• Journal of the Korean Applied Science and Technology
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• v.28 no.4
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• pp.517-525
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• 2011

Squid ink was added to the low salt fermented squid by 4% of concentration and ripened at $10^{\circ}C$ for 6 weeks and at $20^{\circ}C$ for 28 days. The effect of the squid ink on the titrable acidity and free amino acids of low salt fermented squid were investigated. The results are as follows; The titrable acidity in the salt fermented squid without addition of the squid ink was continuously decreased except for the salt fermented squid with 9% salt content till the latter stage of the ripening, had larger decreasing range than treatment groups. Seeing the composition of free amino acid, the major amino acids are proline, arginine, glutamic acid. leucine and glycine.

• Journal of Nutrition and Health
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• v.15 no.1
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• pp.22-29
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• 1982

As sugar and amino acid were added to the ascorbic acid solution the content of ascorbic acid was quantitatively determined by 2, 4-dinitrophenyl hydrazine method. The residual ascorbic acid was shown to increase slightly when sorbose, rhamnose or mannose was added to the ascorbic acid solution whereas residual ascorbic acid was shown to decrease in time to the addition of other sugars. The effects of amino acid to the ascorbic acid solution were found that monoamino-mono, or dicarboxylic acids and aromatic amino acids increased the residual ascorbic acidity whereas diamino-monocarboxylic acids and sulfur containing amino acids decreased the residual ascorbic acidity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.8
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• pp.1204-1210
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• 2013

Various commercial vinegars of high-strength acidity (10% or more of total acidity) were investigated to compare their physicochemical and antioxidant properties. The total acidity of double-strength vinegars was relatively lower than triple-strength vinegars. Irrespective of the acidity, sugar and reducing sugar content ranged from $7.00{\sim}10.80^{\circ}Bx$ and 1.32~3,885.90 mg%, respectively. Free sugars were mainly composed of fructose and glucose, and were relatively high in double-strength vinegars. The content of acetic acid (a principal organic acid in vinegars) increased with acidity, but oxalic acid was not identified in commercial high-strength acidity vinegars. Double-strength vinegars using malt extracts were the highest in free amino acid content, showing 24 kinds of amino acids. The content of total phenolics and flavonoids was highest in apple vinegars of double-strength acidity, which affected the scavenging ability of DPPH and ABTS radicals. Overall, the quality of high-strength acidity vinegars was affected by its content and production methods, and double-strength acidity vinegar using apples showed the best antioxidant activities.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.418-424
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• 2014

High-acidity vinegar was manufactured using pear concentrate by fed-batch fermentation without additional nutrients, and the physicochemical properties and volatile components were investigated at different fermentation stages (Stages 1-4) and at various initial alcohol concentrations (IAC; 6-9%). The levels of reducing sugar, free amino acids, total phenolic content, total flavonoid content, and radical scavenging ability increased slightly during Stage 4 (high-acidity vinegar), which was affected by alcohol feeding. The contents of approximately 20 types of volatile compounds differed between the moderate- and high-acidity vinegar samples, as determined by solid-phase microextraction/gas chromatography-mass spectroscopy. The level of acetic acid in high-acidity vinegar increased according to the initial alcoholic content applied. The high-acidity vinegar produced by fed-batch culture at an IAC of 6-7% showed improved physicochemical and volatile properties as compared to the moderate-acidity vinegar.

• The Korean Journal of Food And Nutrition
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• v.8 no.1
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• pp.6-12
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• 1995

The purpose of this study was to examine the aptitude of wheat flour-Nuluks, for Takju brewing, which were made with Aspergillus oryzae, Rhizopus japonicus or Aspergillus usamii mut. Shirousamii, and to know the way of effective use the Aspergillus oryzae-Nuluk showed high saccharogenic activity, and Rhizopus japonicus-Nuluk high proteolytic activity. When these two Nuluks were combined, the activities of saccharogenic amylase and protease were more balanced. The Takju mash of Aspergillus oryzae-Nuluk was high in acidity and in amino acidity, and that of Rhizopus japonicus-Nuluk high in the content of free sugar, but, that of Aspergillus usamii mut. Shirousamii-Nuluk was low in amino acidity, free sugar and ethanol content. The Takju of Rhizopus japonicus-Nuluk was high in the content of suspended solid and slow in its sedimenting rate, but that of Aspergillus usamii mut. Shirousamii-Nuluk was not. The Takju which was made with combined use of Aspergillus oryzae-Nuluk and Rhizopus japonicus-Nuluk was more balanced in the composition of flavoring ingredients, and was slow in sedimenting rate of suspended solid. Moreover, it gained good result in sunsory evaluation test.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.4
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• pp.207-212
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• 1970

