• Journal of Environmental Health Sciences
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• v.30 no.1
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• pp.22-28
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• 2004

This study was performed to investigate the changes of amino nitrogen, total amino acids, free amino acids, and color of Korean traditional soy sauce (kan-jang) during the ripening and storage for 12 months and the characteristics of the changes. All of the preparation methods for soy sauce followed the recommendations of the Korea Food Research Institute. The components of soy sauce were analyzed at 0,6, and 12 months. The contents of amino nitrogen of soy sauce were significantly higher than that of soybeans or meju (soybean cakes) at the initial stage of storage (p<0.05), and decreased during the storage. The content of total amino acids of soybean sauce was significantly lower than that of soybeans, and the content of free amino acids was higher than that of soybeans (p<0.05). The contents of total and free amino acids decreased in soy sauce after 12 months of storage (p<0.05). The composition of total and free amino acids and their ratios of soy sauce were changed during the storage. The ratios of free to total amino acids of soybeans, meju, and soy sauce were 0.8％, 17.3％, and 53.1-59.8％, respectively. Glutamic acid, which represents the savory taste, was detected the most abundantly in soy sauce during the storage. The ratios of free to total amino acids of glutamic acid were 42.9-59.5％ in soy sauce. Lightness of Hunter color of soy sauce decreased over time (p<0.05). This study indicates that the ratios of free to total amino acids of soy sauce were much higher than those of soybeans, although its contents of total amino acids were much lower than those of soybeans. This study also indicates that this comes from the preparation and fermentation of meju. It was suspected that the organoleptic characteristics of soy sauce derived from the amino nitrogen, amino acids, and color might be inferior over 1 year of storage time. However, more detailed research should be conducted to interpretate this characteristics more accurately.

• The Korean Journal of Food And Nutrition
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• v.11 no.4
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• pp.402-408
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• 1998

A rapid processing method for fermented sauce of favorable flavor was investigated with low-usefulness marine resources. Hydrolyzed at optimal conditions for 6 hours usuing alcalase, and separated by molecularporous membrane. It's very effective for remove bitter taste at below M.W. 100 dalton, and effective at below M.W.500 dalton. Added 2% invert sugar in fermented sauce at below M.W.500 dalton, and thermal treatment at 100$^{\circ}C$ for 30 minutes were improved flavor. Chemical composition of fermented sauce using hair tail were 80.7% of moisture, 2.2% of carbohydrate, 1.8% of total nitrogen, 1.6% of amino nitrogen and pH was 6.5. The ratio of amino nitrogen in total nitrogen was 77.8%. And chemical composition of fermented sauce used gizzard shad, kangdale, pen shell and oyster were similar to fermented sauce used hair tail. Total nitrogen were above 1.8% and the ratio of amino nitrogen in total nitrogen was 77.7∼84.2% in all fermented sauce. Amino acid contents in fermented sauce used hair tail, gizzard shad, kangdale, pen shell and oyster were 4,318.1mg%, 4,681.3mg%, 3,156.2mg% and 4,175.0mg%, respectively. And the predominant free amino acid were glutamic acid, lysine and glycine in all fermented sauce.

• Journal of the Korean Home Economics Association
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• v.19 no.1
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• pp.25-31
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• 1981

The changes of various nitrogenfractions and free amino acid composition were investigated at various growing stages. The results are summarized as follows 1) Total nitrogen, water soluble protein nitrogen, and true protein nitrogen were decreased with growth. 2) Free amino acid increased with sprout-growth. the content of free amino acid were about 74.4%(combined Ser, Asp, Arg, Val) after 4 day sprout. It is belived that serine, aspartic acid, arginine and valine play an important role as taste compounds in mungbean sprout. 3) 16kinds of amino acid, including essential amino acids in human nutrition except tryptophan and cystin were quantified.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.1
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• pp.92-97
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• 2013

