• Food Science of Animal Resources
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• v.33 no.6
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• pp.744-751
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• 2013

The objective of this study was to assess the physicochemical and sensory changes of a kefir manufactured by a two-step fermentation (MTY, $1^{st}$ step: $37^{\circ}C$ for 9 h; $2^{nd}$ step: $24^{\circ}C$ for 15 h) and compare it with kefirs produced by two conventional methods (GTY, fermentation at $37^{\circ}C$ for 24 h; KEY, $22^{\circ}C$ for 24 h). Rapid changes in pH and titratable acidity (TA) were observed in samples from all three manufacturing methods during fermentation process and storage period. Lactic acid bacteria (LAB) counts of MTY increased gradually up to 12 h of fermentation, reaching 9.28 Log CFU/mL, with maximum value observed in this experiment of 9.48 Log CFU/mL. The LAB counts of all samples decreased significantly during storage. The highest viscosity was observed for MTY (1750-1771 cPs), compared with the lowest viscosity observed for KEY (1250-1277 cPs). The viscosity of all samples increased slightly during storage (1250-1805 cPs, p<0.05), as well as carbon dioxide content (0.01-1.36%, p<0.05), except for GTY. The most significant increase in alcohol concentration during storage period was seen in MTY from 0.01% to 1.36% (p<0.05). MTY scored significantly higher in most items of the sensory analysis, indicating that the product manufactured by the two-step fermentation method is more acceptable compared with conventionally produced kefirs.

• The Korean Journal of Food And Nutrition
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• v.29 no.5
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• pp.706-715
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• 2016

Nutritional composition and physicochemical properties changes in mustard leaf kimchi were investigated during fermentation of up to 3 months. The pH decreased, and the titratable acidity gradually increased according to increase of fermentation periods. Fructose and glucose were the major free sugars in mustard leaf kimchi, and their amounts were significantly decreased with fermentation periods (p<0.05). Lactic acid content showed a significant increase with maximum increase at 3 months. All types of kimchi contained 20 amino acids, but the content of most amino acid fluctuated during fermentation. Except for K and Zn, the content of other ingredients including Ca, Fe, Mg, Na, Se were the highest in kimchi fermented for 2 months. The unsaturated fatty acid of mustard leaf kimchi was higher than that of saturated fatty acid, and total fatty acid of kimchi significantly decreased after 2 months (p<0.05). Most vitamin contents showed a tendency to decrease with fermentation, in particular, vitamin B complex except for $B_2$ significantly decreased after 3 months (p<0.05). The results provide fundamental data for determining the appropriate fermentation period to improve the quality of kimchi.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.1
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• pp.1-9
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• 1998

This study was designed to determine the most suitable manufacturing conditions of stewed pumpkin juice(SPJ) in terms of nutrition and taste. Well ripened pumpkin was heated for 3, 4, 5, 6 and 7 hours in a pressure cooker and then extracted and packed in retort pouches. These were kept at 4$^{\circ}C$ and 28$^{\circ}C$ for 30 days, respectively and changes of the physicochemical components of SPJ were investigated. The free amino acid compositions of pumpkin and SPJ occupied asparagine, aspartic acid, glutamine, arginine and serine in increasing order of abundance. Except SPJ heated for 3 hours, SPJ stored at 28$^{\circ}C$ had the most abundant free amino acids, followed by SPJ stored at 4$^{\circ}C$, and SPJ not stored. The fatty acid composition of pumpkin occupied behenic acid, erucic acid, palmitic acid, linoleic acid, heneicosanoic aicd, in order of abundance. When SPJ was heated over 3 hours, palmitic acid and linolenic acid decreased greatly. SPJ stored at 4$^{\circ}C$ and 28$^{\circ}C$ increased contents of saturated fatty acids such as behenic acid, palmitic acid than SPJ not stored. As SPJ was heated for a long time, carotenoid was mostly destroyed and the Hunter "L", "a" and "b" values of SPJ decreased. Among the mineral constituents of SPJ, Na and Ca were dominantly occupied. It was found that the range of the total visible cell count was 3~4CFU/ml from the SPJ which was heated for 3 hours and it increased by 1$\times$109CFU/ml when the SPJ was stored at 28$^{\circ}C$. It seems that the contamination by microorganism have occurred at packing process. In sensory evaluation, the SPJ which was heated for 5 hours had the highest scores in overall preference, sweet smell and sweetness.ce, sweet smell and sweetness.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1267-1272
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• 1998

The changes in physicochemical properties of gamma irradiated porks were investigated during storage at different temperature and periods. TBA values increased according to the increment of irradiation dose levels. TBA values of nonirradiated and irradiated samples drastically increased with storage period and temperatures at both $5^{\circ}C\;and\;-20^{\circ}C$. The acid value of porks stored at $5^{\circ}C$ was increased rapidly with the elapse of storage period in both nonirradiated and irradiated samples. However, the value decreased with increasing irradiation dose levels. VBN values increased more rapidly in nonirradiated samples than in irradiated samples with the storage period. Especially, VBN value of nonirradiated pork was four times higher than that of 3 kGy-irradiated one. No significant differences in the composition of fatty acids were observed in gamma irradiated samples. Free amino acids were changed with storage periods, but were not significantly affected by gamma irradiation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.601-605
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• 1997

Physicochemical properties of kochujang and doenjang using extrudated wheat flour(EWF) during aging were evaluated. Moisture content and crude protein were no great changes during fermentation and among samples(En, wheat flour, and wheat). NaCl and pH value were decreased(pH was decreased from 5.1 to 4.7 for kochujang and 5.4 to 5.0 for doenjang in EWF) and while titratable acidity increased during aging in each samples(8.7 to 9.1 for kochujang and 11.0 to 11.3 for doenjang in EWF). Amino acid type nitrogen and color value were decreased. En had the highest a value(5.9 for kochujang and 5.3 for doenjang) after 30 days fermentation. This results showed the applicability of good quality of kochujang and doenjang prepared with EWF.

