• Title/Summary/Keyword: physico-chemical change

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Physico-chemical properties and mechanism of color change of methyl 5-hydroxy-dinaphtho [1, 2-2', 3'] furan-7, 12-dione-6-carboxylate (메틸 5-하이드록시 디나프토 [1, 2-2', 3'] 후란-7, 12 디온 6-키복시레이트의 물성 및 변색기전)

  • 장혜선;박유미;강경환;우영아;박정일;김박광
    • YAKHAK HOEJI
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    • v.37 no.2
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    • pp.198-203
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    • 1993
  • Physico-chemical properties of methyl 5-hydroxy-dinaphtho[1,2-2',3'] furan-7,12-dione-6-carboxylate(MHDDC) were examined. The yellowish color of the solution at pH 8 below changes to a bluish color when the solution is basified to pH 10 above. This color change was presumed to a change of the molecular structure from a quinoid-type to a quinoid-type with the dissociation to the hydroxyl group as shown in chart 1.

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Studies on the Variation of Physico-Chemical Characteristics During Storage and Frying (고추씨 기름의 저장 및 가열에 따른 이화학적 변화에 관한 연구)

  • Choi, Young-Jin;Ko, Young-Su
    • Korean journal of food and cookery science
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    • v.6 no.2
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    • pp.67-76
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    • 1990
  • To observe the propability as the frying oil and oxidative stability of red pepper seed oil, some physico-chemical tests of the oil were examined during 21 days storage period at 5$^{\circ}C$, 15$^{\circ}C$ and 30$^{\circ}C$, and AOM value determined and after heating the oil at 180${\pm}$5$^{\circ}C$ for 40 hours with or without antioxidants. The analysis storage stability of red pepper seed oil showed that the quality of storage group at 5$^{\circ}C$ was almost as good as fresh oil, and the storage group at 30$^{\circ}C$ showed certain degree of rancidity. Change of physico-chemical characteristic during storage were so small so that storage stability of red pepper seed oil was found to be good. AOM stability of red pepper seed oil was 7 hours which is lower than other vegetable oil, but the degree of stability grew greatly after adding phenolic antioxidants, such on TBHQ or PG. As for the chemical change after heating continuously for 40 hours, acid value, peroxide value and refractive index increased, but iodine value decreased as the heating processed. The fatty acid composition also showed the remarkable reduction of linoleic acid. The addition of antioxidants resulted in the delay of oxidation, the degree of which was greater in TBHQ than in PG.

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Sensory Characteristics and Physico-Chemical Change of the Loin of Lamb by Four Cooking Methods (네 가지 조리 방법에 따른 양등심의 이화학적 및 관능적 특성 연구)

  • Seo, Min-Suk;Yoo, Seung-Seok
    • Journal of the East Asian Society of Dietary Life
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    • v.20 no.1
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    • pp.84-94
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    • 2010
  • Physico-chemical analysis and sensory test of loin of lamb were carried out by four different methods such as grilling, pan-frying, oven-roasting and boiling. The crude fat content was all the same at three cooking methods except boiling. The moisture content was not different among grilling, pan-frying and oven-roasting. Hunter's color L-value(lightness) was lowest at grilling method. However, the heating loss appeared greatly at grilling. The hardness of the lamb-loin after cooking showed big differences with the control except boiling treatment. Amino acids in fillet contained highly in the order of glutamic acid > aspartic acid > cystein. The grilling showed a good value not only color of a sensory test but also the appearance. The oven-roasting cooking gave the tenderness and juiciness. The oven-roasting method showed good sensation to overall taste. Therefore, the oven-roasting (at $150^{\circ}C$ for 9 minutes) was suggested as the superior method when the loin of lamb is cooked for reducing off-flavour.

Effect of cement dust on soil physico-chemical properties around cement plants in Jaintia Hills, Meghalaya

  • Lamare, R. Eugene;Singh, O.P.
    • Environmental Engineering Research
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    • v.25 no.3
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    • pp.409-417
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    • 2020
  • Investigation was carried out to assess the effect of cement dust deposition on the physico-chemical properties of soil near some cement plants in Jaintia Hills, Meghalaya. Soil samples were collected and analysed and compared with the control site. Comparison of various soil physico-chemical parameters revealed that cement dust emanating from cement plants has changed the soil quality in the surrounding areas of cement plants. The normal soil pH in the area is generally acidic. However, due to the continuous deposition of cement dust soil pH was found slightly alkaline near the cement plants. The higher values of soil parameters such as electrical conductivity and bulk density were also noticed near the cement plants. However, lower values of water holding capacity, soil moisture content, soil organic carbon and total nitrogen content were found compared to the control sites. The effect of cement dust deposition on soil is more in areas nearer to the cement plants. At present the changes may not be so serious but if this trend continues, soil properties of a vast area around the cement plants are likely to change leading to multiple effects on flora, fauna and socio-economy of the area.

