• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.118-118
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• 2003

편의와 fresh-like quality를 선호하는 소비 경향에 맞추어 가공한 fresh-cut사과의 선도 연장을 위한 저해제를 탐색하였다. 실험에 사용된 사과는 박피하여 속심을 제거한 사과를 8조각으로 절단하여 저해제에 3분간 침지한 후 물기를 제거하고 각각 LDPE 포장지에 포장하여 실온에서 저장하면서 colorimeter와 rheometer를 이용하여 색도와 물성을 측정하였다. 저해제로는 1% ascorbic acid, citric acid, NaCl, MgCl$_2$, CaCl$_2$, KCl, CaSO$_4$, MgSO$_4$, $Na_2$SO$_4$, oxalic acid, calcium lactate, calcium citrate를 사용하였으며 천연저해제로는 건칡, 맥문동, 목향, Rhubarb, 당귀, 오약, 시체, 지각, 천문동, 청피, 계피, 구기자, 당귀, 진피, 감초, 녹차, 후추 등을 열수추출하여 사용하였다. 물리적인 변화는 시간이 경과함에 따라 감소하는 추세를 보였으며 일부 건조로 인해 texture의 증가를 나타내기도 했다. 처리에 따른 물리적인 변화로는 CaCl$_2$, NaSO$_4$, Cl, 시금치를 처리하였을 때 그 변화가 가장 작았으나 시금치의 경우 시금치로 인한 사과의 색변화로 관능적으로 좋지 않았다. 한약재는 목향, 당귀, 지각, 계피를 처리하였을 때 물리적인 변화가 가장 작았으나 시금치와 마찬가지로 처리 초기에 한약재 자체의 향과 색으로 인하여 관능적으로 좋지 못한 결과를 나타냈다. 갈변 정도를 나타내는 ΔE의 변화는 KCl과 CaCl$_2$, CaSO$_4$를 처리한 구에서 변화가 가장 작았으며 한약재를 처리하였을 경우 당귀, 천문동을 처리한 구에서 효과를 보였다. oxalic acid는 갈변저해에는 효과적이었으나 시간이 경과함에 따라 수분의 용출이 증가하였으며 물성의 변화도 컸다. 또한 ZnCl$_2$를 처리한 구에서는 이취 발생과 수분 용출이 컸으며 색의 변화도 컸다.

• Applied Biological Chemistry
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• v.30 no.4
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• pp.323-327
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• 1987

Takju, a Korean traditional rice wine, was prepared using Koji and Nuluk which were inoculated with single or combination culture of Aspergillus niger, Aspergillus shirousamii, and Aspergillus kawachii to investigate changes in mineral, amino acid and organic acid during fermentation. The mineral content showed a range of $1.50{\sim}15.20ppm\;for\;Ca,\;0.22{\sim}0.25ppm\;for\;Cu,\;1.60{\sim}2.10ppm\;for\;Fe,\;0.17{\sim}0.55ppm\;for\;Mn,\;0.68{\sim}1.00ppm\;for\;Zn,\;3.00{\sim}40.50ppm\;for\;K,\;5.25{\sim}19.50\;for\;Mg,\;1.43{\sim}2.95ppm\;for\;Na,\;and\;3.00{\sim}63.0ppm$ for P. It has been found that Takju had 16 kinds of amino acid including aspartic acid. A. niger Nuluk showed the highest contents in total amino acids, while A. kawachii Koji was the lowest in amino acids. The major amino acids were glutamic acid, alanine, leucine, and phenylalanine. The order of organic acids from the highest content in Takju were citric acid> tartaric acid> pyruvic acid> malic acid> lactic acid> acetic acid.

