scholarly journals ISOLATION AND CHARACTERIZATION OF CHITIN AND CHITOSAN PREPARED UNDER VARIOUS PROCESSING TIMES

2010 ◽  
Vol 8 (2) ◽  
pp. 189-192 ◽  
Author(s):  
Crescentiana Dewi Poeloengasih ◽  
Hernawan Hernawan ◽  
M. Angwar
Keyword(s):  
Reaction Time ◽  
Processing Time ◽  
The Other ◽  
Degree Of Deacetylation ◽  
Processing Times ◽  
Isolation And Characterization ◽  
Chitin And Chitosan ◽  
Nitrogen Contents

Generally production of chitosan from crustacean shells consists of 4 steps, i.e. deproteinization, demineralization, decolorization and deacetylation. Simplification of chitosan production by elimination of deproteinization and/or demineralization, or reducing of reaction time would give many advantages, e.g. reduction of processing time and cost production due to reduction of chemical and power usage. The objectives of this research were to prepare chitosan under various processing times and to characterize the obtained chitin and chitosan. Chitin was prepared under various deproteinization times (0, 15, 30 min at 90 ºC using NaOH 2N) and demineralization times (0, 15, 30 min at ambient temperature using HCl 2N). Chitin was then bleached using aceton/etanol (1:1) for an hour. Deacetylation was achieved by treatment of chitin under condition at 120 ºC for 5 hr using NaOH 50%. Ash and nitrogen content, and degree of deacetylation of chitosan were evaluated. Demineralization and/or deproteinization times influenced the quality of chitin. Chitin and chitosan prepared without demineralization had white and chalky appearance, whereas the other chitosan were off-white in color. Ash and nitrogen contents of the chitosan products were 0.18 - 32.40% and 3.56 - 7.59%, respectively. Chitosan prepared under various processing times, except chitosan without demineralization treatment, had degree of deacetylation ≥ 70%.   Keywords: chitosan, deproteinization, demineralization, deacetylation, processing times

scholarly journals Isolation and characterization of bleomycin-resistant clones of CHO cells

1979 ◽  
Vol 34 (3) ◽  
pp. 269-279 ◽  
Author(s):  
Sylvia Brabbs ◽  
J. R. Warr
Keyword(s):  
Enzyme Activity ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Tween 80 ◽  
The Other ◽  
Resistant Clone ◽  
Ovary Cells ◽  
Isolation And Characterization ◽  
Significant Difference

SUMMARYFive clones of Chinese hamster ovary cells with increased resistance to bleomycin have been isolated following ethylmethanesulphonate mutagenesis. Resistance was stable in three of the clones, but unstable in the other two. One of the stably resistant clones was cross resistant to unrelated drugs, and in contrast to the parental cells, its response to bleomycin was potentiated by tween 80. These two observations suggested a membrane alteration in the resistant clone. There was no significant difference in bleomycin-inactivating enzyme activity between the parental and resistant clones.

scholarly journals Characterization of Streptomyces scabies isolates from potato tubers its pathogenic variations in Rawalpindi District

2014 ◽  
Vol 4 (1) ◽  
pp. 1-6
Author(s):  
S. Shazia ◽  
F. Naz ◽  
A. Rauf ◽  
M. Inam-ul-Haq ◽  
S. Bushra
Keyword(s):  
Solanum Tuberosum L ◽  
Economic Loss ◽  
Streptomyces Scabies ◽  
Potato Tubers ◽  
Yield And Quality ◽  
Isolation And Characterization ◽  
Pathogenic Variation ◽  
Important Disease

Potato (Solanum tuberosum L.) has various biotic constraints in its production due to pest attack. Among these, common scab caused by streptomyces scabies is an important disease in potato which causes economic loss with respect to plant yield and quality of tubers. The present study was conducted to determine the pathogenicity, pathogenic variation, characterization of morphological, physiological and biochemical aspects of Streptomyces associated with potato tubers grown in Rawalpindi district. Severity data and pathogenic variation of disease was studied by using different isolation and characterization techniques.

