• Applied Biological Chemistry
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• v.34 no.2
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• pp.154-161
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• 1991

An objective method for measuring rancidity in soybean oil was developed based on the volatile contents obtained by headspace gas chromatographic analysis. Apparatus for headspace volatile cold trapping-thermal desorption was described, designed to collect and analyze volatiles of soybean oil. Samples of commercially processed soybean oil were stored under controlled condition and then evaluated for flavor by a eight member trained panel and for volatile contents by headspace gas chromatographic analysis. Twenty-three GC peaks were identified on the basis of relative retention time of reference compounds and gas chromatography-mass spectrometry. The volatile compounds identified were autoxidation products of principal unsaturated fatty acids of soybean oil. The simple linear regressions of flavor score with the pentanal or hexanal contents in aged soybean oil gave correlation coefficient of 0.990 and 0.994. respectively. Pentanal and hexanal contents could be used as a potentially useful index for predicting flavor scores of soybean oil.

• Food Science of Animal Resources
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• v.30 no.6
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• pp.1024-1030
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• 2010

The focus of the study was to maximize the output data for Korean cuisine. This study evaluated the nutritional retention factor for different cuts of Korean beef (Hanwoo beef) subjected to various cooking methods. Five cuts (short rib, sirloin, chuck roll, tenderloin, and fore shank) of Korean Hanwoo beef were prepared and used in this experiment. Two different cooking methods (dry-heat cooking and moisture-heat cooking) were applied to each cut. The sodium contents of dry-heat cooked short rib (86.44), sirloin (76.81), tenderloin (86.65), and fore shank (85.89) decreased. Potassium contents of dryheat cooked sirloin (94.99), chuck roll (89.19), and fore shank (92.66) decreased. Calcium contents of dry-heat cooked sirloin (61.49), chuck roll (73.97), and fore shank (91.46) decreased. Iron contents of dry-heat cooked chuck roll (79.71), and tenderloin (90.79) decreased. Phosphorus contents of dry-heat cooked sirloin (87.87), and tenderloin (99.88) decreased. Mineral contents of all cuts cooked by moisture-heat decreased. Finally, the nutritional retention factor represents output data of each cooking method with yield % of each item.

• Applied Biological Chemistry
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• v.35 no.1
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• pp.36-41
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• 1992

Several commercial cottonseed, corn and rapeseed oils were stored at $60^{\circ}C\;and\;70^{\circ}C$ with daily exposure of fluorescent light for 12 hours and evaluated their rancidity by headspace gas chromatographic analysis of pentanal and hexanal. The data of gas chromatographic analysis was compared with organoleptic flavor evaluation. For headspace gas chromatographic analysis, the volatile compounds were recovered by porous polymer trap and flushed into a fused silica capillary column at $250^{\circ}C$. Twenty-three GC peaks were identified on the basis of relative retention time of reference compounds and gas chromatography-mass spectrometry. The results showed that the contents of pentanal and hexanal were linearly increased during storage. A very simple linear relationship was found between organoleptic flavor scores and amounts of two volatile compounds with very high correlation coefficient. This results suggested the possible implication of pentanal and hexanal as an quality index for rancidity evaluation of cottonseed, corn and rapeseed oils.

• Korean Journal of Community Nutrition
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• v.22 no.2
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• pp.145-158
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• 2017

Objectives: The importance of kimchi as a traditional food in Korean cuisine has gradually decreased due to rapid industrialization, economic growth and changes in dietary patterns in Korea. This study aimed to examine the shifts in kimchi consumption by region and by income level between 2005 and 2015 in Korea. Methods: Data from the Korea National Health and Nutrition Examination Surveys III (2005) and VI (2015) were used in the study (n=15,558). Intake of kimchi was estimated using a single 24-hour dietary recall. The sample weights were applied in all analyses to reflect population estimates. All statistical analyses were carried out by using SPSS IBM Statistics 20. Results: Kimchi intake has significantly decreased by 27.6 g/day per capita during the last decade in Korea; 25.0 g for males and 29.9 g for females, respectively. Over the past decade, the decline of kimchi intake has been particularly significant in Seoul, Busan, Incheon, Gyeonggi, and Gwangju, while there has been no significant change in males living in rural areas. The consumption of kimchi across all income levels has decreased, however, the decrease was higher in 'middle and low income level'. The amount of kimchi consumption in 2015 was the highest in 'low income level'. The results were similar after adjusting for gender and age. Conclusions: For the past decade, the overall intake of kimchi in Korea has decreased, however, it has been found that the decrease of kimchi intake for males living in the rural areas was not significant. Therefore, in order to keep our traditional kimchi culture and promote a balanced diet including kimchi for Korean, it is necessary to develop more efficient policies and approaches. A variety of dishes using kimchi should be developed, besides merely serving kimchi with rice as a side dish, to increase the consumption of kimchi.

