• 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.

• 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.

• Korean Journal of Food Science and Technology
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• v.26 no.4
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• pp.389-392
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• 1994

Changes in free amino acids and amino nitrogen of traditional kochujang were investigated during 180 days of fermentation. Tested kochujang included Sunchang kochujang prepared with glutinous rice, Boeun kochujang prepared with barley, and Sachun kochujang prepared with wheat. Amino acids remarkably increased during fermentation were methionine, glutamic acid, isoleucine, leucine and tyrosine. However, regardless of kinds of kochujang major free amino acids were serine, aspartic acid, glutamic acid and proline. Glutamic acid was noted as the most contributing to the savory taste of kochujang in relation to the increasing ratio and content among tree amino acids during fermentaion. The correlation coefficent between totals of free amino acids and the contents of amino nitrogen were relatively high (0.87

• Mycobiology
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• v.33 no.1
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• pp.23-29
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• 2005

The effects of different concentrations of three amino acids as carbon and or nitrogen sources on mycelial dry weights, changes in pH values of synthetic medium, ammonia secretion and extracellular protease activity by three zoosporic fungi, pathogens of fish and shellfish, were studied. As compared with the control, the addition of isoleucine and aspartic acid as nitrogen sources were generally stimulative for mycelial dry weight production whereas phenylalanine was inhibitory irrespective to the tested fungal species. When amino acids served as carbon and nitrogen sources, the mycelial dry weights of the three fungi were increased (mostly non-significantly) relative to untreated control but weights were decreased as the concentrations of the three amino acids raised. The addition of individual amino acids as carbon and nitrogen sources to the medium significantly increased pH values of the medium comparable to the control. The addition of each of the three amino acids as carbon and nitrogen sources to the medium significantly induced ammonia secretion by the three species of zoosporic fungi. Ammonia secretion in synthetic medium amended with amino acids as nitrogen source raised by the three zoosporic fungi relative to untreated control except in case of Achlya racemosa treated with isoleucine. Extracellular protease activity was almost promoted in case of Achlya proliferoides and Saprolegnia furcata cultures treated with isoleucine and aspartic acid individually in presence of glucose and vice versa in case of phenylalanine. However, extracellular protease activity of A. racemosa decreased compared with the control at various concentrations of isoleucine and both phenylalanine and aspartic acid assumed inconsistent effects. Extracellular protease activity of the three zoosporic fungi in the medium devoid of glucose varied depending upon zoosporic fungal species, the tested amino acid and the applied concentrations. The values of protease activity were approximately less two folds than that obtained in presence of glucose.

• Journal of the Korean Society of Food Culture
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• v.12 no.1
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• pp.63-69
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• 1997

This study was carried out in order to analyzed the changes in nitrogen containing taste compounds of three different types of traditional Korean soy sauce with varing ripening period, and to investigates correlation between sensory characteristics and taste compounds contents via contents assay and sensory evaluation of soy sauce samples. Total nitrogen, ammonia type nitrogen and amino type nitrogen contents showed the highest value in Kyupjang. 17 kinds of free amino acid was detected in Chungjangs and 16 kinds of free amino acid was detected in Kyupjang. Nucleotides and their related compounds detected were hypoxanthin, xanthin, IMP, AMP, Inosine, ADP. Free amino acid and nucleotides and their related compounds contents were highest in Kyupjang. Nitrogen related compounds content of high concentration soy sauce ripened over 150 days increased similarly with Kyupjang. In the sensory evaluation of soy sauce taste, Chungjang samples acquired the highest score in the offensive taste test while Kyupjang marked highest score for sweet taste, nutty taste, taste preference. High concentration soy sauce ripend over 150 days yielded the result similar to that of Kyupjang. Sweet taste showed positive correlation with nitrogen compounds. The materials that showed positive correlation with nutty and traditional soy sauce taste and taste preference were nitrogen compound, IMP, AMP. Except for tryptophan, all free amino acid showed positive correlation with nutty and traditional soy sauce taste. Particulary, taste preference correlated to lysine, aspartic acid and glutamic acid.