Effects of Soil Amendment Application on Soil Physico-chemical Properties and Yields of Summer Forage Crops in the Sukmoon Reclaimed Tidal Land in Korea (석문 간척지에서 돈분액비 및 석고처리가 여름철 사료작물 수량 및 토양이화학성에 미치는 영향)

  • Choi, Ki-Choon;Yoon, Sei-Hyung;Shin, Jae-Soon;Kim, Dong-Kwan;Han, Hyo-Shim;Supanjani, Supanjani;Lee, Kyung-Dong
    • Korean Journal of Environmental Agriculture
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    • v.29 no.4
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    • pp.354-361
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    • 2010
  • Soil physico-chemical properties and microbial densities are affected by organic sources and soil amendment applied to improve soil environments or quality. Generally organic fertilizer effects on forage crops yield and soil properties are partly due to changes of soil composition. We investigated the effects of swine slurry (SS), swine slurry composting-biofilteration(SCB) and chemical fertilizer(F) with gypsum(G) combinations on soil physico-chemical properties and yields of summer forage crop in the Sukmoon reclaimed tidal land in Korea. The forage crops used in this experiment were corn and sorghum$\times$sudangrass hybrid(hereafter sorghum). Our results showed that the soil physico-chemical properties in the combined (F+G, SS+G, SCB+G) treatments increased contents of organic matter and exchangeable $Ca^{2+}$, but exchangeable $Na^+$, $K^+$ and $Mg^{2+}$ reduced to 1-10% for two forage crops, compared to non-combined (F, SS, SCB) treatment. The density of soil microorganism such as bacteria, actinomycetes and fungi, increased significantly by SS+G and SCB+G treatments. This means that treatment of combined organic fertilizer with G lowered salinity levels and improved with microbial growth. The combined treatments also increased the total yields 2.3-6.2% for corn and 2.0-8.7% for sorghum, compared with non-combined treatment. This experiment suggests the combined treatments could increase the total yields of summer forage crops and change of soil physico-chemical properties in the Sukmoon reclaimed tidal land in Korea.

Changes in physico-chemical properties of expanded tobacco leaves by $CO_2$ process according to the storage periods (저장기간에 따른 $CO_2$ 팽화처리 원료잎담배의 이화학적 특성 변화)

  • 김병구;이규서
    • Journal of the Korean Society of Tobacco Science
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    • v.22 no.2
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    • pp.143-150
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    • 2000
  • This study was carried out to investigate the effect of storage period on the physico-chemical properties of tobacco leaves expanded by $CO_2$. The flue-cured and burley tobacco leaves produced from 1996 to 1999 were processed, and stored for that year or 3 years in processing plant. As compared with 1996 crop, the expanded rate of flue-cured tobacco leaves in 1999 crop was higher approximately 18%, while that of burley was higher about 10%. The filling capacity of cigarettes was decreased as storage time became shorter, but the combustibility was improved. The rate of large particles (over 3.36mm) of expanded tobacco showed decreasing tendency as the storage period became longer. The change rate of chemical contents in tobacco leaves between before and after expansion had no significant difference among corp years. The tar and CO contents of cigarettes smoke were reduced in the case of flue-cured tobacco leaves as storage time became shorter, while they were slightly increased in the case of burley tobacco leaves. The ammonia content of burley leaves was decreased remarkably in 1996 and 1999 crop.