• Food Science and Preservation
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• v.18 no.4
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• pp.429-435
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• 2011

The demand of packaged baby leaves has been increased for its convenient use as fresh-cut produce. This investigation was aimed to explore the effects of different sanitizers on the quality parameters of 'Tah Tasai' Chinese cabbage (Brassica campestris var. narinosa) baby leaves. Thirteen days old baby leaves were harvested and washed in tap water (TW), 100 ppm chlorine solution (Cl), 2 ppm ozonated water ($O_3$), 15 ppm chlorine dioxide solution ($ClO_2$) and washing with 0.2% citric acid solution followed by 50% ethanol spray (CA+Et). The samples were then packaged in 50 ${\mu}m$ polyethylene bags and stored at $5^{\circ}C$ for 10 days. Off-odor of packaged baby leaves was not detected during storage. There was no significant difference in color parameters among the treatments. Samples treated with $O_3$ showed substantially higher electrolyte leakage throughout the storage. This treatment also rendered a higher accumulation of $CO_2$ in the packages. Samples treated with Cl and CA+Et maintained good overall visual quality with higher scores compared to that of $O_3$ and $ClO_2$. Although Cl treatment showed lower number of total aerobic count at the beginning of storage, citric acid in combination with ethanol treatment was more effective until the end of storage. The combined treatment also showed comparatively lower coliform plate count. This result indicates that citric acid wash followed by ethanol spray could be an alternative to chlorine for environment friendly sanitization of baby leaves.

• Korean journal of food and cookery science
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• v.4 no.1
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• pp.53-57
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• 1988

To obtain basic data for the development of domestic tea manufacture, the physico-chemical properties were analyzed. The content of crude fiber in domestic black tea was abundant of 50%, as compared with those in Sri-Lanka's black tea, while the contents of tanin and caffeine were lower than those of Sri-Lanka's Products. The quantities of mineral in Sri-Lanka's products were determined as 300ppm P, 15,000ppm K, 1,400ppm Mg, 4,000ppm Ca, 22ppm Cu, 21ppm Cr and 45ppm Zn. These contents were higher than those of domestic products. Al content was 4,100ppm in domestic products. Pb and Cd were not detected in two kinds of black tea products. In Sri-Lanka's black tea, 8 kinds of organic acids were identified and the major organic acids were shikimic, citric and quinic acid, while 6 kinds of organic acids were identified in domestic products and were quinic and gallic acid, as the major organic acids. The content of sucrose was higher than that of Sri-Lanka's product and theaflavin, thearubigin and theobromine were abundant, as compared with those in domestic products.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.4
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• pp.194-199
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• 2012

The $LiMn_{1.5}Ni_{0.5}O_4$, substituting a part of Mn with Ni in the $LiMn_2O_4$, the spinel structure has good charge-discharge cycle stability and high discharge capacity at 4.7 V. In this study $LiMn_{1.5}Ni_{0.5}O_4$ powders were synthesized by polymerization complex method. The effect on the characteristics of synthesized $LiMn_{1.5}Ni_{0.5}O_4$ powders was studied with citric acid (CA) : metal ion (ME) molar ratio (5 : 1, 10 : 1, 15 : 1, 30 : 1) and calcination temperature ($500{\sim}900^{\circ}C$). Single phase of $LiMn_{1.5}Ni_{0.5}O_4$ was observed from XRD analysis on the powders calcined at low ($500^{\circ}C$) and high temperatures ($900^{\circ}C$). The crystalline size and crystallinity increased with calcination temperature. At low calcination temperature the particle size decreased and specific surface area increased as the CA molar ratio increased. On the other hand, high particle growth rate at high calcination temperature interfered the particle size reduction and specific surface area increase induced by the increase of CA molar ratio.

• Microbiology and Biotechnology Letters
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• v.17 no.6
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• pp.624-628
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• 1989

A study on the citric acid production using Saccharomycopsis lipolytica (NRRL Y7576) was carried out in shake-flasks, air-lift and membrane recycle bioreactors. The cells entrapped in Ca-alginate beads were used in shake-flasks and air-lift reactor. Repeated batch fermentation in shake-flasks was successfully performed for 34 days and resulted in a yield of 54%. Increased yield (63%) was obtained in the air-lift reactor operation using nitrogen deficient medium (NDM). In the membrane recycle bioreactor operation, the maximal dry cell mass concentration was 39 g/1 at a dilution rate of 0.02 h$^{-1}$ and the yield with NDM was higher than that with growth medium. In addition, the yield and volumetric productivity with pure oxygen supply were greatly improved compared with those with air supply.

