• Title/Summary/Keyword: carboxymethylation

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Improving Solubility through Carboxymethylation of Different-sized Endosperm, Bran, and Husk Rice Powders

  • Choi, Kyeong-Ok;Yang, Seung-Cheol;Kim, Dong-Eun;Kang, Wie-Soo;Shin, Malshick;Choi, Yoon-Hee;Ko, Sang-Hoon
    • Food Science and Biotechnology
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    • v.18 no.6
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    • pp.1439-1446
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    • 2009
  • The surfaces of different-sized endosperm, bran, and husk rice powders were modified using carboxymethylation. Carboxymethylation was carried out using aqueous alkalization and neutralization. After the carboxymethylation process, the centrifuged products were milled and classified by size: particles passed through sieves of 45, 106, and $300-{\mu}m$ width. The effect of carboxymethylation on physical properties such as solubility and dispersibility of endosperm, bran, and husk particles were studied. Overall, carboxymethylation increased solubility of the particles, while size reduction increased dispersibility. In particular, carboxymethylation created good aqueous suspensions by minimizing interparticle agglomeration. Our results show that the combination of size reduction and carboxymethylation improves solubility and dispersibility, resulting in better stability of the suspension. This study may be helpful for expanding the use of rice and its byproducts as ingredients in a variety of food and beverage applications.

The Preparation of CarboxymethylCellulose from Recycled Fiber(I) -The Reactivity in Carboxymethylation of Recycled Fiber- (재생(再生)펄프를 이용(利用)한 카르복시메틸세룰로오스의 제조(製造)(I) -재생(再生)펄프의 Carboxymethylation반응성(反應性)을 중심(中心)으로-)

  • Choi, Jeong-Heon;Jo, Byoung-Muk;Oh, Jung-Soo
    • Journal of the Korean Wood Science and Technology
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    • v.21 no.1
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    • pp.59-64
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    • 1993
  • The purpose of this study is to investigate the preparation of the carboxymethylcellulose from recycled fiber, especially on the reactivity of carboxymethylation. Using a deinked pulp and a dissolving pulp. Green's method is adapted to the carboxymethylation. We conformed that the carboxymethyl group is led for recycled fiber by FT-IR analysis. The recycled fiber is more reactive than the dissolving pulp because the recycled fiber had been defiberated and pretreated with alkali. It suggests that deinking process is in accordance with pretreatment of CMC process. Therefore, it may be possible to prepare CMC from the recylced fiber economically.

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Surface Modification of Cellulose Nanofibrils by Carboxymethylation and TEMPO-Mediated Oxidation (카르복시메틸화 및 TEMPO 촉매 산화 처리에 의한 셀룰로오스 나노피브릴의 표면 개질)

  • Sim, Kyujeong;Youn, Hye Jung;Jo, Yeonhee
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.2
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    • pp.42-52
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    • 2015
  • In this study, cellulose nanofibrils (CNF) were modified through carboxymethylation or TEMPO-mediated oxidation and their effects on ionicity and characteristics of sheet, film, and foam were investigated. Carboxymethylation was carried out on pulp fibers as a pre-treatment before preparation of CNF. The gel-like and translucent CNF hydrogel was obtained by grinding of carboxymethylated cellulose fibers. Carboxymethylated CNF film and freeze dried sheet showed higher transparency than that of untreated CNF. The CNF sheet with high strength and the CNF foam without large ice crystals were obtained by using the carboxymethylated CNF. TEMPO-mediated oxidation was carried out as a post-treatment of CNF. The zeta potential and charge demand of TEMPO-oxidized CNF were increased with an increase in oxidation time and addition amount of NaClO. The density of sheet made of TEMPO oxidized CNF was increased with the amount of oxidizing agent. The TEMPO oxidized cellulose nanofiber (TOCN) which was obtained from supernatant after centrifugation could be converted to transparent film.

Effect of Adrenergic and Cholinergic Agents on the Activities of Protein Methylases in Pancreatic Tissue (생쥐 췌조직내 Protein Methylase에 대한 자율신경계약물의 영향)

  • 유태무;박선미;이향우
    • YAKHAK HOEJI
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    • v.35 no.4
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    • pp.341-347
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    • 1991
  • It was reported that protein carboxymethylation is involved in amylase secretion of parotid gland by isoproterenot. It was also suggested that a small part of the total cellular protein carboxymethylation is directly involved in pancreatic enzyme secretion. On the contrary, other authors reported that there is no relationship between protein carboxymethylation and secretion in pancreas and parotid gland. In recent study, it was proposed that a methyl acceptor protein plays a limited modulatory role in the coupling of cytosolic $Ca^{++}$ accumulation and exocytosis. In this study, the effects of cholinergic and adrenergic agents on the activities of protein methylase II in pancreatic tissues were examined to test the relationship between protein methylation and pancreatic secretion. The results are as follows. The activity of amylase was slightly increased at the concentration of $10^{-5}$ M of isoproterenol and norepinephrine. The activities of protein methylase I and II were decreased by isoproterenol and norepinephrine, but the activities of protein methylase III were hardly changed. The cholinergic stimulants acetylcholine and carbachol at a concentration of $10^{-5}$ M increased the activities of protein methylase I and decreased the activitiy of protein methylase III compared with control.

