• Culinary science and hospitality research
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• v.17 no.4
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• pp.263-272
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• 2011

For tomatoes containing valuable nutrients and biological active substances, this study examined differences in the ascorbic acid, lycopene, ${\beta}$-carotene, and ${\alpha}$-carotene contents in processed tomato products according to tomato cultivar and the part of fully ripened tomatoes. According to the results, the ascorbic acid content was different among tomato cultivars, and it was far higher in jelly than in pulp among the parts of tomatoes. The ascorbic acid content in processed tomato products was higher in tomato juice than in other types of tomato products, but the difference was mainly from various additives used in addition to tomatoes; therefore, it was somewhat unreasonable to compare the ascorbic acid content among the products. It was found that the lycopene content was not significantly different between pulp and jelly in each cultivar. In most of the cultivars, the ${\beta}$-carotene content was not significantly different according to the parts, but in cultivar yeoyong, the content was 2.7 times higher in jelly than in pulp. The ${\alpha}$-carotene content was highest in both pulp and jelly for all the cultivar, and the lycopene and ${\beta}$-carotene contents were lowest regardless of parts for cultivar Yellow Carol. ${\alpha}$ carotene was not detected in either pulp or jelly. The lycopene, ${\beta}$-carotene, and ${\alpha}$-carotene contents showed significant difference among processed tomato products, and the difference came mainly from the type of processing and additives. Tomatoes have superior characteristics, but they are usually consumed uncooked in Korea. Thus, this study aimed to contribute to the various forms of consumption of tomatoes, that is, the development of various nutritionally excellent cooking methods using processed tomato products.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.190-197
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• 2010

Changes in the quality of buckwheat sprout treated with organic acid solutions such as ascorbic, citric and acetic acid were examined during storage in order to judge the feasibility of acid dipping as a pretreatment for extending shelf-life. Quality attributes of buckwheat sprout stored at $5^{\circ}C$ were measured in terms of microbial cell count, moisture content, soluble solids content, chromaticity, and sensory evaluation over different storage times. For microbial growth inhibition, combinations of 0.05% acetic acid and 0.5% citric acid or 1% ascorbic acid and 0.5% citric acid were more effective than other treatments. Slight changes were observed in moisture content among the treatments, whereas soluble solids content of each treatment was increased during storage. In chromaticity, the Hunter's a value of buckwheat sprout treated with acetic acid alone or acetic acid combinations showed the largest increase. Dipping treatment with ascorbic acid and citric acid produced only slight changes in color of the sprout. In the sensory evaluation of discoloration (head, stem and root), wilting and overall quality, ascorbic acid and citric acid treatments gave the highest scores. These results suggest that dipping treatment of buckwheat sprout with citric acid can confer more positive effects on storage stability than others.

• Korean journal of food and cookery science
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• v.10 no.3
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• pp.225-231
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• 1994

This study was intended to observe the effect of cooked glutinous rice flour and soused shrimp on the fermentation of Kimchi samples were fermented for 11 days at 10$^{\circ}C$ after they were previously fermented for 6 hours at 20$^{\circ}C$. Changes of pH, total acidity, salt content, reducing sugar content, free amino acid content, total vitamin C content, and ascorbic acid content were measured. The results were as follows; 1. Soused shrimp and glutinous rice flour added in Kimchi acted as lactobacilli growth enhancer during fermentation. 2. Initial cincentrations of redng sugars in Kimch samples with no soused shrimp, 5% and 10% sosed shrimp were 7.5~8.3 mg/g, 3.0~4.7 mg/g and 0.5~0.6 mg/g respectively. Kinchi samples with glutinous rice flour showed higher reducing sugar contents than Kimchi samples without it. 3. Free amino acid contents in Kimchi samples gradually decreased during fermentation at 10$^{\circ}C$. According to their soused shrimp concentration, contents of free amino acid of Kimchi samples were significantly different. And Kimchi samples with glutinous rice flour showed lower free amino acid contents than Kimchi samples without it. 4. Total vitamin C contentrations of Kimchi samples were 24.5~28.0 mg% at the initial stage of fermentation and 15.0~19.2 mg% at the final stage of fermentation. During the fermentation of Kimchi, the higher soused shrimp concentration, the less total vitamin C contents were remained. 5. During the fermentation, ascorbic acid contents of Kimchi samples were not affected by soused shrimp and glutinous rice flour.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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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.

• Korean Journal of Medicinal Crop Science
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• v.6 no.1
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• pp.6-10
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• 1998

Vitamin contents in different plant parts and harvesting time of Rosa davurica Pall. were determined to examine their applicability for a new medicinal supply. Among plant parts analysed, leaf contained the highest ascorbic acid concent of 1973.9 mg/100g. Fruit contained ascorbic acid (714.6mg/100g) 2. 7 times less than leaf. Vitamin contents in leaf parts also differed depending on harvesting time. Vitamin content in leaves harvested in November was much higher than that in September. Spectrophotometric analysis of total ${\beta}-carotene$ in leaf showed higher contents than that in fruit.

• Journal of Electrochemical Science and Technology
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• v.1 no.2
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• pp.121-126
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• 2010

An amperometric ascorbic acid selective sensor utilizing the transfer reaction of proton liberated from the dissociation of ascorbic acid in aqueous solution across an elliptic micro-hole water/organic gel interface is demonstrated. This redox inactive sensing platform offers an alternative way for the detection of ascorbic acid to avoid a fouling effect which is one of the major concerns in redox based sensing systems. The detection principle is simply measuring the current change with respect to the assisted transfer of protons by a proton selective ionophore (e.g., ETH 1778) across the micro-hole interface between the water and the polyvinylchloride-2-nitrophenyloctylether gel phase. The assisted transfer reaction of protons generated from ascorbic acid across the polarized micro-hole interface was first characterized using cyclic voltammetry. An improved sensitivity for the quantitative analysis of ascorbic acid was achieved using differential pulse stripping voltammetry with a linear response ranging from 1 to $100\;{\mu}M$ concentrations of ascorbic acid. As a demonstration, the developed sensor was applied for analyzing the content of vitamin-C in different types of commercial pharmaceutical tablets and syrups, and a satisfactory recovery from these samples were also obtained.

• 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.

• 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.

• Korean Journal of Veterinary Research
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• v.13 no.2
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• pp.137-140
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• 1973

The concentrations of ascorbic acid and total protein in blood serum of 57 healthy race horses (17 males and 40 females) were observed. The results obtained were summarized as follows: 1) The mean value of ascorbic acid concentration was $0.44{\pm}0.16$ mg/100 ml (SD) ranging 0.20-0.92mg/100ml and sex difference was not significant. 2) The mean value of total protein concentration was $6.11{\pm}0.3$ g/170 ml(SD) ranging 5.6-7.0g/100 ml and their sex differences were significant(P<0.05); male $6.36{\pm}0.09$ (SE), female $6.13{\pm}0.06$ (SE). 3) Observation on the correlation between the total protein and ascorbic acid content (${\gamma}$=+0.3) and a liner repression equation (y=0.123x-0.31) were obtained.

• 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.