• Korean Journal of Food Science and Technology
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• v.43 no.6
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• pp.766-772
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• 2011

This study was conducted to evaluate the daily intakes of propyl gallate, EDTA (ethylenediamine tetra acetate), and erythorbic acid for average consumers by age group and the intake of high consumers ($95^{th}$ percentile) in Korea. The average intake of EDTA was $1.14{\mu}g/kg{\cdot}bw/day$, and 0.0% of the ADI (acceptable daily intake) established by JECFA (Joint FAO/WHO Expert Committee on Food Additives). The $95^{th}$ percentile intake of EDTA was $141.24{\mu}g/kg{\cdot}bw/day$ (5.6% of ADI). The average intake of erythorbic acid was $16.93{\mu}g/kg{\cdot}bw/day$, and the 3-6 year-old group had the highest consumption ($58.43{\mu}g/kg{\cdot}bw/day$), which was <1.0% of the ADI established by the EU (European Union). The $95^{th}$ percentile intake of erythorbic acid was $1,320.31{\mu}g/kg{\cdot}bw/day$ and 22.0% of the ADI. In conclusion, daily intakes of propyl gallate, EDTA, and erythorbic acid in Korea were at safe levels in all age groups and also in high consumers.

• Journal of Food Hygiene and Safety
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• v.13 no.3
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• pp.274-277
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• 1998

The study was focused to investigate the effect of nitrosodimethylamine (NDMA) formation due to nitrosamine (NA) precursor and/or inhibitor addition to Kimchi during the fermentation of Kimchi at room temperature ($16{\pm}2^{\circ}C$). The addition of nitrite and dimethylamine (DMA) to Kimchi showed the average 32-fold ($21.3{\sim}113.9\;\mu\textrm{g}/kg$) and 9-fold ($1.3{\sim}40.3\;\mu\textrm{g}/kg$) higher NDMA formation than control ($O{\sim}5.6\;\mu\textrm{g}/kg$), respectively. Also, the addition of both nitrite and DMA resulted in the increase of NDMA formation to average 42-fold ($39.4{\sim}155.7\;\mu\textrm{g}/kg$) higher than control. On the other hand, the addition of 4 ruM ascorbic acid to Kimchi with nitrite and DMA inhibited the formation of NDMA down to 71.3% of control. However, the addition of cysteine and erythorbic acid affected no inhibition to NDMA formation during the test. The addition of sodium sulfite increased NDMA formation. Accordingly, this showed that the amount of ascorbic acid generated during Kimchi fermentation played an important inhibition role for NA formation.

• Food Engineering Progress
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• v.15 no.1
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• pp.75-79
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• 2011

Analytical methods for food antioxidants including ascorbic acid, erythorbic acid, ascorbyl palmitate (AP), and ascorbyl stearate (AS), were validated using high performance liquid chromatography. Validation parameters such as linearity, limit of detection (LOD), limit of quantification (LOQ), and recovery were tested using lard and cider as food model systems. Linearity of ascorbic acid and erythorbic acid were both higher than ($R^2$> 0.99), LOD of these compounds were 0.46 and 0.48 ${\mu}g/mL$, respectively and LOQ were 1.39 and 1.45 ${\mu}g/mL$, respectively. The recovery rates of these compounds were 86.35-94.78% and 84.76-95.02%, respectively. However, the concentration of AP and AS decreased in methanol stock solution. Four other solvents including ethanol, acetonitrile, mixture of methanol and acetonitrile, and mixture of ethanol and acetonitrile were tested to increase the stability of AP and AS under room temperature and refrigerated temperature. Ethanol provided better stability of AP and AS under both room and refrigerated temperature. This study can help to accurately analyze the content of ascorbic acid and its derivatives in processed foods.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.37-40
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• 1996

Kinchi is and important source of various vitamins, minerals, dietary fiber, organic acids and other nutrients. In order to get a basic information for developing vitamins-rich funtional kimchi, we investigated microorganisms which are capable of synthesis of vitamin C in Kimchi system. Microorganisms isolated from aliquots of kimchi were screened and cultured by using MRS or nutrient agar medium. L-Ascorbic acid produced by microorganism in medium was measured with high performance liquid chromatography. As the result, we isolated two bacteria strins N7 and N5202 preducing L-ascorbic acid from the kimchi system. Morphological and Gram staining experiment showed that N7 was Gram positive bacilli, while N5202 was Gram negative. There were also several bacteria that were considered to synthesizs erythorbic acid which is an analog of ascorbic acid. These results suggested that vitamin C-rich functional food could be developed by using the kimchi microorganisms.

