• Applied Biological Chemistry
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• v.41 no.2
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• pp.166-174
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• 1998

The effects of some organic acids on the shelf life of cooked noodle and the change in textural properties were studied. Organic acids used were vinegar, lactic, citric and malic acid. The pH of noodle was adjusted to $4.7{\pm}0.25$ by dipping it in each solution for 30 seconds. Total microbial count and turbidity of the treated samples were measured storage for 4 days at $15^{\circ}C$. The total count was high in order of control, malic, citric, lactic acid and vinegar. High turbidity was observed in order of control, lactic, malic, citric acid and vinegar. Hardness, adhesiveness, cohesivenes and springiness were measured for 30 days at $35^{\circ}C$ using Rheometer along with concurrent sensory evaluation. The acid treated samples showed higher values in hardness and cohesiveness than control but lower in adhesiveness and springiness. After 30 days storage, the malic or citric acid treated sample led to a somewhat higher gumminess than control. Based on the sensory evaluation the malic acid treated noodle significantly exhibited the highest score followed by citric, lactic acid, control and vinegar.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.1
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• pp.78-84
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• 1993

This study was conducted to investigate the effect of various polyethylene (PE) film packaging on the quality of strawberry during storage at low temperature. Gas composition in film was changed rapidly at early stage of storage and then kept at the level of 5~10% $CO_2$and 1~3% $O_2$. Weight loss and decay rate were low at 0.08mm PE film packed strawberries. Titratable acidity, pH and soluble solids were changed slightly during storage but its large difference according to film thickness was not observed. Decrease of flesh firm-ness and a value was restrained by PE film packaging. Free sugar of strawberry was composed of glucose and fructose in similar content and it was decreased a little during storage but the difference according to film thickness was not observed. The organic acids in strawberry were citric acid, malic acid, succinic acid, ascorbir acid, oxalic acid, tartaric acid and pyruvic acid and the major organic acid was citric acid. The contents of citric acid, malic acid, succinir acid and ascorbic acid were decreased and oxalic acid and tartaric arid were not changed during storage but pyruvic acid was increased in early stage and then decreased. These changes of organic acid were slight in packaged with 0.08mm PE film strawberry.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.913-918
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• 1997

Taste components of traditional kochujang prepared with various raw materials, were investigated during 90 days of fermentation. The major free sugars, maltose and glucose, were higher in malt added kochujang than others. The major organic acids of kochujang were succinic and citric acids, followed by formic acid. The contents of succinic acid in the kochujang decreased during fermentation, whereas that of citric acid increased. Purple sweet potato kochujang was highest in total free amino acids. The major free amino acids were glutamic acid, serine and aspartic acid. They remarkably increased during fermentation. Among the nucleotides and their related components in kochujang, cytidine-5-monophosphate was the most abundant component at the beginning of aging period, while hypoxanthine increased remarkably during fermentation. Kochujang prepared with purple sweet potato Chinese matrimony vine contained higher amounts of organic acids and nucleotides than the others.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.4
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• pp.305-310
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• 1990

The extracts of dried squid(Sepiella maindron) were prepared with water and 70% ethanol at boiling point and the major nonvolatile organic acids in the extracts were investigated. Eight kinds of nonvolatile organic acid were identified as lactic oxalic succinic malic citric pyroglutamic malonic and ${\beta}-ketoglutaric$ acid. Total amount of nonvolatile organic acid in the extracts prepared with water changed from 205.2mg% to 310.1mg% with extraction time while the extracts prepared with 70% ethanol were 272.4 mg% ~ 347.6 mg% The major compo-nents were in the range of 61.7% ~ 70.9% lactic acid 16.4 ~ 22.6% pyroglutamic acid 5.0 ~ 9.9% succinic acid 4.0 ~ 8.2% citric acid and total amount of nonvolatile organic acids in the extracts increased until 2 hour of extraction regardless of extraction solvent and then decreased slowly.

• Food Science and Preservation
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• v.11 no.3
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• pp.331-335
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• 2004

This study was carried out to improve quality of minimally processed lettuce with various treatments. The treatments for preventing enzymatic browning were using different chemical immersion solutions and controlling microbial growth were using chlorine, electrolyzed water, and organic acid. The solution with ascorbic acid 1$\%$ and citric acid 1 $\%$ showed a positive effect on antibrowning of minimally processed lettuce. In the inhibition of microorganisms growth, 200 ppm NaCIO solution was more effective than fermented pollen solution and Na-dichloroisocyanurate solution. In electrolyzed water system, no-diaphragm system showed inhibitory effect of microorganisms growth. Also, total microorganisms count of minimally processed lettuce with ascorbic acid and citric acid solution was lower by about 4 log cycle after 4 days storage at l0$^{\circ}C$.

