• Food Science of Animal Resources
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• v.20 no.1
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• pp.8-14
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• 2000

In order to examine physicochemical gelation behavior of ultra high temperature(UHT) pasteurized milk during storage at 4$^{\circ}C$ and 25$^{\circ}C$, pH, electrophoresis, alcohol test, sialic acid contents and free amino groups contents were biweekly determined. The pH of UHT pasteurized milk decreased with increasing storage time. Gelation of the UHT milk occured faster at 25$^{\circ}C$ than at 4$^{\circ}C$ with larger decreasing rate of pH. The alcohol test showed positive results at lower pH than 6.5, which could indicate the casein instability and beginning of gelation. The electrophoretic patterns showed a decrease in the concentrations of all caseins. Degradation of k-casein was faster in all cases, while $\alpha$-casein and $\beta$-casein were also extensively degraded later. The sialic acid contents of the samples increased gradually during storage, and the increasing rate was higher before gel formation. The free amino groups of the samples increased gradually during storage. The increasing rate of free amino groups was faster at 25$^{\circ}C$ than at 4$^{\circ}C$. The samples stored at 25$^{\circ}C$ gelled earlier than those stored at 25$^{\circ}C$, with corresponding increase of free amino groups. The residual proteolytic enzymes, which survived during the UHT heat treatments and were reactivated during storage, could be responsible for UHT pasteurized milk gelation during storage. It is assumed that proteolytic degradation of caseins followed by aggregation would be attributable to complicated reaction mechanism.

• Food Science and Preservation
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• v.7 no.3
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• pp.278-284
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• 2000

The chemical components in freeze dried Korean Gastrodia elata blume powder were analyzed. The proximate composition was composed of moisture(2.12%), crude protein (4.41%), crude fat(1.20%), crude ash(2.25%), crude fiber(4.60%) and N-free extract(85.15%). Free sugar was composed of glucose(1,314mg%), sucrose(1,081mg%) and fructose(869mg%). Total organic acid content was 2,095mg% and composed of succinic acid(1,238mg%), citric acid, malic acid, oxalic acid and fumaric acid in the order. Among the 11 fatty acids detected, linoleic acid was the most predominant one and unsaturated fatty acid was 80.55 area percent. 18 and 39 amino acids were detected from total and free amino acid, respectively. Arginine, asparagine, proline and sarcosine were the major components of free amino acid. The content of crude saponin and total phenol were 3,768mg% and 821mg%, respectively. Ascorbic acid(6.4mg%), vitamin B1(1.2mg%), vitamin B2(1.7mg%) and niacinamide(0.2m%) were detected as soluble vitamins of the powder. The content of vitamin A and vitamin E was 1.22mg% and 0.32%, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.5
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• pp.366-371
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• 2004

Powder and liquid products of the seasoned and smoked fish were manufactured with small-sized skipjack tuna (Euthynus pelamis) captured in the East Sea, Korea. The property changes of nucleotides and their related compounds, amino acid, and sensory attribute during storage were analyzed. IMP content was the highest among the nucleotides and their related compounds followed by inosine in both powder and liquid products. Nucleotides and their related compounds of the powder product increased slightly as storage period increased, while those of liquid product were constant. Glutamic acid $(15.6{\%})$, aspartic acid $(10.7{\%})$, and lysine $(9.3{\%})$ were major amino acids of the power product, while histidine $(36.2{\%})$ and taurine $(10.6{\%})$ were high in the liquid product. Free amino acid contents of liquid product increased during storage periods. There was no significant difference In the concentration of nucleotides and their related compounds, and composition of free amino acid between the products with/without liquid smoke. Aroma and acceptance were good in both products, while bitterness and sweetness were poor.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.4
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• pp.524-529
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• 2020

Recently, several mutant laver Pyropia yezoensis strains were developed. In this study, control laver Pyropia yezoensis and its mutant Py500G were compared for their amino acid contents and antioxidative activities. There was no significant difference of total amino acid contents between wild-type and mutant Py500G, but mutant had higher free amino acid contents than wild-type. Also, total phenolic content was higher in mutant Py500G. Phycoerythrin and phycocyanin contents were higher in wild-type. But, antixoidative activities were shown to be higher in mutant Py500G. These results will be useful for the development of new cultivar of Pyropia.

• Journal of Korean Society of Forest Science
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• v.6 no.1
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• pp.43-48
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• 1967

In the present experiment the amino acid composition in the pollen of Pinus taeda and Pinus rigida and methbolic changes of the composition occurring in germinating pollen were examined by the method of paper chromatography. The results obtained in this study are as follows. 1. The mature pollen of Pinus taeda and Pinus rigida contained 12.00%, 13.19% crude protein respectively and sixteen protein-constituting amino acids and three unknowns were detected on the chromatogram. 2. Main components of the protein-constituting amino acids were leucines, valine, alanine, glutamic acid and aspartic acid. 3. The free amino acids such as leucines, valine, tyrosine, alanine and glutamic acid increased evidently during germination of the pine pollen.