• 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.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.6
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• pp.368-372
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• 2003

The growth and amino acid contents of the cyanobacterium, Spirulina platensis strain NIES 46, were investigated using ammonium, nitrate, nitrite, or urea as the sole nitrogen source in a batch culture. Chlorophyll a concentration was highest at 2,096$\mu\textrm{g}$/L in the nitrate group after 10days of cultivation, while the dry weight of S. platensis was highest at 4.5g/L in the ammonium group after 30days of cultivation. The total amino acid content was highest at 174mg/g dry weight of S. platensis in the urea group at the end of the cultivation period, yet the amino acid patterns for S. platensis were similar for all the experimental groups. Therefore, it seemed that the growth and amino acid composition of S. platensis varied depending on the type of nitrogen sources, while the amino acid patterns were not changed. Also, the most efficient harvesting time for S. platensis seemed to be approximately 10 days after cultivation.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.12
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• pp.1782-1788
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• 2003

A mathematical model has been constructed to estimate the amino acid requirements for growing Taihe silky fowls in early stage. A requirement was taken as the sum of the needs for maintenance, for gain in carcass weight without feathers, and for the feathers. The maintenance requirement was considered to be the sum of the needs for replacing skin and intestinal losses and for the obligatory creatinine excretion in the urine. A comparative slaughter trial and nitrogen balance trials with growing and adult Taihe silky fowls, respectively, were conducted to estimate the parameters in the model. The amino acid requirements were then calculated with the constructed models. The results showed as following: the replacement needs for skin nitrogen loss was determined at 213.41 mg/d for adult male fowls (body weight 1.60 kg); creatinine excretion in these birds was 4.04 mg/d. when fed an nitrogen-free diets, the adult male fowls with body weight 1.60 kg excreted a total of 246.10 mg/d endogenous nitrogen. The net protein requirement for maintenance was estimated at $11.24mg/w_g{^{0.75}}/d$Per gram of body weight gain contained 27.18 mg carcass nitrogen for growing birds in early stage, but feathers nitrogen in per gram of body weight gain increased with age. The amino acid requirements for growing Taihe silky fowls were slightly higher than for starting and growing pullets, but lower than that of broiler chicks. The amino acid requirements patterns changed with weeks of age.

• YAKHAK HOEJI
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• v.4 no.1
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• pp.14-16
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• 1959

In order to confirm the biochemical process of the fermentation from soybean to maiju and of the fermentation from maiju to kanjang and dainjang, the introgen distributions of soybean, maiju, kanjang, and dainjang are studied on protein nitrogen, peptide nitrogen, amino nitrogen and volatile nitrogen. And the contents of amino nitrogen, peptide nitrogen, and true protein nitrogen to the total nitroge of soybean, maiju, kanjang, and dainjang are shown in table 1 and the ratios are shown in table 2 and the figure. According to the results indicated in the tables and figure, the following conclusions are summerized. 1. The main biochemical process at the fermentation from soybean to maiju would be the degradation from protein in soybean to peptide compounds in maiju. 2. The main biochemical process at the fermentation from maiju to kanjang and dainjand would be the degradation from peptide compounds in maiju to amino nitrogen compounds in kanjang and dainjang. 3. However bacause the protein nitrogen indicated as the ratio of protein nitrogen to total nitrogen is contained still higher content in dainjang. It is assumed that there might be two kinds of proteins in soybean one is the protein which could be converted to peptides at the maiju fermentation and to amino nitrogen compounds lastly at the kanjang fermentation. The other is the protein which would not be effected at these fermentation at all remaining as the protein nitrogen in dainjang. One of the finished products. 4. It can be indicated that the process from maiju to kanjang and dainjang would be due to the fermentation as indicated by HAW and CHOI.