• Journal of the East Asian Society of Dietary Life
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• v.12 no.5
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• pp.379-387
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• 2002

The focus of this study was the influence of organic acids such as acetic, citric and malic acid on the dissolution of calcium (Ca), magnesium (Mg), and phosphorus (P) on chicken thigh bone. As the concentration (0, 0.5, 1, 2, 4%) of acetic, citric, and malic acid increased, the resultant contents of calcium, magnesium, and phosphorus were higher than that of the control. When the boiling time (2, 4, 6, 8, 12 hours) was increased, dissolved amounts of several minerals from the chicken thigh bone increased. Calcium dissolved the most when chicken stock was boiled for 12 hours with 4% of malic acid added. In addition to minerals, amino acids and proteins were further extracted by adding organic acids. The soup stock which contains minerals such as calcium, can be obtained by boiling the chicken thigh bone for 12 hours with an organic acid.

• Korean Journal of Medicinal Crop Science
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• v.22 no.1
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• pp.32-37
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• 2014

To study the cause of physiological disorder in leaf of ginseng cultivated at paddy soil, the degree of brown-colored symptom (BCS) and the contents of inorganic matter in leaf were investigated by irrigating the solution of ferric and ferrous iron of 0.1 ~ 2.0%, and citric acid of 1.0 ~ 4.0% on bed soil, respectively. Ratio of BCS by variety was as high as 85.0% in Yoenpoong, while it was as low as 5.4%, 7.5% in Chunpoong and Hwangsook, respectively. The contents of inorganic matter of leaf in Yoenpoong were lower in $P_2O_5$, Ca, and Mg, while it were higher in K, Fe, and Mn than other variety. Iron solution caused BCS more distinctly when each ferric and ferrous iron were dissolved with 1.0% citric acid than when each iron was dissolved without citric acid. Ferric iron caused BCS more effectively than ferrous iron. BCS occurred in 4.0% citric acid was as same as 2.0% ferric iron mixed with 1.0% citric acid. Low $P_2O_5$ and high Fe content in leaf appeared in both of artificial and natural symptoms. We concluded that excessive Fe uptake caused BCS to leaf because the solubility of iron was increased in condition of low soil pH.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.496-501
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• 2016

This study was conducted to minimize the quality degradation of concentrated blueberry juice after $90^{\circ}C$ treatment for 5 min by means of citric acid (CA) and acidic sodium metaphosphate (ASM) as pH modifiers. The highest anthocyanin content was observed at 1% CA+1% ASM (65.747 mg per 100 g) followed by 1% CA (46.022 mg per 100 g) and control (30.864 mg per 100 g). The DPPH radical scavenging activities of 1% CA+1% ASM, 1% CA and control were 87.338, 75.486 and 67.983% in respectively. The elastase inhibitory activity at 1% CA+1% ASM, 1% CA and in the control was 87.338, 75.486 and 67.983%, and the tyrosinase inhibitory of these samples were 77.891, 67.598 and 26.375%, respectively. Anthocyanin contents, DPPH radical scavenging, elastase inhibitory and tyrosinase inhibitory activities were significantly different (p<0.05) between the 1% CA+1% ASM treatment and control. During the heat treatment, quality degradation of concentrated blueberry juice was reduced by the 1% CA+1% ASM treatment, as expected for new acidulants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.10
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• pp.1518-1524
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• 2016

This study was performed to minimize quality degradation of concentrated strawberry puree after $90^{\circ}C$ for 5 min by heat treatment with citric acid (CA) and acidic sodium metaphosphate (ASM) as pH modifiers. The highest color value was 1% CA+1% ASM (13.027), followed by 1% CA (9.539) and control (6.905). Anthocyanin contents were also 1% CA+1% ASM (3.049 mg/100 g), 1% CA (1.140 mg/100 g), and control (0.757 mg/100 g) in sequence. The DPPH radical scavenging activities of control, 1% CA, and 1% CA+1% ASM were 58.148, 72.638, and 83.736%, respectively. The color values, anthocyanin contents, and DPPH radical scavenging activities were significantly different at P<0.05 between control and 1% CA+1% ASM treatment. For the results of overall preference for hedonic test, there was no significant difference at P>0.05 among the three samples. During heat treatment, quality degradation of concentrated strawberry puree was reduced by 1% CA+1% ASM treatment, which is expected for new acidulants.