• Applied Biological Chemistry
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• v.30 no.1
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• pp.1-8
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• 1987

The distribution of the surface charges in two kinds of peats and their physico-chemical properties have a been studied by means of the potentiometric titration and by ion adsorption in different strength of electrolytes. The organic matter contents were 43.3% and 53.7% in Yeong Yang peat and Peong Tack peat, respectively. Their X-ray diffractograms showed that quartz was dominant in both peats, and illite, kaolinite, hydrated-halloysite and feldspars were contained in a trace. Total acidic group contents was 1.257me/g in Poeng Tack peat that was a little more than of Peong Yang heat were pKa values of Yeong Yang and Poeng Tack peat were 13.1 and 12.65, respectively. The titration curves at different ionic strength of electrolytes crossed at pH 3.9 and 4.4 in Yeong Yang peat, and pH 3.8 and 4.0 in Peong Tack peat. The pH ranges of suspensions when the net surfacecharge of the peats varied from positive to negative value were $pH\;4.55{\sim}5.20\;(NaCl)$ and $pH\;3.95{\sim}5.70\;(CaCl_2)$ in Yeong Fang peat, and $pH\;4.15{\sim}5.40\;(NaCl)$ and $pH\;3.80{\sim}4.15\;(CaCl_2)$ in Peong Tack peat. Therefore it is apparent that the zero point of charge of these peats was about pH 4.0.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.12
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• pp.1799-1805
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• 2015

Rice vinegar (RV) is primarily made from fermented rice or rice wine in Korea, China, and Japan. Ten commercially available naturally-fermented rice vinegars produced in Korea (KRV1~4), China (CRV1~2), and Japan (JRV1~4) were comparatively investigated for their physicochemical properties and antioxidant activities. KRV showed a significantly higher total acidity range (5.07~6.27) than both CRV (4.67~4.84) and JRV (4.64~4.84). These acidity ranges corresponded with respective standards of each country: Korea (Food Code), China (GB), and Japan (JAS). Six different organic acids were detected in RVs; acetic acid and succinic acid were the most prominent. Thirty different amino acids were detected in RVs, and main identified amino acids were alanine (KRV), phenylalanine and aspartic acid (CRV), and leucine and alanine (JRV). ${\gamma}-Aminobutyric$ acid was detected at high concentration in KRV1. KRV1 showed maximum total phenolic content, and DPPH and ABTS radical scavenging activities of samples were also determined with significantly increasing tendency. KRV1 (produced from brown rice with aging period of >1 year) exhibited the highest free amino acid content and antioxidant activity as compared to CRV and JRV.

• Korean Journal of Environmental Agriculture
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• v.26 no.4
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• pp.313-318
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• 2007

In greenhouse farming, a variety of humic acids have been applied to improve soil conditions and plant growth. However, it is still unclear that how humic acids combined with chemical fertilizers affect growth and quality of fruit vegetable crops. This study was conducted to determine the combination effect of humic acids and chemical fertilizers on the growth and fruit quality of tomato (Lycopersicon esculentum MILL.) grown under greenhouse conditions. Three different formulation types of humic acid were used: liquid type A, liquid type B and solid type C. The tomato plants were grown in three treatment combination plots and in conventional fertilizer (CF) plot with recommended levels of nitrogen, phosphorus and potassium: HA combined with CF (HA+CF), HB combined with CF (HB+CF) and HC combined with CF (HC+CF). For most of growth characteristics (i.e. leaf number, internode length, maximum leaf length, leaf width and chlorophyll contents) determined in this experiment, no significant differences were observed between all combination treatments and CF. However, integrated fruit qualities (i.e. averaged weight, sugar contents and acidity) were slightly improved in the humic acid combined with CF treatments when compared with CF alone treatment. No phytotoxicity was observed with humic acid treatments. However, further studies will probably be needed to use widely and safely these humic acids, in order to ensure a maximizing growth, fruit yield and quality of tomato.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.1
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• pp.52-61
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• 2009

