Imagem da capa

Isolation and structural characterization of mannanoligosaccharides from aqueous palm kernel cake extract

Palm kernel cake (PKC) is the most valuable by-product obtained from the palm kernel oil extraction process. It has been used widely as an animal feed owing to its high protein content. PKC also contains about 81% of non-starch polysaccharides, mainly in the form of mannan-based polymers. Hydroly...

ver descrição completa

Na minha lista:
Detalhes bibliográficos
Autor principal: Kalidas, Reddy Naveena
Formato: Thesis
Idioma:English
Publicado em: 2016
Acesso em linha:http://ethesis.upm.edu.my/id/eprint/10014/1/IB%202016%2021.pdf
Tags: Adicionar Tag
Sem tags, seja o primeiro a adicionar uma tag!
id oai:ethesis.upm.edu.my:10014
record_format eprints
spelling oai:ethesis.upm.edu.my:10014 http://ethesis.upm.edu.my/id/eprint/10014/ Isolation and structural characterization of mannanoligosaccharides from aqueous palm kernel cake extract Kalidas, Reddy Naveena Palm kernel cake (PKC) is the most valuable by-product obtained from the palm kernel oil extraction process. It has been used widely as an animal feed owing to its high protein content. PKC also contains about 81% of non-starch polysaccharides, mainly in the form of mannan-based polymers. Hydrolysis of mannan into low molecular weight mannanoligosaccharides (MOS) has been claimed to have prebiotic properties. The biological mechanism and activities of the MOS are associated with its structure and molecular weight. However, very little information was available on the structural characteristics of MOS of different molecular weights from PKC. Therefore, the objectives of the present study were to isolate MOS of different degree of polymerization (DP) from the crude PKC extract and structurally characterize the MOS using chemical derivatization and spectroscopic methods. The crude PKC extract was obtained by hot water extraction method, followed by delipidation and deproteinization step. The deproteinized PKC extract containing mixtures of MOS were then separated into individual compounds based on their molecular weights using refractive index high performance liquid chromatography (RI-HPLC). The molecular weights of the MOS were determined using electrospray ionization mass spectrometry (ESI-MS/MS). The structures of the isolated MOS were investigated using a combination of chemical analyses such as sugar composition analysis and methylation analysis followed by gas chromatography mass spectrometry (GC-MS), and other spectroscopic methods such as nuclear magnetic resonance spectroscopy (NMR). The MOS mixtures were separated into four individual major compounds with different DP, designated as MOS-III, MOS-IV, MOS-V and MOS-VI. The molecular weights of the isolated MOS as determined by ESI-MS/MS were 689, 851, 1013 and 1151 Dalton (Da) corresponding to tetra-, penta-, hexa- and heptasaccharide of the MOS-III, MOS-IV, MOS-V and MOS-VI, respectively. Sugar analysis of the isolated MOS indicated the presence of mannose in each of the oligomers. Methylation and 1D/2D NMR analysis showed that the MOS have a linear structure consisting of (1→4)-β-D-mannopyranosyl residues with DP ranging from 4 to 7. They were identified as: a) β-D-Manp-(1→4)-β-D-Manp- (1→4)-β-D-Manp-(1→4)-β-D-Manp, b) β-D-Manp-(1→4)-β-D-Manp-(1→4)-β-D Manp-(1→4)-β-D-Manp-(1→4)-β-D-Manp, c) β-D-Manp-(1→4)-β-D-Manp-(1→4)-β- D-Manp-(1→4)-β-D-Manp-(1→4)-β-D-Manp-(1→4)-β-D-Manp, d) β-D-Manp- (1→4)-β-D-Manp-(1→4)-β-D-Manp-(1→4)-β-D-Manp-(1→4)-β-D-Manp-(1→4)-β-DManp-( 1→4)-β-D-Manp. In conclusion, the present study revealed a successful application of chromatography, chemical analysis, ESI-MS/MS and NMR to the isolation and characterization of MOS fraction from PKC. 2016-06 Thesis NonPeerReviewed application/pdf en http://ethesis.upm.edu.my/id/eprint/10014/1/IB%202016%2021.pdf Kalidas, Reddy Naveena (2016) Isolation and structural characterization of mannanoligosaccharides from aqueous palm kernel cake extract. Masters thesis, Universiti Putra Malaysia. (IB 2016 21).
