• Title/Summary/Keyword: iodine value

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Changes on rice qualify during long-term storaged (미곡의 장기저장에 의한 품질 특성 변화)

  • Lee, B.Y.;Kim, Y.B.;Son, J.R.;Yoon, I.H.;Han, P.J.
    • Applied Biological Chemistry
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    • v.34 no.3
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    • pp.262-264
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    • 1991
  • In order to establish the optimum storage period of rice, storability of rice for 1, 2. 3 and 4 years was investigated. Fat acidity of stored rice for 1, 2, 3 and 4 years was measured to 12.4, 23.6, 30.8 and 41.1 KOHmg/100g, respectively. Reducing sugar of those was analized to 0.31, 0.41, 0.57 and 0.68%. Germination of the stored rice for 1, 2 and 3 years was 97, 93 and 85%, respectively, but that of stored for four years was very low 32%. The longer storage period the higher, the lower water uptake ratio and expanded volume and much the lower total solid in residual liquid and intensity of starch iodine blue value of residual liquid, and the worse panel scores in color, stickness, taste and smell.

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Properties of Hot-water Extracts and Extract-gels of Starches for Mook (묵제조용 전분에서 분리한 열수추출물의 이화학적성질과 추출물겔의 특성)

  • Song, Young-Me;Chung, Koo-Min;Lee, Won-Jong
    • Korean Journal of Food Science and Technology
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    • v.27 no.4
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    • pp.625-630
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    • 1995
  • In order to know the effects of hot-water extracts of starches on gel formation and gel properties, some physicochemical properties and molecular distribution of the extracts were measured. Also, after acid-hydrolysis of starch gels and extract gels, extent of hydrolysis and $\overline{D.P}._n$, and molecular distribution of hydrolysis-residue were measured. Extraction ratio of grain starches (buckwheat, corn, rice, and wheat) were $4.0{\sim}6.6%$. The ratio of acorn and mungbean starches were 11.7 and 13.5%, respectively. Iodine affinity of the extracts was $17.2{\sim}17.7%$ in starches using for Mook, SM(acorn, buckwheat, and mungbean), $13.7{\sim}14.9%$ in starches not using for Mook, SNM(corn, rice, and wheat). Blue value was also higher in SM than in SNM. $\overline{D.P}._n$. of extracts of SM were bigger than those of SNM. In molecular distribution experiment, amylopectin fraction was not found from the extracts except rice starch extract. The extent of acid hydrolysis of the starch gels were $70{\sim}84%$ after 60 days, and the extent of the extract gels were $22{\sim}35%$. The extent of hydrolysis of starch gels and extract gels made with SM were lower than those of SNM.

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Studies on the Lipid and Fatty Acid Compositions of Ark-Shell, Anadara broughtonii (피조개 지질 및 지방산 조성에 관한 연구)

  • 문숙임
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.21 no.4
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    • pp.436-442
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    • 1992
  • The present study was designed to analyze the lipid and fatty acid compositions of ark shell, Anadara broughtonii. The crude lipid was extracted by Bligh and Dyer's method, and then fractionated by TLC and quantitatively analyzed by TLC scanner. Lipid extracted from ark shell was fractionated into neutral and polar lipid by column chromatography with silicic acid. The fatty acid composition of lipid fractions were determined by gas liquid chromatography. Total lipid content of ark shell was 0.83% base on wet weight. The content of unsaponifiable matter was 20.19%, and iodine value was 156.13. The main components of total lipids were triglyceride, diglyceride, hydrocarbon, and sterol ester. The fatty acid composition of total lipid chiefly consisted of $C_{17 : 0}$, $C_{16 : 0}$, $C_{18 : 1}$ and $CT_{16 : 1}$. The main fatty acids of neutral lipid were $C_{16 : 0}$, $C_{18 : 1}$, $C_{22 : 1}$, $C_{18 : 0}$ and $C_{16 : 1}$. The major fatty acids of polar lipid were $C_{16 : 0}$, $C_{18 : 2}$, $C_{20 : 5}$ and $C_{22 : 6}$. In total lipid fractionation, saturated acid contents were high in all (SA>MA> PA), in neutral lipid fractionation, menoenoic acid contents were high in all (MA > SA> PA), and in polar lipid fractionation, saturated acid con-tents were high in all (SA> PA> MA).