• The Korean Journal of Food And Nutrition
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• v.17 no.2
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• pp.212-219
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• 2004

In this study, we compared that sensory characteristics and nutritional components of ice cream supplements with various levels(1, 2, 3％) raw and frozen citron juice. Vitamin C was not detected in frozen citron juice 1％ added group. The content of vitamin C was 4.7 mg/100g in raw citron juice 3％ added group. But it detected 1.0 mg/100g in 3％ frozen citron juice added group. Free sugars were detected sucrose, lactose and maltose. Those amounts of all samples were lower than control group and were lower goes to citron juice added ratio higher. Organic acids in ice creams were detected oxalic acid, malonic acid, malic acid and citric acid. The citric acid content was higher than other organic acid. Especially, citric acid content was the highest in raw citron juice 3％ added group (6.3 mg/100g). But it's content was low in all frozen citron juice added groups (0.5-0.6 mg/100g). Mineral contents of ice creams were highest in raw citron juice 3％ added group (3399.96 mg/100g). The results of sensory test, citron aroma and citron taste were the highest in raw citron juice 3％ added group. Overall acceptability was the highest in frozen citron juice 2％ added group.

• Journal of the Korean Society of Tobacco Science
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• v.14 no.2
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• pp.151-158
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• 1992

Field experiment was conducted to investigate the effects of stalk position, compound fertilizer application rate (N-P2O5-K2O : 10-10-20 : 75, 100, 125kg/03), paddy and upland soil and varieties, NC82 &KF103, on nonvolatile organic and higher fatty acids of flue-cured tobacco. Followed by stalk position, malic, citric, malonic and succinic acid contents were significantly increased with higher stalk position, but oleic and linoleic acid contents were decreased with higher stalk position. The higher application rate of compound fertilizer results in increasing citric, malic, malonic and succinic acid contents, but the contents of higher fatty acids were not significantly influenced by fertilizer application rate. The cured leaf cultivated in paddy soil was higher citric and malic acid contents than in upland soil, but the contents of higher fatty acids have no difference between paddy and upland soil. The variety of KF103 was higher citric and linoleic acid contents than that of NC82, but the contents of higher fatty acids have no difference between varieties.

• Korean Journal of Materials Research
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• v.19 no.3
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• pp.174-178
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• 2009

The effects of post-CMP cleaning on the chemical and galvanic corrosion of copper (Cu) and titanium (Ti) were studied in patterned silicon (Si) wafers. First, variation of the corrosion rate was investigated as a function of the concentration of citric acid that was included in both the CMP slurry and the post-CMP solution. The open circuit potential (OCP) of Cu decreased as the citric acid concentration increased. In contrast with Cu, the OCP of titanium (Ti) increased as this concentration increased. The gap in the OCP between Cu and Ti increased as citric acid concentration increased, which increased the galvanic corrosion rate between Cu and Ti. The corrosion rates of Cu showed a linear relationship with the concentrations of citric acid. Second, the effect of Triton X-$100^{(R)}$, a nonionic surfactant, in a post-CMP solution on the electrochemical characteristics of the specimens was also investigated. The OCP of Cu decreased as the surfactant concentration increased. In contrast with Cu, the OCP of Ti increased greatly as this concentration increased. Given that Triton X-$100^{(R)}$ changes its micelle structure according to its concentration in the solution, the corrosion rate of each concentration was tested.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.30-34
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• 2000

Salted Chinese cabbage was washed in 1,000 ppm solutions of grapefruit seed extract(GFSE) or citric acid, and used to make kimchi for the retentio of quality characteristics during fermentation at $10^{\circ}C$. Kimchi treated with GFSE or citric acid showed a retarded increase in titratable acidity and decrease in pH and reducing sugar content. Total microbial count and lactic acid bacteria of GFSE treated kimchi were about 1.1 log(CFU/g) lower than those of control and citric acid treated kimchi after making, but the difference was gradually reduced during fermentation.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.4
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• pp.973-980
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• 2015

This study was done to investigate the quality characteristics of salmon frame with citric acid pretreatment. Sliced salmon frame samples were cured in soy sauce, sugar, pepper, and sodium nitrate for 12 h and then dried at 3 h and then dried at $60^{\circ}C$ for 3 h. As the autoclaving at $130^{\circ}C$ for 15 min, the pH, moisture content, crude ash, crude fat, crude protein, acid value (AV), peroxide value (POV), volatile basic nitrogen (VBN), trimethylamine (TMA), total plate count and E. coli were measured at $4^{\circ}C$, $25^{\circ}C$ and $35^{\circ}C$ of storage days. The AV, POV, VBN, TMA and total plate count for all samples significantly increased as during storage days (p<0.05). All samples of storage, for autoclaving on salmon frame, there were no growth on E.coli. In the making of autoclaving on salmon frame, technologies for more safety from microbial growth should accompany pretreatment with citric acid.