• Journal of the Korean Society of Food Culture
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• v.21 no.4
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• pp.420-425
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• 2006

This study was conducted to produce vinegar using maesil. Acetic acid bacteria was 20 strains isolated from several conventional vinegars. Among the isolates, a strain showed highest acetic acid productivity was selected and identified as Acetobacter sp. SK-7. The optimum medium of acetic acid production by Acetobacter sp. SK-7 was 30% of maesil juice, 4% of ethanol, and 2% of starting acidity and 0.2% of glucose. Optomum condition for the high yield of acetic acid was in the shaking culture at 30$^{\cire}$. The acidity of culture medium was reached to 7.1% after 12 days fermentation. Organic acid was identify 6 kinds containing acetic acid. The total content was 7,068.7 mg% after 12 days and malic acid slowly decreased and acetaic and citirc acid gradationally increased according to fermentation

• Journal of the East Asian Society of Dietary Life
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• v.21 no.6
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• pp.844-852
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• 2011

The purpose of this study was to determine the optimum chemical composition, color value, salinity, pH, total acidity, and texture for the production of short-term Green Gochujang using Cheongyang pepper powder and Meju powder. The results were as follows. The moisture content for Green Gochujang made from Cheongyang pepper powder was 33.50% for CON, and 27.21% for GG1. Crude fat and crude protein contents increased as the amount of added Meju powder increased (p<0.001). GG1 and CON contained 9.47% and 9.05% crude ash contents. Water activity was between 0.89 to 0.90. A higher amount of added Meju powder resulted in an increased color L value (p<0.001). CON showed the highest a value and b value compared to GG4, which had the lowest a and b values. Salinity was between 5.10% to 5.83%, which was lower compared to a former study. CON had a pH of 5.25, and GG4 had a pH of 6.06. Regarding total acidity, CON had a total acidity of 0.85, and GG4 had a total acidity of 0.44. Hardness value was highest in GG1 (1535.63), and lowest in CON (422.07) (p<0.001). GG1 showed the highest value in the adhesiveness property test, whereas CON showed the lowest value. GG1, which contained the highest amount of Cheongyang pepper powder showed the highest gumminess value (698.47). In an acceptance test, CON and GG3 showed the best appearance and scent value. GG3 received the highest interest in taste, texture, and overall quality. Through these results, GG3 made with 150 g of Chengyang Green pepper powder, 200 g of Meju powder, 600 g of starch syrup, 500 g of water, and 75 g of salt showed fine overall sensory interest, and therefore can be used for the production of fine Green Gochujang and Gochujang sauce.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.26 no.2
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• pp.71-76
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• 2020

CO₂ concentration in kimchi package has emerged recently as a potential index of product ripening to be monitored or sensed in intelligent packaging. Considering that addition of CO₂ absorber into the flexible kimchi package changes behavior of its CO₂ concentration, ripening of kimchi in total acidity, package CO₂ concentration in partial pressure (P_CO2) and package volume at 10℃ were estimated by mathematical model for two size packages included with different CO₂ absorbers. In small size package containing 0.5 kg of kimchi, relatively less gas permeable low density polyethylene (LDPE) sachet of the absorber was found to give rise of P_CO2 linearly correlated with acidity at acceptable conditions of absorber amount and size. The levels of P_CO2 at optimum ripening were different with absorber amount. However, highly gas permeable microporous spunbonded film (Tyvek) sachet did not show the linear relationship except a condition of 1.5 g of CO₂ absorbent. In large size package containing 2.0 kg, absorber sachets of LDPE and Tyvek could give the linear relationship between product acidity and package P_CO2 but at different levels (P_CO2 of package with LDPE sachet: 0.46~0.79 bar, P_CO2 of package with Tyvek sachet: 0.00~0.75 bar). The P_CO2 at optimal ripening was found to be less variable with LDPE sachets than with Tyvek ones. Use of package CO₂ concentration as an indicator of kimchi ripening was shown to be possible on the limited conditions where the linear relationship between them is established or confirmed.

