• Journal of Nutrition and Health
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• v.18 no.4
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• pp.312-317
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• 1985

This study was attempted to investigate the occurrence and the characteristics of ascorbic oxidase in cucumbers. Ascorbic acid oxidase was isolated from cucumbers and concentrated using ammonium sulfate precipitation. The results of this study are as follows ; 1) Ascorbic acid oxidase activity was detected in whole cucumber homogenate. 2) Highest amounts of ascorbic acid destroyed after 10 minutes' incubation of ascorbic acid oxidase with its substrate. 3) The optimum pH and temperature of this enzyme were found to be pH 6.5 and $40^{\circ}C$, respectively. 4) Ascorbic acid content in cucumber juice prepared using the cold water $(4^{\circ}C)$ was higher than that made with water at $30^{\circ}C$. 5) When orange juice ( pH 3.4 )was added, ascorbic acid destruction was completely ceased. (The ascorbic acid oxidase was inactivated at pH 3.9) Decreasing the temperature and pH are recommended to achieve maximum stability of ascorbic acid in preparing cucumber juice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.853-858
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• 2010

The purpose of the study was to determine fat contents and fatty acid compositions of the lipids in sweetfish cultured in Korea and lipid oxidation during storage at refrigeration temperature ($2^{\circ}C$). Whole or minced sweetfish were vacuum-packaged or treated with ascorbic acid. Changes in thiobarbituric acid (TBA) values, peroxide values (PV) and free fatty acid (FFA) in the fish were determined. Sweetfish contained 72.5% moisture, 5.3% lipid and 1.1% ash. Palmitic acid was the highest (27.4% (w/w) of the total fatty acids) among the saturated fatty acids. Total monounsaturated fatty acids (MUFA) were 33.9% and oleic acid (21.0%) was the highest, followed by palmitoleic acid (7.8%). Total PUFA were 28.2%. Predominant PUFA were linoleic acid (8.1%), EPA (5.7%) and DHA (12.1%). TBA values and PV of the whole sweetfish treated with ascorbic acid and vacuumpackaged were not different from the control. TBA values of the minced sweetfish treated with ascorbic acid were significantly lower than the other groups (p<0.05). PV of the fish treated with ascorbic acid and vacuum packaging were significantly lower than the other groups (p<0.05). The result of this study suggests that cultured Korean sweetfish may be a good source of unsaturated fatty acids including EPA and DHA, and vacuum packaging and addition of ascorbic acid may protect lipids from oxidation.

• Journal of the Korean Society of Food Culture
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• v.28 no.3
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• pp.293-302
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• 2013

We investigated treatments for the browning prevention of black carrot extracts and determined the characteristics and qualities of jelly supplemented with black carrot extract. Ascorbic acid, citric acid, and NaCl were added to black carrot extract and changes in color, texture, and anthocyanin content were evaluated. Changes were also determined and a sensory evaluation was performed for jelly supplemented with black carrot extract. The addition of 0.15 and 0.20% ascorbic acid prevented the browning of black carrot extracts and decreased anthocyanin content during the storage period. However, citric acid did not have a preventative effect, despite decreasing the pH below 5.0. Similar to results on the extract, 0.15% ascorbic acid maintained a reddish-violet color in jelly supplemented with black carrot extract by lowering browning during the storage period. Jelly supplemented with 0.15% ascorbic acid had an increased elasticity, gumminess, and chewiness, but jelly supplemented with 0.15% ascorbic acid+0.05% NaCl had a lowered hardness compared with the control during the storage period. In a sensory evaluation, the overall preference, in descending order, was: 0.15% ascorbic acid+0.05% NaCl > 0.15% ascorbic acid > control. In conclusion, 0.15~0.20% ascorbic acid prevented the browning of black carrot extract and inhibited a decrease in anthocyanin content. Jelly supplemented with black carrot extract and 0.15% ascorbic acid+0.05% NaCl were optimal for producing a soft jelly texture.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.37-40
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• 1996

Kinchi is and important source of various vitamins, minerals, dietary fiber, organic acids and other nutrients. In order to get a basic information for developing vitamins-rich funtional kimchi, we investigated microorganisms which are capable of synthesis of vitamin C in Kimchi system. Microorganisms isolated from aliquots of kimchi were screened and cultured by using MRS or nutrient agar medium. L-Ascorbic acid produced by microorganism in medium was measured with high performance liquid chromatography. As the result, we isolated two bacteria strins N7 and N5202 preducing L-ascorbic acid from the kimchi system. Morphological and Gram staining experiment showed that N7 was Gram positive bacilli, while N5202 was Gram negative. There were also several bacteria that were considered to synthesizs erythorbic acid which is an analog of ascorbic acid. These results suggested that vitamin C-rich functional food could be developed by using the kimchi microorganisms.

