• Journal of Pharmaceutical Investigation
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• v.18 no.1
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• pp.9-13
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• 1988

Physicochemical properties of oil in water microemulsions containing soybean oil and egg phosphatide were observed for 3 weeks under the storage condition of $4^{\circ}C$ refrigerator. Changes in major fatty acid content, particle size distribution, rheogram, acid value and pH value were measured by gas chromatograph, laser particle sizer, Coulter counter and rheometer. From above experiments following conclusions were obtained; 1) Mean particle diameter was shifted from 240 to 266mm. 2) No significant changes were observed in the content of major fatty acids of soybean oil, rheogram, acid value and pH value.

• Macromolecular Research
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• v.10 no.3
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• pp.168-173
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• 2002

Unstabilized low-density polyethylene (LDPE) films and films formulated with hindered amine light stabilizer (HALS) were exposed to UV-radiation; and the physicochemical changes during photooxidation processes have been investigated using tensile, FTIR spectre-photometric and thermal analytical (DSC) techniques. The dependence of tensile properties (elongation- and stress-at-break), carboxyl index and heat of fusion on UV-irradiation time have been discussed. The use of HALS is found to be effective in maintaining the UV-mechanical properties of the LDPE films. The experimental results showed that there exists no correlation between mechanical properties and carbonyl index, whereas crystallinity correlates well with carbonyl index in unstabilized and stabilized films for irradiation times greater than 100 h. The rate of formation of carbonyl groups is found to be dependent on UV exposure time. Crystallinity of the film samples is strongly influenced by both exposure time and presence of HALS.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1221-1227
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• 1997

To measure nutritional components and physical quality of Wanja-jeon(Korean pan fried meat balls)was investigated during storage in a simulated hospital cook/chill foodservice system. The Wanja-jeon was cooked and stored for 4 weeks in chill conditions of 2 and 7$^{\circ}C$ and then reheated in the microwave oven. Moisture, protein, and fat contents were decreased little during 4 weeks storage at 2 and 7$^{\circ}C$. Total unsaturated fatty acids(TUFA) and polyunsaturated fatty acids(PUFA) increased slightly at 7$^{\circ}C$ storage. Total free amino acid contents were reduced after 4 weeks of storage, while total amino acids were affected little during chilled storage. However, volatile basic nitrogen(VBN) increased during the 4 weeks storage from 11.2mg%, immediately after cooking, to 14.1~14.2mg%. After reheating, thiobarbituric acid(TBA) value increased more significantly to 0.19 and 0.20.

• Journal of Ginseng Research
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• v.19 no.2
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• pp.144-152
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• 1995

This study was carried out in order to utilize ginseng marc (GM), a byproduct produced during the preparation of ginseng extract. For the utilization of GM as coffee-replacing beverage, GM was roasted at 140-23$0^{\circ}C$, for 10-30 min to generate coffee-like flavor and taste. The physicochemical changes in GM induced by roasting process was measured. Weight and moisture contents of GM abruptly decreased while roasting at various temperature and period of time, and the amount of water-extracted solid substances decorated beyond 23$0^{\circ}C$. Among the proximate components, total and free sugar decreased remarkably, while crude fat content increased. Crude protein content did not change by the roasting process. pH derides to pH 4.9 after 30 min at 20$0^{\circ}C$, but increased at higher temperatures. Hunter color L value of the GM powder decreased, whereas a and b values, increased up to 10 times as compared to that of the control. The brown color(O, D 490 nm) in 50% ethanol extract of the roasted GM was 46 times higher than that of the control.

• The Korean Journal of Food And Nutrition
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• v.21 no.4
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• pp.499-509
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• 2008

The purpose of this study was to investigate the changes in physicochemical and sensory properties of raw fruits during washing and chlorine treatments. Strawberry and banana were pre-prepared at different concentration of chlorinated water(0 ppm, 50 ppm and 100 ppm), immersion time(3 min and 5 min), and number of post-rinsing(1 time, 2 times and 3 times). The physicochemical properties such as pH, sugar contents, residual chlorine contents, color values and hardness of the fruits were analyzed, and the sensory quality were evaluated throughout the sterilization treatment process. After washing strawberry with 100 ppm chlorinated water and 3 times of post-rinsing, pH and residual chlorine contents were showed a little difference, while sugar contents, hardness, and color values(L, a and b) were reduced. In case of banana, pH, sugar contents and residual chlorine contents were not affected, and hardness and L color value were reduced. However, a and b color values of banana were gradually increased as the development of brown discoloration. Sensory properties of the samples were affected by the chlorine sterilization treatment. In overall acceptance, strawberry and banana treated with 100 ppm chlorinated water showed the lowest scores among treatments. Therefore it could be suggested that the application of 50 ppm chlorinated water for $3{\sim}5$ minutes with over 3 times of post-rinsing was the effective pre-preparation method without affecting the quality of the fruits.

