• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.4
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• pp.342-348
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• 1990

Effects of various monosodium glutamate(MSG_ concentration (0-400mg%) on the quality of Korean cabbage kimchi during fermentation at 2$0^{\circ}C$ were investigated. The growth of lactic acid bacteria titratable acidity pH content of thiamine ascorbic acid $\beta$-carotene and sensory evaluation were observed in the presencve of MSG. Titratable acidity was increased in the kimchi contained MSG during the fermentation.l Wheeas the changes of pH in the kimchi contained MSG were similar to those in control, Maximum growth of lactic acid bacteria was observed after 49 hour of fermentation in kimchi contained with 200mg MSG. The might be due to the fact that MSG was given optimum pH for acid bacteria growth because of its buffering action. Therefore the periods of kimchi fermentation were reduced by addition of MSG, MSG also affected on the stability of ascorbic acid thiamine and $\beta$-carotene. According of MSG. MSG also affected on the stability of ascorbic acid thiamine and $\beta$-carotene. According to sensory evaluation MSG reduced sour taste in kimchi which increased edible periods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.3
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• pp.529-534
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• 1996

Using cystine, ascorbic acid and citric acid, retarding and synergistic effect on the browning reaction of onion juice concentrate was evaluated. Cysteine retarded the browning reaction most effectively followed by citric acid ; on the contrary, ascorbic acid accelerated rather than retarded the reaction at the concentration of 0.1%. The retarding effect of cysteine increased abruptly up to concentration of 0.3% and remained unchanged. Citric acid acted more effectively than ascorbic acid in terms of synergism. The browning reaction of onion juice concentrate exhibited activation energies of 62J/mol with cysteine and citric acid as compared to 73J/mol for control. $Q_{10}$ was determined to be 2.52 and 2.38 for control, 2.2 and 2.09 for treatment in the temperature range of 30~4$0^{\circ}C$ and 40~5$0^{\circ}C$, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.3
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• pp.266-272
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• 1993

Some compounds including flavonoids were tested as scavenger of nitrite which is believed to participate in the formation of N-nitroso compound. Many were found to be potent scavengers and the most potent ones were ascorbic arid, potassium thiocyanate, chlorogenic acid, catechin, morin, luteolin, luteolin-7-glucoside, and naringenin. To evaluate the influence of the above compounds on the endogenous formation of N-nitroso compound, the amount of nitrosoproline (NPRO) was examined by co-incubation of nitrite, proline, and test compounds at various concentrations. The analysis of NPRO by High Performance Liquid Chromatography (HPLC) was newly developed. Most compounds except ascorbic acid and chlorogenic acid were found to be no effects or activatory effects on NPRO formation. From the results obtained, it was suggested that most flavonoids which are contained in our customary diets were not associated with the inhibition of NPRO formation.

• Korean journal of food and cookery science
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• v.23 no.4 s.100
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• pp.423-432
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• 2007

The purpose of this study was to investigate the seasonal variations in water, protein, lipid, ascorbic acid, and ${\beta}-carotene$ contents of 17 vegetables and 4 fruits that are available all the year round and frequently consumed by Koreans. The water contents of the fruits ranged from 83-89%, and the vegetables contained more water than the fruits. The apples and pears had more water in the spring and summer than in the fall and winter. The tangerines showed a high water content in the winter, whereas the strawberries contained more water in the fall. The vegetables also showed seasonal variations in water content. The protein contents of the fruits were lower than 1%; the cucumbers contained 0.1% protein, which was the lowest level, but spinach, lettuce, bean sprouts, sesame leaves, and mushrooms had more than 1% protein. The ascorbic acid and ${\beta}-carotene$ contents of the apples, pears, and tangerines were higher in the fall and winter than in the spring and summer. The vegetables, in general, contained more ascorbic acid than the fruits. The cabbage and radishes showed higher ascorbic acid contents in the fall and winter than in the spring and summer, indicating that vegetables as well as fruits are more nutritious during their harvest season. The zucchini, spinaches, and green peppers had higher ${\beta}-carotene$ contents in the winter than in the other seasons. The above results show that there were seasonal differences in the ascorbic acid and ${\beta}-carotene$ contents of the fruits and vegetables. In addition, the fruits and vegetables had a tendency to contain more ascorbic acid and ${\beta}-carotene$ in the season they were harvested. Therefore, we recommend the consumption of those fruits and vegetables during their harvest season.

• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.175-183
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• 1998

Yulmoo Mul-kimchi was prepared by fermentation of the mixture of 1 part of leafy radish and 2.75 parts of water. It is thought that during the kimchi fermentation both the biosynthesis and destruction of ascorbic acid occurred at the same time. So the ascorbic acid content in Kimchi broth was strongly influenced by the environment of the processing period. In the present studies, an attempt had been made to elucidate the effect of water quality on the content of ascorbic acid and the population change of microorganism during Mul-kimchi fermentation. Five kinds of water such as tap water, an underground water, one commercially available processed water, distilled water and triply distilled water were examined. Nevertheless there were no differences in the population of microorganism and the pattern of acid formation among the five different kind of waters, a large variation of ascorbic acid content was observed. The ascorbic acid content of Kimchi prepared with triply distilled water showed the highest of 7.2 mg% in contrast to 3.37 mg% in tap water kimchi, and 5.72 mg% in the kimchi using underground water which has relatively high concentration of Ca. These results suggested that pure water free of metal ions might prevent the destruction of ascorbic acid during the fermentation. The considerable amount of ascorbic acid in the Kimchi with underground water might be due to Ca ion in the water.