• Journal of Soil and Groundwater Environment
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• v.17 no.4
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• pp.36-43
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• 2012

Various methods are used to remediate soil contaminated with heavy metals or petroleum. In recent years, harsh physical and chemical remediation methods are being used to increase remediation efficiency, however, such processes could affect soil properties and degrade the ecological functions of the soil. Effects of soil washing, thermal desorption, and land farming, which are the most frequently used remediation methods, on the physicochemical properties of remediated soil were investigated in this study. For soils smaller than 2 mm, the soil texture were changed from sandy clay loam to sandy loam because of the decrease in the clay content after soil washing, and from loamy sand to sandy loam because of the decrease in the sand content and increase in silt content during thermal desorption, however, the soil texture remained unchanged after land farming process. The water-holding capacity, organic matter content, and total nitrogen concentration of the tested soil decreased after soil washing. A change in soil color and an increase in the available phosphate concentration were observed after thermal desorption. Exchangeable cations, total nitrogen, and available phosphate concentration were found to decrease after land farming; these components were probably used by microorganisms during as well as after the land farming process because microbial processes remain active even after land farming. A study of these changes can provide information useful for the reuse of remediated soil. However, it is insufficient to assess only soil physicochemical properties from the viewpoint of the reuse of remediated soil. Potential risks and ecological functions of remediated soil should also be considered to realize sustainable soil use.

• The Korean Journal of Food And Nutrition
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• v.36 no.6
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• pp.526-534
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• 2023

To improve usability of super sweet corn, extracts were prepared with hydrolytic enzyme and changes in physicochemical and antioxidant properties were analyzed. Soluble solids and reducing sugars contents were higher in all enzyme treatment groups than in the control. When enzyme treatment time increased, contents of soluble solids and reducing sugars were also increased. There was no significant difference in lightness between treatment groups, with redness showing the highest value in the control and yellowness showing the highest value in the invertase treatment group. Free sugar content in the control was the lowest. However free sugar content in the enzyme combination treatment group was increased by more than four times compared to that in the control. Contents of ascorbic acid, flavonoids and polyphenols were higher in the enzyme treatment group than in the control. In particular, the enzyme combination treatment group showed the highest content. DPPH and ABTS radical scavenging abilities were significantly higher in all enzyme treatment groups than in the control. Radical scavenging abilities of cellulase treatment group and enzyme combination treatment group showed high activity. The activity increased when enzyme treatment time increased. The combined enzyme treatment method for super sweet corn was suitable for food processing.

• Journal of Animal Environmental Science
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• v.3 no.1
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• pp.13-18
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• 1997

This study was conducted to investigate the physicochemical changes during the aerobic composting of swine manure mixed with bulking agent, sawdust(v/v, 1:1), in a full-scale composting plant using rectangular escalator-aginated bed composting system. Physical and chemical properties were analyzed on the samples which were collected at 5, 15, and 25 day of composting, curing and final step. The results of this study were summarized as follows; 1. Moisture and K2O content, and pH of final step were higher than those of 5th day of composting (p＜0.05). 2. Ammonium nitrogen, total organic corbon and organic matter content, and electrical conductivity(EC) were significantly decreased (p＜0.05) but nitrate nitrogen, ash and P2O5 content increased(p＜0.05) throughout the aerobic composting process. 3. Total organic carbon per total nitrogen(C/N) and total organic matter per total nitrogen(OM/N) ratio were significantly decreased throughout the aerobic composting process(p＜0.05). 4. Physical and chemical properties of swine manure were varied by aerobic fermentation using rectangular escalor-aginated bed composting system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.3
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• pp.115-120
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• 1989

Physicochemical changes were investigated during repeated freezing and thawing processes using fish meat paste of alaska pollack (Theragra chalcogramma). During repeated thawing process, the solubility of myofibrillar protein, $Ca^{++}-ATPase$ activity, water holding capacity (WHC), electrophoretic patterns and rheological properties were evaluated at various thawing temperatures. Solubility of myofibrillar protein and $Ca^{++}-ATPase$ activity were decreased with increasing thawing temperatures. Thawing temperatures and the frequency of freezing and thawing processes did not affect WHC significantly. Upon repeated freezing and thawing cycles, electrophoretic patterns showed that only the amount of myosin heavy chain was decreased, whereas the amount of actin remained constant. Young's modulus for viscoelasticity of fish meat pastes increased with increasing thawing temperatures and the value showed maximum at third cycle and decreased thereafter.