• Applied Biological Chemistry
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• v.49 no.1
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• pp.7-14
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• 2006

This study was carried out to examine the quality characteristics of soybean pastes made of Meju with mold-producing pretense isolated from traditional Meju. The changes in moisture content, enzyme activity (amylase, protease, lipase), reducing sugar, amino-type nitrogen contents and anti-oxidant activity were investigated during the aging period. The moisture contents decreased gradually with time. Amylase activity decreased during the aging period while pretense and lipase activities increased until 30-45 days of aging, but decreased thereafter, Especially pretense activity in soybean paste with mold was greater than that in the control. Amino-type nitrogen and ammoniacal nitrogen contents increased, but reducing sugar contents decreased with time. Amino-type nitrogen contents were greater in soybean paste made of Meju with isolated mold than those in the control. Antioxidative activity was also confirmed in soybean paste.

• Journal of the Korean Society of Food Culture
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• v.31 no.4
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• pp.348-356
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• 2016

The purpose of this study was to investigate the chemical contents (sugar, nitrogen, and amino acids) and sensory characteristics of traditional soy sauce according to three different methods. The samples were taken from four different periods (0, 20, 40, and 60 days after fermentation). Total sugar contents increased in all groups according to ripening period, and Gyupjang (G) showed the highest sugar content among the groups. Total nitrogen and amino acid contents of all groups increased after 60 days of ripening, and Gyupjang (G) and Gyupjang mixed with salt water (SG) had higher total nitrogen content compared to Chungjang (S) at the same period. The results from the sensory evaluation show that preferable sensory characteristics, such as color preferences, sweetness, umami taste, and overall preference, were significantly higher in Gyupjang (G) and Gyupjang mixed with salt water (SG) than in Chungjang (S). Preferable sensory characteristics had significantly high positive correlation with most amino acids, total nitrogen, and sugar contents, except for glutamine. Based on the significant difference in preferable sensory characteristics between Gyupjang mixed with salt water (SG) and Chungjang (S), Gyupjang mixed with salt water (SG) can be used to improve sensory characteristics. This research implies that adding salt water during the manufacturing Gyupjang process is advisable to yield high quality soy sauce.

• Journal of the Korean Society for Heat Treatment
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• v.12 no.2
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• pp.117-128
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• 1999

This study was carried out to investigate the surface characteristics of SCM440 steel nitrided with various nitrogen contents for 7 hours at $520^{\circ}C$ by using micro-pulse plasma nitriding apparatus of hot wall type. The effects of oxidation treatment was also investigated on plasma nitrided in 30% nitrogen and post oxidized SCM440 steel at $500^{\circ}C$ in $H_2O$ atmosphere. The ${\gamma}^{\prime}-Fe_4N$ and ${\varepsilon}-Fe_{2-3}N$ phases were detected in compound layer of the nitrided steel. As the content of nitrogen in plasma gas increased with 30, 50, 70% on the micro-pulse plasma nitriding for SCM440 steel, the thickness of compound, diffusion layer and the surface hardness were increased. From the wear test results, the best wear resistance was appeared in the condition of ductile ${\gamma}^{\prime}-Fe_4N$ phase formed specimen at 30% nitrogen, whereas that of the treated with 50% and 70% nitrogen decreased owing to the exfoliation of brittle ${\varepsilon}-Fe_{2-3}N$ phase in the compound layer. On the nitrided and subsequently oxidized SCM440 steel, the surface layer consisted of $Fe_3O_4$, ${\gamma}^{\prime}-Fe_4N$, and ${\varepsilon}-Fe_{2-3}N$ phases. In these treatments, the dissolution of nitrides affect hardness and hardening depth in compound and diffusion layers. For the nitrided in 30% nitrogen and post oxidized specimen at $500^{\circ}C$ for 1 hour, the wear resistance was lower than that of the only nitrided one in 30% nitrogen but higher than those of the nitrided ones in 50 and 70% nitrogen.

