• Title/Summary/Keyword: iodine value

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Comparison of Korean and Japanese Rice Cultivars in Terms of Physicochemical Properties (II) The Comparison of Korean and Japanese Rice by Amylose Content and Cooking Characteristics (한국 쌀과 일본 쌀의 물리화학적 특성 연구 (II) 아밀로즈 함량과 조리특성의 차이에 의한 품질비교)

  • 김혁일
    • Journal of the East Asian Society of Dietary Life
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    • v.14 no.2
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    • pp.145-155
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    • 2004
  • From the cooking data, Japanese rice showed higher water uptake but lower expansion volume, pH and iodine blue value than those of Korean rice. Japanese rice had higher maximum viscosity, breakdown viscosity and pasting temperature but lower final viscosity and setback viscosity than those of Korean rice by RVA analysis. Japanese rice had higher LC (low compression) hardness, U stickiness and HC (high compression) stickiness, LC balance and HC balance, but had lower HC hardness and thickness in the tensipresser data. Also Japanese rice had higher stickiness and balance, and lower hardness from the texturometer analysis. Japanese rice showed higher a cooked taste score than that of the Satake cooked taste machine. The various mean values of Japanese rice after cooking showed better cooking characteristics than the Korean rice. These results might be caused because Japanese rice had a little lower amylose and protein content, but higher tat acidity content.

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Characterization of extracellular fructosyl transferase from aureobasidium pullulans C-23 (Aureobasidium pullulans C-23이 생산하는 세포외 fructosyl transferase의 특성)

  • 이광준;최정도;임재윤
    • Korean Journal of Microbiology
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    • v.29 no.5
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    • pp.301-306
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    • 1991
  • Extracellular fructosyl transferase from Aureobasidium pullulans C-23 was characterized. The molecular weight of the isolated enzyme was determined to be approximately 170,000 by SDS polyacrylamide gel electrophoresis. The enzyme has the pI value of about 3.7. The enzyme was almost completely inhibited by 5mM $Hg^{2+}$ , but was not significantly affected by other cations tested. The enzyme was inactivated by treatment of tryptophan-specific reagent N-bromo- succinimide and tyrosine-specific reagent iodine. The substrate sucrose showed protective effect on the inactivation of the enzyme by the both reagents. These results suggest that tryptophan and tyrosine residues are probably located at or near active site of the enzyme.

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Purification and Properties of Protease Inhibitor from Streptomyces sp. SK-862 (방선균이 생성하는 단백질 가수분해효소 저해물질의 정제 및 특성)

  • 김중배
    • The Korean Journal of Food And Nutrition
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    • v.11 no.6
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    • pp.678-682
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    • 1998
  • A strain of Streptomyces sp. SK-862, isolated from soil in Wonju city, was able to prodce a biologically active substance that has a strong inhibitory activity against proteolsis by trypsin. The inhyibitory substance was extracted by n-butanol, and then purified by the adsorption chromatography followed by the reverse-phase high performacne liquid chromatography. The purified substance was stable over the pH range from 2 to 10, but was unstable when treated at 8$0^{\circ}C$ for 60 min. This substance was soluble in water, methanol, ethanol nd butanol, but insoluble in chlorofrom and ethylacetate. The Rf value of the purified substance on the thin layer chromatography were 0.56 in n-butanol : methanol : water(5 : 3 : 1v/v) solvent system compare dto 0.23 in ethanol : ammonium hydoxide : water(8 : 1 : 1v/v) solvent system. This substance has maximum absorption at 259 nm. The chemical reaction of the substance was negative for sugar but positive for ninhydrine and iodine reaction.

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A Studies on the Chemical Composition of Apricot Seed (살구씨의 화학적 조성에 관한 연구)

  • 이성민;임효진
    • The Korean Journal of Food And Nutrition
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    • v.5 no.1
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    • pp.1-6
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    • 1992
  • For the effective utilization of apricot seed resources of food protein and lipid, the general composition, amino acid composition and chemical characteristics were analysed. The skinned and non-skinned apricot seed contained 53.9% and 48.0% of crude lipid, 24.7% and 26.8% of crude protein, respectively. There were no significant difference in the amino acid composition among skinned and non-skinned apricot seed, The major amino acids were glutamic acid, aspartic acid, alanine, tyrosine and threonine, holding 14.6 to 16.9%, 12.4 to 13.7%, 9.2 to 12.1%, 7.2 to 7.5% and 7.0 to 7.2% of total amino acid content, respectively. The sum of these ammo acids occupied about 50% to total amino acids. While the quantities of methionine, histidine, and Lysine were poor content. The essential amino acids occupied about 30% to total amino acids. The acid, iodine and saponification value of apricot seed oil were 0.7 to 7.1, 80.8 to 107.5 and 182.7 to 208.4, respectively. These values were significant difference in skinned and non-skinned apricot seed.