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Oxidative Stability of Sesame Blended Oils (참기름 혼합유의 산화안정성)

  • 맹영선;박혜경
    • Korean journal of food and cookery science
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    • v.5 no.2
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    • pp.51-62
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    • 1989
  • In the present study, an attempt was made to investigate the oxidative stability of the various sesasme blended oils. Sesame blended oils were perpared by mixing sesame oil with various vegetalbe oils (soybean oil, corn oil, ricebran oil, rapeseed oil, cottonseed oil, and perilla oil) in a ratio of 3:7 (w/w). Fatty acid composition and some of physico-chemical characteristics of the sesame blended oils and vegetable oils including sesame oil were determined before the oxidation experiments. The fatty acid compositions and the physico-chemical characteristics of the vegetable oils changed by blending the oils with sesame oil and the extent of change varied with the type of oil. Particularly, the iodine value of the vegetable oils decreased significantly by sesame oil blending. The sesame blended oils and the vegetable oils including sesame oil were oxidized at $45^{\circ}C$ for 25 days in a dark place, and at $35^{\circ}C$ for 12 days under the irradiation of incandescent electric lamp (40 W). During the oxidation, some physico-chemical characteristics of the oils were determined to evaluate the oxidative stability. Based on the changes of peroxide values, the oxidative stability of the vegetable oils was improved by sesame oil blending.

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THE CHANGE OF MAJOR PHYSICO-CHEMICAL PROPERTIESIN FLUE-CURED TOBACCO PACKED IN HOGSHEAD DURING AGEING (황색종 통담배의 숙성기간중 주요 이화학성의 변화)

  • 민영근;이미자;이경구;이상하
    • Journal of the Korean Society of Tobacco Science
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    • v.9 no.1
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    • pp.65-71
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    • 1987
  • In order to obtain the most suitable ageing term of Flue-cured tobacco in natural condition, leaf tobacco packed in hogshead and stored in leaf tobacco warehouse for 4 years, and the changes of major physico-chemical components were examined at three months intervals, As storage time goes by, except the moisture content, general chemical components of leaf tobacco were decreased until about 9-15 months of storage. Among them, decrement of total sugar was the most significant. After 18 months storage, the chlorophyll was decreased by 50% of initial stage. The content of essential oils, solanone, damascenone, megastigmatrienone I, II, III, IV, were approached the maximum between 12 months and 15 months of storage and then lessened by degrees.

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Changes in Physico-Chemical Properties of Burley Leaf Tobacco by Expansion Process. (팽화처리에 의한 Burley종의 물리화학적 특성변화)

  • 김병구;김기환;임광수
    • Journal of the Korean Society of Tobacco Science
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    • v.21 no.2
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    • pp.144-151
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    • 1999
  • This study was carried out to compare the change physico-chemical properties in the 10 grades of Burley leaf tobacco expanded by $CO_2$. The filling capacity of AB3T was increased from 5.44cc/g to 9.52cc/g with the expansion rate 75.0% and that of CD3W was increased from 5.57cc/g to 10.16cc/g with the expansion rate 82.4%. But the rate of cut tobacco longer than 3.36 mm decreased from 77.2% to 49.9% and from 67.3% to 41.2% in grade B1T and C1W, respectively. The contents of nicotine and total volatile base in the of expanded cut tobacco decreased 11.9% and 10.4% respectively. The contents of onganic acids, except oxalic and palmitic acid, essential oil, amino acids, nicotine, tar and ammonia contents in the cigarette smoke decreased by expansion procecs. These results suggest that expanded tobacco was very useful to make less irritative cigarettes.

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Solid Dispersion of an HIV Protease Inhibitor

  • Park, Jae-Hyeon;Lee, Sung-Hack;Lee, Yong-Hee;Kim, Ae-Ri
    • Journal of Pharmaceutical Investigation
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    • v.41 no.2
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    • pp.75-82
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    • 2011
  • LB71350 is an HIV protease inhibitor with poor aqueous solubility and extensive first pass effect. The purpose of the present study was to test the feasibility of solid dosage form of LB71350 with improved bioavailability utilizing solid dispersion. Three different compositions with varying ratio of (LB71350: Gelucire 44/14: Tween 20) were studied. Capsule filling of these solid dispersion compositions was tested using a semi-automatic capsule filling system. Oral bioavailability in dog was tested. Chemical and physical stability at 4, 25 and $40^{\circ}C$ was monitored by HPLC assay, dissolution test, powder XRD and microscopy. The capsule filling system yielded uniform products of drug loading up to 10%. Oral bioavailability in dog was improved compared to the aqueous suspension of crystalline LB71350. Capsules were chemically stable for up to 6 months at $40^{\circ}C$. However, there were temperature and composition dependent physical changes. Decrease in dissolution rates after storage at $40^{\circ}C$ was due to the polymorphic change. In conclusion, manufacturing process, bioavailability, and physico-chemical stability have been considered to propose a solid dispersion capsule formulation for the HIV protease inhibitor with poor physico-chemical properties. A new less soluble crystalline form identified during the physical stability test warrants further study.