• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.9
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• pp.1560-1565
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• 2004

There are about 50 kinds of salted and fermented fish in Korea, and they have been used as a necessity for the preparation of kimchi. There is next to nothing for the studies of finding out the cause of N-nitrosamine formation by using the salted and fermented anchovies. In order to predict the possibility of N-nitrosamine formation and mutagenicity from gastric digestion of Korean Jeotkal, correlation of N-nitrosodimethylamine (NDMA) and mutagenicity of the salted and fermented anchovy under simulated gastric digestion was investigated through mixture system of nitrate, thiocyanate, formaldehyde and ascorbic acid to the anchovy product aged at room temperature (18~20$^{\circ}C$) for 60 days. NDMA formation of fermented anchovy under simulated gastric digestion was accelerated by the increase of nitrate, thiocyanate and formaldehyde concentration and was inhibited by the addition of ascorbic acid as an inhibitor, showing that its inhibition rate was 71.3% at 4 mM as compared with control group. Mutagenicity in anchovy digest added with several level of nitrite, thiocyanate and formaldehyde was increased, while it was markedly decreased in addition of ascorbic acid.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.4
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• pp.563-569
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• 1995

Myrosinase from Korean cabbage(Bogdoli) was purified and its enzymatic properties were investigated. Myrosinase from the Korean cabbage was purified by DEAE Bio-Gel Sepharose, Concanavalin-A, and Mono-Q column chromatography and exhibited a 55KD molecular weight with a single band on the gel of SDS-PAGE. The enzyme was purified about 21-fold compared to its crude enzyme and a specific activity of purified enzyme was 15, 120units/mg. Optimum pH of the myrosinase was 7.0 in both phosphate and Tris-HCl buffer solutions, the enzyme was stable at pH 6.5~7.0. Optimum temperature of enzyme was 37~38$^{\circ}C$. The enzyme activity was significantly inhibited by Cu2+ and Hg2+, but enhanced by ascorbic acid, resulting in a maximum activity at 1mM ascorbic acid. Among the ascorbic acid analogues, dehydro-ascorbic acid did not affect, whereas others showed a little effect on the enzyme activity, but less than ascorbic acid itself. Reducing agents such as 2-mercaptoethanol and dithiothreitol had no effect on the enzyme activity, but the enzyme activity was enhanced when 2-mercaptoethanol was mixed with ascorbic acid.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.11
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• pp.1705-1709
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• 2010

Peppers (Capsicum annuum L.) are a rich source of phytochemicals including polyphenolics, flavonoids, capsaicinoids and ascorbic acid. Capsaicinoids are a group of 12 or more related alkaloids responsible for the pungent sensation in the fruits of the genus Capsicum. Ascorbic acid is another functional and nutritional constituent of peppers. In this study, the contents of two major capsaicinoids (capsaicin and dihydrocapsaicin) and ascorbic acid in 131 pepper breeding lines were quantified by HPLC. In 131 pepper breeding lines, capsaicin and dihydrocapsaicin contents were in the range of 0.0 to 219.6 and 0.0 to 110.8 mg/100 g, respectively. The breeding lines with higher capsaicin content contained higher dihydrocapsaicin content as well. Ascorbic acid contents were 264.9 to 1695.5 mg/100 g for the 131 pepper breeding lines. The analytical method validation parameters including accuracy, repeatability, and reproducibility were calculated to ensure the method's validity. This study provides basic information to plant breeders and biotechnologists who are planning to breed genotypes with high content of phytochemicals.