• Food Science and Biotechnology
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• v.17 no.4
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• pp.883-887
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• 2008

The purpose of this study was to develop a new preparation process for chemical transformation of ginseng saponin glycosides to prosapogenins. Ginseng and ginseng extracts were processed under several treatment conditions using ascorbic acid solution. Treating with ascorbic acid at pH 2-3 and above $80^{\circ}C$ increased the ginsenoside $Rg_3$ content of samples to over 3% as compared to other pH levels and temperatures. In addition, ginseng and ginseng extracts that were processed under a high ascorbic acid solution treatment condition (pH 2.0, 5 hr) contained more ginsenoside $Rg_3$ (approximately 16 times) than those processed under a low ascorbic acid solution treatment condition (pH 3.0, 5 hr). The highest quantity of ginsenoside $Rg_3$ (3.434%) occurred when a sample of fine ginseng root extract (AG2-9) was processed with the ascorbic acid solution at pH 2.0 for 9 hr. However, there was no change in the amount of ginsenoside $Rg_3$ when fine ginseng root extracts were processed with ascorbic acid solution at pH 2.0 for over 9 hr. In conclusion, the results indicated that ascorbic acid treatment of ginseng extracts can produce a level of ginsenoside $Rg_3$ that is over 90-fold the amount found in commercial red ginseng.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1086-1093
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• 1998

The antimicrobial effect of mixed solutions of grapefruit seed extract(250ppm) and ascorbic acid(1%) on the spoilage microorganisms such as Staphylococcus epidermis, Escherichia coli, Pseudomonas syringae, Candida albicans and Corynebacterium xerosis isolated from the spoiled soybean sprouts were investigated. Cell wall and membrane were partially destroyed and the contents of the destroyed cell were exuded after treatment. Packages with 30 m cast polypropylene(CPP), 16 m polyolefin(RD 106) and 10 m high density polyethylene(HDPE) were applied for soybean sprouts dipped in mixed solutions respectively. Oxygen and carbon dioxide concentration inside packages were dependent on the kind of films during storage at 5oC. The antimicrobial activity of mixed solutions was maintained for 5 days at CPP package. Package with HDPE showed a severe browning than the others after 5 days. Ascorbic acid content of mixed solution treatment was higher than that of control for each package.

• Journal of Nutrition and Health
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• v.22 no.3
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• pp.159-166
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• 1989

The effect of blanching time and power settings of microwave oven on the ascorbic acid retention in seven kinds of vegetables were investigated. The vegetable were blanched for 120 or 180 sec. at three different power setting, 650 watt(high power), 500 watt(medium power) and 160 watt(low power). The retentions of ascorbic acid in cabbage, garland chrysanthemum, mungbean sprout, amaranth and carrot were higher when they were blanched at the high power than those blanced at the lower power stettings. Blanching of spinach and yul-moo(small korean radish) showed that the vitamin was more retained by the medium power heating. Blanching at the low power revealed that the ascorbic acid retention was reduced remarkably as the blanching time increased. From the scoring difference tests the 10-panel members indicated that the texture of three-tested vegetables was more acceptable when they were blanched at the high power setting.

• Journal of Nutrition and Health
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• v.7 no.1
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• pp.37-43
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• 1974

The L-ascorbic acid, when various kinds of flavoring and spices were added to it's solution individually or in combination, was determined by the 2,4-Dinitrophenylhydrazine method. The remaining rate of it in the solution, to which such spices and flavoring as vinegar, sugar, salt, glutamic acid-Na, welshonion, garlic, sesame, rice jelly, soy, pimento, hotbean paste, pepper, ginger and cinnamon were added individually, was higher than in the solution of itself alone. In the case of pinenuts, sesame oil and, bean paste, however, the remained total ascorbic acid was of little quantity, The rate of it's autooxidation in the solution added with fennel, cinnamon, ginger, pepper, bean paste, pinenuts, curry in individual were found high, but relatively low in garlic, sesame oil, glutamicacid-Na, sugar, honey, salt, pickled shrimps, hot bean paste, and soy. When combined spices and flavoring were added, the content of ascorbic acid showed high values in all cases, indicating that particularly high in soy-bean sprout namul, chinese radish namul, and muchim, seasoned with the most frequently used flavoring, No. 7,8,9,10 while low values in the combination of mustard muchim.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.792-798
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• 2000

The objectives of this study were to reduce the characteristic dark color of Korean wheat flour noodles. Several additives were tested to reduce dark color of wheat flour dough and 2% ascorbic acid and 0.05% cysteine were selected as additives to Korean wheat flour noodle. Comparative study was performed between commercial imported wheat flour noodle and Korean wheat noodle with two additives to investigate the color, mechanical and sensory properties of noodles. Addition of 2% ascorbic acid increased the brightness of raw and dried Korean wheat flour noodles and 0.05% cysteine was the most effective in improving the brightness for cooked wheat flour noodles. Mechanical properties of cooked Korean wheat flour noodles with 2% ascorbic acid and 0.05% cysteine were similar to that of the imported wheat flour noodles. However, sensory evaluation test showed Korean wheat flour noodles with 2% ascorbic acid had the darkest yellowish-red color, the strongest aftertaste and the lowest overall quality. Therefore, the addition of cysteine was the most effective in mechanical and sensory attributes as well as discoloration of cooked wheat flour noodles.

• Journal of Nutrition and Health
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• v.13 no.4
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• pp.195-198
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• 1980

The contents of ascorbic acid in milk and fermented milk, yogurt added with fruits were determined by 2.6-dichlorophenol indophenol method using a Spectrophotometer. Threes sample of fruit milks and three of fruit yogurts were collected from the several markets in Busan City. The amounts of the vitamin as the reduced form were 0.16 mg/100m1 of strawberry milk, 0.31mg/100m1 of orange milk, and 0.08mg/100m1 of banana milk. The vitamin was not detected from the fermented fruit yogurt samples.