• Journal of the Korean Society of Tobacco Science
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• v.17 no.2
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• pp.126-138
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• 1995

To investigate the changes of physicochemical properties of leaf tobacco during storage, cured leaves (both flue-cured(KF109) and burley(Burley 21) : 4 grades of leaves) were stored under the natural warehouse condition(room temperature) and processed leaves(both Rue-cured(NC82) and burly(Burley 21) : 6 grades of leaves) were stored at storerooms in tobacco processing plants(flue-cured Cheongju plant ; 2nd, 4th and 5th floor, burley : Kwangju plant ; 2nd floor, Chonju plant : 3rd and 5th floor). Tobacco leaves were sampled and analyzed every 3 months. Total sugar content of flue-cured leaf decreased slightly and the redness degree of leaf increased after 15 months' storage under the natural warehouse conditions. The pH of cured leaves were lowered both flue-cured and burley, and the decreasing rate of pH was large in flue-cured(0.24) as compared with burley(0.14). There was no significant differences of physicochemical properties of processed leaf among storerooms during 15 months' storage. The decreasing rate of processed leaf pH was somewhat large in flue-cured(0.26) as compared with burly (0.20), and in thick leaves as compared with thin leaves. The redness degree of flue-cured leaf increased slightly, while the degree of lightness and yellowness lowered slightly during storage. The lightness degree of burley leaf lowered slightly, too. The ageing process of cured leaf was similar to that of processed leaf, it is considered that the passing days after curing will be more reasonable than the passing days after processing for the establishment of proper ageing period.

• Korean journal of food and cookery science
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• v.18 no.3
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• pp.340-348
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• 2002

Changes in the physicochemical properties of frying oil after single or repeated use in foodservice establishments were studied. The experiment was designed to simulate the practical frying practice based on a survey from the dieticians in the food service establishments. Used oils came from the single frying of mackerel and the sequential frying of 1) potato and mackerel, 2) battered pork and mackerel, and 3) potato, battered pork, and mackerel. The used oil samples were analyzed and compared with the fresh one. Oil quality parameters such as acid value, peroxide value, thiobarbituric acid value, iodine value, viscosity, and color were measured at each step of deep-fat frying. The physicochemical properties of the frying oils have been more or less affected by the frying conditions. However, the used oils resulted from the experimental trials were within the range of acceptance as indicated by the acid and peroxide values.

• Journal of the East Asian Society of Dietary Life
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• v.6 no.3
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• pp.317-323
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• 1996

Physicochemical characteristics of Cassia tora seeds roasted at different conditions were investigated. Intact Cassia tora seeds were composed of water 11.6% crude protein 13.1%, crude fat 4.4%, curde fiber 13.8%, N-free extract 47.2% and ash 4.9%. Stacking volume ratio was increased generally by swelling, but soluble solids were decreased by rosating process L and B values decreased conspicuously as roasting temperature increase, but $\Delta$E value increased. The content of anthraquinones was 1, 200mg% in unroasted Cassia tora seeds, it increased as roasting time and temperature increase and reached maxium amount at 19$0^{\circ}C$-30min, 21$0^{\circ}C$-20min. and 23$0^{\circ}C$-10min. agter that it decreased remarkably. Optimum roasting condition of Cassia tora seeds was 21$0^{\circ}C$-20min.

• Korean journal of food and cookery science
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• v.20 no.4
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• pp.403-408
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• 2004

The purposes of this study were to investigate the physicochemical characteristics and storage stabilities of various sauces with added Yuza(Citrus Junos). Yuza consisted of three parts: peeled (46.17%), fleshed (43.74%) and seeded (10.09%). Yuza juice revealed 11.33% extraction yield, pH 2.85, 4.18% total acidity, 11 $^{\circ}$Brix, 1.16% transmittance and 2.63 $^{\circ}$Brix/acid ratio. Five kinds of sauces with added Yuza juice were Yuza red pepper paste sauce, Yuza soybean sauce for meat, Shabu shabu Yuza sauce, Korean Yuza vegetable sauce and Japanese Yuza soybean sauce. These sauces showed slight changes in pH, total acidity, total bacterial counts and overall sensory characteristics during storage period (60 days). In conclusion, Yuza juice could be applied to various sauces, which remained usable for 60 days.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.99-103
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• 2021

The purpose of this study was to investigate how microwave drying, a method to minimize the scent and physicochemical changes of the final products, affects the quality characteristics of various herbs according to treatment intensity (pulse and continuous waves) and time. In the current study, different physicochemical qualities, such as weight change, moisture content, water activity, color, and microbial growth, of five different Korean herbs were analyzed after microwave drying. The results clearly showed that the pulse wave method was a more effective approach than the continuous wave method for maintaining the physicochemical properties of herbs. Furthermore, pulse wave drying lead to efficient microbial death in various herbs after a short time. Thus, microwave drying with a pulse wave can be applied to herb processing and packaging technology while minimizing the quality changes of herbs.