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Cooking Quality and Texture of Japonica-Indica Breeding Type and Japonica Type, Korean Rice (한국산(韓國産) 미곡(米穀), 통일계(統一系)와 일반계(一般系)의 취반특성(炊飯特性) 및 Texture 에 관(關)한 연구(硏究))

  • Lee, B.Y.;Yoon, I.H.;Tetsuya, Iwasaki;Ikuji, Kamoi;Tetsujiro, Obara
    • Korean Journal of Food Science and Technology
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    • v.21 no.5
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    • pp.613-618
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    • 1989
  • Tirteen rice varieties of Japonica-Indica briefing type (J-I breeding type) and ten of Japonica type produced in Korea in 1985 were studied on cooking quality of milled rice and texture of cooked rice. The results are as follows: in the Looking quality, water uptake ratio of cooked rice and total solid in residual liquid showed significant $(p<2.172^*\;and\;2.419^*,\;respectively)$ between J-I breeding type and Japonica type The water uptake ratio of cooked rice was higher J-I breeding type than Japonica type but the total solid and intensity of iodine blue value in residual liquid were lower J-I breeding type than Japonica type. Minimum cooking time of milled rice showed significant $(p<2.375^*)$ between J-I breeding type and Japonica type for texture of cooked rice. The cooking time of J-I breeding type shorter than Japonica type. Hardness and cohesiveness in texture of cooked rice appeared to be significant cant $(p<4.370^{***}\;and\;2.371^*,\;respectively)$ between J-I breeding type and Japonica type, and then hardness was higher Japonica type than J-I breeding type, but cohesiveness was lower Japonica type than J-I breeding type. The correlation coefficients between amylose content and adhesiveness of varieties in the same type was $-0.922^{**}$ in J-I breeding type and $-0.915^**}$ in Japonica type. The correlation coefficients between protein content and hardness of the varieties in the same type was $0.954^{**}$ in Japonica type and so denoted as positive correlation. And the scatter diagram between protein and hardness could be divided into J-I breeding type and Japonica type.

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Comparison of Nutritive Values of Diets Collected from Organic Dairy Farms and Conventional Dairy Farms from Chungnam and Jeonbuk in Korea (국내 일반 및 유기우유 생산농가의 착유우 급여 사료내 성분 비교)

  • Ki, Kwang Seok;Lim, Dong Hyun;Kim, Tae Il;Park, Seong Min;Lim, Hyun Joo;Choi, Ki Choon
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.36 no.1
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    • pp.29-33
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    • 2016
  • In order to provide basic data to predict changes of milk components in milk yield, this study was conducted to compare nutritive values of diets collected from organic dairy farms (ODF) and conventional dairy farms (CDF) of Chungnam and Jeonbuk in Korea. The contents of crude fat, crude fiver, neutral detergent fiber, and acid detergent fiber in diets of ODF were significantly (p<0.05) higher compared to those of CDF. The contents of crude protein and crude ash in ODF were also higher (p<0.05) than those of CDF. The contents of calcium, ferrum, and phosphorus in diets of ODF were similar to those of CDF. The contents of potassium, magnesium, and iodine in diets of ODF were higher (p<0.05) than those of CDF. The contents of total saturated and unsaturated fatty acids in diets of ODF were higher (p<0.05) compared to those of CDF. The contents of oleic acid, linoleic acid, and linolenic acid in diets of ODF were higher (p<0.05) compared to those of CDF. However, the contents of myristic acid, palmitic acid, and stearic acid in diets of ODF were lower (p<0.05) compared to those of CDF.