The fellowing results are obtained by experiment on the variation of enzyme activity during pickling anchovy (Engraulis japenicus) in vinegar. 1) Protease activity increased during brine-salting. It decreased for a short time by tile addition of acetic acid and gradually changed at an invariable ratio during pickling. 2) Lipase activity decreased during brine salting but increased temporarily by the addition of vinegar, after this no fixed tendency could he observed during pickling whereas acid value abviously increased. 3) VBN (Volatile basic nitrogen) and NaCl content quickly increased during brine salting. During pickling VBN increased slowly while NaCl content scarcely varied. 4) The bacterial plate count decreased suddenly when the anchovy were placed in brine but it increased during brine salting and decreased again when anchovy were pickled and the number of count remained the same thereafter. 5) To maintain preservation effects, the acidity of the vinegar must be maintained more than $2\%$ in the muscle. 6) Based on this experimental condition, it transpires that 8 days of immersion In brine produces sufficient salt concentration in the muscles. From the results of VBN, acidity, amino nitrogen, lipase activity, and organoleptic tests, the quality of pickle was still preserved after 47 days and taste of the pickle seemed best on the thirty second day of the storage.

• Korean Journal of Plant Resources
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• v.11 no.1
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• pp.111-117
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• 1998

The effect of chitosan on physicochemical and organoleptic properties of Nabak kimchi was studied during fermentation at 2$0^{\circ}C$ . Viscosity of the juice of Nabak kimchi added with chitosan was lower than that of control group. The viscosity was gradually increased during storage period, especially from 5 days to ,7 days of storage. Initial pH was higher in control group than inchitosan groups. The pH of controlgroup decreased rapidly during 4 days of storage. The pH of chitosan groups was slightly increased during the first 3 days of storage and decreased thereafter. Acidity was rapidly increased from 3 to 5 days. Reducing sugar contents increased up to 3 days and decreased thereafter. Acidity was rapidly increased from 3 to 5 days. Reducing sugar contents increased upto 3 days and decreased therafter. Glutamic acid, alanine, threonine, aspartic acid, proline and valine were the major free amino acids, and as the fermentation preceeded they were increased gradually. There were signigicant differences in saltiness, sourness and aged odor in sensory evaluation of Nabak kimchi solution during fermentation at 2$0^{\circ}C$.

• Food Science and Preservation
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• v.11 no.2
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• pp.240-245
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• 2004

Chungju(Sambaekju) supplemented with dried persimmon and cordyceps sinensis was prepared and its characteristics were estimated during the brewing. Reducing sugar contents was decreased, ethanol contents was increased in the during fermentation, the final ethanol contents in the first, second and third mash were 5.8%, 11.4% and 16.5%, respectively. Total acidity and amino acidity were increased in the during fermentation. The major organic acid was latic acid, acetic acid, malic acid and succinic acid were a little, and citric acid and tartaric acid were not detected. L-proline(1151.7 mg%) was major in free amino acid. the contents of total and essential amino acid were 11.19% and 217.70 ppm, respectively.

• Preventive Nutrition and Food Science
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• v.7 no.4
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• pp.411-416
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• 2002

The effects of electrodialysis (ED) alone or ED plus ultrafiltration (UF) on deacidification of mandarin orange juice were studied by using a commercial ED stack with ion exchange membranes. ED processing, reduced the total acidity of the juices by 30% (0.6~0.7% as total acidity) after 50 min and by about 60~70% (0.23~0.4% as total acidity) after 100 min, as compared to the control juice. However, the acidity reduction after 50 min of ED was determined to be suitable, when considering total acidity (0.6~0.7%, w/w) and current efficiency. There was no color change in the juices following ED, and the pH and Brix were only slightly decreased. Furthermore, ascorbic acid and citric acid concentrations showed only minor decreases, and amino-N, free sugar, and flavonoid contents remained almost unchanged. Therefore, we concluded that the nutritional integrity of the juice was maintained. ED combined with UF may be effective, not only in preventing membrane fouling, but also in preserving the nutrients, such as ascorbic acid, in citrus juice.

• Korean Journal of Food Science and Technology
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• v.52 no.4
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• pp.415-422
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• 2020

This study was conducted to elucidate how rice with different milling degrees (DOM: 10, 20, 30, and 40%) affects rice yakju properties by accelerated aging. There were significant differences among the treatments with respect to the properties except for brownness before aging, which showed no correlation with DOM (p for trend>0.05). In contrast, the amino acidity and brownness significantly decreased after aging as DOM increased, lightness (L) in particular was affected in all the treatments regardless of DOM. Almost all treatments showed significant differences except for the pH and the total acid and alcohol content between before and after aging. Moreover, the amino acidity, brownness, redness (a), yellowness (b), and color difference in all the treatments showed significant differences regardless of DOM. We found a significant difference in the color change. The yakju free amino acid analysis showed that almost all amino acids slightly decreased as DOM increased.