• Journal of Nutrition and Health
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• v.12 no.4
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• pp.29-42
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• 1979

In order to observe metabolic effects of an oral conceptive, Norinyle, on female Guinea pig, the changes of ascorbic acid amount and alkaline phosphatase activity in the liver and serum were determined, and histochemical changes of the uterus were observed by microscopic and electronmicroscopic methods by administration of Norinyle with or without ascorbic acid. The results obtained are summerized as follows: 1) The metabolic changes were clearly influenced by the administration of Norinyle alone, but the changes were diminshed by administration of Norinyle with ascorbic acid. 2) The adimnistration of Norinyle influenced to increases the requirment of ascorbic acid in the liver. 3) The uterus weight of the Norinyle administered group was much increased, while the weight was less increased in the group of administered Norinyle with ascorbic acid than the control. 4) The Norinyle administration was brought about an atrophy of endometrium, of uterus especially, functional layer, that the formation of glands were inadequately and the fromation of basal layer and stroma were diminished. 5) An acute infarction on the all layers of the uterus was developed at 9th and 25th days of Norinyle administration and 20th day of Norinyle with ascorbic acid administration. 6) A hypertrophy of stromal and endovascular cells were observed on the groups administered of Norinyle alone(group II ) or Norinyle with ascorbic acid(group IV). 7) It was observed that amount of collagen fiber in the basal and muscular layeres of uterus were diminished under a microscopical observation by the special stained specimen on the Norinyle administered group, but the amount and distribution of reticulin fiber were not changed significantly. 8) The fille structure of outer functional layer of the uterus were significantly changed by administration of Norinyle which were shown irregurarity of nuclear membrane, poor development ana significant expansion of enaoplasmic reticulum, decreases of the amount of ribosome due to slip off, increases of the number of dense bodies, obvious formation of vaccule, an4 decreases the amount of collagen in inner and outer layer of the stroma. 9) The amount of ascorbic acid in the serum did not much changed but the amount in the liver was much decreased by the administration of Norinyle, And the administration of Norinyle with ascorbic acid induced for a significant diminishing on the changes of uterus which might be able to developed by the administration of Norinyle alone.

• Archives of Pharmacal Research
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• v.12 no.1
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• pp.26-33
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• 1989

Nineteen flavonoids, five phenolics, two coumarins, maltol and L-ascorbic acid were tested as scavenger of nitrite which is believed to participate in the formation of N-nitroso compounds. Many were found to be potent scavenger and the five most potent ones were (+)-catechin, (-)-epicatechin, phloroglucinol, caffeic acid and L-ascorbic acid. The nitrite scavenging effect was higher at pH 1.2 than pH 3.0 and increased when the incubation time was longer. The possible relationship of structures to scavenging effect of the flavonoids tested was discussed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.586-592
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• 2005

This study was peformed to investigate the synergistic effects of catechin and ascorbic acid on antioxidative activities of methanol and hexane extracts (500 ppm) from rosemary, sage, oregano, and ginger. Ascorbic acid (200 ppm) and (-)-catechin (200 ppm) could be solubilized in a rice bran oil via a reverse micelles using small amount of water and dioctyl sulfosuccinate as the sufactant. Methanol extracts from rosemary, sage, oregano, and ginger showed the synergistic effects by (-)-catechin. However, methanol extracts showed the synergistic effect by ascorbic acid except that of ginger. The synergistic effects of (-)-catechin on methanol extracts were higher than those of ascorbic acid. Hexane extracts of oregano and ginger showed the synergistic effects by (-)-catechin, and no synergistic effects by ascorbic acid. On the other hand, rosemary and sage showed the synergistic effects by ascorbic acid and no synergistic effects by (-)-catechin.

• Preventive Nutrition and Food Science
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• v.5 no.4
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• pp.205-212
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• 2000

The relation of food and supplemental intake of iron, vitamin E and ascorbic acid and other lifestyle variables to packed cell volume (PCV) and serum vitamin levels was studied in urban and rural (71% Amish) communities. Subjects were interviewed (24-h dietary recalls) on three occasions over 18-months, and blood samples were taken (maximum observations = 442). Mean PCV was lower in rural males (43.3) than in urban males (45.4) despite higher man food iron intake (18.7 and 14.4 mg/day, respectively). Mean meal iron availability was higher at lunch and lower at breakfast and dinner for rural than for urban subjects. Smoking was the number one variable in males and females explaining variance in PCV. Supplemental vitamin E and ascorbate intakes explained the most variance in serum vitamin E and ascorbate levels, respectively. Serum vitamin E was also associated with supplemental ascorbate intake (r=0.29). Serum ascorbate was also associated with food ascorbate intake (r=0.28) and body weight (r=-0.24).