Comparison of physicochemical characteristics of horse fat, lard, and beef-tallow (감압추출마유(horse fat) 및 시판 돈지와 우지의 이화학적 특성 비교)

  • Park, Youn Hyung;Cho, Man Jae;Kim, Hyun Jung
    • Korean Journal of Food Science and Technology
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    • v.51 no.1
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    • pp.1-6
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    • 2019
  • Horse fat was vacuum-extracted from fatty tissues of Jeju and Halla horse meat and their physicochemical properties were compared to those of commercial lard and beef-tallow. For color, ${\Delta}E$ was found to be decreased when crystallized. Although acid values of horse fat were higher than those of lard and beef-tallow, p-anisidine and totox values were lower. The iodine value of beef-tallow was the lowest (44.61), and those of horse fat and lard were similar (57.53-57.74). Only horse fat contained ${\alpha}-tocopherol$. The contents of ${\gamma}-tocopherol$ in Jeju and Halla horse fat, lard, and beef-tallow were 7.08, 4.57, 2.13, and 1.91 mg/kg, respectively. Palmitoleic acid ($C_{16:1}$) was found in horse fat. Melting and crystallization curves of horse fat displayed two endothermic and exothermic peaks which were differentiated from lard and beef-tallow. These results indicated that horse fat demonstrates different physicochemical properties compared to lard and beef-tallow, when applied to various types of lipid products.

Changes in Physicochemical Properties of Rice Grain during Long-Term Storage (장기저장한 벼 종실의 이화학적 특성 변화)

  • Lee, In-Keun;Kim, Kwang-Ho;Choi, Hae-Chune
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.38 no.6
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    • pp.524-530
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    • 1993
  • The experiment was carried out to investigate the changes in physicochemical properties of milled rice harvested in different year and stored for four to sixty four months. The fat acidity of milled rice increased sharply from four to sixteen months storage, and after then it was increased slowly to sixty four months. Amylose, magnesium, potassium content, and K/Mg ratio of milled rice were not changed by storage duration. Water absorption rates of milled rice at 21$^{\circ}C$ and 77$^{\circ}C$, and alkali digestion value were increased by longer storage duration. Difference of water absorption rate between rice samples was greater during initial forty minutes after soaking at 21$^{\circ}C$ and with longer the soaking time at 77$^{\circ}C$. Shorter gel length of rice flour was found with prolonged storage duration, while peak, minimum, cool, breakdown and setback viscosity of gelatinized rice flour on amylograph were increased along with increasing the storage duration. The volume expansion rate during cooking and degree of iodine coloration of cooking water were higher in the longer stored rice compared with shorter one, and the amount of soluble solid in cooking water was significantly decreased in rice stored longer period.

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Storage and Acceptability of a Smoked Sebastes schlegeli Product (훈연처리에 의한 조피볼락의 저장성 및 기호도)

  • Lee, In-Sung;Kim, In-Cheol;Chae, Myoung-Hee;Chang, Hae-Choon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.11
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    • pp.1458-1464
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    • 2007
  • This study was conducted to develope a new type of ready-to-eat smoked Sebastes schlegeli product with high acceptability and extended shelf-life. A Sebastes schlegeli was salted at 4% salt concentration for 6 hr at $4^{\circ}C$. The cold smoking conditions for the salted Sebastes schlegeli consisted of drying for 2 hr at $22{\sim}24^{\circ}C$ followed by smoking for 2 hr at $22{\sim}24^{\circ}C$. The warm smoking conditions for the salted Sebastes schlegeli consisted of drying for 2 hr at $22{\sim}24^{\circ}C$, smoking for 2 hr at $22{\sim}24^{\circ}C$, and smoking again for 30 min at $47{\sim}50^{\circ}C$. The rancidity of the smoked Sebastes schlegeli did not change after 1 year storage at $-20^{\circ}C$ by monitoring the iodine value, peroxide value, and acid value. The number of viable cells in the cold and warm smoked samples were counted as $7.4{\times}10^5$ and $6.2{times}10^5$ CFU/g, respectively. Viable cells were not detected after 1 year of storage at $-20^{\circ}C$. The sensory evaluations of the processed Sebastes schlegeli showed that elastic texture increased with smoking as compared to with salting. There were no significant differences between cold and warm smoking in terms of sweetness, elastic texture, color, and smoke flavor. However, for overall acceptability, preference were in the oder of cold smoked, warm smoked, and salted.