• Applied Biological Chemistry
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• v.6
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• pp.79-87
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• 1965

The contents of insoluble protein nitrogen, water soluble protein nitrogen anti peptides' nitrogen were determined of the samples which were taken in seven and half hours intervals during soybean-koji preparation to study changes of soybean protein, and the contents of total nitrogen and amino nitrogen were measured for the fractions resulting from molecular sieving by using Dowex 50 having various cross linkages for the peptides from soybean-koji extracts. As the results of the studies, The followings were obtained: 1. The contents of insoluble protein nitrogen and peptides' nitrogen are fairy constant at the earlier stage, where the former decreased and the latter increased markedly as mycelia grow, then rate of the decreases and the increases of them become lower at later stage after sporulation. The contents of water soluble protein are also constant at the earlier stage until covering of mycelia over the koji and increased since then until the stage of sporulation and then decreased at the later stage. 2. The amount of peptides nitrogen in each fraction obtained by the molecular sieving was almost constant at the earlier stage and the values in fractions of X-16, X-12, X-8. X-4 and X-2 increased considerably together as mycelia grow. Then the values in the fractions showed almost plateaux, after sporulalion, where the effluent fraction showed markedly increased values throughout mycelia growth.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.1
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• pp.325-331
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• 2017

This study was conducted the change of physico-chemical characteristics according to salt types; sun-dried salt, refined salt, Chinese sun-dried salt, salicornia herbacea salt and bamboo salt. As a results, volatile basic nitrogen(VBN) contents were 143.24-148.32 mg/100g, amino nitrogen(AN) contents were 1050.37-1096.91 mg/100g, total nitrogen(TN) contents were 1.62-1.78 %, moisture contents were 64.19-66.00 % and pH were 5.23-5.98. There are various type of salts that have difference in content of salinity, moisture, various mineral content, size and shape of salt crystal, granularity and chromaticity. In this study, Than the difference in the salt, difference in the fish sauce is determined to be insignificant, that is, there are no significant effect on the quality of the fish sauce according to the kind of salt.

• Journal of the Korean Society of Tobacco Science
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• v.25 no.2
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• pp.95-102
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• 2003

To get the informations of quality uniformity of threshed burley tobacco produced from 1997 to 2001 and processed at various leaf processing factories, chemical constituents contents and coefficient of variation(C.V.) were analysed. The average chemical constituents contents of 12 grades during 5 years ranged as follows; nicotine 1.76～2.66%, total nitrogen 4.15～4.80%, crude ash 21.6～22.4% and chlorine 1.08～1.20%. The variations of chemical constituents contents among crop years was higher in nicotine while lower in crude ash. The nicotine content of upper leaves were influenced negatively by rainfalls, while total nitrogen content were influenced positively by air temperature and sunshine hours during July. The C.V. of chemical content in same grade was higher in chlorine and nicotine while lower in crude ash. The ratio of C.V. among leaf tobacco processing factories/C.V. of total sample in same grade was high in nicotine. To reduce the C.V. of chemical constituents, it is recommendable to thresh the leaf tobacco at one processing factory. When the leaves being processed at one factory, the decreasing effect of deviation was higher in nicotine, particularly.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1044-1049
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• 1997

Physicochemical characteristics of kochujangs prepared with the powders from 4 different red pepper varieties, were investigated during 90 days fermentation to obtain information for the industrial production of traditional kochujang. Water activities and consistencies of all varities slightly decreased during fermentation, but in consistency Jangter kochujang was higher than others. The red values in color of all sample remarkably increased after 15 days. Especially L, a and b values of Hongkwang kochujang were higher than those of others. The acidities of 4 kochujangs linearly increased during fermentation. Reducing sugar contents of kochujang increased until 30 days but thereafter decreased slightly, showing highest value for Hongkwang kochujang. Ethanol contents increased until 75 days and were higher in Kumtop and Jangter kochujang. Amino and ammonia nitrogen contents rapidly increased until 30 days. Ammonia nitrogen content was gradually decreased after 30 days. Amino nitrogen contents were higher in Hongkwang kochujang.