• Korean Journal of Materials Research
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• v.32 no.3
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• pp.125-131
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• 2022

Effect of sulfation processes on the physicochemical properties of ZrO₂ and TiO₂ nanoparticles were thoroughly investigated. SO₄/ZrO₂ and SO₄/TiO₂ catalysts were synthesized to identify the acidity character of each. The wet impregnation method of ZrO₂ and TiO₂ nanoparticles was employed using H2SO₄ with various concentrations of 0.5, 0.75, and 1 M, followed by calcination at 400, 500, and 600 ℃ to obtain optimum conditions of the catalyst synthesis process. The highest total acidity was found when using 1 M SO₄/ZrO₂-500 and 1 M SO₄/TiO₂-500 catalysts, with total acidity values of 2.642 and 6.920 mmol/g, respectively. Sulfation increases titania particles via agglomeration. In contrast, sulfation did not practically change the size of zirconia particles. The sulfation process causes color of both catalyst particles to brighten due to the presence of sulfate. There was a decrease in surface area and pore volume of catalysts after sulfation; the materials' mesoporous structural properties were confirmed. The 1 M SO₄/ZrO₂ and 1 M SO₄/TiO₂ catalysts calcined at 500 ℃ are the best candidate heterogeneous acid catalysts synthesized in thus work.

• Journal of Dairy Science and Biotechnology
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• v.33 no.3
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• pp.215-221
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• 2015

This study aimed to establish the optimum culture conditions for Mozzarella cheese by using Streptococcus macedonicus LC743, a strain selected for its immunomodulatory activity. For process optimization, 1.0% and 2.0% strain was inoculated and incubated at $32^{\circ}C$ and $35^{\circ}C$, respectively. The general components, bacterial count, total solids, yields, and immunomodulatory activity of the Mozzarella cheese were investigated. When the strain was inoculated at 2.0% and incubated at $32^{\circ}C$, the product quality and immunomodulatory activity was optimal and required minimal processing time. Therefore, 2.0% of S. macedonicus LC743 starter culture was added to milk at $32^{\circ}C$, after pasteurization at $63^{\circ}C$ for 30 min, and agitated for 4~5 min after addition of $230{\mu}L/kg$ of rennet. Curd was made by setting the milk 25~35 min after addition of 0.01~0.02% calcium chloride. The curd was cut at 0.1~0.12% acidity (81 min later) and after heating the cheese to up to $43^{\circ}C$. Whey was removed at an acidity of 0.17~0.18% by agitation for 53 min. Next, cheddaring for 210 min up to an acidity of 0.6~0.65%, stretching at $72{\sim}75^{\circ}C$, and molding at $65{\sim}70^{\circ}C$ were performed, and the product was allowed to cool down to $5^{\circ}C$. Salting was done with a solution of $18{\sim}20^{\circ}B{\acute{e}}$ at $12^{\circ}C$ for 20 min and drying occurred at 80~90% relative humidity at $10^{\circ}C$ for 2~3 days.

• Food Science and Preservation
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• v.6 no.1
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• pp.55-60
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• 1999

A three variables by three level factorial design and response surface methodology were used to determine optimum conditions for osmotic dehydration of banana. The moisture loss, solid gain, weight loss and reduction of moisture content after osmotic dehydration were increased as temperature, sugar concentration and immersion time increased. The effect of concentration was more significant than those of temperature and time on mass transfer. Color difference and titratable acidity were decreased by higher concentration. Sweetness was increased by increasing sugar concentration, temperature, immersion time during osmotic dehydration. The regression models showed a significant lack of fit (p>0.5) and were highly significant with satisfying values of R2. To optimize osmotic dehydration, based on surface response and contour plots, superimposing the individual contour plots for the response variables. the optimum conditions for this process wire 26$^{\circ}C$, 44 $^{\circ}$brix and 2 hrs for moisture content, sweetness and color difference are less than 72%, 24 obrix and 10 degree.

