylacetate, 2-ethylfuran.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1301-1304
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• 2001

Deodorizing activity of polyphenol cxidase (PPO) extracted from apples was investigated by measuring the changes of methyl mercaptan as an indicator of halitosis in human mouths. In the studies of apple extracts on deodorizing activity, the deodorizing activity was increased with the amount of apple extracts. In the cases of adding PPO to the low molecular fraction of apple extracts, the deodorizing activities were increased with the amount of the law molecular fraction of apple extracts and the reaction time of the extracts with PPO. Deodorizing activities of PPO is thought that o-quinone as an intermidiate produced by an oxidative reaction of PPO during enzymatic browning reactions may react with methyl mercaptan to form a non-volatile and sulfur-containing compound .

• Journal of the Korean Society of Food Culture
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• v.30 no.1
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• pp.86-96
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• 2015

Onions contain antioxidant flavonoids and bioactive sulfur compounds. These substances are more abundant in the peel than in onion flesh. For this reason, whole onions including peels were added to soy milk to produce soy milk with whole onions (SWO), whereas peeled onions were added to soy milk to produce soy milk with peeled onions (SPO). The functional and antioxidant properties of these two kinds of soy milk were then analyzed and compared. Compared to control soy milk (CS) without onion powder, treated samples (to which freeze dried onion powder was added at 1.4, 1.6, 1.8, and 2.0%, respectively) showed significantly increased amounts of quercetin, isoflavone, and total phenol (p=0.05). The magnitude of the increase rose as the amount of added onion powder increased and when onion powder contained onion peels. With regards to antioxidant activity (DPPH and ABTS), SWO showed a greater value than SPO. The sensory evaluation scores of SWO and SPO were lower than CS for roughness and swallowing, as adding onion powder increased solid contents and viscosities. However, higher overall acceptability were obtained 1.8SPO and 1.8SWO.

• Journal of Nutrition and Health
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• v.3 no.2
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• pp.87-94
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• 1970

The amino acid composition of human and cow's milk represents a standard of reference in infantnutrition. The amino acid compositions determined by automatic amino acid analyzer, Yanagimote Model LC-5. Protein in the human and cow's milk were found to be hydrolyzed to yield free amino acids. Qualitative data for free amino acids in the milk are as follows: 1) Amounts of acidic amino acids such as glutamic and aspartic acid in cow's milk were obserbed to be about 2 times compared with human milk and it is considered that the abundance in these amino acids may contribute significantly to the specific flavor of cow's milk. 2) It is much interesting that in the human milk the contents of sulfur-containing amino acids were high comparatively better than cow's milk; cystine was found to be 3 times ana methionine, 2 times. 3) In the human milk a high content of some essential amino acids such as threonine, isoleucine and leucine was demonstrated and a specific flavor sweet amino acids. 4) Large amounts of basic amino acid such as histidine was found to occur in human milk and arginine in cow's milk.

• Journal of Animal Science and Technology
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• v.61 no.3
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• pp.122-137
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• 2019

Methane, one of the important greenhouse gas, has a higher global warming potential than that of carbon dioxide. Agriculture, especially livestock, is considered as the biggest sector in producing anthropogenic methane. Among livestock, ruminants are the highest emitters of enteric methane. Methanogenesis, a continuous process in the rumen, carried out by archaea either with a hydrogenotrophic pathway that converts hydrogen and carbon dioxide to methane or with methylotrophic pathway, which the substrate for methanogenesis is methyl groups. For accurate estimation of methane from ruminants, three methods have been successfully used in various experiments under different environmental conditions such as respiration chamber, sulfur hexafluoride tracer technique, and the automated head-chamber or GreenFeed system. Methane production and emission from ruminants are increasing day by day with an increase of ruminants which help to meet up the nutrient demands of the increasing human population throughout the world. Several mitigation strategies have been taken separately for methane abatement from ruminant productions such as animal intervention, diet selection, dietary feed additives, probiotics, defaunation, supplementation of fats, oils, organic acids, plant secondary metabolites, etc. However, sustainable mitigation strategies are not established yet. A cumulative approach of accurate enteric methane measurement and existing mitigation strategies with more focusing on the biological reduction of methane emission by direct-fed microbials could be the sustainable methane mitigation approaches.