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Changes of Linolenic Acid Content and Reactivity during Partial Hydrogenation of Soybean Oil with and without Lecithin (레시틴의 첨가 유, 무에 따른 대두유의 수소첨가 반응성과 리놀렌산의 변화)

  • Kwon, Hye-Soon
    • Korean Journal of Food Science and Technology
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    • v.27 no.1
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    • pp.41-46
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    • 1995
  • Changes of fatty acid composition and reaction rate were investigated according to reaction condition during partial hydrogenation reaction of soybean oil until its iodine value decreased from 134 to 110. The reaction conditions were varied in the range of from $170^{\circ}C$ to $210^{\circ}C$ of temperature, from 1.3 atm to 4.2 atm of pressure and from 0.005% to 0.1% of nickel concentration as catalyst. Lecithin was added in soybean oil to investigate the change of reaction rate. The result of addition of lecithin showed that reaction rate decreased to from 2 to 6 times in comparison with non-additive system.

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Quality Properties and Carotenoid Pigments of Yellow Sweet Potato Puree (황색고구마 퓨레의 품질과 Carotenoid색소)

  • 정순택;임종환;강성국
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.4
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    • pp.596-602
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    • 1998
  • Two kinds of sweet potato puree were prepared with Benihayato cultivar of yellow sweet potato with or without $\alpha$-amylase enzyme treatment. Chemical and rheological properties of enzyme-treated puree were different from those of control puree. Reducing sugar content and iodine value increased by $\alpha$-amylase enzyme treatment, while alcohol insoluble solids and viscosity decreased by enzyme treatment. However, the changes of carotenoid content were not significantly different. Hunter-b-values(yellowness) were 27.19 and 23.54 for no enzyme-treated puree(NTP) and enzyme-treated puree(ETP), respectively. Hunter-a values(redness) were 2.24 and 6.05 for NTP abd ETP, respectively. Content of total carotenoid of canned puree heated at 13$0^{\circ}C$ for 30 min decreased by 59 percents.

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Study on chemical properties of Pinus koraiensis Sieb. et Zucc. resin (잣나무 송지(松脂)의 화학적(化學的) 성상(性狀)에 관(關)한 연구(硏究))

  • Kang, Ha-Young;Hwang, Byung-Ho
    • Journal of the Korean Wood Science and Technology
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    • v.4 no.1
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    • pp.3-7
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    • 1976
  • This is to reveal the chemical properties of resin of Pinus koraiensis Sieb. et Zvcc, and to give the basic data to resin chemistry and resin processing field. Its results are given; 1) Acid value was shown as 134.12 2) Saponification value was shown as 172.72 3) Iodine value was shown as 109.93 and therefore, it is considered as semi-boiled oil. 4) Ester value was shown as 41.60 5) Moisture content was shown as 11.28% 6) The impurities of resin was shown as 0.09% 7) The amount of turpentine oil was shown as 23.29% 8) Rosin content was shown as 76.74% 9) The amount of resin acid was shown as 72.33% 10) Unsaponification matter was shown as 4.41% 11) The refractive index of resin was shown as 1.5045 at $N^{20}_D$.