• Journal of Microbiology and Biotechnology
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• v.24 no.6
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• pp.781-787
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• 2014

2-Ketogluconic acid production by Klebsiella pneumoniae is a pH-dependent process, strictly proceeding under acidic conditions. Unfortunately, cell growth is inhibited by acidic conditions, resulting in low productivity of 2-ketogluconic acid. To overcome this deficiency, a two-stage fermentation strategy was exploited in the current study. During the first stage, the culture was maintained at neutral pH, favoring cell growth. During the second stage, the culture pH was switched to acidic conditions favoring 2-ketogluconic acid accumulation. Culture parameters, including switching time, dissolved oxygen levels, pH, and temperature were optimized for the fed-batch fermentation. Characteristics of glucose dehydrogenase and gluconate dehydrogenase were revealed in vitro, and the optimal pHs of the two enzymes coincided with the optimum culture pH. Under optimum conditions, a total of 186 g/l 2-ketogluconic acid was produced at 26 h, and the conversion ratio was 0.98 mol/mol. This fermentation strategy has successfully overcome the mismatch between optimum parameters required for cell growth and 2-ketogluconic acid accumulation, and this result has the highest productivity and conversion ratio of 2-ketogluconic and produced by microorganism.

• Journal of Life Science
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• v.14 no.3
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• pp.478-483
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• 2004

In a model reaction using lysyl oxidase purified partilally from bovine aorta, effect of L-ascorbic acid AsA on the oxidative reaction of lysine in collagen was investigated. Addition of Ash to the reaction mixture under aerobic conditions resulted in the decrease of enzymatic activity. In order to examine the specificity of AsA in the oxidative reaction of lysine, other reductants including A derivatives instead of AsA were added to the reaction mixture. Thiol such as glutathione had no effect on the activities of lysyl oxidase. on the other hand, it was observed that erythorbic acid, which was a stereoisomer of AsA, had the same inhibitory effect on this oxidative reaction as AsA. Moreover, by the addition of 3,4-dihydroxybenzoate, which was structural analog of AsA, the activities decreased in a similar manner to that of AsA. These results indicate that the regulatory effect of AsA on lysyl oxidase is attributed to characteristics of the structure. From the determination of Ash remained in the reaction mixture, it is shown that AsA concentration remarkably decreased by lysyl oxidase of the reaction mixture. It is hypothesized that endiol groups reduces the enzyme-bound $Cu^{+2}$ required for further progress of the reaction, and suggests that AsA regulates specifically the reduction of $Cu^{+2}$ required to oxidize lysyl oxidase. This findings support that AsA has an important regulatory role on the oxidative reaction of lysine and on changes of collagen cross-links with aging.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.8
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• pp.1398-1406
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• 2004

To develop the new type of salt-fermented seafoods, the salt-fermented oysters in olive oil (product SO) were manufactured, and food components and quality characteristics of product SO were examined. The optimum processing condition for product SO is as follows. The raw oyster with no shell was washed off with 3% saline solution. Then dewatered, and dipped in the brine-salting solution made up with saturated saline solution and oyster sauce (2 : 1 v/v) mixture added 1% sodium erythorbic acid and 0.2% polyphosphate. After salt-fermentation it ripened by brine salting at 5$\pm$1$^{\circ}C$ for 15 days. Then dried at 15$^{\circ}C$ for 4 hours with cool-air, and packed in No. 3B hexahedron type can. Finally, poured with olive oil and seamed it by double-seamer. The moisture, crude protein, crude ash and volatile basic nitrogen contents of the product SO were 61.6%, 12.0%, 16.3% and 34.3 mg/100 g, respectively. In taste-active components of the product SO, total amount of free amino acids is 2,335.4 mg/100 g and it has increased by 50% overall during salt-fermentation 15 day. Taurine, glutamic acid, proline, glycine, alanine, $\beta$-alanine and lysine were detected as principal free amino acids. The contents of inorganic ions were rich in Na and K ion, while the amounts of nucleotide and its related compounds and other bases except betaine were small. From the results of this research, the product SO had a superior organoleptic qualities compared with conventional oyster product, and could be reserved in good conditions for storage 90 days at room temperature.