In this study, we evaluated the effects of sesame powder on the fermentation of Baechukimchi, by assessing sensory, physicochemical, and microbiological properties during up to 25 days of fermentation. The Baechukimchi, with various levels [0, 1, 2, 3, 4%(w/w)] of sesame powder, was fermented at $10^{\circ}C$. The product containing the control and 1% sesame powder evidenced the highest scores for appearance and smell. Taste and texture were highest in the 1% and 2% sesame powder, and the overall acceptability was highest in the 2% sesame powder sample. During fermentation, titratable acidity increased while pH gradually decreased. pH was higher in the sample with sesame powder than in the control, and the titratable acidity increased with increasing sesame powder content on day O. Reducing sugar increased sharply during fermentation, and then gradually decreased. In particular, the 2% sesame powder sample maintained the highest content. Total vitamin C was slightly increased at initial fermentation and then steadily decreased. The total polyphenol content and antioxidant effect of the experimental groups with added sesame powder were higher than those of the controls. Additionally, the time required to achieve maximum levels of lactic acid bacteria, as determined by log numbers of cells and total viable cells, were more delayed in the experimental groups with added sesame powder than in the controls. Our results indicated that the Baechukimchi with $1{\sim}2%$ added sesame powder was acceptable.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.6
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• pp.977-985
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• 2002

In order to improve the quality of traditional kochujang, submaterials like sea tangle and chitosan were added to kochujang and their effects on microbial characteristics, enzyme activities and physicochemical characteristics were investigated for 24 weeks of fermentation. The activities of $\alpha$,$\beta$-amylase in kochujmg were higher in sea tangle added at 2% level and chitosan added at 0.1% level. However, acidic protease activity decreased as the ratio of submaterials increased. Viable cells of yeasts in the kochujang increased rapidly for 4~8 weeks of fermentation, and bacterial counts decreased in submaterials added groups. Moisture contents of kochujang increased until 12 weeks of fermentation, but water activity decreased. As the ratio of sea tangle increased, water activity decreased. Consistency of kochujang increased after middle of fermentation, and they increased remarkably by addition of sea tangle. The degree of increase in total color difference ($\Delta$E) of sea tangle added group was lowest. The titratable acidity of kochujang decreased after 4 weeks, and they changed a little by addition of chitosan. Amino nitrogen contents of kochujang increased as mixing ratio of submaterials increased in the late period of aging. Ammonia nitrogen contents was lower in chitosan added kochujang at 24 week of fermentation. Reducing sugar contents of kochujang increased rapidly for 4~8 weeks of fermentation, and they increased as the ratio of chitosan increased. Ethanol contents of kochujang increased until 12~16 weeks of fermentation, with lower values in sea tangle added group. After 24 weeks of fermentation, the result of sensory evaluation showed that 0.1% chitosan added kochujang were more acceptable than sea tangle added kochujang in the taste, color and overall acceptability.all acceptability.

• Korean Journal of Food Science and Technology
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• v.19 no.4
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• pp.338-345
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• 1987

The Physicochemical properties of six varieties of domestic orange and orange juices which were grown and produced in Korea, were analyzed their qualities, including taste evaluation based on the amount and the ratio of sugar and acid The physicochemical properties of mandarin were as follows soluble solid $10{\sim}11^{\circ}$ Bx, total acidity $0.76{\sim}1.20%$ ratio of sugar and acid $7.9{\sim}13.8$. Sugars of orange are mainly composed of sucrose, glucose, fructose. The sucrose content of mandarin was a little higher than that of sweet orange. The organic acids in orange were mainly citrate and malate. The content of these two acid in oranges were 0.8-1.4%. Mandarin type oranges tastes more sour than sweet orange. Hesperdin existed 30.8-67.5mg% in oranges. Naringin, one of the bitter components. was not detected in both varieties. The optimum sweetness and acid content were determined based on the results of sensory evaluation.