• 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 Ginseng Research
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• v.44 no.3
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• pp.424-434
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• 2020

Background: Amino acids are one of the major constituents in Panax ginseng, including neutral amino acid, acidic amino acid, and basic amino acid. However, whether these amino acids play a role in ginsenoside conversion during the steaming process has not yet been elucidated. Methods: In the present study, to elucidate the role of amino acids in ginsenoside transformation from fresh ginseng to red ginseng, an amino acids impregnation pretreatment was applied during the steaming process at 120℃. Acidic glutamic acid and basic arginine were used for the acid impregnation treatment during the root steaming. The ginsenosides contents, pH, browning intensity, and free amino acids contents in untreated and amino acid-treated P. ginseng samples were determined. Results: After 2 h of steaming, the concentration of less polar ginsenosides in glutamic acid-treated P. ginseng was significantly higher than that in untreated P. ginseng during the steaming process. However, the less polar ginsenosides in arginine-treated P. ginseng increased slightly. Meanwhile, free amino acids contents in fresh P. ginseng, glutamic acid-treated P. ginseng, and arginine-treated P. ginseng significantly decreased during steaming from 0 to 2h. The pH also decreased in P. ginseng samples at high temperatures. The pH decrease in red ginseng was closely related to the decrease in basic amino acids levels during the steaming process. Conclusion: Amino acids can remarkably affect the acidity of P. ginseng sample by altering the pH value. They were the main influential factors for the ginsenoside transformation. These results are useful in elucidating why and how steaming induces the structural change of ginsenoside inP. ginseng and also provides an effective and green approach to regulate the ginsenoside conversion using amino acids during the steaming process.

• Food Science and Preservation
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• v.7 no.1
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• pp.108-112
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• 2000

Proximate composition , volatile compounds, free amino acids, fatty acids and inorganic compounds in leaf, stem and root of Houttyunia cordata Thunb cultivated from two different area, Bosung and Sunchon , were analyzed. Each part of Houttuynia cordata Thunb from both local area showed moisture contents of 80-84% and crude ash contents of 2.1 ∼2.8%. Crude fat and protein contents were less than 3 % showing slightly higher contents in leaf than in both stem and root . Twenty six volatile compunds were identified from the parts of the plant, the volatile contents were high in the oder of leaf, root and stem. Major volatile compounds were mostly derivatives of decanoic acid ; decanoic acid, 20 tridecanoie, decanal and dodecanoic acid. Of free amino acids in leaf asparagine was the highest, while in stem hydroxyproline, proline and arginine were the major free amino acids. Linoleic acid was the highest in the stem and root, and linolenic acid was highest in leaf. the major minerals of all parts were K, Ca. Mg, P, Fe, Zn and Cu, showing highest with K.

• Food Science and Preservation
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• v.10 no.1
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• pp.65-69
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• 2003

This paper was performed to analyze the nutritional components for the basic of studies to estimate the nutritional and functional valuation of mushroom(Sarcodon aspratus) The contents of moisture, ash, crude protein, crude fat and carbohydrate in mushroom were 89.93, 1.18, 3.67. 0.96 and 4.26%, respectively. The major free sugar were glucose, sucrose, trehalose, xylose, and cantained more trehalose than other sugars. The total content of amino acids was 796.85mg/100g-fr.wt. And the contents of essential and non-essential amino acid of hydrolyzed amino acid was 300.77 and 486.08mg/100g-fr.wt, respectively. Mushroom contained mush valine, leucine, threonine, Iysine, alanine, glycine, aspartic acid, and glutamic acid. The contents of essential and non-essential amino acid of free amino acid was 124.95, 138.52mg/100g-fr.wt., respectively. and were cantained mush methionine, Iysine, valine arginine, Aspartic arid, and tyrosine. The content of Amino acid derivatives 46.81 mg/100g-fr.wt., and were contained mush mornithine, sarcosine, ${\beta}$-alanine, and phosphoserine. The content of vitamin C was 5.43 mg/100g-fr.wt. The contents of sodium and potassium were 375.73, 61.82mg/100g, respectively.

• Food Science of Animal Resources
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• v.18 no.1
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• pp.57-62
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• 1998

Changes of palatability traits such as color texture free amino acid and nucleotide-related compound of mold fermented sausages during ripening were investigated. The a-value of mold fermented sausages rapidly increased up to 7th days if ripening. The hardness of mold fermented sausages rapidly increased while springiness and cohesiveness slightly decreased during ripening. Total free amino acid of mold fermented sausages gradually increased during ripening. Contents of nucleotide-related compounds such as ATP, ADP, AMP and IMP of mold fermented sausages rapidly decreased during ripening.