• The Korean Journal of Food And Nutrition
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• v.3 no.2
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• pp.141-148
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• 1990

This studies were carried out to investigate the effects of non-volatile organic acids in the KimChi by lactic acid bacteria. The organism isolated from KimChi, Pediococcus dextrinicus, Leuconostoc mesenteroides, Lactobacillus plantarum and Lactobacillus brevis, were inoculated for preparation of KimChi. pH of all on the KimChi sample dropped sharply according as fermentation continued. pH of on optimum ripening period KimChi(4.4 and 4.2) reached 1.3 and 1.9 day at all on sample, respectively. Optimum acidity(0.5%) of KimChi were reached within 2 day all on sample. The total number of lactic acid bacteria reached 1.0X107cells/ml in 1 day and decreased slowly after 4 day. Main non-volatile organic acids were identified lactic, malic and succinic acid. The sensory score of mixed lactic acid bacteria inoculated KimChi was better than that of another KimChi.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.4
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• pp.377-380
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• 1992

To produce economically important acid with pear juice, an acetic acid bacterium was selected from many isolated acetic acid bacteria. The alcohoic fermentation was conducted by inoculating pear juice with Saccharomyces cerevisiae ATCC 4124, and then the pear vinegar was prepared by batch cultivation in flaskes with the isolated Acetobacter sp. The optimum conditions for high yield of acetic acid were studied experimentally in the batch shake flask . For seed purposes the Acetobactor sp. was cultivated for 2 -days and transferred to the acid production medium . Optimum alcohol concentration, initial acidity and temperature for the acid production were 8.0% , 2.0% and 28$^{\circ}C$, respectively. Under the same conditions, the addition of yeast extract (1%) was observed to produce relatively high yield of acetic acid.

• Korean journal of food and cookery science
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• v.22 no.6 s.96
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• pp.832-839
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• 2006

Kugija was added to Nabak kimchi to improve the quality and preservation and the optimum addition level was assessed. Kugija extract was prepared by boiling kugija fruits, at different ratios (0, 1, 3, 5, 7%; w/v) in water for 30 minutes. The changes in the physicochemical properties of the Nabak kimchi were measured during storage for 25 days at 10?, and compared to a control (without kugija). The pH was decreased in all treatments. Following the fermentation of Nabak kimchi, the total acidity values were inversely proportional the pH changes according to the nature of mutual dependence. However, in short term, during the initial 7 days of fermentation, the total acidity values decreased with increasing concentrations of kugija extract, whereas the trend was reversed after day 10. Total vitamin C content was directly proportional to the concentration of kugija extract and was decreased with the laps of fermentation. Up to day 25, 7% treatment showed the highest vitamin C content, but at 25 days 1% and 3% treatments ranked the first. The mont of reducing sugar was proportional to the concentration of kugija extract however, the difference of values between all treatments became almost indiscernible after day 25. Turbidity values were generally increased in all samples during fermentation period, although only to a limited extent. The lowest turbidity was shown at 3% treatment up to day 16. Total color difference values were increased up to day 16, but then decreased. The optimum level of kugija extract in Nabak kimchi, as determined through these experiments, was between 1 to 3% per added water content, and was preferably 3% for color and fermentation-retarding effect of the product. Kugija extract could be applied for improving the quality and preservation of traditionally prepared Nabak kimchi.

• Korean Journal of Food Science and Technology
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• v.16 no.2
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• pp.143-148
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• 1984

The effects of various nutrients added to soy protein concentrate (SPC)-yogurt on the growth of Lactobacillus acidophilus and the flavor of SPC-yogurt were investigated. Soy milk was prepared from SPC (4.2% as protein) and various nutrients. One hundred ml of the prepared soy milk was given proper heat treatment, inoculated with 2.5ml of 24 hr-old culture, and incubated for 24 hr at $37^{\circ}C$. The growth of L. acidophilus was estimated from viable cell counts, titratable acidity and pH. The growth curve obtained from the experiment suggested that the log phase ended after 6 hr and the stationary phase ended after 30 hr. Glucose and fructose greatly enhanced the acid production by L. acidophilus. The optimum concentration of these two sugars in the media was approximately 3% each. Yeast extract greatly stimulated the acid production by L. acidophilus, and the optimum concentration of this additive was approximately 0.5%. Higher concentration of SPC resulted in slightly higher acidity in soy yogurt.