• 한국해양학회지
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• v.5 no.1
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• pp.14-29
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• 1970

Tidal variations of various chemical constituents in the laver bed sea waters in Wan Do Gun were determined over one spring tidal cycle from Oct. 1968 to Feb. 1969. Total ranges and means of the contents at Pyung-il Do and Wan Do are as follows. Although the average monthly variations of each content at Pyung-il Do were similar to those at Wan Do, most of the contents at Pyung-il Do were at a slightly higher level than at Wan Do. The values of silicate-silicon, phosphate- phosphorus and soluble iron, however, showed high levels at Wan Do. Chlorinity, magnesium, calcium, dissolved oxygen, silicate-silicon and phosphate-phosphorus contents increased from Oct. 1968 to Feb. 1969, though the content of soluble iron decreased before December and slightly increased in January and February. The average monthly variations of ammonia-nitrogen and nitrate-nitrogen contents were irregular. The nitrite-nitrogen content appeared in trace amounts in the months with a comparatively high water temperature, i.e., October and November, but in midwinter it was undetected. The ranges of the tidal variations of the contents of each chemical constituent were not significantly wide, though the contents varied excessively by the hour, and this may show the irregularity of the water quality in Wan Do Gun coastal area. As a rule, no regular tidal variation of the chlorinity was observed except slightly decreased value at ebb tide at Wan Do. In general, although the pattern of the variations of calcium and magnesium contents were similar to that of the chlorinity, no definite relationships between these constituents and chlorinity were observed. Tidal variations of the dissolved oxygen content, nutrient salts and soluble iron were irregular.

• Korean Journal of Food Science and Technology
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• v.33 no.3
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• pp.353-360
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• 2001

Physicochemical characteristics of kochujang prepared with addition of garlic and onion, were investigated for 22 weeks of fermentation to obtain information on improving the quality of traditional kochujang. Moisture contents of kochujang increased during fermentation, but total nitrogen contents decreased slightly. The pH and titratable acidity of kochujang changed a little by addition of garlic or onion. Total sugar contents of kochujang decreased rapidly after 4 weeks, but reducing sugar contents increased until 2 weeks of fermentation. As the ratio of garlic increased, reducing sugar contents decreased. Ethanol contents increased during fermentation as mixing ratio of onion increased. Amino nitrogen contents of kochujang increased as mixing ratio of garlic or onion increased, but ammonia nitrogen contents decreased. Water activities of kochujang decreased slightly during fermentation, but consistency increased until 18 weeks. The color values of garlic or onion added kochujang were low in the L-values, but a- and b-values increased. Results of sensory evaluation showed garlic added$(2{\sim}4%)$ kochujang were more acceptable than onion added kochujang due to more favorable taste and flavor.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.2
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• pp.112-121
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• 1993

To study management practices suitable for the least production loss of temperate pasture under summer stress, two different cutting dates (late June and mid July) under summer stress and five different nitrogen treatment application levels (0, 100. 200, 300 and 400 kg/ha) were tried during the trial period between Oct. of 1986 and Oct. of 1989. The late June cutting showed a statistically significant increase of dry matter yield of pasture in comparison with the mid-July cutting(P<0.05). Nitrogen application also gave significant increase in dry matter yield. Botanical composition at the 4th cuttings in 1988 and 1989 was dominated by weeds to the level of 50%, Application ofnitrogen at 200 kgs per ha was found to be the best with production of grasses at 70%, legumes at 10 % and weeds at 20% in botanical composition comparison of pastures at the 4th cutting time the last year, showing a great decrease of weeds. K contents of pasture in June cuttings showed to be more than them in July cutting, and N and Na contents increased with increases of the nitrogen application level. It was concluded that treatment with June cutting and nitrogen application of 200 kg per ha was a way to keep temperate pasture from summer stress in the Cheju area.