• The Korean Journal of Food And Nutrition
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• v.11 no.2
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• pp.249-255
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• 1998

New drying method was tested comparison with a traditional one used for production of Kwamaegi, semi dry pacific saury in east coast area of Kyungbuk province. During 15 days of total drying period, change in nucleotides and free amino acids were measured in edible portion of pacific saury from different dry methods, natural(traditional) and artificial method. ADP and AMP detected in raw fish were decrease while IMP, inosine, hypoxanthine increased during drying period. K1 values expressed as(Hx+HxR$\times$100/Hx+HxR+IMP) increased gradually throughout drying period, indicating the decline of freshness by drying. Freshness judged by change in nucleotides and related compounds was better in samples from artificial drying than from natural one. Special flavors of Kwamaegi were regarded to be synergistic actions of IMP and some amino acids. Content of total free amino acids of raw fish comprised 2.9g by weight(100g) and sum of glutamic acid, aspartic acid and histidine was over 34% of total amino acid content. Glutamic acid content. Glutamic acid, aspartic acid contents were reduced rapidly from 3rd to 9th day more decrease by artifical drying than by natural drying. Lysine content were gradually increased under two different drying conditions and threonine didn't change by two drying conditions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.2
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• pp.182-187
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• 1985

This study was attempted to evaluate the chemical components of Aldaegu, Gadus macrocephalus, which consumed as a salted and dried product popularly in Korea. The contents of such compounds as amino acids, nucleotides and their related compounds, fatty acids and minerals were analysed. The content of total free amino acids was 814.9 mg% on dry basis and the major amino acids were tyrosine, alanine, histidine, leucine, phenylalanine, lysine and valine in a decreasing order. These amino acids were resulted as 45% of total free amino acids in Aldaegu. In the nucleotides and their related compounds, inosine and hypoxanthine were the only compounds detected. The overall content of nucleotide and their related nitrogenous compounds, free amino acid-N., ammonia-N., creatine and creatinine-N., and betaine-N., was 78.6% of extractable nitrogen. Ammonia-N was the most abundant of other nitrogenous compounds, resulting 36.6% of extractable nitrogen from the sample. In the fatty acid composition of total lipid and phospholipid, polyenoic fatty acid was abundant holding about 48% respectively. However, higher amounts of saturated fatty acids(39.8%) were found in glycolipid, and the predominant fatty acids in quantity were palmitic $acid(C_{16:0})$, stearic acid $(C_{18:0})$, oleic $acid(C_{18:1})$, docosahexaenoic $acid(C_{22:6})$, eicosapentaenoic $acid(C_{20:5})$ and eicosatetraenoic $acid(C_{20:4})$. Aldaegu contained 27,430 ppm of sodium and the trace amount of lead and cadmium was detected, which gave a good safety in the food sanitation aspects. It was presumed that free amino acids, ammonia, hypoxanthine, betaine, creatine and creatinine, and minerals play an important role for the characteristics of taste and flavor of Aldaegu.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.5
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• pp.368-372
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• 1984

This paper deals with a rapid method for determination of ATP and its related compounds in fish and shellfish products using high performance liquid chromatography(HPLC). The HPLC used is a HPLC/ALC-224 equiped with UV-spectrophotometer (254 nm) as detector and integrator (Yanagimoto system-1000). The column used is a stainless steel tubing ($30.0\;cm{\times}3.9\;mm\;i.d.$) packed with ${\mu}-Bon-dapak\;C_{18}$. A mixture of $1\%$ triethylamine-phosphoric acid(pH6.5) was used as an eluent and the flow rate of the eluent was controlled at 2 ml/min. For the separation of ATP and its related compounds, a standard mixture of ATP, ADP, AMP, IMP, inosine and hypoxanthine was subjected to HPLC under the above mentioned conditions. Six peaks were obtained with retention times within 20 min, and elution order were hypoxanthine, IMP, inosine, AMP, ADP and ATP. But 5'-IMP and 5'-GMP fractions were not separated by this method. In generally, IMP content in boiled-dried fish and shellfish products purchased from the market was comparatively higher than that of other nucleotides. Especially, boiled-dried big eye herring marked higher value in IMP content than other boiled-dried ones. Hypoxanthine and inosine were major components of ATP-related compounds in dried products and seasoned-dried ones. And IMP content in seasoned-dried products was higher than that of dried ones. This fact is suggested that a part of IMP in seasoned-dried ones was derived from flavoring matter (MSG, 5'-IMP and 5'-GMP) which is added during the seasoning treatment.