This study was conducted to understand the quality characteristics of salt fermented anchovies with heat treatment by measuring their chemical compositions. The heat-treated and non-heat treated salt fermented anchovies contained, respectively, 63.21 and 66.51% of moisture, 2.24 and 2.12% of total nitrogen (TN), and 1,537 and 1,520 mg/100 g of amino nitrogen (AN). In addition, heat-treated and non-heat-treated salt fermented anchovies contained 127 and 134 mg/100 g of volatile basic nitrogen (VBN), respectively. Moreover, measured the microbial level of heat-treated and non-heat-treated salt fermented anchovies was $2.58{\times}10^4$ and $3.61{\times}10^2$ CFU/mL, respectively. Also, the heat-treated and non-heat-treated salt fermented anchovies 3.65 and 0.30 units of protease activities, respectively. The total free amino acid contents in heat-treated and non-heat-treated salt fermented anchovies was 4,964 and 6,638 mg/100 g, respectively. The major free amino acid were glutamic acid, leucine, lysine, alanine, valine, isoleucine. Our results provide the characteristics of salt fermented anchovies and encourage their application for the food industry and cooking.

• The Korean Journal of Food And Nutrition
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• v.32 no.4
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• pp.342-348
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• 2019

The objective of this study was to investigate the changes in flavor components of cheonggugjang prepared with hazelnut. Amino nitrogen content in cheonggukjang was significantly lower in the 30~40% hazelnut group compared to the control group. The volatile basic nitrogen of hazelnut added cheongkukjang showed a similar pattern to that of amino nitrogen. The number of B. subtilis was slightly increased in relation to the amount of hazelnut added, but there was no significant difference. The content of glucose increased proportionally with increasing hazelnut. Total amino acid content decreased with increasing hazelnut. The ratio of glutamic acid to total free amino acids increased with increasing hazelnut. Oleic acid content increased proportionally with increasing hazelnut, while linoleic acid content decreased. In conclusion, the addition of hazelnut may contribute to the quality diversification of cheonggukjang by changing the taste and flavor while maintaining the amino nitrogen content of cheonggukjang.

• Applied Biological Chemistry
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• v.31 no.2
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• pp.154-161
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• 1988

In order to improve the quality of amino acid soysauce, this experiment was carried out as follows; koji added amino acid soysauce(KAAS) was prepared by addition of defatted soybean and meal koji into amino acid soysauce containing $0.5%{\sim}1.5%$ of total nitrogen. Various physicochemical characteristics of KAAS during aging were determined. Total nitrogen, amino-nitrogen, specific gravity, pure extract, total acidity and color were high in KAAS at high total nitrogen. After one month aging, reducing sugar was high in KAAS at high total nitrogen, but pH was high in KAAS at low total nitrogen. Ethyl alcohol was 2.07% in KAAS at 0.5% of total nitrogen after five months aging and 1.4% in KAAS at 1.5% of total nitrogen. Levulinic acid and lactic acid were high in KAAS at low total nitrogen. The results obtained above summarized as the quality of KAAS were highly good at $0.5{\sim}0.7%$ of total nitrogen after two or three months aging.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.7
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• pp.979-982
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• 2003

Two rapeseed meal samples (Sample A, hybrid 5900 and sample B, double low rapeseed No.4) obtained from China and one Canola meal sample obtained from a local crushing plant in Canada were used to investigate the amino acid degradability of rapeseed/Canola meal in rumen and amino acid digestibility of ruminal incubation residues by precision-fed rooster bioassay. Results show that in ruminal incubation the degradation rate of non amino acid nitrogen in crude protein is higher than that for amino acid nitrogen in crude protein, the results also suggest that the degradation rate of amino acid nitrogen in Chinese rapeseed meal sample B was lower than that for Canadian Canola, but that in Chinese rapeseed meal sample A is much close to that for Canadian canola meal. For all amino acids the digestibility of the bypass or residual protein as measured by the precision-fed rooster bioassay tended to be lower for Chinese rapeseed meal sample A than for sample B or Canadian canola meal which had similar digestibility values. However following a calculation of total amino acid availability, involving the digestibility of amino acids in the rumen and rooster bioassay the results are less contradictory. Results indicated that in traditional roasting-expelling process, heat treatment, especially dry heat treatmeat could decrease amino acids degradability in rumen of rapeseed/canola meal, but also may decrease total availability of amino acids of rapeseed/canola meal.