• Preventive Nutrition and Food Science
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• v.3 no.3
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• pp.225-229
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• 1998

Formation of a L-Ascorbic Acid 2-O-$\alpha$-glucoside(AA-2G) is a chemically stable dervative of asocrbate that shows a vitamin C acitivity in vitro as well as in vivo. We studied whether ascorbic acid(AA) and AA-2G are formed in baechu kimchi during fermentation at 4 $^{\circ}C$ or 18$^{\circ}C$. To determine the formation of AA and AA-2G during fermentation of kimchi, wheat flour (as a carbhydrate source) added baechu kimchi (WBK) and control baechu kimchi(CBK) were prepared and fermented at 4 $^{\circ}C$ or 18 $^{\circ}C$. A substance like AA-2G was detected by HPLC from WBK fermented at 18 $^{\circ}C$ for 26 days in fall season and confirmed later to be the AA-2G showing distinctive characteristics of heat stability and resistance to ascrobate oxidase catalase. However, none of the kimchi formed AA-2G when the kimchi were fermented under a different temperature condition such as 4 $^{\circ}C$ instead of 18 $^{\circ}C$ or a different season such as summer instead of fall even if they were fermented at 18 $^{\circ}C$. The pH of kimchi was decreased rapidly during the first 3 days. and then decreased slowly after 4 days when the kimchi were fermented at 18 $^{\circ}C$. However, there were slight changes of pH in both CBK and WBK feremented at 4$^{\circ}C$ for 30 $^{\circ}C$ days. Therefore, the AA-2G -forming activity in kimchi seems to be correlated with the formentation temperature, the microorganisms involved in kimchi fermentation and a suitable glycosyl donor for AA as provided by wheat flour in this study.

• Journal of Nutrition and Health
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• v.29 no.9
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• pp.1042-1048
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• 1996

In order to investigate heating rate of commercial milk products in korean market, lactulose content and availability of calcium and ascorbic acid were measured. The pH range for raw and commercial milk was 6.5-6.75, and protein content was 2.5-3.13%. The acid degree value (。SH)showed between 5.3 and 7.1. There were no differences in pH, protein and acid degree among 3 types of milk. The portion ionic Ca content in UHT-milk(32.4%) and pasteurized milk (27%) increased significantly in comparison with raw milk (4.6%). Pasteurization led to loss of 20% ascorbic acid, and losses of UHT-treatment are approximately twice as high. Significant differences of lactulose content between UHT milk and pasteurized milk were observed. Some of UHT milk products showed very high value of lactulose content like sterilized milk. It is well known that the stress caused by indirect UHT treatment is slightly higher compared with the direct process. The results in this experiment suggested that most of UHT milk in korean market may be treated by indirect UHT method. In oder to keep the adventages of milk component, the heating methods of milk have to be reconsidered.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.2
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• pp.171-174
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• 1992

Effects of ascorbic acid and citric acid on pungency and color stabilities in the Horseradish powder during 16 weeks storage were investigated. When the ascorbic arid added 0.1 wt.%, the effect of allyl isothiocynate stability was very significant after 16 weeks storage at 37$^{\circ}C$. However, the effect of citric acid on the allyl isothiocyanate stability was not observed. The results also showed that ascorbic acid and citric arid did not affect the color stability of the Horseradish powder significantly. When the Horseradish powder was tempered with water, the effect of ascorbic acid on stability of allyl isothiocynate and color value was shown.