Composition Ratio Analysis of Transesterification Products of Olive Oil by Using Thin Layer Chromatography and Their Applicability to Cosmetics (올리브 오일의 에스터 교환반응 생성물의 TLC를 이용한 조성비 분석 및 화장품에의 응용가능성 평가)

  • Park, So Hyun;Shin, Hyuk Soo;Kim, A Rang;Jeong, Hyo Jin;Xuan, Song Hua;Hong, In Kee;Lee, Dae Bong;Park, Soo Nam
    • Applied Chemistry for Engineering
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    • v.29 no.3
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    • pp.342-349
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    • 2018
  • In this study, the physicochemical properties, emulsifying capacity, moisture content and cytotoxicity of the composite material produced by transesterification reactions of the olive oil (olive oil esters) were investigated for cosmetic applications. Olive oil esters with short (S) and long (L) reaction times were studied. From the TLC-image analysis, composition ratios of the olive oil esters S were found to be 5.2, 24.1, 46.4, and 21.9% for mono-, di-, tri-glyceride, and fatty acid ethyl ester, respectively. Those of the olive oil esters L were 4.1, 24.7, 40.6, and 28.8% for mono-, di-, tri-glyceride, and fatty acid ethyl ester, respectively. The iodine value, acid value, saponification value, unsaponified matter, refractive index, and specific gravity were determined and purity tests were also carried out and normalized to establish standards and testing methods for using olive oil esters in cosmetics. To evaluate their emulsifying capacities, the O/W emulsion was prepared without surfactants and the formation of the emulsified particles were confirmed. After 5 days of applying the olive oil esters to human skin, the skin moisture retention was improved by 13.1% from the initial state. For the evaluation of toxicity on human skin cells, the olive oil esters showed 90% or more of the cell viability at $0.2-200{\mu}g/mL$. These results suggested that olive oil esters can be applied as natural/non-toxic ingredients to cosmetics industries.

A Study on Quality Changes of Domestic Frying Oils by Thermal Oxidation (시판식용유의 가열시간에 따른 품질 변화에 관한 연구)

  • Chang, You-Kyung;Lee, Joung-Won;Kim, Teak-Je
    • Korean Journal of Food Science and Technology
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    • v.10 no.2
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    • pp.112-118
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    • 1978
  • Four domestic frying oils (soybean, corn, rapeseed and rice bran oil) were studied on their changing properties according to thermal oxidation by means of chemical analysis of their compositions and measurements of various physical and chemical properties. The content of linoleic acid which is an essential unsaturated fatty acid and the total amount of unsaturated fatty acids were highest in soybean oil (53.2% and 80.3% respectively) among the unheated frying oils and the degree of its thermal degradation was lowest during the continuous heating period for 48 hours at $180^{\circ}C$. However in general, the contents of unsaturated fatty acids were sharply decreased by thermal oxidation whereas the saturated fatty acid contents ranging 10-17% were not changed considerably, which largely agreed with the results of iodine value measurements. The free acid and peroxide values were also lowest in soybean oil (0.09 and 5.6 respectively) among the unheated oils whereas an anomalously high free acid value was observed in rapeseed oil (54.8) which was packed in unleveled glass bottles. Such a high value is probably ascribed to the photo-catalyzed oxidation during storage. The viscosity measurements have shown similar values before heating, but after thermal oxidation for 32 hours the rapeseed and rice bran oils became too thick to measure viscosity by capillary flow method with heavy darkening in color.

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