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A Study on Chemical Modification of Papermaking Fibers (I) - Improved Physical Characteristics from Partial Carboxymethylated Pulps - (제지용(製紙用) 섬유(纖維)의 화학적(化學的) 개질(改質)에 관한 연구(硏究) (I) - Partial Carboxymethylation 처리에 의한 물성(物性) 향상(向上) -)

  • Choi, Jeong-Heon;Jo, Byoung-Muk;Oh, Jung-Soo
    • Journal of the Korean Wood Science and Technology
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    • v.23 no.2
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    • pp.37-46
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    • 1995
  • The substitution of carboxymethylated hydroxyl group in pulp revealed more hydrophilic than hydroxyl group. And then fibers were more flexible, swell more which leads to better conformation between fibers in turn this raise paper strength. In this paper, we tried to chemical modifyings of recycled fiber, OCCs(old corrugated containers). Many researchers have examined chemical modification of papermaking fiber by partial carboxymethylation(PCM) using a organic solvent processes. We made modified PCM processes adapted waters m replace of the organic solvent. Our testings for the optimum conditions on the new method, conditions as reaction time, temperature, liquor ratios were designed likely plant system. Freenesses(SR$^{\circ}$) were increased following on carboxyl content of the samples. Handsheets of untreated samples and partial carboxymethylated OCCs were made by optimum conditions on different concentrations of the reagent. As results, maximum 25% strength increasing effects were obtained by the new method.

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Substitution Characteristics of Carboxymethyl cellulose made from Hydrocellulose (수화(水化) 셀룰로오스로 제조(製造)한 카르복시메틸 세룰로오스의 치환(置換) 특성(特性))

  • Choi, Won-Sil;Ahn, Won-Yung
    • Journal of the Korean Wood Science and Technology
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    • v.20 no.2
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    • pp.81-90
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    • 1992
  • The effect of acid treatment of cellulose on the substitution charateristics of carboxymethylation was studied in this paper. Five samples of hydrocellulose(HC), all prepared from ${\alpha}$-cellulose by hydrolysis with five reaction times and determined on average molecular weight and polydispersity, were carboxymethylated to carboxymethyl cellulose (CMC). The CMCs from HCs were examined upon degree of substitution(DS), distribution of carboxymethyl groups in anhydroglucose units of the cellulose, and unsubstituted anhydroglucose(USAG) content. The DS of CMCs increased with increasing the hydrolysis time except CMC from HC at 1 hour hydrolysis time. In carboxymethylation the availability of hydroxyl groups on anhydroglucose units in HCs was the highest on OH(2), and the relative availability of OH(6) increased with the increasing of the hydrolysis time. The USAG contents were more deviated than that calculated based on Spurlin's model, and had a strong tendency of decreasing with increasing the hydrolysis time. The reactivity of HC was lower than that of ${\alpha}$-cellulose and the relative availability of OH(6) in HC increased with the hydrolysis time.

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Evaluation of water holding property for applying a cosmetic moisturizer from oil palm trunk CNF (오일 팜 수간 유래 CNF (cellulose nanofibrils)의 화장품 보습제 적용을 위한 보습력 평가)

  • Song, Woo-Yong;Shin, Soo-Jeong
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.48 no.2
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    • pp.91-98
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    • 2016
  • Cellulose nanofibrils (CNF) was made from oil palm trunk (OPT) with soda-anthraquinone pulping, chlorine dioxide bleaching, carboxymethylation, followed by mechanical grinding. Size of this CNF was 16-40 nm of width confirmed by TEM. To evaluate CNF from OPT as cosmetics raw materials for moisturizing component, water holding properties was compared with hyaluronic acid and collagen. CNF from OPT had better water holding property than collagen or hyaluronic acid whether phenoxyethanol was added as antiseptic or without additive.

