• Korean Journal of Food Science and Technology
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• v.21 no.6
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• pp.800-807
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• 1989

No-time dough process utilizing ascorbic acid as an oxidant was investigated. The farinograph absorption was increased as the amount of L-cysteine increased, while stability and peak time decreased up to 40 and 30 ppm of L-cysteine, respectively. Extensibility of the dough was increased with the increment of L-cysteine, but the ratio of resistance to extensibility was significantly decreased. At the same level of L-cysteine, the addition of ascrobic acid by 1.5 times decreased the farinograph absorption. However, the stability and peak time remained relatively unchanged upon addition of ascrobic acid. Extensibility and resistance of dough were respectively decreased and increased in the presence of both L-cysteine and ascorbic acid. In the range of 30-50 ppm of cysteine, the mixing time decreased and the baking absorption was increased by 1% as the cysteine was increased by 10 ppm. The ascorbic acid had no effects on absorption and mixing time. Bread produced by no·time dough process had no break and shred. The optimum concentrations of L-cysteine and ascorbic acid for no-time dough process were 40 and 100ppm, respectively.

• Korean Journal of Food Science and Technology
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• v.14 no.4
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• pp.330-335
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• 1982

A powdered beverage with afruit flavor was stored at 4, 21, 35 and $45^{\circ}C$ for 180 days to study ascerbic acid destruction at the selected temperatures. Degradation of ascorbic acid in the model followed the first order reaction, and the temperature dependence of reaction rate constants at tested temperatures was accounted for by the Arrhenius equqtion. The calculated activation energy for the destruction of ascorbic acid was 3.3 Kcal/mole. The relationship between ascorbic acid content and sensory flavor score of the beverage indicated that samples with destruction of ascorbic acid over 25% showed objectionable flavor. An attempt was made to predict the quality of powdered beverage by using a simulation model. A comparision between ascorbic acid values from shelflife tests and the simulation program showed a good agreement within acceptable error. This result demonstrated that quality of powdered beverage could be predicted by using a computer simulation model with a desired accuracy.

• Korean Journal of Food Science and Technology
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• v.11 no.2
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• pp.77-80
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• 1979

Effects of interfering substances on the determination of L-ascorbic acid (AsA) in green tea and it's extracts by 2,4-dinitrophenylhydrazine (DNP) method was studied. and the removal of these interfering substances was also investigated. Under the condition prescribed for DNP method, AsA content of green tea are effected by some sugar, reductones, dicarbonyl compounds, organic acids, amino acids and others. All interfering substances except amino acids were eliminated by the chloroform extraction after adding o-phenylendiamine to sample solution. and remaining amino acids were eliminated almost completely by the treatment with ion exchange resin$(Amberlite{\;}IR-120H^{+})$. After removing the interfering substances by the above mentioned procedure, total AsA in green tea was determined by DNP method. The values obtained by this method were in good agreement with those by thin layer chromatography (TLC) method. and the method was more rapid and simple than TLC method.

• Korean Journal of Microbiology
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• v.32 no.2
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• pp.132-138
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• 1994

L-Ascorbic acid-producing enzyme in Neurospora crassa was found to exist in mitochondria and the activity of this enzyme was increased by the addition of D-fluconno-${\gamma}$-lactone or L-gulono-${\gamma}$-lactone in the media. L-Ascorbic acid-producin enzyme in N. crassa has been purified with ammonium sulfate precipitation. DEAE Sepharose CL-6B ion exchange chromatography. Sephacryl S-200 gel filtration chromatography and Reactive yellow 3-agarose dye affinity column chromatography. The specific activity of this enzyme was increased to 239.6 fold and the yield was 2.1%. The molecular weight of the native enzyme was 150.000 dalton when it was estimated with Sephacryl S-200 gel filtration chromatography. Its molecular weight appeared as 75.000 dalton by SDS-polyacrylamide gel electrophoresis. which suggested that this enzyme was consisted with two identical subunits. The optimal pH for this enzyme was 9.0 and the $K_m$ value for D-galactono-${\gamma}$-lactone was 0.073 mM.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.606-613
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• 1997

The changes of contents in trimethylamine oxide nitrogen(TMAO-N), trimethylamine nitrogen(TMA-N), dimethylamine nitrogen(DMA-N), nitrite nitrogen(nitrite-N), nitrate nitrogen(nitrate-N) and the effect on the formation of N-nitrosamine(NA) during fermentation were investigated with salted anchovy added different amounts of sodium nitrite, sodium nitrate and ascorbic acid, respectively. When the sodium nitrite was added in salted anchovy, the contents of nitrite-N was decreased during fermentation . Whereas the formation of N-nitrosodimethylamine(NDMA ) was increased . Contents of TMAO-N was decreased, while TMA-N and DMA-N were increased during fermentation in all samples. Addition of ascorbic acid inhibited the formation of NDMA significantly. The formation of NDMA was inhibited by 81.3% at the concentration of 130mM as compared with non-added the control group. The aqueous model system was used for the evaluation of ascorbic acid(inhibitor) or thiocyanate (promoter) on the formation of NDMA using salt-fermented anchovy added with sodium nitrite. The optimum pH on the formation of NDMA was shown to be 3.8, and ascorbic acid inhibited the formation of NDMA whereas thiocyanate promoted. NDMA was not detected in the salt-fermented anchovy (control sample). However it is a possibility to form carcinogenic NDMA in stomach if both saltfer-mented anchovy and the materials contained abundant nitrite or nitrate were took in.