• Korean Journal of Food Science and Technology
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• v.4 no.4
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• pp.285-290
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• 1972

Oranges (Citrus unshiu var.) from local orchards at Seogwi, Daejeong, Hanrim, Cheju and Seongsan where are in the southern, southwestern, northwestern, northern and eastern parts of Cheju island respectively were stored in a semi-underground room and an air-circulating refrigerated store. To compare the storage qualities between the growing districts, changes in freshness, acidity and sugar content of oranges were investigated during storage. 1) Oranges from Seogwi and Cheju districts showed remarkably lower Percentage of rot fruits with no relation of storage temperature than those of Hanrim, Daejeong and Seongsan. 2) Browning of oil gland was severe on oranges of northern and southern districts while it was little developed in case of the other districts. 3) Water soluble total sugar content was gradually increased and titratable acidity and reducing sugar content of pulp tissues was decreased during storage. 4) Oranges from the western part showed the higher ratio of sugar content to acidity and better taste as compared with the east oranges.

• Food Science and Preservation
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• v.10 no.3
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• pp.333-338
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• 2003

pH values in all samples were in the range of 5.04 to 5.32. pH of kanjang prepared with normal pressure(NPK) was higher than that of kanjang prepared with high pressure(HPK) and kanjang prepared with steam(SPK). Titratable acidity(TA) in all samples were found to be 4.26～7.72 mL. TA in HPK(5.99～6.96 mL) was lower than that in SPK(4.26～5.61 mL) and NPK(7.32 mL). Reducing sugar(RS) contents in all samples were in the range of 25.18 to 194.81 mg％. RS contents of HPK and SPK were a similar pattern and were higher than that of NPK. Major free sugars(FS) were glucose, fructose and xylose. In total FS, SPK was higher than that of NPK and HPK. Major organic acids(OA) were succinic acid, oxalic acid, tartaric acid, malic acid and citric acid. In total OA contents, SPK(40.38～76.96 mg％) was higher than that of NPK(55.85 mg％)and HPK(27.78～34.21mg％). OA contents in HPK and SPK were decreased slightly according to the heating time of whole black bean. The highest percentage of fatty acid (FA) in all samples was palmitic acid(33.28～43.51 ％ as area ％ of GC chromatogram), followed in a decreasing order by stearic acid(14.15～19.16％) and myristic acid(5.93～19.14％). The composition ratios of three FA to total FA ranged from 55.97 to 72.85＆. In all samples, there was myristic acid that was not contained in raw soybean.

• Journal of the Korean Data and Information Science Society
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• v.20 no.2
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• pp.377-385
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• 2009

Twenty five female students in Seoul participated and were divided into two group in the experiment of weight loss effect of two treatments. Fourteen students(Treatment A group), randomly chosen from the students, had fed on diet foods and exercised over 8 weeks, and the remaining students(Treatment B group) had fed on diet foods only for the same periods. Weights of 25 students had been measured repeatedly four times at an interval of two weeks during 8 weeks, It resulted from mixed model analysis of repeated measurements data that separate Toeplitz pattern for each treatment group was selected as the optimal covariance pattern. Based upon the optimal covariance pattern model, the baseline effect and time effect were found to be highly significant, but the treatment-time interaction effect was found to be insignificant. Finally, the students with diet foods and exercises were more effective in losing weight than the students with only diet foods were.

• Journal of Dairy Science and Biotechnology
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• v.29 no.1
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• pp.41-47
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• 2011

The effects of adding Dandalion powder (Taraxacum mongolicum powder, TMP) to yoghurt manufacture on quality characteristics during the fermented and storage were investigated. Yoghurt samples were prepared with 0.3%, 0.6%, 0.9% TMP. Changes in Titratable acidity, Lactic acid bacterial (LAB) population, pH, viscosity, sensory characteristics were monitored during the fermented and storage. LAB and titratable acidity added with the TMP in yoghurt was higher, and pH, viscosity was lower than those of the control yoghurt during the fermented. Also the TMP yoghurt was lower viscosity than control in fermentation but this viscosity became to be increased higher than the control during storage. The sensory values of the yoghurt added with the TMP were low compared with the Control. Regarding taste, appearance, sensory properties it were suggested that the added optimum ratio of TMP for yoghurt was below 0.3%. This study suggests that dandalion powder (TMP) added yoghurt supply additional nutrients while maintaining the flavor and quality.