• Journal of the Korean Society of Food Culture
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• v.31 no.4
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• pp.348-356
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• 2016

The purpose of this study was to investigate the chemical contents (sugar, nitrogen, and amino acids) and sensory characteristics of traditional soy sauce according to three different methods. The samples were taken from four different periods (0, 20, 40, and 60 days after fermentation). Total sugar contents increased in all groups according to ripening period, and Gyupjang (G) showed the highest sugar content among the groups. Total nitrogen and amino acid contents of all groups increased after 60 days of ripening, and Gyupjang (G) and Gyupjang mixed with salt water (SG) had higher total nitrogen content compared to Chungjang (S) at the same period. The results from the sensory evaluation show that preferable sensory characteristics, such as color preferences, sweetness, umami taste, and overall preference, were significantly higher in Gyupjang (G) and Gyupjang mixed with salt water (SG) than in Chungjang (S). Preferable sensory characteristics had significantly high positive correlation with most amino acids, total nitrogen, and sugar contents, except for glutamine. Based on the significant difference in preferable sensory characteristics between Gyupjang mixed with salt water (SG) and Chungjang (S), Gyupjang mixed with salt water (SG) can be used to improve sensory characteristics. This research implies that adding salt water during the manufacturing Gyupjang process is advisable to yield high quality soy sauce.

• Korean Journal of Food Science and Technology
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• v.21 no.4
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• pp.590-594
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• 1989

To determine the change of residual chlorpyrifos during Kimchi fermentation, the Kimchi was prepared and fermented at $4^{\circ}C$ for 4 weeks according to the conventional method. As a model experiment, chinese cabbages which were soaked in the chlorpyrifos solution were used for Kimchi preparation. It was found that the concentration of residual chlorpyrifos which was 0.161 ppm in raw cabbages decreased to 0.0938 ppm by 4 times of washing and further decreased to 0.0099ppm during fermentation of Kimchi for 4 weeks. In the model system, the residual chlorpyrifos decreased by the first order reaction as the fermentation of Kimchi proceeded . It's half life is approximately 1.8 weeks.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1147-1155
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• 1996

In the spray drying with rotating wheel atomizer of cheese powder, the relationships among variables were analyzed with Response Surface Methodology in which several independent variables such as total solid content, wheel rotation speed, and outlet temperature influenced dependent variables such as particle diameter, moisture content, bulk density, and viscosity of suspended liquid. Significance and correlation were tested according to central composite design. As a results of analyzing the correlations between independent and dependent variables, particle diameter and moisture content of cheese powder were decreased with increasing wheel rotation speed, and bulk density was decreased with increasing outlet temperature. Viscosity of suspended liquid were increased with increasing wheel rotation speed and total moisture content. In correlation among dependent variables, moisture content was proportional to bulk density, and particle diameter was inversly proportional to moisture content and bulk density.

• Korean journal of food and cookery science
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• v.24 no.4
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• pp.419-430
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• 2008

The purpose of this study was to investigate the kinds of Tteoks along with their recipes and ingredients occurring in Korean literature published before the 17th century. The reviewed sources included "Sangayorock", "Sasichanyocho", "Soowonjabbang", "Yongjechongwha", "Dongyoebogam", "Domoondaejak", "Geebongyouseul", "New-Guwhangchalyo", "Eumshickdimibang", "Joobangmoon", and "Yorock". Various types Tteoks could be classified into sic groups depending on their cooking methods as follows 23 kinds of Jjjin-tteoks, 8 kinds of Chin-tteoks, 24 kinds of Jijin-tteoks, 6 kinds of Salmeun-tteoks, 4 kinds of Guun-tteoks and 8 other types of tteoks. Within this paper, Tteok recipes and cooking characteristics are discussed and their ingredients, terminology and preparation utensils are reviewed. However some of the Tteok recipes are presently gone or have changed. From this study, we anticipate the development of useful recipes for those who are concerned about health and who seek longevity, and thereby to also advance the culture of Korean rice cakes.

• Food Science of Animal Resources
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• v.36 no.1
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• pp.114-121
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• 2016

This study was performed to improve the techniques used for tenderizing red meat as elderly food. Beef meat was immersed in liposome encapsulated enzyme solution and the effect of protease encapsulation on the beef properties was analyzed. The protease encapsulation properties were analyzed according to the size distribution and enzymatic activity. After enzyme reaction on the beef, the chemical properties of the meat such as pH, water holding capacity, shear rate, lipid oxidation and total volatile basic nitrogen (TVB-N) were analyzed. The pH of the beef increased during the reaction and coating protease (CP) was higher than non-coating protease (NCP). Total color differences were increased remarkably after 36 h and generally, the difference in CP was relatively lower than in NCP. WHC was significantly decreased within 24 h, and no effect from the protease coating was observed. Protease activity was significantly increased within 48 h and no differences in the enzyme coating were observed. The TVB-N value of NCP was increased within 24 h while CP was sustained for up to 36 h. The TVB-N value of protease treated meat increased after 36 h and no effect from the protease coating was detected. Consequently, liposome encapsulated protease was found to have similar properties as non-coated protease. Application of liposome seems to be an interesting option for injecting various functional materials without changing the properties of meat.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.1028-1034
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• 1995

Acid-modified and cross-linked chestnut starch properties and their gel properties were examined. Hardness and cohesiveness of acid-modified starch gels were all reduced as acid treatment time was increased. And hardness of crossed-linked starch gels were increased but cohesiveness were not significantly different. Reduction rate of transmittance in acid-modified starch suspensions were higher than that of unmodified starch suspension. Hardness changes of cross-linked starch gels during 4 days of storage were little, especially in the gels made at $75^{\circ}C\;and\;85^{\circ}C$ of heating temperatures.