institution UPM eTHESES
collection UPM eTHESES
language English
description Palm kernel cake (PKC) is the most valuable by-product obtained from the palm kernel oil extraction process. It has been used widely as an animal feed owing to its high protein content. PKC also contains about 81% of non-starch polysaccharides, mainly in the form of mannan-based polymers. Hydrolysis of mannan into low molecular weight mannanoligosaccharides (MOS) has been claimed to have prebiotic properties. The biological mechanism and activities of the MOS are associated with its structure and molecular weight. However, very little information was available on the structural characteristics of MOS of different molecular weights from PKC. Therefore, the objectives of the present study were to isolate MOS of different degree of polymerization (DP) from the crude PKC extract and structurally characterize the MOS using chemical derivatization and spectroscopic methods. The crude PKC extract was obtained by hot water extraction method, followed by delipidation and deproteinization step. The deproteinized PKC extract containing mixtures of MOS were then separated into individual compounds based on their molecular weights using refractive index high performance liquid chromatography (RI-HPLC). The molecular weights of the MOS were determined using electrospray ionization mass spectrometry (ESI-MS/MS). The structures of the isolated MOS were investigated using a combination of chemical analyses such as sugar composition analysis and methylation analysis followed by gas chromatography mass spectrometry (GC-MS), and other spectroscopic methods such as nuclear magnetic resonance spectroscopy (NMR). The MOS mixtures were separated into four individual major compounds with different DP, designated as MOS-III, MOS-IV, MOS-V and MOS-VI. The molecular weights of the isolated MOS as determined by ESI-MS/MS were 689, 851, 1013 and 1151 Dalton (Da) corresponding to tetra-, penta-, hexa- and heptasaccharide of the MOS-III, MOS-IV, MOS-V and MOS-VI, respectively. Sugar analysis of the isolated MOS indicated the presence of mannose in each of the oligomers. Methylation and 1D/2D NMR analysis showed that the MOS have a linear structure consisting of (1→4)-β-D-mannopyranosyl residues with DP ranging from 4 to 7. They were identified as: a) β-D-Manp-(1→4)-β-D-Manp- (1→4)-β-D-Manp-(1→4)-β-D-Manp, b) β-D-Manp-(1→4)-β-D-Manp-(1→4)-β-D Manp-(1→4)-β-D-Manp-(1→4)-β-D-Manp, c) β-D-Manp-(1→4)-β-D-Manp-(1→4)-β- D-Manp-(1→4)-β-D-Manp-(1→4)-β-D-Manp-(1→4)-β-D-Manp, d) β-D-Manp- (1→4)-β-D-Manp-(1→4)-β-D-Manp-(1→4)-β-D-Manp-(1→4)-β-D-Manp-(1→4)-β-DManp-( 1→4)-β-D-Manp. In conclusion, the present study revealed a successful application of chromatography, chemical analysis, ESI-MS/MS and NMR to the isolation and characterization of MOS fraction from PKC.
format Thesis
author Kalidas, Reddy Naveena
spellingShingle Kalidas, Reddy Naveena
Isolation and structural characterization of mannanoligosaccharides from aqueous palm kernel cake extract
author_facet Kalidas, Reddy Naveena
author_sort Kalidas, Reddy Naveena
title Isolation and structural characterization of mannanoligosaccharides from aqueous palm kernel cake extract
title_short Isolation and structural characterization of mannanoligosaccharides from aqueous palm kernel cake extract
title_full Isolation and structural characterization of mannanoligosaccharides from aqueous palm kernel cake extract
title_fullStr Isolation and structural characterization of mannanoligosaccharides from aqueous palm kernel cake extract
title_full_unstemmed Isolation and structural characterization of mannanoligosaccharides from aqueous palm kernel cake extract
title_sort isolation and structural characterization of mannanoligosaccharides from aqueous palm kernel cake extract
publishDate 2016
url http://ethesis.upm.edu.my/id/eprint/10014/1/IB%202016%2021.pdf
_version_ 1819311034621493248
score 13.4562235

Registos relacionados