• Korean Journal of Food Science and Technology
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• v.27 no.2
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• pp.241-245
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• 1995

Focusing on quality problems of delayed chilling porcine muscle, the effects of delayed chilling and aging on the contents of ATP-related compounds and taste of pork were investigated. Twelve Landrace pigs were employed and bisected: left sides were delay-chilled(DC) at room temperature($20^{\circ}C$) for 3 hrs, whereas right sides were conventionally chilled(CC). ATP-related compounds tested were adenosine triphosphate(ATP) and its derivatives in pork muscle, inosine monophosphate(IMP), guanosine monophosphate(GMP) and L-glutamate in cooked broth. DC sides showed more rapid pH decline and degradation of nucleotides than did CC sides. The levels of ATP and adenosine monophosphate(AMP) were not changed significantly. However, adenosine diphosphate(ADP) and IMP showed the highest levels at the 1st and 5th day, respectively. Hypoxanthine(Hx) was gradually increased(p<0.05) during aging. During aging, the IMP contents cooked broth tended to decrease, while the GMP and L-glutamate contents increase. As a result of these, the taste score got better and finally the results of sensory evaluation became increased(p<0.05). However, compared to CC sides, DC sides did not seem to lower taste of pork.

• The Korean Journal of Food And Nutrition
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• v.9 no.4
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• pp.398-403
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• 1996

To produce low salt fermented anchovy by an accelerated method with Asp. oryzae and Bacillus sp. koji and taste properties after the 60 day fermentation were examined. The main free amino acids of 60 day fermented anchovy paste were valine, isoleucine, proline, alanine, lysine, glutamic acid and aspartic acid. Total amount of free amino acids was the highest in non koji anchovy paste wit 2,624.76mg%. Among the koji added samples, Asp. oryzae koji added on was the highest in the amount o free amino acids. Hypoxanthine accounted for 84.14~95.4% of total nucleotides and their related compounds; Asp. oryzae koji added anchovy paste was the highest in nucleotides other related. Citric acid and lactic acid accounted for 94.9~96.7% of total non-volatile organic acids; Asp. oryzae koji added sample was the highest in non-volatile organic acids with 287.93mg%. The Hunter a and b values gradually increased during the fermentation, but the L value decreased until day 30 or 40 and increased steadily after that. The a and b values were higher in the use of Asp. oryzae koji than in Bccillus sp. koji, but the L value was to the contrary. The Asp. oryzae koji added anchovy paste was good in the aspect of color and taste compared to others. In the aspect of odor, the anchovy paste using the mixture of Asp. oryzae and Bacillus sp. koji was the best. Overall aceptability of sensory evaluation was higher in the mixture of Asp. oryzae and Bacillus sp. koji tan in the others.

• Korean Journal of Food Science and Technology
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• v.6 no.3
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• pp.177-184
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• 1974

File fish Navodon modestus was dehydrated in cabinet type hot-sir drier at $48-50^{\circ}C$ for 11 hours and also yellowfin puffer Fugu xanthopterum was dried in open air at $26-28^{\circ}C$ for 30 hours. Nucleotides and their related compounds were collected by extraction with cold perchloric acid and their amounts were determined by anion exchange column chromatography. The contents of ADP, IMP, ATP and hypoxanthine in fresh file fish muscle were 22.9, 12.1, 4.9, and 3.2 ${\mu}mole/g,$ dry wt. respectively. AMP and inosine were 0.9 ${\mu}mole/g,$ dry wt. equally. In fresh yellowfin puffer muscle, the contents of ADP, ATP, AMP, inosine and hypoxanthine were 25.6, 2.4, 1.6, 0.3, 0.6, and 0.4 ${\mu}mole/g,$ dry wt. respectively. In the case of file fish, ADP and ATP tended to degrade rapidly during hot-air dehydration. The contents of IMP were decreased slightly while AMP and inosine were increased. And another case of yellowfin puffer, ADP also tended to degrade rapidly during sun drying while AMP, IMP, inosine and hypoxanthine were increased. Especially, in both case of file fish and yellowfin puffer, inosine was increased twenty five and thirty five times during drying respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.7 no.2
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• pp.1-6
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• 1978