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Adsorption Characteristics of Granular Activated Carbon Filter Used for Drinking Water Purifier (정수기용 입상활성탄소 필터의 흡착특성에 관한 고찰)

  • Baek, Young-Man;Park, Je-Chul;Kim, Hyung-Jin
    • Journal of Environmental Science International
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    • v.17 no.8
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    • pp.899-905
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    • 2008
  • Quality test for activated carbon(AC) filter used for drinking water purifier is now an obligatory test and the standard material for valid purifying amount in water purifier performance test has been changed from residual chlorine to chloroform according to the notice of Ministry of Environment in 2006. Therefore, this study aimed to compare the ingredients of AC filters by confirming chloroform removal rate of AC filter and conducting 4 adsorption tests (Iodine, methylene blue decolorization, phenol value, ADS value) for AC filters provided by manufacturers. With water pressure of $1kgf/cm^2$, 1,500 liters of prepared inflow went through to check chloroform removal rate. As a result, product with removal rate of below 60% from all products. On the other hand, 4 adsorption tests were conducted for filters in the market and filters from manufacturers. None of the products satisfied all 4 tests. In particular, they showed great shortage to the standard in phenol value and ADS value test. However, manufacturers' filter showed much better performance than filters in the market. Also, the result of valid purifying amount test for each of five products of appropriate product and inappropriate product based on filter quality test showed average 4,440 liters for appropriate product and average 2,620 liters for inappropriate product. According to the result, it is shown that the filter with good adsorption also had good chloroform removal efficiency and adsorption efficiency. Therefore, it is expected that customers can screen good quality product through obligatory conduct of filter quality test. However, it is considered that complementation in system is required for future inspection.

Studies on the Lipid Components of Torreya nucifera Seed -I. Physico-Chemical Properties of the Seed Oil- (비자(榧子)의 지방질(脂肪質) 성분(成分)에 관한 연구(硏究) -제 1 보(濟 1 報) : 비자유(榧子油)의 물리화학적(物理化學的) 특성(特性)-)

  • Im, Hee-Soo;Yoon, Kwang-Ro;Chung, Dong-Hyo
    • Korean Journal of Food Science and Technology
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    • v.12 no.4
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    • pp.324-327
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    • 1980
  • The seeds of Torreya nucifera, which were shown to contain high level of oil, were characterized to evaluate their possible utilization as oil source. Oil was extracted by compression from the seeds and its physico-chemical properties and, total fatty acid composition were determined. The results are summarized as follows: 1. Proximate components of the seeds were shown to be: moisture, 12.3% ; crude protein, 9.46%; crude fat, 54.29 %; fiber, 5.28 %; ash, 2.13%. 2. Physico-chemical characteristics of the seed oil were determined as follows: specific gravity 0.92, refractive index 1.470, iodine value 127, saponification value 182.2, acid value 9.5, ester value 172.7. 3. The major fatty acids of the total lipids were linoleic (46.77%), oleic (31.68%) and palmitic acid (6.92%).

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Oxidative Stability and Quality Characteristics of Duck, Chicken, Swine and Bovine Skin Fats Extracted by Pressurized Hot Water Extraction

  • Shin, Dong-Min;Kim, Do Hyun;Yune, Jong Hyeok;Kwon, Hyuk Cheol;Kim, Hyo Juong;Seo, Han Geuk;Han, Sung Gu
    • Food Science of Animal Resources
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    • v.39 no.3
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    • pp.446-458
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    • 2019
  • The aim of this study was to investigate the oxidative status and quality characteristics of four animal skin-derived fats extracted using an identical extraction method. Pressurized hot water extraction, a green extraction method, was used to extract animal skin fats (duck, chicken, swine, and bovine skin). Multiple experiments were performed during accelerated storage at $60^{\circ}C$ for 90 days. Quality characteristics, such as extraction yield, iodine value (IV), fatty acid composition, and fat viscosity were determined. In addition, indicators for oxidative status, including acid value (AV), peroxide value (PV), p-anisidine value (p-AV), thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD), and total oxidation (totox) values were evaluated. The fat extraction yield was highest in bovine fat, followed by duck, swine, and chicken fats. The IV was higher in duck and chicken fats. Duck fats contained the most unsaturated fats and the least saturated fats. Fat oxidation indicators, such as PV, TBARS, and totox values, were relatively higher in duck fats during storage compared to the other fats. Other indicators, including AV, p-AV, and CD, were similar in duck, chicken, and swine fats. Viscosity was similar in all the tested fats but markedly increased after 70 days of storage in duck fats. Our data indicate that duck skin fat was more vulnerable to oxidative changes in accelerated storage conditions and this may be due to its higher unsaturated fatty acid content. Supplementation with antioxidants might be a reasonable way to solve the oxidation issue in duck skin fats.