• 한국식품영양과학회지
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• 제27권5호
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• pp.852-857
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• 1998

Three kinds of kimchi using Chinese cabbage, leafy radish and mustard leaf were prepared by conventional method and stored at 5$^{\circ}C$ or 2$0^{\circ}C$ for 13 dyas. During storage at both temperatures, changes of the amounts of salt and ascorbic acid, pH and total acidity were determined, and the relationship of the decomposition of chlorophylls with the production of their derivaties was studied. At both storage temperatures, salt concentration of Chinese cabbage kimchi(3.7%), leafy radish kimchi(3.6%), mustard leaf kimchi(3.5%) was relatively constant during the entire storage period. However, pH and total acidity wre fluctuating with the remarkable changes during 3 days of storage. Ascorbic acid content was slowly decreased during the storage period and the decompositin rate of ascorbic and was greater at 2$0^{\circ}C$ than 5$^{\circ}C$. Among the kinds of kimchi tested, mustard leaf kimchi with the slow decomposition rate of ascorbic acid contained relatively high ascorbic acid content, while leafy radish kimchi contained the lowest content. At both storage temperatures, the production of pheophytin and pheophorbide from decomposition of chlorophyll was least in mustard leaf kimchi, but similar production rates in leafy radish and Chinese cabbage kimchi were observed.

• 한국식품영양과학회지
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• 제26권2호
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• pp.261-269
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• 1997

수산식품 중 비교적 다량의 다불포화지방산과 함께 콜레스테롤을 함유하고 있는 고등어를 50일간 염장하면서 콜레스테롤 및 지질의 산화와 이들 산화에 미치는 아스코르빈산 및 BHA의 영향에 대해 조사하였다. 고등어의 염장 중 콜레스테롤은 계속 산화분해되어 대조군의 경우 50일간 염장한 후에는 23.3mg/kg으로 생시료 함량의 33%에 불과했으나 아스코르빈산 첨가군은 염장 $10{\sim}30$일 사이에 비교적 콜레스테롤의 감소가 억제되었으며 BHA는 특히 100, 200mg/kg첨가한 실험군이 영장 50일 후에도 각각 생시료 함량의 80%와 85%를 보유함으로써 항산화효력을 크게 발취하였다. 7-Ketocholesterol과 지질산화의 척도로 정량된 malonaldehyde의 함량변화는 대조군의 경우에는 비슷한 경향을 보였으나 항산화제의 첨가군에서는 제각기 다른 경향을 보였다. 즉, 7-ketocholesterol의 생성에 대해 아스코르빈산의 첨가는 염장 10일 이후로 계속 억제효과를 보였으나 BHA는 염장 초기부터 후기까지 항산화효과가 월등하였다. 한편 아스코르빈산 첨가군에서 malonaldehyde의 생성은 염장 $10{\sim}30$일 사이에만 대조군에 비해 약 40%가 억제되었으며 BHA 첨가군에서는 염장 초기부터 50일까지 억제효과가 뚜렷히 나타났다. 결론적으로 염장고등어에서 지질과 콜레스테롤의 산화는 동시에 일어났으며 본 실험에서 사용된 아스코르빈산과 BHA는 모두 이들 산화에 대해 염장 30일까지 뚜렷한 항산화 효력을 나타내었고 특히 BHA의 첨가가 더 유효했다.

• 한국영양학회:학술대회논문집
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• 한국영양학회 1996년도 추계학술대회 초록
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• pp.57-57
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• 1996

• 식품산업과 영양
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• 제5권2호
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• pp.65-69
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• 2000

• Nutrition Research and Practice
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• 제1권2호
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• pp.105-112
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• 2007