• Journal of the Korean Applied Science and Technology
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• v.39 no.1
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• pp.10-17
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• 2022

This study attempted to investigate the antioxidant capacity and whitening effects of the extract from the mixture of 7 different vegan cosmetic ingredients. To examine radical scavenging capacity, DPPH, ABTS and FRAP assays were performed. In addition, polyphenol and flavonoid concentrations were measured to check antioxidant substances. Specifically, in a DPPH test, 105.74 mg ascorbic acid/g antioxidant capacity was observed. In an ABTS assay, 85.31 mg ascorbic acid/g antioxidant capacity was found. Lastly, in an FRAP assay, 1mg of the extract revealed ascorbic acid 198.01±5.50 ㎍ reducing power. Polyphenol and flavonoid concentrations were 30.19±0.75 mg/g and 9.12±0.36 mg/g respectively. In a cell-based assay, cytotoxicity and whitening activity were examined. In terms of cytotoxicity, '20% or less' was observed. Furthermore, the inhibition of melanin synthesis was '34.70±2.97%' at 100 ㎍/mL, confirming the possibility of the extract from the mixture of 7 different substances as a cosmetic ingredient.

• 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.

• Applied Biological Chemistry
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• v.33 no.2
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• pp.147-153
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• 1990

To investigate the effect of spice oils on the nitrite role in processed meat products, eight spice oils, ascorbic acid, and nitrite at different combinations were added to marcerated pork, and cooked at $70^{\circ}C$ lot 30min or $121^{\circ}C$ for 15min. The cooked sample were stored at $5.5^{\circ}C$ for 12days and pH, residual nitrite, redness, TBA value, and antimicrobial activity were analyzed. pH of the uncooked samples were stable at $5.6{\sim}5.8$ except in samples with nitrite alone, anise, ascorbic acid, and black pepper in which pH increased to $6.7{\sim}7.8$ after 5 days of storage. The pH of the cooked samples were stable at $5.9{\sim}6.1$ during the storage. Residual nitrite decreased rapidly on the first day of storage in each model. Residual nitrite decreased rapidly on the first day of storage in each model. The nitrite reducing effect was greatest in sample with ascorbic acid, followed by clove eugenol and thyme, but was small with peppermint. The redness of the sample was increased with ascorbic acid, colve, eugenol, thyme, anise, black pepper, coriander and rosemary except peppermint, specially samples with ascorbic acid, clove and eugenol were prominent. The TBA values of the samples with cloves, eugenol and ascorbic acid, stored after nine days, were $4{\sim}6.5$ lower than that of nitrite added sample and indicated strong antioxidant activity. The antimicrobial activity determined by inhibition zone, was strong in samples with clove, eugenol, peppermint, thyme, coriander, black pepper, rosemary and anise had antimicrobial activity to the Penicillium sp. Specially with clove, eugenol, peppermint and thyme, while all the samples showed $7{\sim}10mm$ inhibition zone to the Salmonella sp. The above results suggest that addition of eugenol, clove and thyme oil to the processed meat may increased the antioxidant, antimicrobial activity, and redness of the product so that could provide a way of reducing nitrite addition into meat products.

• 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 Applied Science and Technology
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• v.37 no.4
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• pp.906-914
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• 2020

To investigate the usefulness of natural plants, physicochemical characteristics, functional components and physiological activities of dodder(Cuscuta australis R.Brown) were experimented. The extraction of dodder was carried out at 60℃ in shaking bath with 10 times of distilled water for three hours. Harmful metals such as lead, cadmium and arsenic were not detected, but the content of mercury from dodder was 0.0004ppm in acceptable standards. The extraction yield was 23.45%, total content of phenolics equivalent to gallic acid was 699.8 mg/100g and total content of flavonoid equivalent to naringin was 373.8 mg/100g. 28 kinds of free amino acids were detected with the contents of 252mg/100g in the dodder extract, and the contents of anserine and sarcosine were analysed highest in all amino acids. From the comparison of physiological activities of dodder extract with those of ascorbic acid, total reducing power, electron donating ability based on DPPH radical scavenging and ferric reducing antioxidant power was equivalent to 88%, 56% and 40%, respectively, of ascorbic acid. The nitrite scavenging activity of dodder extract was 78% of ascorbic acid on pH 1.5, but the antioxidant index of dodder on perilla oil was about 4 times greater than that of ascorbic acid.