Effect of processing time on the quality of dry-cured ham obtained from a native pig breed (Chato Murciano)

2015 ◽  
Vol 55 (1) ◽  
pp. 113 ◽  
Author(s):  
Eva Salazar ◽  
Adela Abellán ◽  
José M. Cayuela ◽  
Ángel Poto ◽  
Francisco Girón ◽  
...  
Keyword(s):  
Processing Time ◽  
Consumer Preference ◽  
Ripening Stage ◽  
High Quality ◽  
Processing Times ◽  
Consumer Study ◽  
Dry Cured Ham ◽  
Sensory Changes ◽  
Sensory Parameters

The compositional and sensory parameters of Chato Murciano dry-cured ham at different ripening times (14, 18, 22 and 24 months of processing) were studied. A sensory consumer study of dry-cured ham with a short ripening stage (14 months of processing) and a similar ham with a long ripening stage (22 months of processing) was carried out. Dry-cured hams remained in the ripening stage at 18−20°C and 70–75% relative humidity. The different processing times studied had no effect on the ash, intramuscular fat, sodium chloride and protein contents of the final ham, but significantly affected the moisture (P < 0.05) and saturated (P < 0.01) and monounsaturated (P < 0.05) fatty acid contents. Sensory analysis showed that processing time enhanced redness, fat colour, all of the odour and flavour traits studied, and all the texture traits except juiciness. In the taste profile, only saltiness showed a significant increase. However, sensory changes were only significant up to 22 months of processing (for most of the parameters), the resulting ham showing higher level of consumer preference and acceptability than dry-cured ham with the shorter ripening. Based on these results, it is recommended that an appropriate processing time to obtain a high-quality Chato Murciano dry-cured ham is 22 months.

Isolation and Characterization of a Chlorogenic Acid Esterase from Aspergillus niger

1980 ◽  
Vol 35 (3-4) ◽  
pp. 209-212 ◽  
Author(s):  
B. Schöbel ◽  
W. Pollmann
Keyword(s):  
Enzyme Activity ◽  
Chlorogenic Acid ◽  
Divalent Cations ◽  
Hydrolysis Product ◽  
The Other ◽  
Temperature Optimum ◽  
Pig Liver ◽  
Isolation And Characterization

Abstract The isolation and characterization of a specific chlorogenic acid esterase is described. The enzyme activity is measured by determination of the hydrolysis product caffeic acid. The enzyme had been concentrated by means of ultrafiltration and column-chromatography. The pH- and temperature optimum were 6.5 and 45 °C respectively. Divalent cations were not required for the enzyme activity. As other esterases, this enzyme is inhibited by di-isopropyl-phosphorofluoridate. The Km-value is 0.70 mᴍ chlorogenic acid, the molecular weight 240000. The described enzyme is specific for chlorogenic acid. On the other hand a typical unspecific esterase like the pig liver esterases does not split chloro­genic acid. The isoelectric focusing reveals several isoenzymes of chlorogenase within a pI-range of 4.0-4.5.

ISOLATION AND CHARACTERIZATION OF RIBONUCLEIC ACID FROM RAT LENS

1962 ◽  
Vol 40 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Anima Devi
Keyword(s):  
Amino Acids ◽  
The Other ◽  
Ocular Lens ◽  
E Coli ◽  
Isolation And Characterization ◽  
Coiled Structure ◽  
Calf Thymus ◽  
Original Procedure ◽  
Polynucleotide Chain

RNA from rat ocular lens has been isolated by a method based on Kirby's original procedure (7), but greatly modified so as to avoid any degradation of RNA by RNase during the process of its extraction from lenses. The absorption at 260 mμ of a 1.0% solution of this purified material in a 1-cm cell is 1.95. Its N/P ratio is 1.58. It has 20 to 25% activity of that of yeast-soluble RNA in accepting activated amino acids. When this RNA (like all other RNA's) is heated and cooled the polynucleotide chain can again form loops, thus suggesting a randomly coiled structure for this RNA. On the other hand, DNA preparations from calf thymus, rat liver, and E. coli showed irreversible changes when heated and cooled.

PROBLEMS OF TRIBOLOGIC CHARACTERIZATION OF SHOE – WALKING SURFACE FRICTION PAIRS

Tribologia ◽  
2018 ◽  
Vol 282 (6) ◽  
pp. 125-129 ◽  
Author(s):  
Jacek PRZEPIÓRKA ◽  
Marian SZCZEREK
Keyword(s):  
Friction And Wear ◽  
Friction Pair ◽  
Surface Friction ◽  
The Other ◽  
Tribological Characteristics ◽  
Footwear Industry ◽  
Energetic Condition ◽  
Basic Parameters

Tribological characteristics of shoe sole in a friction pair with the walking surface are important parameters due to the safety of shoe exploitation and time of its durability. The footwear industry methods of analysing friction coefficient are obsolete, and, on the other hand, modern tribological equipment that allows credible results requires long data processing. The authors suggest using a previously developed formula that binds tribological characteristics with energetic condition of the walking surface. By doing so, this formula evaluates the force of friction and wear of shoe – walking surface pair. It may shorten the time needed to evaluate the basic parameters of shoe exploitation in variable conditions of their utilization and, thus, contribute to the formulation of material resolutions aiming to improve the quality of shoe usage while reducing the costs of performing required examinations.