• The Korean Journal of Food And Nutrition
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• v.35 no.5
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• pp.353-358
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• 2022

To confirm the applicability of crab apple, the composition and content of amino acids and minerals with 'Fuji' apple were measured. Apple and crab apple were extracted with water, 70% and 100% ethanol, respectively. The contents of polyphenols, flavonoids, and ascorbic acid, antioxidant activities of these extracts were measured. The amino acid composition of apples comprised a total of 17 amino acids. The total amino acid contents of apple and crab apple were 2,050.45 mg/kg and 900.05 mg/kg, respectively. For minerals, the total mineral content of apple and crab apple were 489.14 mg%, 529.77 mg%, respectively. The contents of polyphenols, flavonoids, and ascorbic acid of apple and crab apple extracts were highest in 70% ethanol extracts. The content of polyphenols, the crab apple extract, showed a generally higher content than the apple extract. The content of flavonoids, apple and crab apple extracts revealed no difference between extracts. The content of ascorbic acid, apple extract showed a generally higher content than the crab apple extract, but there was no significant difference between extracts. In the case of DPPH and ABTS radical scavenging abilities, 70% ethanol extract showed the highest antioxidant activity, and crab apple showed higher activity than apple extracts.

• Journal of Nutrition and Health
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• v.10 no.1
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• pp.44-48
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• 1977

The purpose of this experiment was performed for ascorbic acid contents of market milk in Seoul city area during the period of two seasons from spring (April, 13 to 30) to summer (July, 5 to 16) 1976. The samples were collected into five groups (A,B,C.D and E) according to factory products of market milks. The results obtained were as follows : 1. On an average, the value in spring was significantly lower than in summer, that is $0.228{\pm}0.222\;and\;0.374{\pm}0.028\;mg/100ml,$ respectively. 2. The differences among the groups of each factory product showed highest in C,A group and lower in E, B and D group. Thus, there were statistically significant (p<0.01) among-them.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1071-1076
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• 1998

Threetypes of Korean traditional kimchi were prepared using green onion, leek or godulbaegi as raw materials and stored at 5oC and 20oC for 13 days. Changes in salt and ascorbic acid contents, pH and total acidity as well as the relationship of the decomposition of chlorophylls and the production of their derivatives were investigated. For the all kimchi samples tested, salt content was not significantly changed during storage at both temperatures, whereas pH and total acidity were decreased and increased, respectively. Especially their remarkable changes were shown at the third day of storage. Ascorbic acid content was remained at high level in the leek kimchi for the experimental period at both storage temperatures, meanwhile godulbaegi kimchi retained the least amount of ascorbic acid. Chlorophylls were decomposed to pheophytin and pheophorbide during storage at both storage temperatures, and this phenomenon was apparent at the third day of storage. Reduction of chlorophylls and increasements of its decomposed products such as pheophytin and pheophorbide were the least in leek kimchi and the greatest in godulbaegi kimchi during storage at both temperatures. These results indicate that decomposition of chlorophylls in kimchi and increasements of pheophytin and pheophorbide were closely related to the ascorbic acid content in kimchi.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.4
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• pp.773-779
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• 1999

This study was conducted to determine the changes in the contents of vitamin C and fermentation characteristics of kimchi on different Chinese cabbage variety(Koreangji Yureum: KY, Kalak Shin Il Ho: KS) and fermentation temperature(5oC, 15oC). Kimchi were fermented at 5oC and 15oC for 140 days and 25 days respectively. In all samples, total acidity increased, and the pH, total sugar and reducing sugar content decreased as the fermentation proceeded. Also, the number of lactic acid bacteria reached the maximum at the optimum fermenting stage. On the other hand, total ascorbic acid, dehydroascorbic acid and ascorbic acid from individual kimchi solid tissue significantly decreased with fermentation periods, however, increased kimchi liquid at the 7day in KS 15(kimchi prepared with Kalak Shin Il Ho at 15oC), KY 15(kimchi prepared with Korangji Yureum at 15oC) and at the 65day in KY 5(kimchi prepared with Korangji Yureum at 5oC) respectively. Therefore, different fermentation temperature as well as variety affected ascorbic acid contents and chemical characteristics of kimchi.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.49-56
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• 2000

The 2-O-$\alpha$-D-glucopyranosyl L-ascorbic acid (AA-2G) which was enzymatically glucosylated with the cyclodextrin glucanotransferase (CGTase) [EC 2.4.1.19] from Bacillus sp. JK-43 has been reported previously. The presnet experiments examined the optimal conditons for the productio of AA-2G from AA and soluble starch, and characterized the properties of the CGTase from Bacillus sp. JK-43. The reaction mixture for the maximal production of AA-2G was followings; 12% total substrate concentration, 1,400 usits/mL of CGTase and a mixing ratio of 2 : 3(g or AA : g of soluble starch). Under this condition, 1.76mM of AA-2G, which corresponded to 2.53% yield based on AA, was produced after incubation for 24hrs at 45$^{\circ}C$ (pH 5.5). The optimum pH and temperature for the CGTase activity were 6.0 and 45$^{\circ}C$, respectively. The enzyme was stable at pH 5.5 to 9.5, and at temperature up to 5$0^{\circ}C$. The thermostability of the enzyme could be enhanced up to 6$0^{\circ}C$ by the addition of 30mM CaCl2.