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Studies on physico-chemical characteristics of iota-carrageenan extracted by ultrasonic method

Carrageenans are water-soluble natural gums/ which occur in certain species of seaweeds. They are sulfated natural biopolymers made up of galactose units. The major varieties of seaweeds are available from South China Sea at Sabah are Caulerpa, Ulva, Sargassum, Eucheuma, Gracilaria, Gelidiella and K...

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Main Author: D.M.Reddy Prasad
Format: Thesis
Language:English
English
Published: 2006
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TP Chemical technology
Online Access:https://eprints.ums.edu.my/id/eprint/6246/1/24%20PAGES.pdf
https://eprints.ums.edu.my/id/eprint/6246/2/FULLTEXT.pdf
https://eprints.ums.edu.my/id/eprint/6246/
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spelling my.ums.eprints.62462024-05-13T07:22:32Z https://eprints.ums.edu.my/id/eprint/6246/ Studies on physico-chemical characteristics of iota-carrageenan extracted by ultrasonic method D.M.Reddy Prasad TP Chemical technology Carrageenans are water-soluble natural gums/ which occur in certain species of seaweeds. They are sulfated natural biopolymers made up of galactose units. The major varieties of seaweeds are available from South China Sea at Sabah are Caulerpa, Ulva, Sargassum, Eucheuma, Gracilaria, Gelidiella and Kappaphycus. The thermal extraction of i-carrageenan from seaweed does not give high yield and time consuming. Ultrasonic assisted extraction was proposed as an alternative method. The 20 kHz high intensity ultrasound was used in the extraction of i-Carrageenan from Eucheum denticulatum by using water as solvent. i-carrageenan yield increased from 50 to 57.2%. A simple mathematical correlation for the estimation of the solid-liquid mass transfer coefficient was derived in terms of operating conditions VIZ, amplitude, particle size and temperature for ultrasonic extraction of i-Carrageenan. The diffusion coefficient of i-Carrageenan in water was estimated from the mass transfer coefficient. Further more the conventional estimation methods of i-carrageenan in aqueous solutions need depolymerization and longer duration. The ultrasonic spectroscopy technique coupled with neural network has been developed as a alternative. In that the artificial neural network models such as Back Propagation (BPJ Radial Basis Function (RBF) and modified Functional Link Neural Network (FLNN) were used. As the RBF method showed the low estimation time of 26 sec. The modification of i-carrageenan in presence of Ag+ produced better gel characteristics. It could be more useful in pharmaceuticals industries. The physico-chemical properties like passive diffusion gel strength hysterisis and micro structure of modified i-Carrageenan gels were tested. The weight loss of the gels in passive diffusion was found to be in the range 0.7-1.2% at 240 h. The gels exhibited high firmness as the Ag+ concentration increased while decrease in the elasticity was observed. The relaxation time reached maximum at 70 mM of Ag+ and at higher concentration the gels exhibited saturation. The hysterisis of the modified gels was observed between gelation (Tg) and dissolution (Tf) temperatures and it was strongly dependent on Ag + concentration. The SEM images of the blended films showed that the roughness varies inversely with the percentage of i-Carrageenan. The results of new methods and correlations developed offer unprecedented scope of applications for developing new i-Carrageenan based products in the process industries. 2006 Thesis NonPeerReviewed text en https://eprints.ums.edu.my/id/eprint/6246/1/24%20PAGES.pdf text en https://eprints.ums.edu.my/id/eprint/6246/2/FULLTEXT.pdf D.M.Reddy Prasad (2006) Studies on physico-chemical characteristics of iota-carrageenan extracted by ultrasonic method. Doctoral thesis, Universiti Malaysia Sabah.
institution Universiti Malaysia Sabah
building UMS Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Malaysia Sabah
content_source UMS Institutional Repository
url_provider http://eprints.ums.edu.my/
language English
English
topic TP Chemical technology
spellingShingle TP Chemical technology
D.M.Reddy Prasad
Studies on physico-chemical characteristics of iota-carrageenan extracted by ultrasonic method
description Carrageenans are water-soluble natural gums/ which occur in certain species of seaweeds. They are sulfated natural biopolymers made up of galactose units. The major varieties of seaweeds are available from South China Sea at Sabah are Caulerpa, Ulva, Sargassum, Eucheuma, Gracilaria, Gelidiella and Kappaphycus. The thermal extraction of i-carrageenan from seaweed does not give high yield and time consuming. Ultrasonic assisted extraction was proposed as an alternative method. The 20 kHz high intensity ultrasound was used in the extraction of i-Carrageenan from Eucheum denticulatum by using water as solvent. i-carrageenan yield increased from 50 to 57.2%. A simple mathematical correlation for the estimation of the solid-liquid mass transfer coefficient was derived in terms of operating conditions VIZ, amplitude, particle size and temperature for ultrasonic extraction of i-Carrageenan. The diffusion coefficient of i-Carrageenan in water was estimated from the mass transfer coefficient. Further more the conventional estimation methods of i-carrageenan in aqueous solutions need depolymerization and longer duration. The ultrasonic spectroscopy technique coupled with neural network has been developed as a alternative. In that the artificial neural network models such as Back Propagation (BPJ Radial Basis Function (RBF) and modified Functional Link Neural Network (FLNN) were used. As the RBF method showed the low estimation time of 26 sec. The modification of i-carrageenan in presence of Ag+ produced better gel characteristics. It could be more useful in pharmaceuticals industries. The physico-chemical properties like passive diffusion gel strength hysterisis and micro structure of modified i-Carrageenan gels were tested. The weight loss of the gels in passive diffusion was found to be in the range 0.7-1.2% at 240 h. The gels exhibited high firmness as the Ag+ concentration increased while decrease in the elasticity was observed. The relaxation time reached maximum at 70 mM of Ag+ and at higher concentration the gels exhibited saturation. The hysterisis of the modified gels was observed between gelation (Tg) and dissolution (Tf) temperatures and it was strongly dependent on Ag + concentration. The SEM images of the blended films showed that the roughness varies inversely with the percentage of i-Carrageenan. The results of new methods and correlations developed offer unprecedented scope of applications for developing new i-Carrageenan based products in the process industries.
format Thesis
author D.M.Reddy Prasad
author_facet D.M.Reddy Prasad
author_sort D.M.Reddy Prasad
title Studies on physico-chemical characteristics of iota-carrageenan extracted by ultrasonic method
title_short Studies on physico-chemical characteristics of iota-carrageenan extracted by ultrasonic method
title_full Studies on physico-chemical characteristics of iota-carrageenan extracted by ultrasonic method
title_fullStr Studies on physico-chemical characteristics of iota-carrageenan extracted by ultrasonic method
title_full_unstemmed Studies on physico-chemical characteristics of iota-carrageenan extracted by ultrasonic method
title_sort studies on physico-chemical characteristics of iota-carrageenan extracted by ultrasonic method
publishDate 2006
url https://eprints.ums.edu.my/id/eprint/6246/1/24%20PAGES.pdf
https://eprints.ums.edu.my/id/eprint/6246/2/FULLTEXT.pdf
https://eprints.ums.edu.my/id/eprint/6246/
_version_ 1800089059278716928
score 13.211869

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