Ascorbic acid has been reported to extend replicative life span of human embryonic fibroblast (HEF). Since the detailed molecular mechanism of this phenomenon has not been investigated, we attempted to elucidate. Continuous treatment of HEF cells with ascorbic acid at ($200{\mu}M$) from 40 population doubling (PD) increased maximum PD numbers by 18% and lowered $SA-{\beta}-gal$ positive staining, an aging marker, by 2.3 folds, indicating that ascorbic acid extends replicative life span of HEF cells. Ascorbic acid treatment lowered DCFH by about 7 folds and Rho123 by about 70%, suggesting that ascorbic acid dramatically decreased ROS formation. Ascorbic acid also increased aconitase activity, a marker of mitochondrial aging, by 41%, indicating that ascorbic acid treatment restores age-related decline of mitochondrial function. Cell cycle analysis by flow cytometry revealed that ascorbic acid treatment decreased G1 population up to 12%. Further western blot analysis showed that ascorbic acid treatment decreased levels of p53, phospho-p53 at ser 15, and p21, indicating that ascorbic acid relieved senescence-related G1 arrest. Analysis of AP (apurinic/apyrimidinic) sites showed that ascorbic acid treatment decreased AP site formation by 35%. We also tested the effect of hydrogen peroxide treatment, as an additional oxidative stress. Continuous treatment of $20{\mu}M$ of hydrogen peroxide from PD 40 of HEF cells resulted in premature senescence due to increased ROS level, and increased AP sites. Taken together, the results suggest that ascorbic acid extends replicative life span of HEF cells by reducing mitochondrial and DNA damages through lowering cellular ROS.

• 대한가정학회지
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• 제4권1호
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• pp.589-594
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• 1963

Ascorbic acid has a strong power to reduce other materials, so by using this reducing power we can analise many materials quantitatively. Dihydro-ascorbic acid is quantitatively changed into ascorbic acid under a certain condition, if reduced by hydrogen-sulfide. Dihydro-ascorbic acid also has physiolosical effect, but less effect than ascorbic acid. The effect of dihydro-ascorbic acid is regarded as a half of that of ascorbic acid. Among the analytical methods applying this theory the method using 2.6 dichlorophenol indophenol what called the method of Indophenol is used most widely; so does Hydrazine-method. But comparing these two methods the former shows a little higher rate in analytical value. Vegetable are vital sources for vitamin C. According to the report of the commitee of FAO Korean branch the amount of daily per head average intake of vitamin C is about 70mg in raw materials. Since vitamin C is easily affected by heating or oxidation in Cooking the loss is not a little. Consequntly it is regarded that the actual amount of intake will be much less than basic amount. It is therefore very important to find out that how much percent of the loss there will be in case of cooking, in order to dicide the actual amount of in take as proper nutrition for a person. Therefore this paper intended to give some help in setting a standard amount of V.C intake, by measuring the change of the V.C amount using the general cooking method and by measuring amount of V.C contained in the part of vegetable, used in Korea abundantly.

• 한국식품영양과학회지
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• 제12권1호
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• pp.27-30
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• 1983

전촌(田村)가 개량(改良)한 DNP법(法)에 의(依)하여 녹차(錄茶)의 침출조건(浸出條件)에 따른 ascorbic acid용출량(溶出量)에 대(對)하여 검토(檢討)를 하였다. (1) 녹차(錄茶)는 양질(良質)의 것 일수록 ascorbic acid의 용출율(溶出率)이 높고 저온(低溫)에서도 잘 용출되었다. (2) 녹차(錄茶)는 물의 온도가 높을수록 ascorbic acid의 용출율(溶出率)이 높고 $80^{\circ}C$의 온탕(溫湯)을 사용(使用)했을 때 제 1 회의 3 분(分)간 침출(浸出)에서 85%가 용출되었다. (3) 증류수의 비등시간(沸騰時間)과 ascorbic acid용출량(溶出量)과의 관계(關係)에 있어서는 비등시간(沸騰時間)이 길수록 용출량(溶出量)이 증가(增加)하였다.