• Applied Biological Chemistry
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• v.15 no.1
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• pp.35-40
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• 1972

The contents of free amino acids in deembryod brown rice of two varieties were investigated by amino acid autoanalizer in relation to specific gravity grade. The analytical methods of free amino acid were also discussed. 1) The lower the specific gravity of the unhulled rice the higher the content of total free amino acids in the deembryod brown rice, and the similar trend appears to hold on each amino acids. 2) Main free amino acids were serine+asparagine, glutamic acid, aspartic acid, alanine and valine, and maximum values of them were 7.3, 5.1, 4.0, 3.4, 0.9mg/100g rice, respectively. They consist about 85% of total free amino acids in most cases. 3) The contents of soluble nitrogen and free amino acids appear to be lower in high protein variety (IR 667) than in low protein variety (Jinhung). The percentage of free amino acid nitrogen to soluble nitrogen, however, appears to be higher in high protein variety (IR 667). 4) Alanine was much lower than aspartic acid in IR 667 having Indica blood while alanine appears to be higher than aspartic acid in Jinhung (Japonica rice) suggesting varietal difference in amino acid metabolism. 5) Threonine peak was overlaped with glutamine, and serine was with asparagine in this study.

• Journal of Food Hygiene and Safety
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• v.19 no.1
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• pp.31-37
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• 2004

This study was performed to investigate the changes of amino nitrogen, total amino acids, free amino acids, and cole. of traditional Korean soybean paste (doen-jang) during the ripening and storage for 12 months. All of the preparation methods for soybean paste followed the recommendations of the Korea Food Research Institute. The components of soybean paste were analyzed at 0, 6, and 12 months. The content of amino nitrogen of soybean paste was significantly higher than that of soybeans or meju (soybean cakes) at the initial stage of storage (p〈0.05), and decreased during the storage. The composition of total and free amino acids and their ratios of soybean paste were changed during the storage. The ratios of free to total amino acids of soybeans, meju, and soybean paste were 0.8%, 17.3%, and 20.4∼32.9%, respectively. Glutamic acid, which represents the savory taste, was detected the most abundantly in soybean paste during the storage. The ratios of free to total amino acids of glutamic acid were 21.1∼41.5% in soybean paste. Lightness, redness and yellowness of Hunter color of soybean paste decreased over time (p〈0.05). The results of this study indicate that the ratios of fee to total amino acids of soybean paste were much higher than those of soybeans, although its contents of total amino acids were much lower than those of soybeans. The results also indicate that this comes from the preparation and fermentation of meju. It was suspected that the organoleptic quality of soybean paste derived from these three components might be inferior over 1 year of storage time.

• Journal of Plant Biology
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• v.16 no.1_2
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• pp.30-38
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• 1973

To study the response to plant growth by the environmental factors, the effects of application of nitrogen on changes in the yield, crude protein, amino acids, chlorophyll, carotene, total phosphorus, acid-soluble phosphorus, phospholipids, RNA, and DNA were investigated with westerworlds 9Lolium sublatum) and perennial rye-grasses (Lolium perenne). The amounts of dry weight, crude protein, amino acids, chlorophyll, carotene, total phosphorus, acid-soluble phosphorus, phospholipids, RNA and DNA of both rye-grasses increased with adequately increasing nitrogen, and reached a maximum with an adequate application of nitrogen. The relationships between yields and crude protein contents, crude protein and RNA contents, and yields and RNA contents of westerworlds and perennial rye-grasses were found to be positively correlated, respectively. Therefore, in general, the response to plant growth by the environmental factors such as nitrogen nutrient may be summarized as follows: Environmental factors\longrightarrowDNA\longrightarrowRNA\longrightarrowProtein\longrightarrowPlant growth