scholarly journals IBPC: An Approach for Mitigation of Cache Pollution Attack in NDN using Interface-Based Popularity

2021 ◽  
Author(s):  
Naveen Kumar ◽  
Shashank Srivast
Keyword(s):  
Quality Of Service ◽  
Processing Time ◽  
The Other ◽  
Named Data Networking ◽  
Pollution Attack ◽  
Cache Pollution ◽  
Data Networking

Abstract The performance of Named Data Networking (NDN) depends on the caching efficiency of routers. Cache Pollution Attack (CPA) refers to colonization of unpopular contents in the Content Store (CS) of an NDN router, which leads to declined Quality of Service (QoS) in NDN. CPA has very few solutions proposed for its mitigation. Most of these solutions are based on the statistics of the router itself. However, an attacker can influence these statistics by requesting unpopular contents repeatedly. This article proposes a new parameter for the detection of CPA, which is based on the number of distinct users requesting interest packets for a content over a period of time. The local popularity of the attackers’ content does not affect the proposed approach. Results show that the proposed approach consumes less storage, reduces processing time, and more effectively mitigates the CPA, as compared to the other existing approaches.

scholarly journals Identification, Isolation and Origin of Potential Dimer Impurities of Dichlorphenamide: A Carbonic Anhydrase Inhibitor Drug (Antiglaucoma)

2021 ◽  
Vol 33 (6) ◽  
pp. 1249-1252
Author(s):  
T. Purendar Reddy ◽  
Nageshwar Dussa ◽  
Srinivas Mamidi ◽  
Mahesh Panasa ◽  
Ramadas Chavakula ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Drug Product ◽  
Carbonic Anhydrase Inhibitor ◽  
Drug Substance ◽  
Substantial Impact ◽  
Isolation And Characterization ◽  
New Process ◽  
Inhibitor Drug

Present work describes the identification, isolation and characterization of two new process related dimeric impurities of dichlorphenamide (1). During the synthesis of dichlorphenamide, the formation of two new dimeric impurities namely 2,3-dichloro-5-(3,4-dichloro-5-sulfamoyl-phenyl)sulfonylbenzenesulfonamide (2) (1,1Œ-dichlorphenamide dimer) and 2,3-dichloro-5-(2,3-dichloro-5-sulfamoylphenyl) sulfonyl-benzenesulfonamide (3) (1,3Œ-dichlorphenamide dimer) was observed. In addition, origin and the strategies adapted to control these potential dimer impurities were also described. These impurities have a substantial impact on the quality of the drug substance as well as drug product.

scholarly journals The Use of Different Deacetylation Temperature Toward Quality of Chitosan Mud Crab Shell (Scylla serrata)

2021 ◽  
Vol 934 (1) ◽  
pp. 012092
Author(s):  
R Karnila ◽  
S Loekman ◽  
S Humairah
Keyword(s):  
Moisture Content ◽  
Ash Content ◽  
Scylla Serrata ◽  
Crab Shell ◽  
Mud Crab ◽  
Degree Of Deacetylation ◽  
Randomized Design ◽  
Chitin And Chitosan ◽  
Two Stages

Abstract This research aims to determine the chemical composition (proximate) of chitosan and chitin, The best deacetylation temperature for obtaining chitosan, and the yield of chitosan and chitin from mud crab. This research was conducted in two stages, that is: 1) Preparation of mud crab flour and 2) Extraction and analysis of chitin and chitosan. The experimental design used for chitosan isolation was Completely Randomized Design (CRD). The process of deacetylation chitin becomes chitosan by using 50% NaOH with varying heating temperatures (120, 130, and 140°C). Parameters observed were yield, moisture content, ash content, and degrees of deacetylation. The result showed that the best chitosan was obtained by chitin deacetylation process into chitosan using a temperature of 130°C (KO2). Characteristics quality of the chitosan mud crab shell produced are KO1: yield 61.00%, moisture content 6.47%, ash content 17.18% (db), and degree of deacetylation 49.63%. KO2: yield 59.94%, moisture content 6.48%, ash content 14.85% (db) with degree of deacetylation 51.13%. KO3: yield 53,97, moisture content 6.54%, ash content 14.66% (db) and degree of deacetylation 52.63%. Characteristic quality of chitin included yield was 27.81%, moisture content 7.29%, ash 44.05%, and degree of deacetylation 33.09%.

Sign in / Sign up

Export Citation Format

Share Document