• 한국식품영양과학회지
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• 제25권4호
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• pp.687-694
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• 1996

한국산 겨자에서 myrosinase를 분리 및 정제하고, 이들의 효소학적 특성을 조사한 결과는 다음과 같다. 겨자 myrosinase를 DEAE-cellulose, Concanavalin A-Sepharose 및 FPLC Soporose 6 칼럼을 이용하여 분리 및 정제하였을 때 적어도 3개의 이성효소가 존재하는 것으로 나타났으며, Myrosinase II-2의 최종 비활성도는 57.lunits/mg, 정제도는 약 248배였다. SDS-PAGE상에서 myrosinase(II-2)의 단일밴드를 확인한 결과, 그 분자량은 약 67KD로 추정 되었다. 최적 pH는 phosphate 및 Tris-HCI 완충액에서 7.0이 가장 활성이 높았고, 그 효소는 pH 7.0에서 안정하였으며, 최적 활성을 나타내는 온도는 $37^{\circ}C$ 부근이었고, $40^{\circ}C$ 이상에서는 비교적 불안정하게 나타났다. Ascorbic acid의 영향은 1mM에서 가장 안정하였으며, 그 이상의 농도에서는 변화가 없었다. 망간과 마그네슘 및 나트륨은 효소활성을 촉진시키는 것으로 나타났으며 구리, 수은 및 철 이온은 약간 저해하였다. Ascorbic acid analogue 중 dehydroascorbic acid는 효소 활성을 저해하였으며, 나머지 것들은 거의 영향을 미치지 않았다. 2-Mer-captoethanol과 dithiothreitol과 같은 환원제는 효소활성을 억제하였으나 이들과 ascorbic acid를 함께 첨가 하였을 때는 활성이 다소 증가하였다.

• 한국식품영양과학회지
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• 제24권6호
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• pp.1016-1019
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• 1995

This study was conducted to investigate the nutrient composition of hydroponic water dropwort and the effect of blanching condition on ascorbic acid content. Nutrient composition of hydroponic water dropwort of mid harvest on the 30th day was measured in three portions of leaves, petioles and stems, and was compared with that of late harvest on the 40th day. Hydroponic water dropwort was obtained from the Department of Horticultural Science, Seoul National University. The results were as follows. The nutrients content of leaves were significantly higher in ash and ascorbic acid and lower in moisture, crude fat and crude fiber than those of stems and petioles. There was no significant difference in total vitamin A and thiamin contents between three portions. Ascorbic acid content of leaves harvested on the 30th day was the highest, 57mg/100g, and decreased to 18mg/100g in the leaves harvested on the 40th day. Marked increase in crude fiber and vitamin A content of leaves was observed in late harvest may be due to the maturation. The results of nutrient composition analysis suggest that the leaves of hydroponic water dropwort is important in ascorbic acid and ash. It is recommended that shorter blanching time and addition of 0.5% NaCl to the blanching water are better for higher ascorbic acid retention of hydroponic water dropwort. In conclusion, as hydroponic water dropwort has high content in ash, calcium, vitamin and free sugar with alkalinity, leaves as well as stems and petioles can be recommonded as a vegetable of high nutritional quality.

• Preventive Nutrition and Food Science
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• 제14권4호
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• pp.367-372
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• 2009

Apple, persimmon, and strawberry slices were dehydrated after treating with 30, 50, and 80% (w/w) maltodextrin solution. The dried apple, persimmon, and strawberry slices were compared with hot air-dried and freeze-dried samples in terms of rehydration ratio, ascorbic acid, color, and sensory evaluation. The rehydration ratio of maltodextrin-treated samples was greater than that of hot-air or freeze-dried samples. Maltodextrin-treated samples had higher content of ascorbic acid than other dried samples. Additionally, maltodextrin-treated apple, persimmon, and strawberry slices had better color and sensory evaluations than those of freeze-dried or hot-air dried samples. These results suggest that, compared to other drying methods, dehydration of apple, persimmon, and strawberry slices using maltodextrin is very efficient, resulting in good rehydration capacity, minimal destruction of ascorbic acid, and good color and sensory evaluation.