Effects of Ammonia Swelling Treatment in Carboxymethylation of Domestic Kraft Pulp on Characteristics of Corboxymethylcellulose(CMC) and CMC Solution (국산(國産) 크라프트 펄프의 카르복시메틸화시(化時) 암모니아 팽윤처리(膨潤處理)가 카르복시메틸셀룰로오스와 카르복시메틸셀룰로오스 용액(溶液)의 특성(特性)에 미치는 효과(效果))

  • Ahn, Byoung-Kuk;Ahn, Won-Yung
    • Journal of the Korean Wood Science and Technology
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    • v.18 no.2
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    • pp.25-35
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    • 1990
  • To investigate the effects of swelling treatment by ammonia on characteristics of carboxymethy1cellulose(CMC) and CMC solution, the domestic kraft pulp pretreated with 5%, 10%, 15% and 20% $NH_4OH$ solution, was carboxymethylated by the standard method, and then the CMC prepared was tested. The physical properties of CMC and CMC solution, such as degree of substitution, transparency. viscosity, weight increase and solubility, were measured, and the comparison with commercial domestic CMC used as a food additive was done. The results obtained were as follows; 1. In CMC manufactured by standard solvent method, hardwood bleached kraft pulp(LBKP) was more substituted than safwood bleached kraft pulp(NBKP), and viscosity of NBKP was higher than that of LBKP. 2. When ammonia swelling treatment was done, degree of substitution gradually decreased with increasing concentration of $NH_4OH$, and degree of substitution of LBKP decreased with a larger range than that of NBKP. 3. When ammonia swelling treatment was done. transparency of CMC solution from LBKP was hardly effected, but in case of NBKP gradually increased with increasing concentration of $NH_4OH$. 4. When ammonia swelling treatment was done, viscosity of CMC solution was higher than that of CMC solution without ammonia swelling treatment. Especially, CMC of high viscosity could be manufactured in 5%, 10% concentration levels of $NH_4OH$. 5. In CMC manufactured from domestic NBKP, CMC at the range of 0.40 to 0.50 in DS was dispersed easily and quickly dissolved, and CMC at more than 0.50 in DS was dispersed slowly in water solution. 6. In comparison with commercial domestic CMC used as a food additive, CMC manufactured from domestic NBKP was higher in DS, and was lower in viscosity and transparency.

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Effect of Cations on the Sorption and the Tensile Properties of CMC Fibers (CMC섬유내의 양이온이 섬유의 흡습성과 인장 성질에 미치는 영향)

  • 이미식
    • Journal of the Korean Society of Clothing and Textiles
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    • v.18 no.1
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    • pp.113-120
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    • 1994
  • The Purpose of this study was to improve the moisture related properties of viscose rayon fibers. Viscose rayon filament yarns were partially etherified to make CMC fibers. CMC fibers were converted to the sodium, calcium, and ferric salt forms by an ion exchange method. The property changes of ion exchanged CMC fibers were examined. Cation contents of fibers were varied depending on the degree of substitution of CMC fibers. The strength of Na, Ca, Fe-CMC was higher than H-CMC owing to the plasticization by moisture sorption and the crosslinking by cations. The moisture regain was increased by carboxymethylation and that of Fe-CMC showed the highest value. The degree of swelling determined by the water retention value was observed to be Na-CMC > Ca-CMC > H-CMC > Fe-CMC. The solution retention value was decreased in the order . Ca-CMC > Na-CMC > H-CMC > Fe-CMC.

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Characteristics of Glucose-6-phosphate Dehydrogenase from Leuconostoc mesenteroides (Leuconostoc mesenteroides에서 分離한 Glucose-6-phosphate Dehydrogenase의 特性)

  • Byun Si Myung;Yang Do Choi;Moon H. Han
    • Journal of the Korean Chemical Society
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    • v.23 no.4
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    • pp.248-258
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    • 1979
  • Glucose 6-phosphate dehydrogenase of Leuconostoc mesenteroides which was purifid by an affinity chromatography was studied on the characterization, kinetics and chemical modification. The apparent molecular weight of the enzyme was 112,000 by the gel filtration method of Sephadex G-200 column. The optimum temperature of $NAD^+$-linked reation was 50$^{circ}C$ and the activation energy and the heat of inactivation were 8.36 kcal/mole and -58.2kcal/mole, respectively. The steady state kinetic study showed KG6P, Kemp, and CX KNADP to be 76.9 PM, 7.46${\mu}M$ and 7.14 ${\mu}M$, respectively, and KGGP, KNAD,and aKNm to be 53.7${\mu}M$, 115.2${\mu}M$ and 702.2${\mu}M$ for the $NAD^+$-linked reaction at pH 7.8, optimum pH. The pH dependent kinetic constants suggested that the two ionizing groups whose pKa is 7.2 .and pKb is 9.0-9.6 were involved in the enzyme-substrate interaction. Evidence by photooxidation and carboxymethylation of the enzyme suggested that the imidazole group of histidine with pKa group may participate in the catalytic site.

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