Changes of nucleotides and their related compounds during the fermentation of oyster were analyzed by high speed liquid chromatography. In raw oyster, dominant 5'-UMP was $26.1{\mu}mole/g$ and the content of uracil, hypoxanthine, 5'-GMP were 5.2, 3.8, 2.8 and $2.7{\mu}mole/g$ on moisture and salt free base, respectively. The content of cytosine, 2',3'-CMP, 5'-AMP and 2',3'-GMP were lower than $1.0{\mu}mole/g$ and guanine were detected in trace amount. 5'-UMP, uracil, hypoxanthine, 5'-IMP and 5'-GMP were abundant in both raw sample and fermented products. 5'-UMP and 5'-IMP were decreased slowly while 5'-AMP, 2'3'-CMP, cytosine and guanine were increased during the fermentation, and the increase of 5'-GMP and uracil were fluctuated. The content of hypoxanthine in raw oyster was increased to 3.1, 4.2 and 7.7 times of raw sample after 19, 36 and 68 days of fermentation, respectively.

• Applied Biological Chemistry
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• v.23 no.2
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• pp.89-105
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• 1980

Soysauce was made in the salt concentrations of 22.0% and 28.5%, and the changing aspects in nucleotides and their related compounds, free amino acids, free sugars and non-volatile amines which are related to the taste components during the fermentation process with a view to examining the taste components in the ordinary Korean soysauce were studied. And then artificial soysauce was prepared by applying the values derived from the analysis and measurement, and its sensory evaluation was performed. As the result of the sensory evaluation of artificial soysauce prepared according to the value of components analyzed from soysauce which had been fermented for fourty days in the salt concentration of 22.0%, it has been found that artificial soysauce was similar in taste to ordinary Korean soysauce. So, the following facts have been found: glutamic acid and aspartic acid have MSG-like taste, and IMP has a synergistic effect with these acids, which play great roles in ordinary Korean soysauce; both free sugars such as galactose and amino acids such as glycine, alanine and lysine have sweet taste; both amines such as tyramine and histamine, and amino acids such as valine, leucine, isoleucine, and phenylalanine have bitter taste; these components, combined with saline taste of salt and sour taste of organic acids, are assumed to form the unique taste in the ordinary Korean soysauce.

• Journal of Animal Science and Technology
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• v.65 no.6
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• pp.1151-1168
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• 2023

Tenderness and taste characteristics of meat are the key determinants of the meat choices of consumers. This review summarizes the contemporary research on the molecular mechanisms by which postmortem aging of meat improves the tenderness and taste characteristics. The fundamental mechanism by which postmortem aging improves the tenderness of meat involves the operation of the calpain system due to apoptosis, resulting in proteolytic enzyme-induced degradation of cytoskeletal myofibrillar proteins. The improvement of taste characteristics by postmortem aging is mainly explained by the increase in the content of taste-related peptides, free amino acids, and nucleotides produced by increased hydrolysis activity. This review improves our understanding of the published research on tenderness and taste characteristics of meat and provides insights to improve these attributes of meat through postmortem aging.

• Korean Journal of Food Science and Technology
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• v.15 no.1
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• pp.1-5
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• 1983

Large quantities of an ascidian, Styela plicata, are harvested annually as the by-product of oyster culture on the south coastal area in Korea. It has been traditionally favored and consumed because of its peculiar taste and flavor. But no study on its taste compounds has been reported. An investigation on the taste compounds of fresh meat and integument of an ascidian has been carried out by a series of analysis of taste compounds including nucleotides, free amino acids, betaine, TMAO, TMA and total creatinine. The most abundant nucleotides in fresh meat were AMP and IMP. Their contents were $1.2\;and\;0.8{\mu}mole/g$, respectively. The contents of nucleotides and their related compounds in integument show similar tendency as in fresh meat but their quantities were very low as compared with those in fresh meat. Seventy two percentage of the total free amino acids in fresh meat was consisted of proline, alanine, glutamic acid, glycine and serine. They occupied also 82% of the total free amino acids in integument, but the amount of free amino acids in integument was about 1/10 of that in fresh meat. The contents of betaine-N and creatinine-N were 6.1 and 2.1% of the extractive-N in fresh meat, respectively. The amounts of TMAO-N and TMA-N were very low contents in fresh meat and trace in integument.